Carbimazole-associated hypersensitivity vasculitis in a cat.

Feline hyperthyroidism can be treated medically, surgically or with radioactive iodine. Carbimazole inhibits both triiodothyronine and thyroxine synthesis in the thyroid gland and reported side effects include mild eosinophilia, leucopenia and lymphocytosis, thrombocytopenia, elevated liver enzyme activities, gastrointestinal signs and skin abnormalities. This case report describes a cat with carbimazole-associated apparent hypersensitivity vasculitis causing digital and tail necrosis, with multiple renal infarcts. Withdrawal of carbimazole resulted in stable disease.

Generalized alopecia with vasculitis-like changes in a dog with babesiosis.

A locally bred, 12-year-old, intact female Satsuma dog presented with generalized alopecia. Erythema, crusts and desquamation were observed primarily on the truck. Papules and erosions were present in the pinnae, and there were multiple areas of skin necrosis on the right forelimb. The cutaneous lesions had not responded to treatment with systemic antibiotics and prednisolone. The dog also had progressive anemia. Babesia gibsoni was detected in the blood, and the dog was treated with antiprotozoal agents. The skin lesions and anemia improved, but relapsed after the treatment was discontinued. Histopathological examination of skin biopsies revealed findings suggestive of early leukocytoclastic vasculitis or ischemic vasculopathy.

Leucocytoclastic vasculitis associated with Staphylococcus intermedius in the pastern of a horse.

A pregnant quarterhorse mare became acutely lame as a result of severe swelling of its right hind leg, thought to have been caused by a fracture or a muscle tear. Diagnostic procedures ruled out a traumatic musculoskeletal cause and a physical examination revealed chronic pastern dermatitis ('scratches'/'grease heel'). Histopathological evaluation of biopsy samples from the right hind leg was consistent with a leucocytoclastic vasculitis, and culture yielded Staphylococcus intermedius. The treatment and infectious causes of pastern dermatitis are discussed.

A retrospective study of canine and feline cutaneous vasculitis.

Twenty-one cases of cutaneous vasculitis in small animals (dogs and cats) were reviewed, and cases were divided by clinical signs into five groups. An attempt was made to correlate clinical types of vasculitis with histological inflammatory patterns, response to therapeutic drugs and prognosis. Greater than 50% of the cases were idiopathic, whereas five were induced by rabies vaccine, two were associated with hypersensitivity to beef, one was associated with lymphosarcoma and two were associated with the administration of oral drugs (ivermectin and itraconazole). Only the cases of rabies vaccine-induced vasculitis in dogs had a consistent histological inflammatory pattern (mononuclear/nonleukocytoclastic) and were responsive to combination therapy with prednisone and pentoxifylline, or to prednisone alone. Most cases with neutrophilic or neutrophilic/eosinophilic inflammatory patterns histologically did not respond to pentoxifylline, but responded to sulfone/sulfonamide drugs, prednisone, or a combination of the two.

Cutaneous vasculitis and vasculopathy.

Although uncommon to rare in occurrence, cutaneous vasculitides and vasculopathies are becoming better recognized entities in veterinary medicine. The heterogeneity in their clinical presentations can be confusing, and the diagnostic evaluation of suspected cases can be clinically and financially challenging. The most important step is confirming a vasculitic/vasculopathic process histologically and then searching for an underlying cause. As many cases are diagnosed as idiopathic by exclusion, a familiarity with treatment options is important and may be guided in some cases by the histological inflammatory pattern. Because of the frequent temporal association with drug administration, any case of vasculitis requires a thorough drug history and physical examination for systemic complications. Familiarity with breed-associated vasculopathies is also key in properly diagnosing and managing these problems.

Probable hypersensitivity vasculitis in a dog.

Allergy immunotherapy (hyposensitization) injections or ibuprofen were implicated as causes of hypersensitivity vasculitis in a dog suffering from probable food allergy. The vasculitis was associated with increased complement component, C3, and resulted in deep, ulcerated draining nodules and plaques on the forelimbs, lateral aspects of the thorax, and thighs. Injections had been given as immunotherapy for suspected atopy. Vasculitis, associated with allergy immunotherapy and increased complement component, C3, as well as with nonsteroidal anti-inflammatory drugs, has been reported in human beings.

Cutaneous vasculitis in horses: 19 cases (1978-1985).

The medical records of 19 horses with cutaneous vasculitis were reviewed. Most (73.7%) affected horses were between 3 and 10 years old, and there were significantly more mares (14) than stallions or geldings (5) (P less than 0.01). Subcutaneous edema of the limbs, body, and/or head was the predominant clinical sign (18/19 horses; 94.7%). The single most prevalent laboratory abnormality was neutrophilia (greater than 7,000 neutrophils/microliter), which was detected in 10 horses (52.6%). Leukocytoclastic vasculitis was evident in skin biopsy specimens from 12 of 14 horses (85.7%). All horses were treated with corticosteroids and supportive care, and the overall survival rate was 63.1% (12/19). The mean duration of treatment with corticosteroids in surviving horses was 14 (+/- 5.3) days. Of the 7 horses that died, 5 failed to respond to treatment (4 were euthanatized, 1 died), and 2 others had persistent debilitating sequelae (euthanatized). The only significant clinical or laboratory abnormality predictive of poor prognosis was fever (odds ratio, 17.81; P less than 0.05). Seven horses had history of, or were exposed to horses with, abscessed peripheral lymph nodes and likely were suffering from equine purpura hemorrhagica. In spite of histopathologic evidence of hypersensitivity-vasculitis and/or the clinical suspicion that the cause for vasculitis was immune mediated, 7 of 19 horses (36.8%) had no history of bacterial or viral infection nor a history of current drug administration.

Focal cutaneous vasculitis and alopecia at sites of rabies vaccination in dogs.

A focal cutaneous lesion developed at the site of previous rabies vaccine administration in 13 dogs. Ten of the affected dogs were Poodles. The interval between vaccination and first observation of the lesion varied from 3 to 6 months. Skin lesions were hyperpigmented, alopecic macules, 2 to 5 cm in diameter. The consistent histologic lesion was vasculitis affecting arterioles of the deep dermis and subcutis. Other histologic lesions included epidermal, follicular, and adnexal atrophy, hyperpigmentation, chronic septal panniculitis, fat necrosis, and focal lymphocytic nodules in the deep dermis and subcutis. Rabies-specific fluorescence was seen in the walls of dermal blood vessels and in the epithelium of hair follicles in each of 3 dogs tested. Immunoglobulin G was detected in similar locations in one of 3 dogs tested. No difference in serum neutralizing anti-rabies antibody titers were detected between 5 affected dogs tested and 4 clinically normal dogs.