Investigation of Wild and Feral Carnivores as Reservoirs of Aleutian Disease Virus
Mark L. Drew, MS, DVM
Aleutian disease (AD) is a parvovirus of ranched mink that is associated with poor kit production and adult mortality. All color phases of ranched mink are susceptible, but the light colors derived from the Aleutian color phase are most prone to morbidity and mortality. Ranched mink can be tested for AD and an eradication program implemented. Wild carnivores are thought to be a potential reservoir for AD in ranched mink. Wild and feral carnivores including feral cats (n=19), skunks (n=5), mink (n=13) and raccoons (n=2) were live trapped, euthanatized and sampled. Blood and tissue samples were collected and submitted for testing for AD and related viruses. Serum samples were tested for AD using the counter electrophoresis test (CEP) and the lateral flow test, and for canine parvovirus and feline panleukopenia using indirect fluorescent antibody assays. One feral cat, 4 skunks, and 7 mink were positive for AD on the CEP. All animals except one mink were negative for AD on the lateral flow test. A total of 15/19 and14/15 feral cats and 1/2 raccoons were positive for canine parvovirus and feline panleukopenia, respectively, but none of the mink or skunks were positive for exposure to either virus. The tests could not easily distinguish between the three pathogens. Fecal samples were tested for the presence of AD virus using PCR, but all samples were negative. Liver and kidney samples were tested for the presence of AD by IHC, but all tissues from all animals were negative. The cause of the serologic reactions in the feral cats is likely due to exposure to feline panleukopenia virus which appears to have cross reactions with the CEP and LF test in this species. The cause of the positive CEP and LF in the mink is unknown as no evidence of AD virus was found in any of the mink. It appears that feral cats and wild skunks, raccoons and mink do not appear to be important as reservoirs of AD for ranched mink in Idaho.