Panniculitis is inflammation of the fat tissue just underneath the skin marked by deep-seated skin nodules that often become ulcerated and develop draining tracts. Fat cells can be damaged by many factors including vaccines and antibiotics. Traumatic panniculitis occurs when blunt trauma, chronic pressure, or decreased blood supply are present. Infectious panniculitis develops when bacteria or fungi become established in the layer of fat beneath the skin. Immune-mediated panniculitis occurs with systemic lupus erythematosus, drug reactions, infectious agents, or internal malignancy. The Dachshund, Collie and German Shepherd Dog seem to be predisposed to sterile nodular form of panniculitis which is marked by multiple lesions. There is no age or sex predilection.
Image provider: Infectious Diseases and Pathology
(University of Florida)
Lesions associated with sterile nodular panniculits are most commonly located over the neck and trunk. Some nodules are mobile and some rupture and drain an oily brown or blood-tinged discharge. There may be evidence of scarring in the area of the ruptured nodules, and a secondary staphylococcal infection may occur after rupture. Fever, depression, lethargy, anorexia may be present in dogs with multiple lesions. Sterile foot panniculitis of the German Shepherd Dog appears as well-defined tracts that have slightly swollen inflamed borders. They are most frequently located on the footpads.
The definitive diagnosis can be made only by biopsy that will reveal inflammation of the subcutaneous fat. Solitary lesions may be removed surgically. If the panniculitis is due to infectious agents, appropriate treatment is administered. Animals with multiple sterile lesions respond well to systemic corticosteroids. Many animals will enter long-term or permanent remission. If lesions recur, long-term alternate dose corticosteroid therapy is prescribed. In some cases, dogs responded to anti-inflammatory doses of prednisone. It has been established that the lesions in these dogs relapse once the levels of steroids are reduced. However, in two of the cases, oral vitamin E therapy at a dose of 300 IU twice daily allowed to reduce the amount of steroid drugs. In another case, vitamin E acted to control the clinical signs without steroid therapy.
- Nesbitt G.E. & Ackerman L.J. Miscellaneous Canine Skin Diseases. In: Canine and Feline Dermatology: Diagnosis and Treatment. Veterinary Learning Systems, Trenton, New Jersey, 1998
- Scott, Miller & Griffin. Miscellaneous Skin Diseases. In: Small Animal Dermatology. W.B. Saunders, Philadelphia, 1995
- Paterson S. Animal Medical Centre Referral Services, Chorlton, Manchester. Sterile idiopathic pedal panniculitis in the German shepherd dog--clinical presentation and response to treatment of four cases.