Heartworm control in Grenada, West Indies: Results of a field study using imidacloprid 10% + moxidectin 2.5% and doxycycline for naturally-acquired Dirofilaria immitis infections

Canine heartworm disease (CHD) results from infection with Dirofilaria immitis and while it is of global concern, it is most prevalent in tropical climates where conditions support the parasite and vector life cycles. Melarsomine dihydrochloride is the sole treatment for CHD recommended by the American Heartworm Society. However, in cases where cost or access to melarsomine precludes treatment of an infected dog, therapeutic alternatives are warranted. This randomized, controlled field study evaluated the adulticidal efficacy of a combination therapeutic protocol using 10 % imidacloprid + 2.5 % moxidectin spot-on and a single 28-day course of doxycycline and compared with that of a 2-dose melarsomine dihydrochloride protocol. Of 37 naturally-infected domestic dogs with class 1, 2 or early class 3 CHD enrolled in the study, 30 were evaluated for a minimum of 12 months. Seven dogs were withdrawn due to canine ehrlichiosis, non-compliance, or wrongful inclusion. Dogs were randomly assigned to a control (CP, n = 15) or investigational (IVP, n = 15) treatment group. CP dogs received two injections of melarsomine dihydrochloride (2.5 mg/kg) 24 -hs apart and maintained on monthly ivermectin/pyrantel. IVP dogs were treated with oral doxycycline (10 mg/kg twice daily for 28 days) and topical 10 % imidacloprid + 2.5 % moxidectin once monthly for 9 months. Dogs were evaluated up to 18 months - monthly for the first 9 months, then every 3 months. Parasiticidal efficacy was based on antigen status using the IDEXX PetChek® 34 Heartworm-PF Antigen test. By month 18, antigen was not detected in any study dog except one from the IVP group. One other IVP dog was persistently antigenemic and treated with melarsomine at month 12 according to the initial study protocol. Mean antigen concentration (based on optical density) decreased more rapidly in the CP group and by month 15 was 0.11 for the IVP and 0.07 for CP groups, with equivalent median concentrations (0.04) in both groups. Conversion following heat-treatment of antigen-negative samples occurred frequently and at similar rates in both treatment groups. Based on the bias of diagnostic tests towards detection of female worms, we conclude that monthly application of 10 % imidacloprid + 2.5 % moxidectin for 9 months combined with a course of doxycycline twice daily for 28 days resulted in effective therapy against female adults in CHD. This therapeutic option may be particularly useful in cases where financial constraint or access to melarsomine precludes treatment of an infected individual. This study was supported by Bayer Animal Health.

Prevalence of Angiostrongylus vasorum, Aelurostrongylus abstrusus and Crenosoma vulpis larvae in native slug populations in Germany

Metastrongyloid parasites represent sparsely studied parasites of dogs and cats in Germany. Recent European surveys indicate that these parasites are spreading in Europe. Actual data on prevalence of Angiostrongylus vasorum in dogs and foxes reveal several endemic foci in Germany. However, actual data on the prevalence of A. vasorum and other metastrongyloid lungworm larvae in a wide range of slug and snail intermediate hosts, such as Arion lusitanicus, are missing for Germany. To fill this gap, we conducted an epidemiological survey on native German slugs in selected regions of Hesse and Rhineland-Palatinate. The focus was on slugs, because in study areas slugs appear to be more abundant than snails. Slugs were collected throughout different seasons of the year in areas that were previously proven to be hyperendemic for A. vasorum fox infections. Overall, a total of 2701 slugs were collected and examined for lungworm larvae via artificial digestion. The number of A. vasorum larvae per slug varied considerably (1-546 larvae per specimen). Some hotspot areas with high A. vasorum prevalence in slugs (up to 19.4%) were identified. The overall A. vasorum prevalence varied with season with largest number of slugs infected in summer (9.1%) and lowest number in winter (0.8%). The current study revealed a total A. vasorum prevalence of 4.7% in slugs based on microscopic analyses. Confirmation of lungworm species was made by specific duplex-real-time PCRs. Hence, these data demonstrate that final hosts are at a permanent risk for A. vasorum infections during all seasons when living in investigated areas. Besides A. vasorum, other lungworm larvae were also detected, such as Crenosoma vulpis (the fox lungworm, 2.3%) and Aelurostrongylus abstrusus (feline lungworm, 0.2%).

Regression models to assess the risk factors of canine gastrointestinal parasitism

Gastrointestinal parasites, protozoa and helminths, remain a common important finding in dogs presented to veterinary medical practices. Moreover, dogs may play an active role in the transmission of enteric parasites to humans, given their cohabitation, making canine gastrointestinal parasitism an issue of major concern for public health. To get an overview of the current state of canine gastrointestinal parasites' prevalence in Greece, a total of 1036 faecal samples were collected from dogs either presented in veterinary clinics or in animal shelters. Samples were examined by a combined sedimentation-flotation technique. Possible risk factors (age, ownership status, co-existence with other animals, coinfection with other parasites) were assessed using binary regression models for each one of the most prevalent parasites. The overall gastrointestinal parasite prevalence in dogs' faecal samples was 39%. A total of 11 intestinal parasitic species were detected and up to five different parasites were isolated in the same faecal sample. Toxocara canis was the most prevalent parasite in the studied population, followed by Isospora spp., Giardia spp., Uncinaria spp., Trichuris vulpis, Ancylostoma spp., Toxascaris leonina, and Dipylidium caninum. Additionally, other genera (Taenia, Capillaria and Angiostrongylus) were also detected in very low percentages. Young, stray, living without other dogs, coinfected with T. vulpis or T. canis and free of Isospora spp. dogs were more likely to be infected by Giardia spp. Likewise, young, stray, coinfected with T. vulpis or T. canis but free of Giardia spp. dogs were more likely to be infected by Isospora spp. T. canis infections were more common in dogs coinfected with Isospora spp., Giardia spp., D. caninum, Τaenia spp., T. vulpis and T. leonina Finally, T. vulpis more often infected older dogs and dogs coinfected with Isospora spp., Giardia spp. and T. canis Consequently, the prevalence of parasitized dogs was high and the diversity of parasites found was notable, which calls for a greater awareness among veterinarians and pet owners. The proposed prediction models should be taken under consideration in diagnostic approach of clinical cases, as well as in planning sustainable antiparasitic strategies.

