Efficacy of a combination of esafoxolaner, eprinomectin and praziquantel (NexGard® Combo) against Thelazia callipaeda in naturally infected cats

This clinical study assessed the efficacy of a topical combination of esafoxolaner, eprinomectin and praziquantel (NexGard® Combo) in treating cats naturally infected with the eyeworm Thelazia callipaeda (Nematoda, Thelaziidae). On Study Day (SD) 0, sixteen client-owned cats with eyeworm infection were allocated to an untreated control group (G1, 8 cats) or to a NexGard® Combo treated group (G2, 8 cats) and subjected to ocular examination. Cats in G2 received the treatment as per label recommendations. On SD 7 and 14 (±1), cats were examined for the presence of eyeworms and clinical signs. On SD 14, eyeworms were collected and counted. On SD 7 and 14, all cats in G1 were still infected with eyeworms, while G2 cats were free from eyeworms on SD 7 and 14, demonstrating 100% efficacy (p < 0.0001). All collected eyeworms were morphologically and molecularly confirmed to be T. callipaeda. On SD 0, fifteen out of the sixteen cats (7 in G1 and 8 in G2) displayed inflammatory ocular signs. On SD 7, all eight untreated cats and seven treated cats displayed inflammatory ocular signs. On SD 14, five out of eight G2 treated cats had recovered, while the eight untreated cats still displayed inflammatory ocular signs. The treatment significantly reduced lacrimation and conjunctivitis (p = 0.0001). No adverse reactions occurred. This clinical study provides evidence that NexGard® Combo is highly safe and effective for the treatment of T. callipaeda infection in cats under field conditions.

Efficacy of a topical formulation containing eprinomectin, esafoxolaner and praziquantel (NexGard® Combo) in the treatment of natural respiratory capillariosis of cats

Feline pulmonary capillariosis is a significant disorder due to its distribution and clinical impact. This study evaluated the safety and efficacy of two administrations 28 days apart of a topical solution containing esafoxolaner, eprinomectin and praziquantel (NexGard® Combo) in treating Eucoleus aerophilus (syn. Capillaria aerophila) infection in naturally infected cats. Cats were allocated to two groups: G1 cats (n = 23) received two treatments at study days (SDs) 0 and 28 (±2) and were evaluated for 6 weeks, and G2 cats (n = 17) served as a negative control for 6 weeks and were then treated twice on SDs 42 (±2) and 70 (±2), allowing for an additional 6-week assessment of efficacy. Each cat was subjected to McMaster coproscopy at SDs -7/0, 28 (±2) and 42 (±2) for both groups, 70 (±2) and 84 (±2) only for G2. Clinical examination and chest radiographic images were performed at SDs 0, 28 (±2) and 42 (±2) for G1 and G2, 70 (±2) and 84 (±2) only for G2. The comparison of EPG (eggs per gram of feces), clinical (CS), and radiographic scores (RS) at each time-point was used as a criterion. The efficacy based on the EPG reduction was 99.5% (G1) and 100% (G2) after two administrations of NexGard® Combo 2 weeks apart. At SD 0, no significant differences for CS and RS were recorded between G1 and G2, while a significant reduction (p < 0.05) was observed post-treatment for CS, RS, oculo-nasal discharge, auscultation noises, and cough. Two doses of NexGard® Combo 28 days apart stopped egg shedding and significantly improved clinical alterations in cats infected by E. aerophilus.

Efficacy of afoxolaner or the combination of afoxolaner with milbemycin oxime against Otodectes cynotis in naturally infested dogs

Otodectes cynotis, commonly known as "the ear mite," is a highly contagious ectoparasite and a significant cause of otitis externa in canines. The objective of the current study was to determine the efficacy of the isoxazoline afoxolaner (Nexgard®), and the combination of afoxolaner with milbemycin oxime (Nexgard Spectra®), in dogs naturally infested with O. cynotis. In total, 32 infested client-owned dogs from two different sites in Greece were included. The animals were randomly divided into four equal groups based on their infestation score. Group 1 served as the negative control, group 2 received one oral administration of Nexgard (Day 0), group 3 received two monthly oral administrations of Nexgard (Days 0, 30), and group 4 received two monthly oral administrations of Nexgard Spectra (Days 0, 30), according to label instructions. Otoscopic examinations for mites and observations on debris/cerumen in the ears were carried out on Days 0, 15, 30, and 45. A quantitative assessment of ear mites by ear duct flushing and live mite counts was performed on Day 45. The results demonstrated that a single oral dose of afoxolaner and two monthly doses of afoxolaner or afoxolaner with milbemycin oxime resulted in a 99.9% reduction in live mite counts compared to the untreated control group by Day 45. Additionally, treated dogs showed improved clinical symptoms, such as ear cerumen/debris decrease, while untreated dogs experienced worsening symptoms over the study duration. No adverse events were reported. Overall, these results support the use of afoxolaner-based products to treat O. cynotis infestation in dogs.

Efficacy of an oral formulation of afoxolaner and milbemycin oxime against Tunga penetrans in naturally infected dogs

BACKGROUND

The sand flea Tunga penetrans is one of the agents of tungiasis, an important parasitic skin disease affecting humans and several mammalian species. Tungiasis is mainly observed in disadvantaged rural and peripheral urban communities in Latin America and sub-Saharan Africa. The dog is a major reservoir of Tunga fleas. Hematophagous adult female Tunga spp. embed and grow in their host's epidermis and cause cutaneous inflammatory disorders. NexGard Spectra® is an orally administered endectocide for dogs, a co-formulation of the isoxazoline afoxolaner and the macrocyclic lactone milbemycin oxime. The objective of this study was to assess the efficacy of this product against canine tungiasis.

METHODS

A blinded, negative-controlled field trial was conducted in a Brazilian community known to be highly endemic for tungiasis. Sixty-six dogs naturally infected with live T. penetrans were randomly allocated to a treated group (44 dogs) and an untreated control group (22 dogs). In a first phase, dogs from the treated group were treated on days 0, 30, and 60. Efficacy was evaluated on the basis of the macroscopic parasitic skin lesions (Fortaleza classification) on days 7, 14, 21, 30, 45, 60, 75, and 90. In a second phase, to evaluate natural reinfections, all dogs were treated on day 90 and evaluated every 2 weeks thereafter until at least 30% of dogs were infected with live sand fleas.

RESULTS

During the first phase, efficacy (reduction in live sand fleas) of 92.4% was demonstrated on day 7. From day 14 until day 90, the efficacy of NexGard Spectra® was 100%. In the second phase, all dogs were free of live T. penetrans from 15 until 45 days after the day 90 treatment; 60 days post-treatment, 11% of dogs were reinfected, and 75 days post-treatment, 40% of dogs were reinfected.

CONCLUSIONS

NexGard Spectra® was demonstrated to be highly effective against canine tungiasis. In addition to an obvious beneficial effect on the health and welfare of the treated dog, the use of this product may have a one-health benefit on human cases by controlling the main reservoir of sand fleas.

Afoxolaner (NexGard®) in pet snakes for the treatment and control of Ophionyssus natricis (Mesostigmata: Macronyssidae)

BACKGROUND

Ophionyssus natricis is the main species of mite that infests captive reptiles. High infestations may result in the host experiencing general discomfort and deleterious effects, even death. Moreover, O. natricis is an important vector of reptile vector-borne diseases and is considered to be the putative vector of the Reptarenavirus, the causal agent of the inclusion body disease. Despite the cosmopolitan distribution of O. natricis in captive reptiles, treatment options are limited. The aim of the present study was to assess the efficacy of afoxolaner (NexGard®; Boehringer Ingelheim, Ingelheim, Germany) in heavily infested, privately owned snakes, evaluate the prevalence of mites and drug availability in the plasma of treated snakes (pharmacokinetics) and perform a clinical examination of animals.

METHODS

The study was conducted in two snake breeding facilities, where many snakes were infested with mites. Each animal was clinically examined and weighed, and mite infestations were assessed on the animals and in their enclosures (environment). Animals were treated with a dose of 2.5 mg afoxolaner per kilogram body weight (2.5 mg/kg) administered orally. All animals were examined pre-treatment (T0) and at various time points post-treatment (T1, 6 h; T2, 24 h; T3, 14 days; T4, 28 days). The collected mites were morphologically identified at the species level and the species identity also confirmed molecularly.

RESULTS

Overall, 81 snakes from the two participating facilities (i.e. 70 from site 1 and 11 from site 2) were screened, and 31 (38.3%) snakes were found to have at least one mite. All mites were identified morphologically and molecularly as O. natricis. Lampropeltis was the genus of snakes with highest number of infested individuals. Mites were found to be alive on snakes at T1, but at T2 only dead mites were observed, and at T3 and T4 mites were no longer present on the animals or in their environment. No side effects were observed in the treated snakes.

CONCLUSIONS

A single oral administration of afoxolaner at 2.5 mg/kg was a safe treatment for snakes and 100% effective for the eradication of natural O. natricis infestation without the need to treat the environment of the snake.

