The lack of appropriate husbandry and management is the most common cause of the problems encountered in large reptile collections around the world. On the other hand, the evaluation of postmortem specimens is an integral aspect in the diagnosis of reptile diseases.
The objective of this study is to know the main fatal pathologies of reptiles in two zoological collections in Gran Canaria, with special attention to those diseases derived from poor facility management.
We necropsied 148 reptiles belonging to two zoological collections in Gran Canaria during the years 1998-2000. We studied 39 chelonians belonging to the families Testudinidae (n=30), Chelidae (n=4), and Emydidae (n=5). Within the suborder Sauria we necropsied 52 reptiles, belonging to the families Gekkonidae (n=6), Chamaeleonidae (n=14), Agamidae (n= 10), Iguanidae (n=6), Scincidae (n=7), Lacertidae (n=3), and Varanidae (n=6). We studied 43 snakes belonging to the families Boidae (n=25), Viperidae (n=2), Colubridae (n=8), Xenopeltidae (n=2), Hydrophiidae (n=2), and Crotalidae (n=4). Within the order Crocodylia we necropsied 14 reptiles, belonging to the families Crocodylidae (n=11) and Alligatoridae (n=3).
Clinical history of each reptile was recorded, and necropsy of freshly dead or refrigerated for less than 24 hours specimens was performed. Tissues were fixed in 10% neutral buffered formalin, routinely processed, and stained with hematoxylin and eosin. Selected samples were also stained with periodic acid-Schiff, Gram, and Grocott's methenamine silver nitrate stains. Immunohistochemical procedures were applied when necessary.
The main diseases observed within the order Chelonia were bacterial granulomatous hepatitis (12.8%), necrotizing enteritis (10.2%), purulent bronchopneumonia (7.7%), hepatic lipidosis (7.7%), and severe gastrointestinal parasitization by nematodes (7.7%).
Within the suborder Sauria we detected bacterial granulomatous hepatitis (13.4%), mineralization of blood vessels (11.5%), visceral gout (9.6%), filariasis (9.6%), and bacterial granulomatous pneumonia (9.6%).
Within the suborder Serpentes we observed necrotizing esophagitis-gastroenteritis (18.6%), bacterial granulomatous hepatitis (13.9%), interstitial pneumonia by paramyxovirus infection (13.9%), and bacterial purulent pneumonia (9.3%).
The main diseases diagnosed within the order Crocodylia were bacterial dermatitis (21.4%) and septicemic lesions (21.4%).
In our study, nutritional diseases were infrequently diagnosed. Mineralization of blood vessels was diagnosed in lizards, but clinical history of these lizards showed that they were donated previously by private owners to the zoological collections. However, bacterial diseases were the most frequently diagnosed. Poor hygiene and sanitation practices were common causes of these bacterial diseases. In addition, the lack of an appropriate quarantine area in one of the zoological collections contributed to the propagation of several infections.
Ophidian paramyxovirus infection was the only viral disease diagnosed. The reptile trade probably contributes to propagation of viral diseases. Because there is only effective treatment against secondary bacterial infections, strict quarantine of newly acquired reptiles should be followed to prevent viral infections from spreading.
Although several authors state that filarial infection rarely cause clinical disease in reptiles, filariasis was the main parasitic disease found in our study. Efforts should be made to develop safe and commercially available treatments against these parasites in reptiles.