Cardio-pulmonary parasites of the European wildcat (Felis silvestris) in Germany.

BACKGROUND: In the last years, research on feline cardio-pulmonary parasites has considerably increased in Europe. Not only domestic cats (Felis catus), but also European wildcats (Felis silvestris) can serve as definitive hosts for these nematodes. The F. silvestris population in Germany has been growing rapidly within the last decades; therefore, the assessment of its cardio-pulmonary parasite status is of importance to unravel whether the wildcat population serves as a substantial reservoir for these nematodes and might pose a health threat to domestic cats. METHODS: As part of a nature conservation project for European wildcats in the German federal state Rhineland-Palatinate, lungs (n = 128) and hearts (n = 111) of 128 F. silvestris found dead were examined for cardio-pulmonary parasites. All isolated parasites were identified morphologically, and results were confirmed by molecular analysis of a total of 3-11 specimens of each worm species. RESULTS: A total of 70.3% (90/128) wildcats were positive for at least one lungworm species. Angiostrongylus chabaudi was most common (53.1% [68/128]), followed by Aelurostrongylus abstrusus (42.2% [54/128]), Troglostrongylus brevior (31.3% [40/128]) and Capillaria spp. (3.1% [4/128]). Of note, about two-thirds of the infected wildcats harboured coinfections. Infection intensities ranged from 1 to 167 nematodes per wildcat. Generalised linear models revealed a strong correlation between A. chabaudi and A. abstrusus infection, and prevalences were higher in adult than in younger wildcats, except for T. brevior. Moreover, the T. brevior prevalence varied significantly with nutritional status. CONCLUSIONS: This study shows that feline cardio-pulmonary nematodes are common parasites in European wildcats in Germany but do not appear to have a serious impact on the overall health of the population. Due to presumed spillover events via prey, cardio-pulmonary nematodes may circulate between the wildcat population and domestic cats and might therefore pose a health risk to individual domestic cats.

Efficacy of two topical combinations containing emodepside plus praziquantel, and emodepside plus praziquantel plus tigolaner, for the treatment of troglostrongylosis in experimentally infected cats.

Feline troglostrongylosis caused by Troglostrongylus brevior is increasingly reported in European countries. Although the disease can be severe and potentially life-threatening, especially in kittens and young cats, effective treatment options are still limited. Two administrations of emodepside 2 weeks apart have shown promising results for the treatment of T. brevior infection in single cases and in a field trial. Therefore, the present study has been conducted to evaluate the efficacy of two spot-on combinations containing emodepside (i.e. 2.14% w/v emodepside and 8.58% w/v praziquantel - Profender®, and 2.04% w/v emodepside, 8.14% w/v praziquantel and 9.79% w/v tigolaner - Felpreva®) in the treatment of troglostrongylosis under experimental conditions. Twenty-four cats were experimentally infected with T. brevior and randomly assigned to one of three groups of eight cats each, i.e. (i) Group 1 (G1) left untreated, (ii) Group 2 (G2) receiving Profender® on Days 28 and 44, and (iii) Group 3 (G3) receiving Felpreva® on Day 28 and Profender® on Day 44. Doses corresponded to the minimum effective dose of 0.140 and 0.148 ml/kg body weight, for Profender® and Felpreva®, respectively. The primary efficacy criterion was the number of viable adult T. brevior counted at necropsy conducted between Days 69 and 72. The fecal shedding of first-stage larvae (L1) was also assessed. L1 of T. brevior were detected in samples from all cats within 20 days post-infection. At necropsy, 4 of 8 G1 cats harbored adult T. brevior, while no adult T. brevior worms or other development stages were recovered from any of the G2 and G3 cats. The primary efficacy criterion was not evaluated as the worm counts in G1 did not meet VICH guideline requirements. After the first treatment (Day 28), most G2 and G3 cats were negative at the Baermann examination. After the second treatment (Day 44), L1 were found in two cats from G2 on Day 49 and in one G3 cat on Day 51. No adverse events occurred in G2 and G3 cats. These results indicate that two applications of emodepside spot-on given 2 weeks apart represent a safe and efficacious treatment regime against troglostrongylosis.

Efficacy of a spot-on combination containing 10% w/v imidacloprid and 1% w/v moxidectin for the treatment of troglostrongylosis in experimentally infected cats.

BACKGROUND: Parasitic bronchopneumonia in domestic cats in Europe, which can manifest with moderate to severe clinical signs, is frequently caused by Troglostrongylus brevior. Data on epizootiological and clinical relevance of cat troglostrongylosis have been published in the last decade but treatment options are still limited. Promising effectiveness data have been generated from clinical cases and field trials for a spot-on formulation containing 1% w/v moxidectin and 10% w/v imidacloprid (Advocate®, Elanco Animal Health). Therefore, two studies have been conducted to confirm under experimental conditions the efficacy of moxidectin 1% contained in Advocate® for the treatment of cat troglostrongylosis. METHODS: Sixteen and 20 cats experimentally infected with T. brevior were included in two separate studies, i.e., Study 1 and 2, respectively. Cats were infected with T. brevior third-stage larvae via gastric tube. In both studies cats were randomized to untreated (control, Group 1) and treatment (Group 2) groups. In Study 1 and Study 2, the two groups comprised eight and 10 cats each. Treated cats received Advocate® spot-on twice at a 4-week interval. The primary efficacy criterion was the number of viable adult T. brevior counted at necropsy. Throughout the trial, the fecal shedding of first-stage larvae (L1) was assessed in treated and untreated control cats. RESULTS: The experimental model was successful in both studies, as all cats started shedding T. brevior L1 within 25 days post-infection. At necropsy, T. brevior adults were found in 4/8 and 4/10 cats of the control groups in Study 1 and 2, respectively, while none of the treated cats harbored adult worms. The necropsy worm counts in controls did not meet relevant guideline requirements for adequacy of infection, with fewer than six infected cats in the control groups, thus limiting conclusions on treatment efficacy. The fact that 6/8 and 8/10 control cats in Study 1 and 2, respectively, shed L1 up to necropsy while larval shedding ceased in all treated animals after the first treatment provides supporting evidence on the level of efficacy. No remarkable adverse events were recorded in the two studies. CONCLUSION: These results indicate that Advocate® spot-on is a safe and effective option for treating cats infected by T. brevior.