Geographical analysis of seroprevalence of Ehrlichia spp., Anaplasma spp., Borrelia burgdorferi and Dirofilaria immitis, in clinics and dog shelters in different Mexican states

This study aimed to determine the seroprevalence and geographical distribution of Ehrlichia spp., Anaplasma spp., Borrelia burgdorferi and Dirofilaria immitis in dogs in Mexico, including owned dogs from veterinary clinics with regular medical care and shelter dogs. The Mexican territory was divided into eight geographical regions; 22 out of 32 states were included; 110 veterinary clinics and 53 dog shelters participated. SNAP® 4Dx Plus® (IDEXX® Laboratories) was used to detect antibodies against Ehrlichia spp., Anaplasma spp., Borrelia burgdorferi and Dirofilaria immitis antigens. A total of 3522 apparently healthy dogs were tested, 1648 from clinics and 1874 from shelters. The highest seroprevalence of infection/exposure was found for Ehrlichia spp. (30.9%), followed by Anaplasma spp. (14.6%), D. immitis (5.3%) and B. burgdorferi (0.1%). Significantly more positive dogs were older than 3 years. Regarding differences between facility types, there were only differences for D. immitis which was more prevalent in clinics than in shelters (OR ​= ​1.97; 95% CI: 1.45-2.69; P ​< ​0.0001). Co-infections were detected in 38.4% of the positive samples. Dogs from Mexican states located on the Atlantic and the Pacific coast were significantly more at risk for Ehrlichia spp. and Anaplasma spp. infections than dogs from interior states. Dogs in Atlantic coastal states were more at risk for Dirofilaria immitis infection.

Efficacy of a topical formulation containing esafoxolaner, eprinomectin and praziquantel (NexGard Combo®) against natural infestations with the cat louse, Felicola subrostratus under field conditions

Felicola subrostratus is the only species of louse affecting domestic cats. Although it is considered a rare ectoparasite of pet cats, it occurs mainly in stray or shelter animals and is sometimes associated with intense pruritus and secondary bacterial infections. The aim of the present study was to evaluate the efficacy of a single dose of the topical formulation of esafoxolaner, eprinomectin and praziquantel (NexGard Combo^®, Boehringer Ingelheim) in cats for the treatment of naturally acquired chewing lice infestation in a multi-site, positive-control, blinded clinical field study. Thirty-one domestic cats presenting natural F. subrostratus infestation were included in the study. The animals had not been treated with any ectoparasiticide within the previous 60 days. After inclusion, each cat was randomly assigned to one of the two groups: group 1, 14 cats treated with NexGard Combo^® or group 2, 17 cats treated with Frontline Combo^®. A clinical evaluation was performed at days 0 (inclusion), 14 and 30 and consisted in scoring the skin lesions and symptoms and scoring the presence of lice. On day 30, all cats from both groups scored 0 for the presence of live lice and no dead lice were found, demonstrating 100% efficacy. The clinical scores significantly improved from day 0 to day 30 in both groups. During the 30 days of surveillance, no reinfestations due to the hatching of eggs were observed and none of the cats had any adverse reactions. Esafoxolaner demonstrated high efficacy for the treatment of F. subrostratus infestation.

Efficacy of a topical product combining esafoxolaner, eprinomectin and praziquantel against bedbug (Cimex lectularius) experimental infestations in cats

Bedbugs (Cimex lectularius) are a persistent nuisance pest for humans and their home environment, and may also opportunistically feed on other mammals, including household pets like dogs and cats. NexGard® Combo is a topical endectoparasiticide product for cats combining esafoxolaner, an isoxazoline compound with insecticidal and acaricidal properties, the nematocide eprinomectin and the cestocide praziquantel. The insecticidal efficacy of this product was evaluated in cats experimentally infested with C. lectularius in a blinded, negative controlled and randomized study. Two groups of 7 cats were formed: an untreated control group, and a NexGard® Combo group treated once on Day 0 at the label dose. Cats were then challenged weekly, each with twenty unfed adult C. lectularius, on Days 1, 7, 14, 21 and 28. After close contact with the cat's skin for 15 min, live fed C. lectularius were collected and incubated for 96 h. The weekly efficacy evaluations were based on a comparison of the number of surviving bedbugs in the control and the treated group after 48, 72 and 96 h of incubation. The model was demonstrated to be robust as in the control group the average feeding rate after the 15-minute challenge was 94%, and as 96% of incubated bed bugs were alive after 96 hours of incubation. Significant live bedbug reductions were demonstrated in the Nexgard® Combo treated group: after 96 h of incubation, the reductions ranged from 80.6 to 88.0% during the Day 1 to Day 21 period, and dropped to 58% at Day 28.

Efficacy of afoxolaner (NexGard®) against natural infestations with Trichodectes canis in dogs under field conditions

Background

Trichodectes canis is a small chewing louse found globally that primarily infests dogs. Limited information is available on the efficacy of isoxazolines against infestation with the chewing louse. In the present study, we evaluated the efficacy of afoxolaner, an isoxazoline class compound, in naturally infested domestic dogs.

Methods

The field study was carried out in Romania. Between September 2021 and December 2021, 43 dogs with confirmed T. canis infestation were included in the study. On the day of the inclusion (day 0), each animal was clinically examined and randomly treated with a control product labeled for use against lice [fipronil-(S)-methoprene combination (Frontline Combo®; Boehringer Ingelheim)] or with the investigational product [chewable tablets containing afoxolaner (NexGard®; isoxazoline)]. Each animal was evaluated for the presence of lice at 15 and 30 days post-inclusion.

Results

Of the 48 dogs initially included in the study, 43 completed the treatment period [18 in the control group (CG) and 25 in the investigational group (IG)]. At day 14, no living T. canis lice were detected on the dogs in either group. At day 14, dead lice were detected in four dogs in the IG, while eggs were present in two dogs in the IG and in one dog in the CG. At day 30, no lice were detected in either group, while eggs were still present in one dog in the CG.

Conclusion

These results suggest that afoxolaner is a feasible treatment option against chewing lice in dogs, providing 100% curative efficacy.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-022-05428-y.

Faecal prevalence, distribution and risk factors associated with canine soil-transmitted helminths contaminating urban parks across Australia

Dog parks provide an ideal urban space where dogs and their owners can exercise, play, and socialize in a safe environment. However, these parks can also increase the risk of exposure to a series of infectious agents including canine soil-transmitted helminths (cSTHs) such as hookworms, roundworms, Strongyloides stercoralis, and Trichuris vulpis, which are endemic to Australia. In this study, we collected 1581 canine faecal samples in 190 urban parks across Australia and subjected these to faecal floatation and multiplex real-time PCRs (qPCR) to detect a range of cSTHs. In total, 44.2% of the parks sampled were contaminated with at least one species of cSTH, with hookworms being the most prevalent parasites (10.2%) followed by Trichuris spp. (1.3%) and Strongyloides spp. (1.2%). This is the first large-scale study investigating the contamination of urban parks with cSTHs in Australia, and the first nation-wide study to demonstrate the occurrence of Strongyloides spp. in canine faecal samples from urban areas in the country. This study reveals a high rate of contamination with cSTHs in dog parks in urban Australia, most of which having proven zoonotic potential. Preventive measures, including awareness-raising educational programs promoting responsible pet ownership, should be encouraged to minimise the health risks associated with cSTHs for both dogs and humans.

Occurrence and bacterial loads of Bartonella and haemotropic Mycoplasma species in privately owned cats and dogs and their fleas from East and Southeast Asia

Bartonella spp. and haemoplasmas are pathogens of veterinary and medical interest with ectoparasites mainly involved in their transmission. This study aimed at molecular detection of Bartonella spp. and haemoplasmas in cats (n = 93) and dogs (n = 96), and their related fleas (n = 189) from countries in East and Southeast Asia. Ctenocephalides felis was the dominant flea species infesting both cats (97.85%) and dogs (75%) followed by Ctenocephalides orientis in dogs (18.75%) and rarely in cats (5.2%). Bartonella spp. DNA was only detected in blood samples of flea‐infested cats (21.51%) (p < .0001, OR = 27.70) with Bartonella henselae more frequently detected than Bartonella clarridgeiae in cat hosts (15.05%, 6.45%) and their associated fleas (17.24%, 13.79%). Out of three Bartonella‐positive fleas from dogs, two Ct. orientis fleas carried Bartonella vinsonii subsp. berkhoffii and Bartonella clarridgeiae, while the 3rd flea (Ct. felis) carried Candidatus Bartonella merieuxii. Felines represented a risk factor for Bartonella spp. infections, where fleas collected from cats (32.25%) presented an increased likelihood for Bartonella spp. occurrence (p < .0001, OR = 14.76) than those from dogs (3.13%). Moreover, when analysing infectious status, higher Bartonella spp. DNA loads were detected in fleas from bacteraemic cats compared to those from non‐bacteraemic ones (p < .05). The haemoplasma occurrence was 16.13% (15/93) and 4.17% (4/96) in cat and dog blood samples from different countries (i.e. Indonesia, Malaysia, the Philippines, Taiwan and Thailand), with cats more at risk of infection (p < .01, OR = 5.96) than dogs. Unlike Bartonella spp., there was no evidence for flea involvement in the hemoplasmas' transmission cycle, thus supporting the hypothesis of non‐vectorial transmission for these pathogens. In conclusion, client‐owned cats and dogs living in East and Southeast Asia countries are exposed to vector‐borne pathogens with fleas from cats playing a key role in Bartonella spp. transmission, thus posing a high risk of infection for humans sharing the same environment.

