Fatty Tissue Inflammation in Cats

Alex German
Feb 27, 2010
3 min read
Image: Photo Grapher / via Image Bank

Steatitis in Cats


Steatitis is a rare disease in cats, characterized by a lump under the skin surface due to inflammation of the fatty tissue. Nutrition is often involved in the pathology of this condition. Ingestion of large amounts of 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. Cats that are fed large amounts of tuna, particularly red tuna, tend to be more prone to steatitis.


Steatitis in cats 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 disorder has become less prevalent in cats as more cats are fed commercially prepared diets that have added antioxidants. Steatitis can be found in any part of the body. It may be mistaken for a tumor, making it important to have the lump examined and biopsied as soon as possible. 


Steatitis is more likely to be found in young to middle-aged cats, from four months to seven years.


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




  • Vitamin E deficiency
  • Decreased antioxidant capacity with subsequent free-radical peroxidation of lipids
  • Oily fish-based diet (red tuna, whitefish, sardines, mackerel, herring, cod); rarely, liver-based diet
  • 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)




You will need to give a thorough history of your cat'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 cat's symptoms, your veterinarian will start with a physical examination of the affected area. A full physical workup will include a 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.

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