Enlarged Spleen in Ferrets

By PetMD Editorial on Jan. 9, 2009

Splenomegaly in Ferrets

Splenomegaly is a medical condition in which a ferret's spleen is enlarged. The spleen is an organ that produces the immune system's B and T cells, and where old blood cells, bacteria, and other infectious agents are filtered and destroyed.

Additionally, the spleen stores viable blood cells, so that in the case of an emergency (e.g., an injury causing the ferret to bleed extensively) the organ can distribute blood to the rest of the body.

Splenomegaly is reported to be extremely common in ferrets. Often, ferrets live most of their lives normally with an enlarged spleen.

Symptoms and Types

Occasionally, ferrets will display no signs of the illness. However, some symptoms which may be seen in a ferret suffering from splenomegaly include fever, anorexia, and lethargy.



Splenomegaly is occasionally deemed normal in certain ferrets, especially if the ferret is three years old or older. Other common causes for the medical condition include:

  • Infection
    • Bacterial
    • Viral (e.g., Aleutian Disease)
  • Insulinoma (a benign tumor of the pancreas)
  • Cardiomyopathy
  • Splenitis/Hyperspenism
  • Eosinophilic gastroenteritis (immune cells flock to an inflamed intestine)
  • Cancer (e.g., lymphosarcoma, Adrenal neoplasia, systemic mast cell neoplasia; occurs in only about 5 percent of splenomegaly cases)


Your veterinarian will perform a physical exam on the ferret and ask you questions to complete a medical history of the animal. Your veterinarian will then order a blood chemical profile, a complete blood count, an electrolyte panel, and a urinalysis, so as to discover any underlying systemic disease(s).

Next, your veterinarian will sedate the ferret and take a fine needle aspirate of the spleen. An ultrasound will help your veterinarian to visualize whether the ferret's spleen is diffusely enlarged or enlarged with nodules. The ultrasound is also very important in guiding the veterinarian while he/she takes fine needle aspirate samples. These samples may then be sent to the laboratory for histopathology.


The condition hypersplenism is not fully understood. However, since it is accompanied by a dearth of red and white cells, along with depression and high fever in a ferret, infection is suspected to be a cause. Consequently, the treatment for hypersplenism is a splenectomy. This seems to work well in ferrets as opposed to many other species. Likewise, any cancer of the spleen (especially lymphosarcoma) requires splenectomy.

If the ferret is showing signs of a systemic infection which responds to antibiotic administration, then a splenectomy may be unnecessary. If an underlying disease like cardiomyopathy or Aleutian Disease is present, then these illnesses must receive treatment (cardiomyopathy) or supportive care (Aleutian Disease). In most cases, if a ferret is acting normally and its bloodwork is normal, splenomegaly may be safely ignored.

Living and Management

Your veterinarian will schedule regular follow-up appointments depending on the underlying cause of your ferret’s splenomegaly. If your ferret has had a splenectomy, feed it only small meals for the first few days after surgery and call your veterinarian immediately if you see any swelling, redness, or oozing from the surgical site.

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