Drug resistant parasites and fungi from a one-health perspective: A global concern that needs transdisciplinary stewardship programs

Antimicrobials including antibiotics, antiparasitic, and antifungals, are subjected to resistance. In this context, Public Health Organizations called for a One Health approach because antimicrobials used to treat different infectious diseases in animals and plants may be the same than those used in humans. Whereas mechanisms of resistance transmission from animals or environment to humans should be considered differently if related to prokaryotic or eukaryotic pathogens, their impact can be considered as a whole. In that respect, we discussed the use of anti-parasitic in animals including anticoccidials, anthelmintics, and insecticides-acaricides, and the use of azoles in the environment that may both favor the development of drug resistance in humans. In light of the current situation, there is an urgent need for a transdisciplinary approach through anti-parasitic and antifungal stewardship programs in humans, animals, and environment, especially in the era of COVID-19 pandemic that will probably aggravate antimicrobial resistance.

Efficacy of afoxolaner for the treatment of ear mite infestation under field conditions

Otodectes cynotis is a commonly occurring surface mite that can be easily transmitted between suitable hosts, including dogs, causing otocariosis. The activity of the systemic insecticide afoxolaner against O. cynotis has been tested once under experimental conditions, showing a high efficacy. The present study aimed to i) assess the efficacy of two consecutive monthly oral administrations of afoxolaner (NexGard®) against O. cynotis in naturally infested dogs under field conditions and ii) evaluate its impact in reducing bacteria or fungal secondary infections. Dogs, positive for O. cynotis (n = 20), were included in the study and allocated in two groups of ten animals each (G1, control group, and G2, treated group). The first group of ear mite-infested dogs was treated with a placebo, while afoxolaner was administered orally to the second group of dogs at Day 0 (D0) and Day 30 (D30), following label instructions. Otoscopic assessments, deep-swab method and swab samples were performed on all dogs (Days 0, 30, 42) to evaluate the presence or absence of live mites and their number throughout the study, as well as to conduct bacterial and fungal assessments. No adverse events likely related were recorded throughout the study. By Day 42 (D42), all dog's ears were flushed to recover ear mites. All treated dogs became negative, as well as two dogs of the control group. The treatment efficacy of afoxolaner was 100 % based on the arithmetic means of the live mite counts. The clinical scores did not change significantly in the control group, whereas they significantly improved in the treated one from D0 to D30 (p-value = 5.47 10^-5). No live mites were present in the afoxolaner-treated group at D42 (p-value = 0.00073). In this field study, two oral administrations of afoxolaner at the recommended dose allowed a complete cure of the infestation. Bacterial and Malassezia pachydermatis infections were detected in both groups, although no significant trend was associated to the ear mite treatment.

Efficacy of fipronil/(S)-methoprene/eprinomectin/praziquantel (Broadline®) against Thelazia callipaeda in naturally infected cats

Background

The present clinical field trial was conducted to assess the efficacy of a broad-spectrum parasiticide spot-on formulation containing eprinomectin (Broadline^®) against Thelazia callipaeda eyeworm in naturally infected cats.

Methods

Fifteen privately owned cats harboring at least one live adult T. callipaeda were included in the study. Cats were randomly allocated to an untreated control group of seven cats or to a Broadline^®-treated group of eight cats. Cats were treated on Day 0; ocular examinations were performed at inclusion and on Days 7 and 14; eyeworms were recovered and counted on Day 14. The primary efficacy assessment was based on group comparison of number of T. callipaeda on Day 14.

Results

Seven days after treatment, six of eight treated cats were negative for eyeworm infection per visual examination, and on Day 14 no eyeworms were found in the treated cats while the seven untreated cats were still infected (geometric mean: 1.97). All cats had inflammatory ocular signs at inclusion; on Day 14, five of eight treated cats had recovered while all untreated control cats were still symptomatic. All collected parasites were confirmed to be T. callipaeda by morphology and molecular characterization.

Conclusions

A single treatment with Broadline^® provided 100% efficacy against feline thelaziosis and improved related ocular inflammation signs.

Graphical abstract

Efficacy of afoxolaner (NexGard®) in preventing the transmission of Leishmania infantum and Dirofilaria immitis to sheltered dogs in a highly endemic area

Background

Leishmania infantum and Dirofilaria immitis are among the most important canine vector-borne pathogens (CVBPs) of zoonotic concern in Europe. In endemic areas for both of these CVBPs, the use of systemic ectoparasiticides, such as afoxolaner (NexGard®; Boehringer Ingelheim Animal Health), may have the potential for controlling these infections. The aim of this study was to assess, for the first time, the insecticidal efficacy of NexGard® in decreasing the transmission of D. immitis and L. infantum to sheltered dogs living in a hyperendemic area, compared to the year before treatment, as well as its impact on the abundance of mosquito and sand fly populations.

Methods

All dogs (n = 179) enrolled in the study were divided into two groups based on their infection status at enrollment: a non-infected group (G1) and an infected group (G2; infected with D. immitis, L. infantum or both). The study was conducted from March 2020 to March 2021. In order to exclude all animals infected with L. infantum and D. immitis before March 2020 (sampling time: T0), dogs in G1 were sampled in June (T1; i.e. T0 + 90 days) and in October 2020 (T2; i.e. T0 + 210 days). From March to September 2020, all animals (G1 and G2) were weighed and treated monthly with NexGard®. Animals in G1 were tested for the last time in March 2021 (T3; i.e. T0 + 330 days) for assessing post-treatment incidence rate of infection and prevention efficacy.

Results

The post-treatment incidence of D. immitis was 3.7% (1/27; 95% confidence interval [CI]: 0.2–18.1) and that of L. infantum was 3.6% (3/83; 95% CI: 1.0–10.1). Considering the annual incidence in 2019 and 2020, the protective efficacy against D. immitis and L. infantum infections was 94.2 and 64%, respectively. Of the female mosquitoes collected (n = 146), only one pool out of 50 tested positive for D. immitis DNA, whereas out of 1252 female Sergentomya minuta specimens collected, only four tested positive for L. infantum (0.3%).

Conclusions

Afoxolaner is efficacious in decreasing the rate of transmission of both D. immitis and L. infantum; however, comparison of the pre- and post-treatment period demonstrated that there was a significant difference only in the seasonal incidences of D. immitis infection. Preventive measures are recommended throughout the year in endemic areas to reduce the risk of pathogen transmission to animals and humans.

Graphical abstract

Efficacy of milbemycin oxime/afoxolaner chewable tablets (NEXGARD SPECTRA®) against Capillaria aerophila and Capillaria boehmi in naturally infected dogs

BACKGROUND

Capillaria aerophila and Capillaria boehmi parasitize the respiratory system of wild and domestic carnivores. Capillaria aerophila inhabits the trachea and bronchi of dogs and cats, while C. boehmi affects the nasal cavities and sinuses of dogs. In dogs the infection may be subclinical or characterized by varying respiratory distress.

METHODS

The present study evaluated the efficacy of an oral formulation containing milbemycin oxime and afoxolaner (NEXGARD SPECTRA^®) in dogs naturally infected with C. aerophila and/or C. boehmi from three enzootic areas of Italy. Dogs were enrolled pending fecal examination and molecular confirmation of respiratory capillarioses. Dogs were allocated in two groups: Group 1 (G1, 25 dogs), treated with a negative control product with no anthelmintic activity (afoxolaner, NEXGARD^®), and Group 2 (G2, 26 dogs), treated with NEXGARD SPECTRA^®. At the day of treatment administration (Day 0), all dogs were clinically examined. Dogs were again subjected to clinical and fecal examinations at Days 28 (± 4) and 56 (± 2). The primary criterion for treatment efficacy was the reduction of fecal Capillaria egg counts in G2 compared with G1. The regression of/recovery from baseline clinical signs was considered as a further efficacy criterion.

RESULTS

Percentage reduction of fecal Capillaria egg counts in the NEXGARD SPECTRA^® group compared to the control group was > 97% on Day 28 and 100% on Day 56, respectively (p < 0.05 for both time points). Twelve of the 13 dogs in the NEXGARD SPECTRA^® group with respiratory signs prior to treatment were free of clinical signs at the end of the study. Conversely, the six control group dogs with respiratory signs prior to treatment remained symptomatic.

CONCLUSIONS

Results of the present study showed that NEXGARD SPECTRA® was safe and highly efficacious in the reduction of C. aerophila and C. boehmi eggs after one treatment with a complete reduction of the egg output after the second administration associated with a recovery from respiratory signs.

Incidence of Dirofilaria immitis and Leishmania infantum infections in sheltered dogs from Southern Italy

Leishmania infantum and Dirofilaria immitis are among the most important vector-borne pathogens in Europe, affecting animal and human health. In endemic areas, the epidemiology of both infections is conditioned by abundance of vectors and chemoprophylaxis measures. However, knowledge on the incidence of heartworm (HW) and Leishmania infections occurring in sympatry is still scant. Thus, this study aimed to evaluate the incidence of both infections in two dog shelters from southern Italy, which represent hotspots for these two diseases. In June and in October 2020, all dogs that previously scored negative for L. infantum (n = 111, site 1; n = 70, site 2) and D. immitis (n = 58, site 1; n = 61, site 2) in 2019 were tested for the estimation of the incidence of both infections. Anti-L. infantum IgG was detected by immunofluorescence antibody test, whereas D. immitis infection was diagnosed by modified Knott's test, SNAP 4Dx Plus test and real-time PCR. The overall D. immitis and L. infantum infection incidence values were both higher in site 2 (i.e. 63.9% and 10%, respectively) than site 1 (i.e. 39.7% and 1.8%, respectively). The dog shelter in site 2 was shown to be more suitable for the development of the mosquito/sand fly populations and, consequently, for the spreading of both parasites representing a potential threat for animal and human health. The high incidence of both infections recorded in this study suggests the need for chemoprophylaxis measures and vector monitoring and control to minimize the risk for animals and humans living in shelters or in their neighbourhoods.

