Melena in Ferrets

If you ferret's stool appears green, black, or tarry, it may have melena, which typically occurs due to the presence of digested blood in the intestines. It has also been seen in ferrets after they have ingested a sufficient amount of blood from the oral cavity or respiratory tract.

Melena is not a disease in itself but a symptom of some other underlying disease. The dark color of the blood is due to the oxidation of iron in the hemoglobin (the oxygen carrying pigment of red blood cells) as it passes through the small intestine and colon.

Symptoms and Types

In addition to the black, tarry appearance of the feces, ferrets with melena may demonstrate some of the following:

• Anorexia
• Dehydration
• Weight loss
• Hypersalivation
• Vomiting
• Regurgitation
• Pallor of the mucous membranes
• Poor haircoat or hair loss
• Bruxism (clenching, grinding of the teeth)
• Fecal staining around the anus

Causes

The most common cause of melena in ferrets is due an infection with the bacteria Helicobacter mustelae gastritis. Salmonella and mycobacterium avium-intracellulare infections can also cause melena, though it is more rare. Other potential causes and factors include:

• Viral infection
• Obstruction—foreign body, tumor (lymphoma, adenocarcinoma)
• Intussusception (folding of one intestine in another)
• Drugs and toxins—NSAIDs, vaccine reaction
• Infiltrative—inflammation of cells.
• Ingestion of blood—oropharyngeal (portion of pharynx behind the mouth), nasal, or sinus lesions (abscess, trauma, tumor, fungal).
• Metabolic disorders—liver disease, kidney disease.
• Coagulation disorder
• Stress
• Blood poisoning
• Unsupervised chewing
• Exposure to other ferrets
• Vaccine reaction

Diagnosis

Your veterinarian will first rule out other causes with a physical examination of the ferret. He or she will probably also conduct a blood test. If these are not sufficient to arrive at a diagnosis, your veterinarian may conduct coagulation studies to rule out bleeding disorders.

An abdominal X-ray may indicate an obstruction such as a mass or a foreign body, while an ultrasound may be used to see the internal structures more clearly. Your veterinarian may also conduct a fecal culture and even do an exploratory laparotomy and surgical biopsy if there evidence of obstruction or intestinal mass.