Serological survey for canine angiostrongylosis in Slovakia

In recent years Angiostrongylus vasorum has become another important heart parasite of dogs besides Dirofilaria immitis, with intense spread into new areas of Europe. The first two cases of canine angiostrongylosis in Slovakia were observed in 2013, demonstrating that this life-threatening parasitic disease of dogs has expanded into this territory too. One year after the first A. vasorum findings, a serological survey was conducted to assess the current distribution of this parasitic infection in dogs from Slovakia. Serum samples from 225 dogs were collected from 29 veterinary practices situated in 22 districts of Slovakia and tested by ELISA for the presence of circulating A. vasorum antigens and additionally for the detection of specific antibodies against A. vasorum. Fourteen samples (6.22 %) were seropositive in at least one ELISA. Of these, 7 dogs (3.11 %) were only antibody-positive and 4 dogs (1.78 %) were positive only for circulating A. vasorum antigen. Three animals out of 225 examined (1.33 %) were positive in both ELISAs

Endoparasites in dogs and cats in Germany 1999-2002

Infections with endoparasites in dogs and cats have been determined by analysing the results of faecal examinations (Flotation, MIFC, sedimentation, Baermann, smear, ProSpecT Giardia Microplate Assay). Samples of 8438 dogs and 3167 cats from the years 1999 until 2002 have been included in the investigation. 2717 dogs (32.2%) and 771 cats (24.3%) have been infected with endoparasites. In the infected dogs the following parasites have been identified: Class Nematodea: Toxocara canis: 22.4%, Toxascaris leonina: 1.8%, Ancylostomatidae: 8.6%, Trichuris vulpis: 4.0%, Capillaria spp.: 2.3%, Crenosoma vulpis: 0.9%, Angiostrongylus vasorum: 0.3%; Class Cestodea: Taeniidae: 1.2%, Dipylidium caninum: 0.4%, Diplopylidium/Joyeuxiella: 0.1%, Mesocestoides: 0.2%, Diphyllobothrium latum: < 0.1%; Class Sporozoea: Sarcocystis spp.: 9.0%, Cystoisospora spp.: 22.3%, C. canis: 8.0%, C. ohioensis: 17.0%, Hammondia/Neospora: 1.7%; Class Zoomastigophorea: Giardia spp.: 51.6%. In the 771 infected cats the following prevalences of parasites have been found: Class Nematodea: Toxocara mystax: 26.2%, Ancylostoma tubaeforme: 0.3%, Capillaria spp.: 7.0%, Aelurostrongylus abstrusus: 2.7%; Class Cestodea: Taeniidae: 2.6%, Dipylidium caninum: 0.1%; Class Sporozoea: Sarcocystis spp.: 2.2%, Cystoisospora spp.: 21.9%, C. felis: 15.3%, C. rivolta: 7.9%, Toxoplasma/Hammondia: 4.5%; Class Zoomastigophorea: Giardia spp.: 51.6%.

Synergistic effects of pyrantel and the febantel metabolite fenbendazole on adult Toxocara canis

Pyrantel embonate and febantel are both constituents of Drontal Plus and Drontal Puppy broad spectrum anthelmintics for dogs. The effects of pyrantel and the febantel metabolite fenbendazole were investigated against Toxocara canis in-vitro by studying changes in worm motility and tissue damage. Pyrantel and fenbendazole were added to worms incubated in media for 8 h at the following concentrations: pyrantel: 12.2 microg, 25 microg, or 50 microg; fenbendazole: 50 microg, 100 microg or 200 microg; mixture of pyrantel and fenbendazole: 12.2 microg p + 50 microg f, 25 microg p + 100 microg f, 50 microg p + 200 microg f. Following this 8 h incubation period, one group of the worms was immediately fixed and studied by light- and electron microscopical examination. Other groups have been observed for further 8 h periods up to 56 hours and then studied in the same way.

[The seasonal toxigenicity of different cultured plants for clostridia in relation to so-called wildlife mortality]

In the juice of plants which could be eaten by hares different amounts of toxins (haemolysin, lecithinase) could be found after the partly addition of a C. perfringens field strain and subsequent anaerobic incubation. Sterile filtrates showed a very pronounced toxigenicity. The presented results proof in tendency that oilseed-rape (00-rape seed), wheat, and barley as green plants can contribute in clostridial toxicosis in hares, whereas grass and beets are involved only partially, and clover is practically completely atoxigenic.

[Comparison between the caries-protective effects of the fluoride containing dentifrices "Fluorodent" and "Silca mit Flour"]

The comparative testing of the tooth-pastes "Silca mit Fluor", "Fluorodent" and "Silica" (without fluorine) in a programmed animal experiment for 6 weeks revealed differences in caries-protective efficiency and and in deposition of fluoride in dental enamel, "Silca mit Fluor" being superior to "Fluorodent".