Insecticidal efficacy of afoxolaner against bedbugs, Cimex lectularius, when administered orally to dogs

The objective of this experimental study was to assess the insecticidal efficacy of afoxolaner (NexGard^®) against bedbugs (Cimex lectularius) on dogs. For each challenge, 20 bedbugs were placed in two chambers positioned in contact to the dog’s skin for 15 min, after which live fed parasites were counted and incubated for survival evaluations. On Day 0, 7 dogs assigned to the treated group were administered afoxolaner orally at the registered dose. All 14 dogs were challenged on Days 1, 7, 14, 21 and 28, and the collected live fed C. lectularius incubated for 72 h (Day 1), and 72 h and 96 h (Days 7, 14, 21 and 28) for survival evaluation. The percent feeding in the control group ranged from 95% to 98.6% and the percent of live fed bedbugs at 96 h ranged from 99.3% to 100% in the control group, demonstrating the viability of the strain and their capacity to feed on dogs. Significantly fewer live fed bedbugs were counted in the treated group, compared to the control group, at all time-points. The reduction of live fed C. lectularius in the afoxolaner group was 41.4% at 72 h after the Day 1 challenge, and 77.2%, 82.7%, 85.0% and 63.5% at 96 h after the Days 7, 14, 21 and 28 challenges, respectively. It is hypothesized that monthly treatment of dogs with afoxolaner could help in preventing a bed bug population from installing in a household if bedbugs bite dogs in the presence of humans.

First record of Hepatozoon spp. in domestic cats in Greece

Feline hepatozoonosis is an emerging disease of domestic and wild felids though there is limited knowledge of this infection, e.g. regarding geographical distribution and parasite species involved. The present study evaluated microscopically and molecularly the occurrence of Hepatozoon spp. in domestic cats from insular (Crete, Mykonos and Skopelos) and continental (prefectures of Attica and Thessaloniki) Greece. Out of 282 cats examined, 72 (25.5 %) scored positive by PCR for Hepatozoon spp. and of them, 9 (12.5 %) showed gamonts on the blood smear microscopic examination. Sequences obtained from 35 of the amplicons proved the presence of two haplotypes of Hepatozoon felis. One, herein called H1 (34/35 amplicons) resulted 100 % identical with H. felis from Italy and isolates from other continents, and ∼98 % similar with a H. felis isolate causing severe clinical signs in Austria. The haplotype H2, found in a cat in Skopelos, had ∼94 % identity with H1, with H. felis isolates from Italy, Israel, Spain, a ∼92 % identity with the isolate from Austria, and ∼94-98 % with isolates from South Africa. These are the first records of H. felis in cat populations from Greece and indicate that the infection may be present at high prevalences in different regions of the country. Furthermore, the results of the molecular and phylogenetic analysis support a recent hypothesis indicating the existence of a species-complex classification for H. felis. Further studies aiming at elucidating the genetic make-up of Hepatozoon populations and possible variations in terms of geographic distribution and clinical relevance are necessary. The importance of a continuous epizootiological monitoring is crucial for the establishment of preventative and control measures protecting the health of cats living in or travelling to enzootic areas.

Molecular detection of pathogens in ticks and fleas collected from companion dogs and cats in East and Southeast Asia

Background

Ticks and fleas are considered amongst the most important arthropod vectors of medical and veterinary concern due to their ability to transmit pathogens to a range of animal species including dogs, cats and humans. By sharing a common environment with humans, companion animal-associated parasitic arthropods may potentially transmit zoonotic vector-borne pathogens (VBPs). This study aimed to molecularly detect pathogens from ticks and fleas from companion dogs and cats in East and Southeast Asia.

Methods

A total of 392 ticks and 248 fleas were collected from 401 infested animals (i.e. 271 dogs and 130 cats) from China, Taiwan, Indonesia, Malaysia, Singapore, Thailand, the Philippines and Vietnam, and molecularly screened for the presence of pathogens. Ticks were tested for Rickettsia spp., Anaplasma spp., Ehrlichia spp., Babesia spp. and Hepatozoon spp. while fleas were screened for the presence of Rickettsia spp. and Bartonella spp.

Result

Of the 392 ticks tested, 37 (9.4%) scored positive for at least one pathogen with Hepatozoon canis being the most prevalent (5.4%), followed by Ehrlichia canis (1.8%), Babesia vogeli (1%), Anaplasma platys (0.8%) and Rickettsia spp. (1%) [including Rickettsia sp. (0.5%), Rickettsia asembonensis (0.3%) and Rickettsia felis (0.3%)]. Out of 248 fleas tested, 106 (42.7%) were harboring at least one pathogen with R. felis being the most common (19.4%), followed by Bartonella spp. (16.5%), Rickettsia asembonensis (10.9%) and “Candidatus Rickettsia senegalensis” (0.4%). Furthermore, 35 Rhipicephalus sanguineus ticks were subjected to phylogenetic analysis, of which 34 ticks belonged to the tropical and only one belonged to the temperate lineage (Rh. sanguineus (sensu stricto)).

Conclusion

Our data reveals the circulation of different VBPs in ticks and fleas of dogs and cats from Asia, including zoonotic agents, which may represent a potential risk to animal and human health.

Hyperendemic Dirofilaria immitis infection in a sheltered dog population: an expanding threat in the Mediterranean region

A study on the occurrence of Dirofilaria immitis and its vectors was carried out in order to assess the prevalence of the disease in dogs in previously non-endemic areas of southern Italy. Blood samples (n = 385) and mosquitoes (n = 1540) were collected in two dog shelters and analysed by Knott's test and duplex real-time PCR, respectively. Dirofilaria immitis was the most prevalent filarioid (44.2%), while Culex pipiens was the most prevalent mosquito species (68.8%). This high prevalence of D. immitis infection confirms this location as one of the most hyperendemic foci of dirofilariosis in Europe.

Experimental assessment of permethrin-fipronil combination in preventing Leishmania infantum transmission to dogs under natural exposures

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Controlled experimental field study allowing natural exposure to sandflies.

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Two groups of 20 dogs each in two close sub-unit kennels.

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7/20 dogs infected by L. infantum in the untreated group.

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0/20 dogs infected by L. infantum in the fipronil-permethrin monthly treated group.

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100 % protection obtained during this one-year study.

Canine vector-borne disease transmission can be reduced with regular use of repellent insecticides. The objective of this year-long experimental study was to assess the efficacy of a topical formulation of fipronil/permethrin (Frontline Tri-Act®) in preventing transmission of Leishmania infantum by sandflies. This clinical field trial was conducted in Xanthi (Northern Greece), an area highly endemic for canine leishmaniosis, from April 2018 to March 2019. Forty purpose-bred Beagle dogs, testing negative for L. infantum prior to study initiation, were enrolled in the study, which consisted of three phases: Phase 1 (field exposure phase) took place from Day 0–196. The dogs were randomly allocated to two groups, group 1 (sham-treated topically with sterile water) and group 2 (treated topically with Frontline Tri-Act®). Dogs in both groups were housed in two subunits of an open-air kennel for a period of 7 months, spanning the Leishmania transmission season. All dogs were treated or sham-treated on Days 0, 28, 56, 84, 112, 140 and 168. Clinical examinations, PCR analysis of conjunctival swabs, and serological tests were performed on a monthly basis. Sandflies were collected every 2 weeks, during a 12 -h period overnight using light traps. Each collection was placed in a container and kept refrigerated until speciation and PCR analysis could be performed. In the second phase of the study, from Day 197 to 252, the dogs were moved into a protected environment (insect-proof protected environment phase). CDC light traps were activated every 2 weeks inside and outside the kennels to ensure the vector-free status of the facility. Monthly clinical examinations, including PCR analysis of conjunctival swabs, and serological tests continued. At the end of the phase 2, bone marrow samples were collected on all dogs. Phase 3 (the final post-winter check) took place from Day 253 to 350. Dogs were released and adopted by individual private owners on Day 253. Follow up analyses included blood collection for SNAP tests and conjunctival swaps for PCR analysis on Days 304 and 350. Additionally, bone marrow collections were also performed on Day 350.

Presence of sandflies was observed only in the phase 1 exposure period, and 1714 sandflies were collected (1427 females and 287 males). Two species were identified, Phlebotomus perniciosus var. tobbi and Phlebotomus neglectus. Out of the 62 pooled samples of sandflies assessed by PCR, three were considered positive (4.8 %). By the end of the study, 35 % of the Group 1 dogs (7/20) became positive based on PCR (conjunctival swab and bone marrow) and 30 % (6/20) based on SNAP/IFAT and ELISA tests, while all the dogs in the Frontline Tri-Act® treated group 2 remained negative for all tests (G1 vs G2, p = 0.008). All tests identified the same positive animals, and PCR allowed the detection of one additional infected dog. This clinical field trial demonstrated that monthly administration of Frontline Tri-Act® to dogs exposed to Leishsmania infection in a high endemic area provided 100 % preventive efficacy against transmission of L. infantum.

