Toxocara canis Larval Migration Causing Verminous Pneumonia in Fading Puppies From 2 Scottish Terrier Litters.

Migration of vertically transmitted Toxocara canis larvae through the liver and lungs is poorly documented as a cause of periparturient mortality in puppies. This case series describes 4 cases of fading puppies in 2 litters from 2 different bitches owned by the same breeder. Of the 4 cases, 4 had verminous pneumonia, 2 had fibrinoid necrosis of pulmonary arterioles, 4 had hepatic necrosis and inflammation, 2 had hepatic thrombophlebitis, and 1 had tracheal occlusion. These lesions were associated with migrating nematode larvae morphologically consistent with T. canis. The identity of the larvae was confirmed by sequencing of a portion of the ITS-2 region of nuclear ribosomal DNA. The tissues involved are consistent with the known migration pathways of this parasite. The dam of the first litter was negative for Toxocara spp. and other intestinal parasites by fecal floatation. This report highlights the need to consider T. canis migration in the differential diagnosis of fading puppies.

Clinicopathologic observations on laryngoplasty failure in a horse.

OBJECTIVE: To report morphologic findings associated with laryngoplasty failure in a horse. STUDY DESIGN: Clinical report. ANIMALS: A 9-year-old Thoroughbred cross gelding. METHODS: Necropsy and histopathology were performed on a horse that died peracutely during anesthetic recovery after correction of a right dorsal displacement of the ascending colon. Three weeks earlier the horse had left laryngoplasty and ventriculocordectomy. RESULTS: Dissection of the larynx revealed that the laryngoplasty suture had pulled through the muscular process of the left arytenoid cartilage, which appeared grossly normal. Histopathology of the arytenoid muscular process revealed cartilage necrosis, granulation tissue, and inflammation around the cartilage and within the cartilage failure line, and small numbers of coccoid bacteria in a minority of cartilage canals. Multifocal cardiomyopathy and pulmonary congestion, edema, and hemorrhage were also observed histologically. CONCLUSION: Death was attributed to peracute pulmonary edema associated with cardiac abnormalities and airway obstruction from laryngoplasty failure. Morphologic changes in the muscular process indicate gradual progression toward laryngoplasty failure, possibly associated with suture-induced pressure necrosis and/or microscopic low-grade postoperative infection.

Hepatotoxicity of Two Progoitrin-Derived Nitriles in New Zealand White Rabbits.

Cattle occasionally develop brassica-associated liver disease (BALD) and photosensitisation when grazing turnip or swede (Brassica spp.) forage crops. The liver toxin in these brassica varieties has yet to be discovered. Progoitrin is the dominant glucosinolate in incriminated crops. Apart from goitrin, progoitrin hydrolysis yields the nitrile, 1-cyano-2-hydroxy-3-butene (CHB), and the epithionitrile, 1-cyano-2-hydroxy-3,4-epithiobutane (CHEB). The two compounds were custom-synthesised. In a small pilot trial, New Zealand White rabbits were given either CHB or CHEB by gavage. Single doses of 0.75 mmol/kg of CHB or 0.25 mmol/kg of CHEB were subtoxic and elicited subclinical effects. Higher doses were severely hepatotoxic, causing periportal to massive hepatic necrosis associated with markedly elevated serum liver biomarkers often resulting in severe illness or death within 24 h. The possibility that one or both of these hepatotoxic nitriles causes BALD in cattle requires further investigation.