Steroid Related Liver Disease in Cats
Vacuolar hepatopathy causes liver cells (hepatocytes) to undergo reversible vacuolar changes due to glycogen accumulation. The storage form of glucose, glycogen accumulates in liver cells because of steroid medication overuse, an overproduction of steroids in the body, or due to an endocrine disorder (e.g., hyperadrenocorticism, atypical adrenal hyperplasia).
Vacuolar hepatopathy is rare in cats.
Symptoms and Types
Symptoms are ultimately based on the underlying cause of the hepatopathy; some of the more common signs include:
- Loss of hair (alopecia)
- Increased thirst and urination (polydipsia and polyuria)
- Increased appetite (polyphagia)
- Abdominal distention
- Muscle weakness
- Bruises on skin
- Friable (easily crumbled) skin
Although it is rare, the cat may demonstrate symptoms of liver failure.
- Drug administration (e.g., glucocorticoids)
- Atypical adrenal hyperplasia
- Chronic infections
You will need to give a thorough history of your cat’s health, including the onset and nature of the symptoms. The veterinarian will then conduct a complete physical examination, as well as a biochemistry profile, urinalysis, and complete blood count (CBC) -- the results of which will depend on the underlying cause of the condition.
Blood testing, for example, may reveal anemia, abnormally high number of red blood cells (polycythemia), increased number of leukocytes or white blood cells, and abnormally high number platelets (thrombocytosis). Biochemistry profile, meanwhile, may reveal abnormal levels of liver enzymes, high levels of albumin (blood protein), and bilirubin, and abnormally high levels of cholesterol.
Your veterinarian will conduct the abdominal X-rays to identify the size of the liver, and thoracic X-rays to determine the size of lymph nodes, or metastasis, in the case of tumor(s) and cardiac or pulmonary disorders. Abdominal ultrasound, meanwhile, may reveal enlarged liver and changes in liver tissue due to extensive lesions and other concurrent problems within abdominal cavity.
There are also other, more specific and sensitive tests available to evaluate the liver, thyroid gland, and pituitary gland functions. Your veterinarian may take a live tissue sample to be sent to veterinary pathologist for further evaluation, often revealing the presence of vacuoles within liver cells and changes related to this abnormal accumulation. In addition, liver biopsies help in ruling out other liver diseases.
If infection is suspected, your veterinarian will take the sample to be sent to laboratory for culture and sensitivity. Culturing the sample helps in growing and identifying the causative organisms and sensitivity provide information related to antibiotics most effective against isolated organisms.
The course of treatment will depend on the underlying cause of the disease. However, due to reversible nature of this condition, early treatment will usually completely resolve the problem.
If pituitary masses are present, radiation therapy is used to destroy these masses within pituitary glands. Tumor(s) may also be excised surgically. In case of dental disease, proper antibiotics are used to control the infection. In case of infections, proper antibiotics are used to control and treat infections after culture and sensitivity testing. And in cases of underactive thyroid glands (hypothyroidism), thyroxine supplementation is required.
Living and Management
The cat will require regular follow-up exams following treatment to evaluate the animal its liver function. Your veterinarian will also often recommend modifying the cat's diet, especially if it has developed pacreatitis, which will require a low-fat diet.
Prognosis depends on the extent of disease; in some patients, prognosis is poor despite treatment.