Leishmania infantum and Dirofilaria immitis infections in Italy, 2009-2019: changing distribution patterns

BACKGROUND

For long time, canine leishmaniosis (CanL) was considered endemic in the southern, central, and insular regions of Italy, whereas heartworm disease (HW) caused by Dirofilaria immitis was considered endemic in the northern region and in the swampy Po Valley. Following the reports of new foci of both diseases, in this study we update the distribution patterns and occurrence of new foci of CanL and HW discussing the main drivers for the changes in the epidemiology of these two important zoonotic canine vector-borne diseases.

METHODS

Based on the statistical analyses of serological assays (n = 90,633) on L. infantum exposure and D. immitis infection performed by two reference diagnostic centres in Italy over a ten-year period (2009-2019) irrespective of the anamnesis of dogs. The distribution patterns of both parasites are herein presented along with the occurrence of new foci.

RESULTS

Results highlighted the changing distribution patterns of L. infantum vs D. immitis infection in Italy. CanL is endemic in some areas of northern regions and HW has endemic foci in central and southern regions and islands. Significant differences in L. infantum exposure and HW infection prevalence among the study macroareas were detected. The overall results of the positive tested samples were 28.2% in southern Italy and islands, 29.6% in central Italy and 21.6% in northern Italy for L. infantum and 2.83% in northern Italy, 7.75% in central Italy and 4.97% in southern Italy and islands for HW. HW positivity significantly varied over years (χ2 = 108.401, df = 10, P < 0.0001), gradually increasing from 0.77% in 2009 to 8.47% in 2016-2017.

CONCLUSIONS

New potential epidemiological scenarios are discussed according to a range of factors (e.g. environmental modifications, occurrence of competent insect vectors, transportation of infected animals to non-endemic areas, chemoprophylaxis or vector preventative measures), which may affect the current distribution. Overall, the results advocate for epidemiological surveillance programmes, more focussed preventative and control measures even in areas where few or no cases of both diseases have been diagnosed.

Correction to: Assessment of the efficacy of firocoxib (Previcox®) and grapiprant (Galliprant®) in an induced model of acute arthritis in dogs

The original article [1] contains two mistaken instances of the molecule 'fipronil' in the results. These should instead have stated 'firocoxib'.

Assessment of the efficacy of firocoxib (Previcox®) and grapiprant (Galliprant®) in an induced model of acute arthritis in dogs

Background

Non-steroidal anti-inflammatory drugs (NSAIDs) are an important tool in the management of canine osteoarthritis, with the most recent introduction into the category being grapiprant, a piprant that selectively targets the EP4 prostaglandin receptor. To date there have been no efficacy studies comparing grapiprant with other NSAIDs. A randomized, two-sequence, assessor-blinded study involving two separate experiments was undertaken to measure the potency and persistence of acute pain control over 24 h resulting from a single oral dose of either firocoxib (Previcox®) or grapiprant (Galliprant®) in an acute arthritis model.

Results

Force-plate derived lameness ratios (0, no force recorded on the plate; 1, normal force) for the untreated group remained at 0 for most post-arthritis induction (PAI) assessments in both experiments. Throughout Experiment 1, mean PAI lameness ratios of the firocoxib-treated group remained at or above 0.80. In the grapiprant-treated group, ratios were 0 at 5 and 7 h PAI (7 and 9 h post-treatment), and 0.16 at 10 h PAI (12 h post-treatment). For lameness ratios, relative to the firocoxib group, the control and grapiprant group ratios were significantly lower at each PAI assessment (p ≤ 0.026 and p < 0.001, respectively), except at 1.5 h PAI at which acute pain was still not installed in untreated control dogs. In Experiment 2 the mean lameness ratios for the control group were 0 at 3, 5 and 7 h PAI, and in the grapiprant group at 5, 7 and 10 h PAI (i.e., 19, 21, and 24 h post-treatment). In the firocoxib group the lowest mean lameness ratio of 0.36 occurred at 3 h PAI (i.e. 17 h post-treatment). Except at 1.5 and 3 h PAI (i.e. 15.5 and 17 h post-treatment), due to the needed time for pain to install in the untreated control dogs, the lameness ratio differences between the firocoxib and both the control and grapiprant groups were significant at all assessments (p ≤ 0.033 for both groups). No significant differences were detected between the grapiprant and control groups in either experiment.

Conclusions

Firocoxib treatment prior to induction of arthritis in dogs resulted in a high level of analgesia from the first post-treatment assessment at 1.5 h through 24 h post-treatment. The reduction in lameness provided by firocoxib was consistently superior to that provided by grapiprant, which was not significantly different from untreated controls.

Prevention of the transmission of Babesia rossi by Haemaphysalis elliptica in dogs treated with Nexgard®

This experimental study aimed to determine the efficacy of Afoxolaner (NexGard^®) to prevent Babesia rossi transmission by Haemaphysalis elliptica ticks on dogs. The study included three groups of seven dogs each. Groups 1 and 2 remained untreated, whereas group 3 dogs received NexGard^® on Day 0. All dogs were infested by 50 Haemaphysalis elliptica adult ticks: Group 1 on Day 2, Group 2 on Day 28 and Group 3 on Days 2 and 28. The ticks were originally nymphs having fed on B. rossi infected donor dogs. Their infection rate, assessed by PCR, was 12.8% at Day 2 and 6% at Day 28. On Days 0, 7, 14, 21, 28, 35, 42, 49 and 56, and in case of suspicion of babesiosis, blood samples were collected for blood smears, PCR and ELISA. The B. rossi infection rate in the untreated group 1 was 100% (6/6, as one dog was inadvertently treated on Day 15 and removed from statistical analysis). The infection rate was 57.1% (4/7) in group 2, and 0% (0/7) in the afoxolaner treated group 3 at all time-points until the end of the study on Day 56. After tick removal and count 144 h after each infestation, the control groups had an arithmetic mean of ticks of 23.8 (group 1) and 26.8 (group 2). No tick was recovered from any treated dogs. This study demonstrated that NexGard^® protected dogs against infection by B. rossi for at least 28 days.

Endoparasites and vector-borne pathogens in dogs from Greek islands: Pathogen distribution and zoonotic implications

The present study investigated the presence of endo- and ecto-parasites, and vector-borne pathogens, in dogs from four islands of Greece. A total of 200 (123 owned and 77 sheltered) dogs were examined with different microscopic, serological and molecular methods.

Of the examined dogs, 130 (65%) were positive for one or more parasites and/or vector-borne pathogens. The most common zoonotic intestinal helminths recorded were Ancylostomatidae (12.5%) and Toxocara canis (3.5%). Ninety-three dogs (46.5%) seroreacted to Rickettsia conorii. Twenty-two (11%) of them were also PCR positive and 7 (3.5%) showed corpuscles suggestive of Rickettsia spp. on the blood smears. Nineteen dogs (9.5%) were seropositive for Ehrlichia canis, three of them being also PCR positive. Dogs positive for Anaplasma phagocytophilum-Anaplasma platys (1%), Dirofilaria immitis (0.5%) and Babesia canis (0.5%) were also found. Fleas and ticks were recorded in 53 (26.5%) and 50 (25%) dogs, respectively, and all specimens were identified as Ctenocephalides felis felis and Rhipicephalus sanguineus sensu lato. Binary multiple univariate Generalized Linear Models were used to investigate factors and clinical signs related to the recorded positivity, while the association of specific signs with the pathogens was evaluated using tests of independence. Knowledge of occurrence and impact of zoonotic parasites and vector-borne pathogens in dog populations is crucial to prevent the infection in animals and people, and to control the risk of spreading of these pathogens in endemic and non-endemic areas.

Both owned and sheltered dogs can harbor a variety of intestinal and extra-intestinal endoparasites, as well as vector-borne pathogens and ectoparasites, of zoonotic concern. Dog shelters and stray dogs are present in several touristic areas of Greece, including Sporades and Cyclades islands, where tourists often bring their pets with them, likely travelling from non-endemic to endemic areas. The present study has been carried out with the aim to evaluate the occurrence of the aforementioned pathogens. Data obtained showed that they are present in canine populations of Greece, with possibilities of infection for travelling dogs, which can also contribute to the spreading of zoonotic vector-borne diseases, introducing new pathogens in previously non-endemic areas. For these reasons, a constant monitoring of the epidemiological situation, improving control measures and correct diagnostic approaches are of primary importance for the prevention of canine and human infections, decreasing the spreading of potentially deadly pathogens.

Prevention of canine ocular thelaziosis (Thelazia callipaeda) with a combination of milbemycin oxime and afoxolaner (Nexgard Spectra®) in endemic areas in France and Spain

In the past decade, canine thelaziosis due to Thelazia callipaeda has been diagnosed in an increasing number of European countries, with endemic areas being identified. A multi-center field trial was conducted in endemic areas in France and Spain to evaluate the efficacy of monthly administrations of the oral milbemycin oxime/afoxolaner combination (NexGard Spectra^®) for the prevention of T. callipaeda infection in at-risk dogs. A total of 79 dogs negative for T. callipaeda and with a clinical history of eyeworm infection in the past two years completed the study. Dogs were randomly allocated either to a negative control group (42 dogs) or to the NexGard Spectra^® treated group (37 dogs). All dogs were followed up for a 6-month period and assessed monthly for the presence of nematodes on the eyes and for the signs of ocular thelaziosis (e.g., conjunctivitis, keratitis, and ocular discharge). When the presence of nematodes was confirmed, the conjunctival fornix was flushed with a saline solution for parasite recovery and counting, and the dogs were treated appropriately. Recovered parasites were stored in 70% alcohol for subsequent morphological identification. During the course of the study, 57.1% (24/42) of the control dogs were diagnosed positive for Thelazia infection, which illustrates a high incidence rate of parasite infection. Conversely, no eyeworm was recovered from any of the 37 dogs that received NexGard Spectra^®. All parasites sampled were confirmed to be T. callipaeda. This clinical field study demonstrated that monthly administrations of NexGard Spectra^® provided 100% preventive efficacy against canine thelaziosis.

