ADV is a form of parvovirus. Like other parvoviruses, the production of antibodies by the animal that has been exposed to ADV is what produces symptoms. Antibodies get deposited in high concentration in critical organs.

Unfortunately, the antibodies that the ferret produces in response to ADV are not effective at neutralizing the virus. Thus, the main symptom of ADV in ferrets is immune system depression.

ADV is transmitted through the bodily secretions of the ferret. Ferrets, humans, and other animals can all be the vector for transmission. While there are tests to determine if a ferret has been infected by ADV, there is currently no cure.

Adrenal disease is a condition affecting the adrenal gland of ferrets, which can be accompanied by benign or cancerous nodules on the adrenal glands. It manifests itself primarily in hair loss and aggression. Hair loss from adrenal disease is very unique, and is used as one of main external diagnostic clues by veterinarians. The loss of hair usually begins at the base of the tail, around the rump, and proceeds away from this point, traveling down the tail and up the torso of the animal.

As the adrenal gland produces hormones, cancer of the gland also can result in ferret aggression. The prostate glands of male ferrets can also be affected by adrenal disease, resulting in difficulty with urination.

Diagnosis involves external clues, and blood tests to assess hormone levels and the like. Treatment involves hormone shots given on a regular basis, ranging from once monthly to once every six months or so. There is some argument that hormone treatments only mask symptoms of adrenal disease, but other studies do show that there is some control of the disease afforded by this treatment. In addition, melatonin has been shown to have some effect on hair loss, though no direct effect on the adrenal glands themselves. Surgical removal of part or all of the left or right adrenal gland may also be advisable, depending on the age of the ferret. In addition to the fact the surgery is difficult on any animal, adrenal gland surgeries run the risk of causing the remaining adrenal tissue to overcompensate, causing more of the same symptoms.

The causes of adrenal disease are unknown, though some hypothesize that abnormal exposure to natural and artificial light affects internal cycles and thus disrupts the functioning of the adrenal gland and its hormones. In addition, some evidence has suggested that spaying or neutering ferrets at too early of an age could affect this hormone balance in a negative way and render a ferret more susceptible to the disease.

Insulinoma refers to cancers of the pancreas that manifest in low blood sugar due to overproduction of insulin. Ferrets with insulinoma often show any combination of weight loss, lethargy, weakness, salivation, pawing at the mouth, and seizures.

Diagnosis is confirmed by blood test that shows low blood sugar, and treatment can include medication, diet control, and/or surgical removal of part of the pancreas. Medication can include Prednisone, which stimulates production of blood sugar, and Diazoxide, which has an anti-insulin effect. Diet control must include a balance of foods high in sugar (treats) with high-protein foods to stabilize blood sugar levels.

ECE is a virus that causes diarrhea in the ferret. The condition is nicknamed "Green Slime" disease or "The Greenies." Ferrets with ECE show extremely vibrant green, loose, mucousy stools.

Though there is no specific treatment for ECE, the major concern is to keep the ferret fed and hydrated. Occasionally, antibiotics are prescribed to treat underlying bacterial infections. However, since ECE is caused by a virus, antibiotics do little to abate symptoms.