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.

Ear Mites as an Overlooked Source of Ear Itching and Tinnitus - A Case Series

Otoacariasis is a rare condition characterized by ticks and mites in the ear canal. Human otoacariasis remains underrepresented in literature as otoacariasis is more common in animals. Systemic diseases being transmitted by these arachnids pave the way for potential complications. This case series sheds light on this uncommon condition by highlighting the diverse symptomatology and difficulties in diagnosis and treatment. Three different presentations highlight the diversity of this condition. A 40-year-old male exhibited itching and tinnitus, revealing a mite on the tympanic membrane on otoscopy. A 35-year-old female with persistent itching and tinnitus showed multiple whitish mites on examination. A 50-year-old female complained of ear pain and was found to have a tick attached to the external auditory canal. The relevance and rarity of human otoacariasis are highlighted in this study, thereby encouraging caution in situations of earache. We aim to increase clinician awareness about this condition and the necessary interventions required by conducting a thorough literature review.

Efficacy of Felpreva®, a new spot-on formulation containing tigolaner, emodepside and praziquantel, applied as a single application to cats artificially infested with ear mites (Otodectes cynotis)

The efficacy of Felpreva® (Vetoquinol), a new spot-on application containing the novel acaricide and insecticide tigolaner in combination with emodepside and praziquantel, was evaluated in cats artificially infested with ear mites (Otodectes cynotis). A total of three pivotal dose confirmation studies were conducted, two of them designed as non-interference studies. Cats were artificially infested with O. cynotis mites and randomly allocated into groups of 8 cats based on pre-treatment mite counts. Cats were treated once on Day 0, either with Felpreva® (14.5 ​mg/kg tigolaner, 3 ​mg/kg emodepside and 12 ​mg/kg praziquantel) or with placebo. Studies with a non-interference design included two additional groups of cats, treated with Profender® spot-on solution (Vetoquinol) (3 ​mg/kg emodepside and 12 ​mg/kg praziquantel) and tigolaner as a mono product (14.5 ​mg/kg tigolaner). Efficacy was evaluated on Day 28/Day 30 based on total live mite counts after ear flushing. Efficacy was claimed when: (i) at least six control cats per group were adequately infested with mites; (ii) calculated efficacy was ≥ 90% based on geometric mean mite counts; and (iii) the difference in mite counts between Felpreva®-treated cats and control cats was statistically significant (P ​≤ ​0.05). In two of the three studies, Felpreva®-treated cats were mite-free (100% efficacy) on Day 28/Day 30 and almost full efficacy (99.6%) was seen in the third study. The difference in mite counts between Felpreva®-treated cats and control cats was significant (P ​< ​0.0001) in all three studies. All control cats were adequately infested in all three studies. The efficacy of Felpreva® against ear mite (Otodectes cynotis) infection in cats was confirmed.

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 a novel topical combination of esafoxolaner, eprinomectin and praziquantel against ear mite (Otodectes cynotis) infestations in cats

Esafoxolaner, a purified enantiomer of afoxolaner with insecticidal and acaricidal properties, is combined with eprinomectin and praziquantel, nematodicidal and cestodicidal compounds, in NexGard® Combo, a novel topical endectoparasiticide formulation for cats. The efficacy of this formulation was assessed against Otodectes cynotis in two laboratory studies conducted in South Africa and in the USA with local isolates, and in one field trial conducted in Europe. In each study, cats were randomly allocated to a placebo-treated control group and a novel formulation-treated group. In the laboratory studies, cats were treated at the minimum recommended dose; in the field trial, cats were treated at label dose. All included cats were diagnosed positive for O. cynotis prior to treatment by otoscopy. The main variable of efficacy was a comparison of the number of live O. cynotis collected in both ear canals of all cats in the treated and control groups, one month after treatment. Efficacy of the novel topical formulation exceeded 97% in the three studies. These studies demonstrated the high effectiveness of NexGard® Combo in cats for the treatment of O. cynotis infestations. No health abnormalities were attributed to the treatment in any of the studies.

Otodectic and bacterial etiology of feline otitis externa in Tripoli, Libya

Background

Feline otitis externa is a dermatological disorder with a multifactorial complex etiology.

Aim

This study aimed to investigate the prevalence of different etiological agents, particularly the parasitic and bacterial, responsible for the cases of feline otitis externa in Tripoli, Libya, and to assess the antimicrobial susceptibility of the bacterial isolates from those cases.

Methods

Cerumen and otic discharges of the suspected cats were collected for parasite detection and bacterial culture. Kirby-Bauer's disk diffusion method was used for antimicrobial susceptibility testing.

Results

The results showed that otodectic mites and bacterial causes were equally the most prevalent in those cases, with a prevalence of 47.1% each. Otodectes cynotis infestation was more frequently bilateral and severe. Staphylococcus spp. were the most prevalent among bacterial causes (75%), followed by Proteus spp. (16.6%) and Pseudomonas spp. (8.4%). Norfloxacin and gentamicin were the most effective antimicrobials against bacterial isolates, as they were effective against 83.3% and 70.8% of isolates, respectively.

Conclusion

Otodectes cynotis infestation and staphylococcal infections constituted the most common etiology of feline otitis externa in Tripoli, Libya, and norfloxacin represented a cogent antibacterial for the treatment of otitis externa.