Treatment of canine sarcoptic mange with afoxolaner (NexGard®) and afoxolaner plus milbemycin oxime (NexGard Spectra®) chewable tablets: efficacy under field conditions in Portugal and Germany

The efficacy of NexGard^® and NexGard Spectra^® against sarcoptic mange in dogs was evaluated in a clinical field study. Skin scrapings from dogs presenting signs suggestive of sarcoptic mange were examined to confirm infestation. A total of 106 dogs were screened at eight sites in Portugal and Germany. In all, 80 dogs that had demonstrated ≥5 live Sarcoptes mites in five skin scrapings were enrolled, scored for specific clinical signs (pruritus; papules and crusts; alopecia), and allocated at random to receive either NexGard^® or NexGard Spectra^® twice, one month apart per label instructions. To determine efficacy, live Sarcoptes mites in five skin scrapings per dog were counted, and clinical signs were scored one month and two months after first treatment and compared to pre-treatment (baseline) values. Based on compliance, 65 dogs were determined to be evaluable cases at the end of the study. The efficacy, in terms of reduction of geometric mean live Sarcoptes mite counts, was 98.9% and 99.7% for NexGard^®-treated (n = 38) and 99.6% and 100% for NexGard Spectra^®-treated dogs (n = 27) at one month and two months after treatment initiation (p < 0.001, both treatments). Both treatments resulted in a significant improvement in pruritus, papules and crusts, and alopecia one month and two months after treatment initiation (p = 0.0001, both treatments). In conclusion, this field study confirms that both NexGard^® and NexGard Spectra^® administered twice one month apart provide an effective and safe treatment against sarcoptic mange in dogs.

Six-month field efficacy and safety of the combined treatment of dogs with Frontline Tri-Act® and NexGard Spectra®

BACKGROUND

Safety and efficacy of the combined monthly use of spot-on fipronil 6.76% w/v / permethrin 50.48% w/v (Frontline Tri-Act®) and chewable tablets of afoxolaner 1.9% w/w / milbemycin oxime 0.4% w/w (NexGard Spectra®) in dogs was evaluated in a field study over a period of 6 months.

METHODS

Forty-one healthy dogs living in highly endemic area for canine leishmaniosis and other canine vector borne diseases (VBD) were included in the study at the beginning of the Leishmania transmission season. Sixteen dogs were pet dogs living each in a single household; twenty-five dogs were hunting dogs living in three kennels. At inclusion, the dogs were ELISA (rapid test) negative for antibodies to Anaplasma, Borrelia, Ehrlichia, and for antigens of Dirofilaria. The dogs were also negative for blood microfilariae at the Knott's test, and no clinical or haematological abnormalities were observed. Of the included dogs, six hunting, apparently healthy, dogs were ELISA (rapid test) positive to Leishmania, and some were naturally infected by gastrointestinal nematodes (58.5%) and/or infested by fleas (58.5%) and ticks (9.8%). All the included dogs were treated at Days 0, 28, 56, 84, 112 and 140, and followed-up for efficacy until the study end (Day 168).

RESULTS

No adverse events related to the two products, nor skin reactions, general signs, or changes in the haematological profile, were observed during the study. At Day 14, anthelminthic efficacy was 100% for Toxocara canis, Toxascaris leonina and Capillaria aerophila, while few hunting dogs were still shedding eggs of Trichuris vulpis (1/25 hunting dog) and Ancylostomatidae (9/25 hunting dogs). All pet dogs were nematode free at the end of the study. Hunting dogs were free of roundworms and whipworms. Twenty-four hours after the first treatment, 95.8% of the ectoparasite infested dogs were free from fleas and ticks. Ectoparasites were significantly controlled during the 6-month study period, with 100% efficacy on both fleas and ticks from Day 56 to Day 168. Blood and serum samples collected on Day 168 were tested for vector-borne pathogens using same methods of the inclusion and no new seroconversions or circulating blood microfilariae were observed.

CONCLUSIONS

Concomitant use of Frontline Tri-Act® and NexGard Spectra® in dogs for six months was well tolerated. The combination was effective in controlling fleas, ticks, gastro-intestinal nematodes, and neither new seroconversion to the tested vector-borne pathogens nor blood microfilariae were detected in treated dogs at the end of the study.

Feline gastrointestinal parasitism in Greece: emergent zoonotic species and associated risk factors

BACKGROUND

Feline gastrointestinal parasitism constitutes an issue of concern for veterinarians since parasites are widespread and affect animals' health and welfare. Furthermore, some of these pathogens have zoonotic potential. To provide detailed data on the current epizootiology of feline endoparasitism, a multicentric survey was conducted during 2016.

METHODS

Faeces from 1150 cats were collected from all regions of Greece and examined by sedimentation and flotation techniques. Possible risk factors including gender, age, ownership status, living conditions and co-infections with other parasites were assessed using binary regression models for each one of the most prevalent parasites.

RESULTS

The overall gastrointestinal parasite prevalence in cats was 50.7%. The study population consisted of cats of both sexes, different age groups, ownership status and living conditions. A total of 10 gastrointestinal parasitic species were detected and up to 5 different parasites were isolated in the same faecal sample. The most frequently identified parasites were Toxocara cati (n = 278; 24.2%), followed by Cystoisospora spp. (n = 189; 16.4%), Ancylostomatidae (n = 186; 16.2%), Aelurostrongylus abstrusus (n = 40; 3.5%), Giardia spp. (n = 26; 2.3%), Joyeuxiella pasqualei (n = 14; 1.2%), Capillaria aerophila (n = 8; 0.7%), Dipylidium caninum (n = 3; 0.2%), Toxascaris leonina (n = 2; 0.1%) and Troglostrongylus brevior (n = 2; 0.1%). The occurrence of co-infections was 11.6%. Concerning risk factors, the likelihood of T. cati infection was higher for female cats living outdoors and for cats being infected with Cystoisospora spp. In the same frame, young, stray, male and free of A. abstrusus cats were more likely to be infected with Cystoisospora spp. Correspondingly, stray, infected with Giardia spp. but free of Cystoisospora spp. cats were more likely to be infected with Ancylostomatidae. Regarding A. abstrusus infection, a higher probability was reported for cats living outdoors and for cats free of Cystoisospora spp., while Giardia spp. infections were more common in young and co-infected with Ancylostomatidae animals.

CONCLUSIONS

The prevalence of parasitized cats in Greece was high and thus consideration should be paid to control the risk factors, to implement targeted preventive antiparasitic treatments and educate cat owners on the value of prevention for the health and welfare of their cats.

Lungworms and gastrointestinal parasites of domestic cats: a European perspective

With the exception of Aelurostrongylus abstrusus, feline lungworms have been poorly studied. Information on their distribution is patchy and mostly limited to case reports. In this study, the occurrence of feline lungworms and co-infecting gastrointestinal parasites has been investigated in 12 European countries (i.e. Austria, Belgium, Bulgaria, France, Greece, Hungary, Italy, Portugal, Romania, Spain, Switzerland and the United Kingdom). An average of 10 domestic cats, with regular outdoor access, was sampled each month for 12months, and freshly passed faeces were collected. Stools were processed using a McMaster assay and a quantitative Baermann-Wetzel method. Animals positive for lungworms and/or gastrointestinal parasites were treated with a formulation containing fipronil, (S)-methoprene, eprinomectin, and praziquantel (Broadline®, Merial), and re-sampled 28days post-treatment. The association between lungworm infection and risk factors was analysed using statistical medians/means and the efficacy of the treatment against each lungworm species was assessed. Of 1990 cats sampled, 613 (30.8%) were positive for at least one parasite, while 210 (10.6%) were infected by lungworms. The prevalence of lungworm infection varied between the sampled sites, with the highest recorded in Bulgaria (35.8%) and the lowest in Switzerland (0.8%). None of the cats from Austria or the United Kingdom were infected by lungworms. Aelurostrongylus abstrusus was the species most frequently detected (78.1%), followed by Troglostrongylus brevior (19.5%), Eucoleus aerophilus (14.8%) and Oslerus rostratus (3.8%). The overall efficacy of the treatment was 99% for A. abstrusus and 100% for T. brevior, O. rostratus and E. aerophilus. Data presented provide a comprehensive account of the diagnosis, epidemiology and treatment of feline lungworms in Europe, as well as of the occurrence of co-infections by gastrointestinal parasites.

