Feline calicivirus (FCV) has been associated with upper respiratory tract disease in domestic felines.2 Recently, strains of FCV resulting in severe systemic forms of FCV infection have been recognized, particularly as outbreaks in catteries or humane shelters.1,3 These virulent systemic strains of FCV have been associated with clinical signs such as cutaneous ulcers, subcutaneous edema, and alopecia, and pathologic findings including pancreatic, hepatic, and splenic necrosis with mortality rates as high as 60%.
An FCV epidemic in exotic felids presented with a 5-day-old, Amur tiger cub (Panthera tigris altaica) with tongue ulcerations. Tongue ulcerations appeared and progressed in three littermates of this cub the following day. Disease progressed in all cubs to include sloughing of the tongue epithelium and sloughing of the carpal, tarsal, metacarpal, and metatarsal foot pad epithelium. Oral ulcerations were also noted in adult African lions (Panthera leo), and Amur tigers, but not two adult snow leopards (Panthera uncia) housed in the same building. All adult cats had been previously vaccinated for FCV. Detection of FCV RNA in oral secretions by a reverse transcription polymerase chain reaction assay (RT-PCR) confirmed FCV infection in the tiger cubs and one lion. A male lion and a male tiger cub died during the epidemic with gross lesions of FCV including tongue ulcerations and footpad sloughing. RT-PCR confirmed FCV in multiple tissues. A stray cat live-trapped outside the feline building during the epidemic was found by virus isolation to be positive for FCV.
The authors would like to thank Doug Armstrong for his assistance. The authors would also like to thank Potter Park Zoo staff, Potter Park Zoo Society staff, Baker College Veterinary Technology students, and all the Michigan State University College of Veterinary Medicine staff and students who assisted with these cases.
1. Hurley, K.F., P.A. Pesavento, N.C. Pedersen, A.M. Poland, and J.E. Foley. 2004. An outbreak of virulent systemic feline calicivirus disease. J. Am. Vet. Med. Assoc. 224:241–249.
2. Hurley, K.F. and J.E. Sykes. 2003. Update on feline calicivirus: new trends. Vet. Clin. North Am. Small Anim. Pract. 33:759–772.
3. Schorr-Evans, E.M., A. Poland, W.E. Johnson, and N.C. Pedersen. 2003. An epizootic of highly virulent feline calicivirus disease in a hospital setting in New England. J. Feline Med. and Surg. 5:217–226.