Cardiopulmonary helminth parasites of the red fox (Vulpes vulpes) in the north-east of The Netherlands

Abstract

Background: The wild red fox (Vulpes vulpes) is considered a reservoir for various cardiopulmonary helminth species of veterinary importance. Improved knowledge of fox cardiopulmonary parasite prevalence and geographic distribution in The Netherlands provides essential information for epidemiological studies about the complex relationship between wildlife, domestic animals and parasites.

Methods: The presence of four cardiopulmonary helminth species – Angiostrongylus vasorum, Crenosoma vulpis, Eucoleus aerophilus and Dirofilaria immitis – was examined in the heart and lungs of 95 Dutch wild red foxes originating from the north-eastern part of The Netherlands (Groningen and Drenthe) by the washing and sieving technique. The prevalence of each species was determined and a logistic regression was applied to examine the correlation between fox age, sex, geographical origin, bodyweight-length index and single and multiple cardiopulmonary helminth infections.

Results: 81/95 (85.3%) of the foxes were infected with one or more cardiopulmonary helminth species. Three species were identified: Angiostrongylus vasorum (31/95, 32.6%), Crenosoma vulpis (27/95, 28.4%) and Eucoleus aerophilus (76/95, 80.0%). These prevalences were all higher than those previously reported in Dutch wild red foxes. Dirofilaria immitis was not found in the cardiorespiratory tract of the examined foxes. The prevalence of E. aerophilus was significantly higher in male foxes than in female foxes. Juvenile foxes were significantly more often infected with E. aerophilus and C. vulpis and were more frequently infected with 2 or 3 cardiopulmonary helminth species than adult foxes. There were no significant correlations between province of origin or BWL-index of the foxes and infection rates.

Conclusions: Cardiopulmonary helminth parasites A. vasorum, C. vulpis and E. aerophilus are present in high prevalences in wild red foxes in the north-east of The Netherlands. Future studies should be focused in the prevalence of these helminths in the domesticated dog population and attempt to evaluate the factors involved with parasite transmission between foxes and domesticated dogs.