Intestinal parasites and vector-borne pathogens in stray and free-roaming cats living in continental and insular Greece

This survey investigated the distribution of various intestinal parasites and vector-borne pathogens in stray and free-roaming cats living in four regions of Greece. A total number of one hundred and fifty cats living in three Islands (Crete, Mykonos and Skopelos) and in Athens municipality was established as a realistic aim to be accomplished in the study areas. All cats were examined with different microscopic, serological and molecular assays aiming at evaluating the occurrence of intestinal parasites, and exposure to or presence of vector-borne infections. A total of 135 cats (90%) was positive for one or more parasites and/or pathogens transmitted by ectoparasites. Forty-four (29.3%) cats were positive for one single infection, while 91 (60.7%) for more than one pathogen. A high number of (n. 53) multiple infections caused by feline intestinal and vector-borne agents including at least one zoonotic pathogen was detected. Among them, the most frequently recorded helminths were roundworms (Toxocara cati, 24%) and Dipylidium caninum (2%), while a high number of examined animals (58.8%) had seroreaction for Bartonella spp., followed by Rickettsia spp. (43.2%) and Leishmania infantum (6.1%). DNA-based assays revealed the zoonotic arthropod-borne organisms Bartonella henselae, Bartonella clarridgeiae, Rickettsia spp., and L. infantum. These results show that free-ranging cats living in areas of Greece under examination may be exposed to a plethora of internal parasites and vector-borne pathogens, some of them potentially able to infect humans. Therefore, epidemiological vigilance and appropriate control measures are crucial for the prevention and control of these infections and to minimize the risk of infection for people.

Several intestinal parasites and vector-borne pathogens, some of that with zoonotic potential, often occur in free-ranging cat populations. Stray cats are abundant in touristic areas of Greece, where they live in free colonies. With the aim to enhance our knowledge on the hazard posed by cats living in Greek touristic spots, the present research has evaluated the presence of intestinal parasites and vector-borne pathogens in stray cats living in selected areas. The study demonstrates that these pathogens are present in Greece and that appropriate control measures should be implemented to minimize the risk for cats and people.

Five-month serological monitoring to assess the effectiveness of permethrin/fipronil (Frontline Tri-Act®) spot-on in reducing the transmission of Leishmania infantum in dogs

Canine vector-borne diseases are highly endemic in European countries of the Mediterranean basin. The use of repellent insecticides aids to reduce the risk of pathogen transmission. The primary objective of this 5-month serological field study conducted in a highly endemic area of canine leishmaniosis in Greece was to comparatively assess the effectiveness of a topical formulation of fipronil/permethrin (Frontline Tri-Act®/Frontect®) and of a deltamethrin collar (Scalibor®) for the prevention of Leishmania infantum transmission. Initially, 72 clinically healthy owned dogs were sampled for inclusion. Ten out of the 72 (13.8%) were seropositive according to the Snap Leish® ELISA test and removed. Ultimately, a total of 56 dogs were followed from May to October 2015 with monthly blood samples and serological tests based on Snap Leish® and Snap 4Dx® ELISA tests. Twenty-five dogs were treated with deltamethrin collar (Scalibor®) (Group 1) and 31 were treated monthly with the topical fipronil/permethrin formulation (Group 2). In group 1, three dogs out of 25 (12%) seroconverted for Leishmania whereas none of the dogs (0/31) seroconverted in group 2. In addition, this trial provided means to serological assess the transmission of other vector-borne pathogens. Regarding Anaplasma spp., one dog in each group was seropositive at the beginning of the study and no dogs became positive during the study. For Ehrlichia canis, 9/25 (36%) dogs in group 1 and 5/31 (16.1%) in group 2 were seropositive at inclusion time. Two out of 16 (11.8%) and 3/26 (11.5%) dogs became positive for E. canis after 3months in groups 1 and 2, respectively. No Borrelia burgdorferi sensu lato seropositive dog was found during the study. In regard to Dirofilaria immitis, 7/25 (28%) dogs and 12/31 (38.7%) were antigen-positive in groups 1 and 2, respectively, at inclusion. There was no significant difference between groups 1 and 2 in regard to new seroconversions during the trial. This study, conducted in a highly endemic area for vector-borne pathogen transmission, confirmed that the use of deltamethrin and permethrin is a suitable approach to reduce the risk of L. infantum infection by sandflies.

Knock-down and speed of kill of a combination of fipronil and permethrin for the prevention of Ctenocephalides felis flea infestation in dogs

BACKGROUND

A topical combination of fipronil + permethrin (Frontline Tri-Act/Frontect, Merial) has recently been developed to control fleas, ticks, mosquitoes, sandflies and stable flies on dogs. Two studies were conducted to assess its speed of kill and knock-down effect on Ctenocephalides felis fleas. The combination was compared to either fipronil alone or to a combination of permethrin, dinotefuran, and pyriproxyfen,

METHODS

In each study, 18 dogs were randomly allocated to one of three groups: (Group 1: untreated dog; Group 2: treated once on D0 with the combination of fipronil and permethrin; Group 3: treated once on D0 either with fipronil alone (study 1) or with a combination of permethrin, dinetofuran and pyriproxyfen (study 2)). Each dog was infested with 100 unfed adult C. felis fleas on Days 2 (study 2), 7, 14, 21 and 28. Fleas were collected from dogs at 1 h and 12 h post- infestations (PI) (study 1) or at 2 h and 6 h PI (study 2) to assess efficacy and from collection pans underneath cages 1 h (study 1) or 5 min (study 2) PI to assess knock-down effect.

RESULTS

All treated dogs had significantly (p ≤ 0.01) lower flea counts than untreated dogs at every time point in both studies. For a whole month, a significant knock-down effect against infesting fleas is obtained in five minutes PI with the combination of permethrin and fipronil. Complete efficacy (>95%) was achieved in 1 h (study 1) or 2 h (study 2) PI for 14 days and by 6 h PI for all challenges conducted throughout the month. Efficacy remains >85% at 2 h PI for the whole month. A significantly higher efficacy of the fipronil + permethrin combination compared to other treatments was demonstrated at the earliest time points for the month (1 h knock-down effect and insecticidal efficacy compared to fipronil alone; 5 min knock-down effect compared to the combination of permethrin + dinetofuran + pyriproxyfen).

CONCLUSIONS

The rapid flea knock-down effect and speed of kill demonstrated by the spot on combination of fipronil + permethrin provide a reliable strategy against flea infestations in dogs.

Babesiosis

Babesiosis is the disease caused by infection of the erythrocytes of mammals by Babesia species, which are Apicomplexa protozoa belonging to the suborder Piroplasmidea and the family Babesiidae. They are different from the Theileriidae, which can also infect white blood cells and endothelial cells. Babesiosis is one of the most important tick-borne infectious diseases of domestic and wild mammals and still poses significant diagnostic and therapeutic challenges for veterinary practitioners around the world. It is an increasing problem worldwide because of the expansion of tick habitats and the increased mobility of animals, which promote the spread of parasites into new geographical areas. Babesia species can, exceptionally, infect humans, especially splenectomised or immunocompromised individuals. The majority of human cases involve B. microti, a parasite of rodents, but human infections may also be caused by B. divergens, which infects cattle, or by Babesia related to B. odocoilei, which infect cervids. The majority of new developments, in regard to taxonomy, epidemiology, pathogenesis and control, concern canine babesiosis, whereas piroplasmosis in horses or cattle retains the classical description, therefore the focus of this article will be on infection in dogs.

A novel combination of fipronil and permethrin (Frontline Tri-Act®/Frontect®) reduces risk of transmission of Babesia canis by Dermacentor reticulatus and of Ehrlichia canis by Rhipicephalus sanguineus ticks to dogs

Background

The ability of Frontline Tri-Act®/Frontect®, a topical ectoparasiticide containing fipronil and permethrin for dogs, to prevent the transmission of Babesia canis as well as Ehrlichia canis was evaluated by infesting dogs with infected vector ticks.

Methods

For the Babesia canis study, 16 dogs were randomly allocated to two groups. Eight dogs were treated on day 0 with a topical spot-on formulation containing 6.76 % w/v fipronil plus 50.48 % w/v permethrin and eight dogs served as the untreated control group. Dermacentor reticulatus ticks, with a B. canis infection rate ranging between 2 and 10 %, were placed onto dogs on days 7, 14, 21 and 28. In situ tick counts were performed on Days 9, 16 and 23. Ticks were counted and removed on Day 30. Infection of the dogs with B. canis was monitored by rectal temperature readings, clinical examinations and blood smears as well as PCR and IFA (indirect fluorescent antibody assay).

For the Ehrlichia canis study, another 16 dogs were allocated to two groups. Eight dogs were treated with the fipronil and permethrin combination on days 0 and 28 and eight dogs served as untreated controls. Rhipicephalus sanguineus ticks, carrying an infection rate of 13 % for E. canis, were released in the sleeping kennels of the dogs on days 7, 14, 21, 28, 35, 42, 49 and 56. Ticks were counted in situ on the dogs on a weekly basis. All ticks were removed and counted on the final assessment day 58. Infection of the dogs with E. canis was monitored by rectal temperature, clinical examinations, and testing of blood samples by PCR, IFA and platelet counts.

Results

B. canis was transmitted by D. reticulatus ticks to all eight untreated control dogs and to one treated dog, which was confirmed by blood smears, PCR and IFA. E.canis was transmitted by R. sanguineus ticks to all eight untreated control dogs. Two of the dogs in the treated group were found positive based on PCR and/or IFA.

Conclusions

Frontline Tri-Act®/Frontect® significantly lowered the risk for dogs to acquire a B. canis infection by 87.5 % over a challenge period of 28 days. The risk for dogs to acquire E. canis was reduced by 75 % over a period of 56 days.

