Fatty Tissue Inflammation in Dogs

Steatitis in Dogs

Steatitis is characterized by inflammation of the fatty tissue. Nutrition is often involved in the pathology of this condition. Ingestion of large amounts of dietary unsaturated fats without sufficient antioxidant activity may result in peroxidation (where free radicals “steal” electrons from the lipids in cell membranes, resulting in cell damage) with subsequent fat necrosis (death of fat cells) and steatitis.

Steatitis in dogs can also occur secondary to infection, inflammatory disorders, vasculopathy (disease of the blood vessels), cancer, injury, and immune-mediated disease. Some cases are idiopathic (cause is unknown). This is an uncommon disorder in dogs, and has become less prevalent with the addition of antioxidants to standard commercial pet food. It is most often reported in dogs with concurrent diseases, such as liver or pancreatic cancer. It is also more likely to be found in older dogs. Steatitis can be found in any part of the body as a lump under the skin. It may be mistaken as a tumor, making it important to have the lump examined and biopsied as soon as possible.

Symptoms and Types

• Lump in the subcutaneous tissue (fatty tissue)
• Decreased appetite
• Lethargy
• Reluctance to move, jump, play
• Pain with handling or with abdominal palpation
• Fever

Causes

• Vitamin E deficiency
• Decreased antioxidant capacity with subsequent free-radical peroxidation of lipids
• Homemade diet with large fish base or pig’s brain
• Large amounts of dietary unsaturated fatty acids
• Pancreatitis or pancreatic cancer
• Infection (viral, fungal, bacterial)
• Immune-mediated, cancer
• Trauma, pressure, cold, foreign material
• Radiation therapy
• Idiopathic (unknown cause)

Diagnosis

You will need to give a thorough history of your dog’s health, onset of symptoms, and possible incidents that might have led to this condition. The history you provide may give your veterinarian clues as to what underlying conditions are causing the outward symptoms.

To determine the exact cause of your dog’s symptoms, your veterinarian will start with a physical examination of the affected area. A full physical workup will include a complete blood profile, including a chemical blood profile, a complete blood count, and a urinalysis. To determine the full makeup of the inflamed mass of tissue, your veterinarian will also need to do a fine-needle aspiration, taking a sample of the tissue and fluid in order to conduct a cell examination and a fungal/bacterial culture.