Opportunistic veterinary research in zoo populations

In the course of daily veterinary work with exotic animals in Antwerp and Planckendael, we are frequently, yet often at unpredictable times, confronted with rare and for science very novel findings and observations. This creates opportunities to increase our basic understanding about the biology, medicine and treatment of zoo animals and where relevant their pathogens. Projects generally concentrate on evidence-based pathology, microbiology, parasitology, haematology and biochemistry, serology, reproduction, nutrition and surgery which, when strategically chosen, can over time be combined through meta-analyses and integrated into peer reviewed scientific publications. In addition to classical microscopy and cultivation we intend to gradually move more towards applying modern techniques, in particular molecular tools such as monoclonal antibodies and PCR, to study infectious diseases and to develop new diagnostic tools and methodologies that will help improve the management of zoo and wildlife populations. Moreover, a thorough basic knowledge of infectious agents is crucial for the adequate management of animal populations. After the discovery of the new infectious agent, Devriesea agamarum , we carried out a prevalence study in our captive population. Devrieseasis is more frequently diagnosed as the causative organism of dermatitis in lizards, particularly in spiny-tailed lizards. Other lizard species such as bearded dragons are known as asymptomatic carriers posing a potential threat to the healthy animals in a collection. By isolating, phenotypic identification and confirming by PCR, we found D. agamarum in six healthy jeweled curly-tailed lizards and in three clinical cases (two frilled lizards and a Philippine sailfin lizard) with abscesses in their beaks. It was concluded from this study that a quarantine programme for newly acquired animals is important to detect healthy carriers and prevent the spread of infection. Another retrospective study focused on fungal agents in our captive animals, trying to evaluate their impact during the last 34 years. Fungal infections causing dermatological or systemic disease in all 5 animal orders were demonstrated in a total of 675 samples, corresponding with an overall prevalence of 1.6%. These samples were from: 5 amphibia, 26 fishes, 49 reptiles, 150 (22%) mammals and 445 (66%) birds, in total 169 (25%) from living animals and 506 (75%) from dead animals. Fungal infection was 50% more prevalent in birds (2.2%) than in mammals (1.5%). More than half (56%) of all infections were due to Aspergillus species (predominantly A. fumigatus), of which 93% occurred in birds (i.a. 24% gallinaceous birds, 15% geese and ducks, 14% penguins, 9% songbirds, 8% parrots, 5% turacos and 4% birds of prey). Although the overall prevalence may not seem very high, mortality due to fungi is important bearing in mind that these samples came from 25% live animals and 75% dead animals.