Occurrence of Aelurostrongylus abstrusus and Troglostrongylus brevior in domestic cats in Greece

Background

Despite the evidence that Mediterranean Europe offers suitable conditions for the biology of felid respiratory metastrongyloids, no updated data on the presence of felid lungworms are available for Greece. Although the cat lungworm Aelurostrongylus abstrusus is considered as enzootic in domestic cats (Felis silvestris catus) living in some areas of continental Greece, conversely, Troglostrongylus brevior, has only been reported in the island of Crete. The present study aimed to evaluate the occurrence of Aelurostrongylus abstrusus and Troglostrongylus brevior in domestic cats from four different Greek locations including islands where European wildcats (Felis silvestris silvestris), believed to be the natural reservoir of T. brevior, are considered absent.

Methods

Faeces were collected from 125 stray cats in the city of Athens, and in Crete, Mykonos and Skopelos Islands, and examined by copromicroscopic techniques for the presence of lungworm larvae. When present, larvae were morphologically and molecularly identified.

Results

The occurrence of A. abstrusus and T. brevior was confirmed in 10 (8 %) and 7 (5.6 %) of the samples, respectively. In particular, T. brevior was detected in domestic cats in the city of Athens, and in Mykonos and Skopelos Islands, where wildcats are not present.

Conclusions

This information illustrates that T. brevior may infect domestic cats regardless of the presence of the natural host. Considering the relevant clinical impact of this nematode especially in young animals, it is advisable to include troglostrongylosis in the differential diagnosis of cat respiratory diseases also where this parasite is unexpected.

Repellency and acaricidal efficacy of a new combination of fipronil and permethrin against Ixodes ricinus and Rhipicephalus sanguineus ticks on dogs

Background

A blinded, controlled laboratory study was conducted to assess the repellency and acaricidal activity of a topical spot on formulation, a combination of fipronil and permethrin, against Ixodes ricinus and Rhipicephalus sanguineus ticks on dogs.

Methods

A group of 16 adult mixed breed dogs were randomly divided into treatment and control groups based on pre-treatment live tick counts. On Day 0, the topical spot on formulation of fipronil + permethrin (commercialized under the name Frontline Tri-Act®/Frontect®) was administered to dogs in the treatment group at the minimum recommended dose of 0.1 mL/kg, corresponding to 6.76 mg fipronil/kg and 50.48 mg/kg permethrin. Tick infestations were performed with I. ricinus (50 females, 50 males) and R. sanguineus (25 females, 25 males) on each dog on Days 2, 7, 14, 21, and 28. Dogs were sedated prior to exposure and confined to crates for approximately 4 h following tick challenge. Ticks were released next to the sedated dogs and tick counts were performed at 4 h and 24 h after the start of exposure for tick counts and removal.

Results

Repellency at 4 h against I. ricinus was 72.6, 96.3, 92.8, 89.0, and 88.7 % on Days 2, 7, 14, 21, and 28, respectively. Repellency was 100 % 24 h after exposures on Days 2, 7, and 14 and 99.6 % after exposures on Days 21 and 28. For R. sanguineus, repellency at 4 h was 78.0, 96.8, 91.5, 88.0, and 56.8 % on Days 2, 7, 14, 21, and 28, respectively. Repellency at 24 h was 98.6, 100, 98.7, 96.1, and 95.1 % for exposures on Days 2, 7, 14, 21, and 28, respectively.

For I. ricinus, acaricidal efficacy recorded at 4 h was ≥ 91.1 % during the full month and was ≥ 99.5 % for the full month when counted at 24 h. Acaricidal efficacy against R. sanguineus was ≥ 94.7 % at 4 h from Day 2 to Day 21 and was 71.4 % on Day 28. Acaricidal efficacy at 24 h, was > 97.7 % during the month. Tick counts were statistically significantly reduced in treated dogs at all time-points during the study.

Conclusions

A combination of fipronil and permethrin was highly effective at rapidly repelling and killing both I. ricinus and R. sanguineus ticks on dogs for at least 4 weeks, with a significant effect at 4 and 24 h after tick exposure.

Efficacy of Broadline® spot-on against Aelurostrongylus abstrusus and Troglostrongylus brevior lungworms in naturally infected cats from Italy

The increasing reports of Aelurostrongylus abstrusus infection and the new information on Troglostrongylus brevior have spurred the interest of the scientific community towards the research of pharmaceutical compounds effective against both pathogens. A novel topical combination of fipronil, (S)-methoprene, eprinomectin and praziquantel (Broadline®, Merial) has been released for the treatment of a variety of feline parasitic infections. The present study reports the efficacy of this spot-on in treating cats naturally infected by feline lungworms. Client owned cats (n=191) were enrolled from three geographical areas of Italy and faecal samples were examined by floatation and Baermann techniques. Twenty-three individuals were positive for L1 of A. abstrusus (n=18) or T. brevior (n=3) or for both species (n=2) and they were topically treated with Broadline®. Seventeen of them were also concomitantly infected by other parasites. Four weeks after treatment, faecal samples were collected and examined to assess the efficacy of a single administration of the product. Based on lungworm larvae counts, the efficacy of the treatment was 90.5% or 100% for A. abstrusus or T. brevior, respectively. Cats released significantly lower amounts of lungworm larvae after treatment compared to pre-treatment (p<0.0001). All but three cats were negative for other nematodes after treatment and all cats recovered from respiratory signs. Results of this study indicate that a single administration of the topical combination fipronil, (S)-methoprene, eprinomectin and praziquantel is effective and safe for the treatment of A. abstrusus and/or T. brevior infections in cats living under field conditions.

Sustained speed of kill and repellency of a novel combination of fipronil and permethrin against Ctenocephalides canis flea infestations in dogs

BACKGROUND

Ctenocephalides canis is a major flea species in dogs in several European countries. The new topical combination of fipronil and permethrin (Frontline Tri-Act/Frontect, Merial) has been developed to control fleas, ticks, mosquitoes, sandflies and biting flies on dogs. Considering the repellent and insecticidal effects of permethrin and the insecticidal effect of fipronil, the efficacy of the combination against fleas including C. canis was expected to be rapid. The study was conducted to measure the 1-hour, 6-hour and 24-hour efficacy, as well as the repellent activity, of the fipronil-permethrin combination on treated versus untreated dogs.

METHODS

12 Beagle dogs were randomly allocated to one of two groups based on pre-treatment live flea counts. Dogs in Group 1 remained untreated whereas dogs in Group 2 were treated once on Day 0. Each dog was infested with 100 unfed adult C. canis on Days 2, 7, 14, 21 and 28. Dogs were combed for fleas 1 and 6 h after each infestation. Following this examination, fleas remaining on the liner at the bottom of each cage were collected and counted. All live fleas were placed back on each dog after the 1- and 6-hour counts. A comb-count was performed at 24 h post infestation on all dogs.

RESULTS

Treated dogs had significantly (p ≤ 0.01) lower flea counts than untreated dogs at every time point. The percent efficacy was ≥99.1% at 6 and 24 h after each weekly challenge up to the month. The 1-hour counts also showed good efficacy of 96.5%, 98.9%, 92.0%, 70.2% and 55.7% on Days 2, 7, 14, 21 and 28, respectively. The repellent efficacy, assessed on the liners at 1 h, was 86.5%, 94.9%, 79.5%, 58.4% and 43.9% on Days 2, 7, 14, 21 and 28, respectively.

CONCLUSIONS

This study demonstrates the beneficial effect of the fipronil and permethrin combination against C. canis, providing both a repellent and insecticidal effect as early as 1 h post infestation, and >99.1% efficacy calculated at 6 h during a month.

Repellent and insecticidal efficacy of a new combination of fipronil and permethrin against the main vector of canine leishmaniosis in Europe (Phlebotomus perniciosus)

BACKGROUND

Two successive laboratory experiments (A and B) were conducted to confirm the efficacy of a new fipronil and permethrin combination to repel and kill Phlebotomus perniciosus sandflies when applied once topically on dogs.

METHODS

Due to the difficulty to get enough available dogs and sandflies in one run, the study was divided into 2 experiments which had exactly the same design, and were conducted at the same place, with the same technicians. They compared dogs treated with a combination containing 67.6 mg/mL fipronil + 504.8 mg/mL permethrin (Frontect/Frontline Tri-Act, Merial) to untreated dogs. The treatments were applied topically once on Day 0. Sandfly exposures were performed on Days 1, 7, 14, 21 and 29 with 80 P. perniciosus female sandflies. After 60 min, sandflies were assessed for vitality and engorgement status. Live sandflies were kept in an insectary and observed for mortality counts 4 h after the exposure period ended.

RESULTS

Percent sandfly repellency on treated dogs was 98.2, 98.5, 99.2, 90.9 and 90.3%, for Days 1, 7, 14, 21, and 29, respectively. There was a significant difference (p ≤ 0.05) between the treated and control groups in both experiments and for the pooled data on every assessment day. Insecticidal efficacy on treated dogs at 4 h post-exposure on Days 1, 7, 14, 21 and 29 was 98.7, 99.7, 96.8, 93.4, and 78.9%, respectively. There was a significant difference between the treated and control groups for live sandflies observed at 4 h post-exposure for all assessment days (p < 0.05).

CONCLUSIONS

A single topical administration of a new combination of fipronil and permethrin demonstrated a significant repellent effect (i.e., > 80%) against P. perniciosus which lasted for 29 days after application. The repellent effect was accompanied by a significant insecticidal effect on sandflies. The results suggest that in endemic areas, the application of the fipronil-permethrin combination could be integrated into canine leishmaniosis prevention program.