Abstract

The goal of the project was evaluation of vaccination protocols and antibody persistence to canine distemper and rabies vaccination in captive African wild dogs (Lycaon pictus) (AWD). Although vaccination offers the best protection against canine distemper virus (CDV), morbidity and mortality from suspected modified-live virus vaccine-induced canine distemper have been reported in captive AWD litters.^2,3,5 This species is also highly susceptible to rabies virus, where high mortality rates have occurred in captive, reintroduced, and wild packs in southern and east Africa with and without rabies vaccination.^4,7 Vaccine recommendations for domestic dogs have substantially changed over the past 5 years. Routine annual vaccinations are no longer recommended; rather, antibody concentration monitoring is suggested to determine duration of immunity from specific vaccination schedules.^1,6 Currently, however, annual vaccination is practiced for many species of exotic carnivores due to unknown efficacies of vaccines in species where challenge studies are not practical and lack of serologic studies to determine antibody titers after vaccination.

U.S. institutions that house AWD were contacted, requesting vaccination and banked serum records. Analysis of records from participating institutions were used to request specific serum samples for CDV antibody titer via serum neutralization and for rabies antibody testing by the rapid fluorescent focus inhibition test method. Results from this study will assist in establishing vaccine protocols similar to those of revised domestic canine vaccine recommendations. The expectation is that risk will be reduced due to less frequent vaccinations considering the documented sensitivity of this species to the modified-live CDV vaccine.

Literature Cited

1.  AVMA Council on Biologic and Therapeutic Agents. 2001. Principles of vaccination. J. Am. Vet. Med. Assoc. 219: 575–576.

2.  Deem, S.L., L.H. Spelman, R.A. Yates, and R.J. Montali. 2000. Canine distemper in terrestrial carnivores: a review. J. Zoo Wildl. Med. 31: 441–451.

3.  Durchfeld, B., W. Baumgartner, W. Herbst, and R. Brahm. 1990. Vaccine-associated canine distemper infection in a litter of African hunting dogs (Lycaon pictus). J. Med., Series B37: 203–212.

4.  Hofmeyer, M., D. Hofmeyr, L. Nel, and J. Bingham. 2004. A second outbreak of rabies in African wild dogs (Lycaon pictus) in Madikwe Game Reserve, South Africa, demonstrating the efficacy of vaccination against natural rabies challenge. Anim Conserv. 7: 193–198.

5.  McCormick, A.E. 1983. Canine distemper in African cape hunting dogs (Lycaon pictus) possibly vaccine induced. J. Zoo Anim. Med. 14: 66–71.

6.  Paul, M.A., L.F. Carmichael, H. Childers, S. Cotter, A. Davidson, R. Ford, K.F. Hurley, J.A. Roth, R.D. Schultz, E. Thacker, and L. Welborn. 2005. Report of the American Animal Hospital Association (AAHA) Canine Vaccine Task Force: 2006 AAHA canine vaccine guidelines. J. Am. Anim. Hosp. Assoc. 42: 80–89.

7.  Visee, A.M. 2001. Distemper, rabies, and parvovirus vaccinations in a captive-breeding programme for the African wild dog (Lycaon pictus) in northern Tanzania. Verh. ber. Erkrg. Zootiere 40: 243–250.