Naturally occurring mucocutaneous histoplasmosis in a rabbit.

Mucocutaneous histoplasmosis was diagnosed in a pet rabbit. A mass protruding through the anal opening was histologically composed of a densely cellular infiltrate of macrophages which expanded the anorectal submucosa. Macrophages contained abundant yeast forms of fungi morphologically consistent with Histoplasma capsulatum. Infection appeared to be localized. Histoplasmosis should be considered in the differential diagnosis of granulomatous inflammatory disease in the rabbit.

Gastrointestinal zygomycosis in suckling pigs.

Gastrointestinal zygomycosis was diagnosed in 3 suckling pigs (10, 14, and 28 days old) with diarrhea that was unresponsive to treatment with broad-spectrum antibiotics. The 3 pigs were from separate farms, and littermates of the 3 pigs with similar clinical signs had died. At necropsy, 2 of the 3 pigs had catarrhal to fibrinonecrotic gastroenteritis, and the third pig had hemorrhagic gastritis without intestinal lesions. Microscopically, transmural necrosis of the stomach and intestines was associated with marked inflammatory cell infiltration and thrombosis and vasculitis of vessels of the lamina propria and submucosa. Numerous broad, irregularly branching, nonseptate, mucoraceous fungi were seen in the lumens of blood vessels and in the necrotic mucosa and submucosa.

Studies on the sequential development and pathogenesis of citrinin mycotoxicosis in turkeys and ducklings.

The toxic effects of citrinin in turkeys and ducklings was studied in four trials. Citrinin dissolved in dimethyl sulfoxide-70% ethanol solution (3:1, volume/volume) was administered by gavage to male turkey poults and male white Pekin ducklings. When seven-day-old ducklings were given doses of citrinin between 30 to 110 mg/kg body weight, most of the treated ducklings which died (49/80) did so within four to 12 hours. Blood samples were collected sequentially at 3, 6, 12, and 24 hours after administration from seven-day-old ducklings given the single lethal dose (LD50). The alterations included hyperkalemia (P less than or equal to 0.01) and metabolic acidosis characterized by reduced blood pH (P less than or equal to 0.01) and base excess (P less than or equal to 0.01). Fourteen-day-old turkeys and ducklings given 56 or 57 mg/kg, respectively, were killed at 1, 3, 6, 12, 24, 48, and 72 hours after treatment. The principal alteration in both species was nephrosis that was more severe in turkeys than in ducklings. Tubular necrosis was the dominant lesion at three to 72 hours in turkeys and at six to 24 hours in ducklings. Hepatic and lymphoid lesions occurred in both turkeys and ducklings treated with citrinin.

Mycotoxicoses produced in ducklings and turkeys by dietary and multiple doses of citrinin.

Citrinin was mixed in the diet (100, 250, 500 parts/10(6)) and fed to 1-day-old male White Pekin ducklings (Trial I), or it was dissolved in dimethyl-sulphoxide-70% ethanol (3:1, v/v) and administered by crop gavage to 14-day-old male White Pekin ducklings (Trial II) or 7-day-old male turkey poults (Trial III). Ducklings given 250 or 500 parts/10(6) citrinin diet for 15 days had clinical signs of citrinin toxicity. Body weight gain was significantly decreased by the 500 parts/10(6) diet (P < 0.05). Ducklings fed 250 and 500 parts/10(6) developed nephropathy that was more severe in the 500 parts/10(6) group. The nephropathy was characterised by degeneration, necrosis, mineralisation and regeneration of tubular epithelial cells of both the cortical and medullary regions. Interstitial fibrosis was found in the medullary regions of the 500 parts/10(6) group only and focally was accompanied by interstitial nephritis. Seven daily doses of citrinin equal to a half or three-quarters of the single-dose LD(50) produced no additive toxic effects in either ducklings or turkeys, but body weight gain was significantly decreased in duckling given three-quarters of the single-dose LD(50).

Acute toxicity of citrinin in turkeys and ducklings.

Citrinin, a naturally occurring mycotoxin, was dissolved in dimethyl-sulphoxide - 70% ethanol (3:1, v/v) and administered orally in two trials to 7-day-old male turkey poults and male white Pekin ducklings. The single dose LD50 value in 7-day-old male turkey poults was 56 mg/kg and in 7-day-old male white Pekin ducklings it was 57 mg/kg. The mycotoxin was nephrotoxic in both species, but the renal lesions were more severe in turkeys and were characterised by degeneration and necrosis of renal tubular epithelium. In turkeys, lesions were found in the liver and included hepatic cell necrosis and biliary hyperplasia. Lymphoid necrosis with depletion involved the thymus and cloacal bursa of turkeys and ducklings. These latter lesions were the most prominent histopathological alterations in citrinin-treated ducklings.