• Veterinary Radiology
• Gastrointestinal Diseases
• Exotic Animals
• Infectious Diseases
• Companion Animals
• Veterinary Medicine

• Veterinary Radiology
• Gastrointestinal Diseases
• Exotic Animals
• Infectious Diseases
• Companion Animals

Digestive system disorders in reptiles are a diagnostic challenge because of the variations in gastrointestinal (GI) anatomy and physiology among species of reptiles. Christoph Mans, DVM, University of Wisconsin, Madison, Wisconsin, USA, presented an update on the latest advances in diagnostic techniques and therapy that have provided practicing veterinarians with tools for improved diagnosis and treatment of GI disorders in reptiles commonly maintained as companion animals.

Diagnosis is based on evaluation of the animal's history and clinical signs, tests for parasites, and imaging studies. Environmental temperature should be considered a factor in digestive problems because of its effects on enzyme secretion, peristalsis, and intestinal absorption. Generally, digestion cannot take place at temperatures < 45°F (7°C) and is slow between 45°F and 60°F (7° to 15°C). Other factors to look for are anorexia and weight loss, regurgitation in snakes, vomiting in lizards, diarrhea, constipation, cloacal tissue prolapse, and abdominal or coelomic distention.

If a parasite is suspected, a fecal sample or cloacal wash may be microscopically examined on a direct wet mount or stained smear. Cryptosporidium and Entamoeba invadens can be diagnosed with polymerase chain reaction. Pseudoparasites, or “pass-through” parasites, may be accidentally ingested with prey or soil that are not infectious to reptiles. Pollen, spores, or food mites might also be mistaken for a parasite.

Radiography is useful for evaluating tympany, foreign bodies, and constipation. However, plain x-ray films provide insufficient information about the liver or obstructions and filling defects. Contrast radiography is more effective for visualizing the upper GI, organ size, GI obstructions, and filling defects. Results can be affected by temperature, the disease process, and the type and volume of contrast media. Barium sulfate is an excellent contrast medium and should be used at 5 to 25 mL/kg. Diatrizoic acid is faster and less radiopaque; the usual dose is 5 to 7 mL/kg.

Ultrasound is used to assess scales, scutes, and shells, as well as GI obstruction and ileus. Hyperechoic fat bodies in snakes and lizards can be identified with ultrasound. Computed tomography (CT) is superior to radiography and ultrasonography. CT with or without iodinated contrast media is useful for evaluating the GI, respiratory, urogenital, and skeletal systems. It is faster than contrast radiography for detecting impactions and obstructions. The liver can be evaluated for hepatic lipidosis and other disorders.

Periodontal disease can be a cause of digestive and eating disorders. Etiologies include inappropriate diet, age, plaque formation, gingival recession, and osteomyelitis. Diarrhea in herbivorous reptiles may be due to inappropriate diet, such as too little fiber or too much sugar. Endoparasites, including pinworms, coccidia, flagellates, and Strongyloides, are also a cause of diarrhea. Other GI conditions seen in reptiles include tympany, constipation, foreign bodies, and liver disorders. Vomiting is a common ailment in reptiles and is associated with a poor prognosis in lizards. Gastric ulceration with possible perforation has been observed in green iguanas. Neuroendocrine carcinomas can affect bearded dragons and are highly malignant. The etiology, diagnosis, and treatment of digestive disorders in reptiles are described in Table 1.

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