Abstract

Retrospective studies of case files pertaining to monitor lizards have been limited to specific disease processes.^1-3 To the author’s knowledge, a retrospective study specifically addressing the diseases of monitor lizards has not been published. This report summarizes the disease processes in 333 monitor lizards representing 39 species submitted to Northwest ZooPath from 1995–2007. Infectious/inflammatory disease processes (73%) and deposition disorders (37%) were the most prevalent disease classes. The prevalence of cardiovascular, degenerative, nutritional, neoplastic, traumatic and reproductive disease was approximately equal (10–13%).

Within the various classes the most common diseases were as follows: cardiovascular (47 cases): cardiac fibrosis (21%); degenerative (37 cases): chronic renal disease (24%) and chronic hepatopathies (24%); deposition disorders (127 cases): gout (33%), hepatocellular lipidosis (32%), and metastatic mineralization (23%); nutritional (37 cases): inanition (76%); neoplastic (41 cases): soft tissue sarcomas (20%), squamous cell carcinoma (17%), and lymphoma (12%); inflammatory diseases (243 cases): bacterial (44%), unknown cause (35%), parasitic (15%); and reproductive (40 cases): yolk coelomitis (33%), oophoritis (30%), and follicular degeneration/rupture (20%).

Species with higher-than-average prevalence of specific diseases were as follows: Asian water monitor (Varanus salvator salvator) (6 cases): osteomyelitis (50%). Black-throated monitor (V. albigularis ionidesi) (13 cases): meningoencephalitis and myenteric ganglioneuritis (23%). Black tree monitor (V. beccarii) (29 cases): various neoplasia (24%). Crocodile monitor (V. salvadorii) (39 cases): metastatic mineralization (21%). Desert monitor (V. griseus) (12 cases): osteomyelitis (34%). Dumeril’s monitor (V. dumerilii) (3 cases): gout (100%). Green tree monitor (V. prasinus) (25 cases): sepsis (36%). Komodo dragon (V. komodoensis) (15 cases): amyloid-like deposition disorder (38%), metastatic mineralization (31%), yolk embolism (31%), various female reproductive disorders (40%). Peach-throated monitor (V. jobiensis) (6 cases): hepatic lipidosis (50%), gout (50%). Savannah monitor (V. exanthematicus) (52 cases): cryptosporidiosis (10%), various neoplasms (20%). Storr’s monitor (V. storri) (5 cases): emaciation (40%), hepatic lipidosis (40%). “Water” monitor (V. salvator) (11 cases): gout (36%). White-throated monitor (V. albigularis albigularis) (5 cases): gout (40%), inanition (40%). Rough-necked monitor (V. rudicollis) (15 cases): various female reproductive disorders (40%).

Diseases of special concern for which the etiology, significance to conspecifics/pen mates, or zoonotic potential was unknown, or for which the disease presentation or histologic lesion was considered unique, where as follows: degenerative encephalomyelopathy (five cases), ganglioneuritis/meningoencephalitis (five cases), hypertrophic osteopathy (one case), megacolon (two cases), and nonsuppurative myocarditis (three cases).

Literature Cited

1.  Garner MM, Divers SM, Raymond JT. Reptile neoplasia: a retrospective study of case submissions to a specialty diagnostic service. Vet Clin Exotic Anim. 2004;7(3):653–672.

2.  Garner MM, et al. An amyloid-like deposition disorder in Komodo dragons. Proc Assoc Reptilian Amphibian Vet. 2003:50–52.

3.  Hernandez-Divers SM, Garner MM. Neoplasia of reptiles with an emphasis on lizards. Vet Clin Exotic Anim. 2003;6(1):251–273.