Serosurvey for Feline Leukemia Virus and Lentiviruses in Captive Felids at Fundação Parque Zoológico De São Paulo, São Paulo State, Brazil
Abstract
Feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) are recognized pathogens that cause persistent infections in domestic cats. Although these retroviruses have been found in domestic cats in Brazil, serosurveys carried out in captive small neotropical felids in São Paulo state were negative.1 Retroviral infections in large cats have been recognized as “emerging diseases.” Lentiviruses have been shown to be endemic in free-ranging large cats and FeLV seems to infect wild cats that are exposed to infected domestic cats.2
The aim of this study was to investigate the prevalence of lentivirus and FeLV infections in 126 nondomestic felids kept in captivity at Fundação Parque Zoológico de São Paulo. Serum samples collected from 29 Panthera leo, 14 Panthera tigris altaica, 6 Panthera onca palustris, 2 Puma concolor, 2 Uncia uncia, 3 Panthera pardus, 1 Panthera pardus melas, 2 Acinonyx jubatus, 33 Leopardus tigrinus, 9 Leopardus wiedii, 10 Oncifelis geoffroyi, and 15 Herpailurus yaguarondi were tested by immunoassay (Snap™ Combo FeLV Antigen/FIV Antibody Test Kit, IDEXX Laboratories, Inc., Westbrook, ME, USA).
Lentivirus infection was detected in five of 29 lions tested (17%). All other animals resulted negative for both retrovirus infections. Three out five lions seropositive were female and two were males. One out of three seropositive females had been kept with one positive male, the second female was kept in a group of animals that were lentivirus negative and the last female, as well as the remaining positive male, was maintained along with negative individuals. These negative individuals eventually died with a history of neoplastic disease and emaciation; however, no lentivirus infection was suspected in these animals.
All positive animals showed episodes of anemia and/or leucopenia during their lifetime. The average time in zoo for positive lions was 15 years, while negative animals had an average time of 9 years and 50% of these had been at the São Paulo Zoo for less than 4 years. Considering that there was no possibility of segregating the seropositive animals, all positive animals were submitted to euthanasia and material was preserved for future studies. Due to the endemic aspects of lentivirus infections in African lions, associated with the chronic characteristics of lentivirus infections in this group of animals, all felids will be tested periodically.
Acknowledgments
This work was supported by a fellowship provided by Universidade Paulista and had the staff support of Fundação Parque Zoológico de São Paulo. Financial support: CAPES.
Literature Cited
1. Filoni, C., C.H. Adania, E.L. Durigon, J.L. Catão-Dias. 2003. Serosurvey for feline leukemia virus and lentiviruses in captive small neotropic felids in São Paulo state, Brazil. J Zoo Wildl Med. 34:65–68.
2. Kennedy-Stoskopf, S. 1999. Emerging viral infections in large cats. In: Fowler M.E., Miller R.E. eds. Zoo and Wild Animal Medicine Current Therapy 4. WB Saunders, Philadelphia, Pennsylvania, 401–410.