Fatty Tissue Inflammation in Dogs

Fatty tissue inflammation is the swelling of the fat cells just underneath of the skin, which can cause bumps that may be painful for your dog. This disorder is most common in dogs with other disorders, such as cancer. These bumps can be found in any area of skin on your dog, but is most often found in the neck, back, legs, and abdomen. This disease can be caused by infection (infectious), too much fat in the diet (nutritional), lupus (autoimmune), injury (traumatic), pancreatitis (neoplastic), vaccinations (post-injection), or unknown (idiopathic).

Fatty tissue inflammation can be one of two disorders, which are panniculitis and steatitis. The only difference being that panniculitis can happen at any age, but steatitis only affects older dogs. Inflammation in the fat tissue usually presents as painful nodules in the skin that may be large or small, movable or fixed, hard or soft.

• Lumps or nodules in the fat containing tissue right under the skin
• Loss of appetite
• Extreme tiredness
• Tenderness in areas with lumps
• Higher than normal body temperature
• Abscessed sores or ulcerations
• Change of color in areas of skin affected

 Types

• Infectious panniculitis/steatitis can be caused from a bacteria, fungus, virus, or microbacteria
• Nutritional panniculitis/steatitis is caused by too much fat in the diet
• Autoimmune panniculitis/steatitis is from lupus, erythema nodosum, vasculitis, or a reaction to a drug
• Traumatic panniculitis/steatitis may be from an injury, frostbite, or sunburn
• Neoplastic panniculitis/steatitis is caused by mast cell tumors, lymphoma, or pancreatic cancer
• Post-injection panniculitis/steatitis can be the result of immunizations, subcutaneous injection, or steroids
• Idiopathic panniculitis/steatitis (non-conclusive) can be anything not on this list, but it means that they cannot find a cause of the condition

• Bacterial infection
• Fungal infection
• Viral infection
• Microbacterial infection
• Too much fat in your dog’s diet (i.e. feeding your dog human foods)
• Lupus
• Erythema nodosum
• Vasculitis
• Reaction to medication
• Injury/trauma
• Tumors
• Lymphoma
• Pancreatic cancer
• Injections (i.e. corticosteroids, immunizations)
• Vitamin E deficiency
• Radiation therapy
• Unknown cause

Be prepared to let the veterinarian know a thorough medical history including any recent illnesses or injuries, changes in diet, what the symptoms are and when they started, changes in behavior. Let the veterinarian know if you have been feeding your dog any kind of people food or scraps or if he has been on a high fat diet because that may indicate nutritional panniculitis/steatitis, which is easy to treat just by changing his diet.

Your veterinarian will also need to do a complete physical examination, which usually includes body temperature, weight, heart rate, and blood pressure. He will also check your dog’s eyes, teeth, and skin for any clues that may help the diagnosis. A complete blood count (CBC), blood chemistry, needle biopsy of one of the lesions for microscopic evaluation, urinalysis, and possibly digital radiographs (x-rays) of the affected areas. The veterinarian may also run fungal, viral, and bacterial swab cultures to rule out these as causes for your dog’s condition. In some cases, if the veterinarian suspects cancer, he will remove the lumps and perform a microscopic biopsy to get an accurate diagnosis to rule out a cancerous tumor.

Your dog’s treatment is dependent on the cause of the panniculitis/steatitis. The veterinarian will probably remove the lumps that can be removed and any necrotized (dead) tissue that was damaged. For infectious, traumatic, and idiopathic panniculitis/steatitis, the veterinarian will prescribe antibiotics (i.e. amoxicillin), immunosuppressant (i.e. cyclosporine), antifungals (i.e. ketoconazole) antimicrobials (i.e. cephalexin) and steroids (i.e. prednisone) to relieve the inflammation and pain. If your dog has nutritional panniculitis/steatitis, the veterinarian will prescribe vitamin E and a special diet. It is very important that you stick to this diet.

Autoimmune and neoplastic panniculitis/steatitis is treated with a variety of medications depending on the actual cause, but it will usually include antibiotics and steroids as well. Sometimes surgery is needed to remove excessive or cancerous tumors, but with early treatment, your dog has a great chance of a full recovery. Traumatic panniculitis/steatitis is treated with the removal of the lump and supportive care. Post-injection panniculitis/steatitis is treated by discontinuing the steroid shots.

This condition may take a long time (3-6 months) to clear up depending on the cause of the panniculitis/steatitis. Because it is usually such a painful disorder, it is important that you provide your dog with whatever medication your veterinarian prescribed or recommended. You should also be sure to stick to whatever diet regimen your veterinarian prescribed along with any other medications. You will have to take your dog back for a follow-up to be sure the condition is being treated correctly. Since panniculitis/steatitis sometimes recurs, you have to be vigilant about watching for signs of it returning.