Otodectes cynotis in urban and peri-urban semi-arid areas: a widespread parasite in the cat population

The ear mite Otodectes cynotis is a parasite of cats and dogs of considerable veterinary importance, being the most common etiological agent of otitis externa in pets. This study investigates the presence of this parasite in 296 cats from Murcia municipality (SE Spain), and describes possible factors associated with the infestation. Cats were grouped by sex, age, lifestyle, season and provenience. Scraping samples were examined by a microscope to identify the mite. Chi square test was computed and odds ratio was used to measure the association of risk factors with parasite prevalence. Additionally, the spatial distribution of prevalences was investigated and represented through GIS software. Around 30% of the cats (CI₉₅ 25-35%) were found positives to O. cynotis. The mite infestation was significantly higher in adult cats, during the winter and in individuals from peri-urban areas. The ectoparasite was found to be widely distributed in the cat population of the study area, with an increased risk of infestation in specific peri-urban areas. The results highlight that O. cynotis is a common parasite in areas with Mediterranean semi-arid climate. Given the importance of otodectic mange, and considering that O. cynotis is not a parasite specific to cats, but may also affect dogs and wild carnivores, the information provided by this study is of great value to both pet owners and veterinarian practitioners, and it might help to implement appropriate preventive and control strategies, mainly in free-roaming cats.

Efficacy of fluralaner plus moxidectin (Bravecto® Plus spot-on solution for cats) against Otodectes cynotis infestations in cats

Background

The efficacy of the fixed combination of fluralaner plus moxidectin for the treatment of Otodectes cynotis infestations was evaluated in cats after topical application.

Methods

Sixteen cats experimentally infested with O. cynotis were allocated randomly to two groups of 8 cats each. One group was treated topically with the fixed combination of fluralaner plus moxidectin at the minimum dose rate of 40 mg fluralaner and 2 mg moxidectin/kg body weight. The other group was treated with physiological saline solution. Before and 14 and 28 days after treatment the ears of all cats were examined otoscopically for live mites and for the amount of debris and cerumen. Twenty-eight days after treatment, the cats were sedated and had both ears flushed to obtain the total number of live mites per animal. Efficacy was calculated, based on the results of the ear flushing, by comparing mean live mite counts in the fluralaner plus moxidectin treated group versus the saline group.

Results

A single topical application of the fixed combination of fluralaner plus moxidectin to cats reduced the mean mite counts by 100% (P < 0.001) by 28 days after treatment. No mites were visible during otoscopic examination at either 14 or 28 days after treatment. All fluralaner plus moxidectin treated cats had less ceruminous exudate 28 days after treatment compared to pre-treatment and 14 days after treatment. No treatment related adverse events were observed in any cats enrolled in the study.

Conclusions

Single topical application of the fixed combination of fluralaner plus moxidectin was highly effective against O. cynotis infestations in cats.

Efficacy of fluralaner against Otodectes cynotis infestations in dogs and cats

Background

The efficacy of fluralaner for the treatment of Otodectes cynotis infestations in dogs and cats was evaluated after oral (dogs) or topical administration (dogs and cats).

Twenty-four dogs and sixteen cats were experimentally infested with O. cynotis and randomly allocated to equal sized groups (n = 8/group). Dog groups were treated once, either orally with fluralaner at a minimum dose of 25 mg/kg body weight, topically with fluralaner at a dose of 25 mg/kg body weight or topically with saline solution (control). Cat groups were treated once, either topically with fluralaner at a dose of 40 mg/kg body weight or topically with saline solution. Ears of all animals were examined otoscopically for live visible mites and the amount of debris and cerumen before, and 14 and 28 days after treatment. Twenty-eight days after treatment, animals were sedated and both ears were flushed to obtain the total number of live mites per animal. The efficacy was calculated, based on the results of the ear flushing, by comparing mean live mite counts in the fluralaner treated groups versus the saline solution treated group.

Results

A single topical treatment of cats with fluralaner reduced the mean mite counts by 100% (P < 0.001) at 28 days after treatment. Similarly, a single oral or topical treatment of dogs with fluralaner reduced the mean mite counts by 99.8% (P < 0.001) at 28 days after treatment. Cats treated topically with fluralaner had no mites visible during otoscopic examination at either 14 or 28 days after treatment. All dogs treated orally or topically with fluralaner had no mites visible during otoscopic examination at 28 days after treatment. At 14 days after treatment, only 1–2 mites were visible in three dogs (oral treatment: 2 dogs, topical treatment: 1 dog). All fluralaner-treated animals showed improvement in the amount of cerumen exudation compared with observations performed before treatment. No treatment related adverse events were observed in any dogs or cats enrolled in these studies.

Conclusions

In this study, fluralaner administered topically to cats and orally or topically to dogs was highly effective against Otodectes cynotis mite infestations.

Ear mite infestation in four imported dogs from Thailand; a case report

Otodectes cynotis, ear mite or ear canker mite, is the most common cause of otitis external in cats (approximately 50%) and to a lesser extent in dogs, foxes and ferrets. The mite is living on the epidermal surface of auditory canal without burrowing into the tissue and feeding on tissue fluids and debris. In most of the cases they induce hypersensitivity reactions in the host. Four puppies; Siberian husky, Cocker spaniel, Terrier and mixed Pekignese with different genders and ages were referred to the Small Animal Hospital, Veterinary Faculty of Tehran University, Tehran, Iran for routine clinical examination just after they were imported from Thailand in a timeframe between June to August 2008.Clinical examinations showed an excessive dark brown discharge in both ears. No signs of other clinical situations were observed. White moving mites were seen during otoscopy examination, the specimen of ear discharge was sent to parasitology laboratory for precise identification of genus and species. Mites were identified as Otodectes cynotis and the presence of concurrent yeast and bacterial infection was showed by laboratory examinations. Topical Amitraz solution in combination with otic antibacterial and antifungal agents were administered as the treatment. Since, all the reported cases were imported from Thailand, careful clinical examination and quarantine strategies are highly recommended at the borders.