CAHFS Connection June 2024

Avian

Avian metapneumovirus (aMPV) type A, respiratory bacterial infection, necrotic enteritis, and hemorrhagic enteritis (HE) were diagnosed in six, 7-week-old broad breasted white turkeys that experienced increased mortality. Grossly, sinusitis, polyserositis, mottled spleens, moderately distended small intestines with diphtheritic pseudomembrane, and gizzard erosions were identified. Microscopically, the spleen had lesions typical of adenovirus infection with large, basophilic intranuclear inclusions consistent with HE. The intestine had severe, multifocal necrotizing enteritis. E. coli was isolated from the trachea, pericardial sac, and air sac, and Ornithobacterium rhinotracheale was isolated from the pericardial sac. Clostridium perfringens and Paeniclostridium sordellii were isolated from the intestine. Immunohistochemistry for both C. perfringens and P. sordellii was positive in the intestine, and positive for C. perfringens in the gizzard. HE virus was detected in the spleen pool by PCR. aMPV type A was detected in tracheal pool swabs by PCR. This virus predisposes birds to respiratory bacterial infections. Ventriculitis and necrotic enteritis were possibly secondary to immunosuppression caused by HE virus infection. 

Bovine

White muscle disease (nutritional myopathy) was diagnosed in a 5-week-old Angus calf that was found dead. Gross examination revealed multifocal to coalescing white linear streaks in the heart, which microscopically corresponded to myocardial necrosis with mineralization. Analysis of the liver revealed no detectable selenium, confirming the diagnosis of white muscle disease.

Hemolytic anemia caused by garlic toxicosis was diagnosed in approximately 300, 13-month-old Holstein heifers. The heifers were fed a ration containing 25% - 27% garlic and developed depression, weakness, anorexia, icterus, and hemoglobinuria. Complete blood counts revealed significant anemia with evidence of regeneration and abundant Heinz bodies, consistent with oxidative-related hemolysis. Tests for Leptospira spp. and Anaplasma spp. were unrewarding. Allium species (including onion, garlic, leek, scallion, shallot, and chive) have several organic sulfur-containing compounds that cause hemolysis. Cats and dogs are highly susceptible to poisoning, while cattle, horses, and pigs are moderately susceptible; sheep and goats are more resistant. 

Equine

Salmonellosis was the cause of death of a 10-year-old Lusitano mare with enterocolitis. On necropsy, watery, blood-tinged contents were found in the small intestine, and the large colon mucosa was edematous. Histologically, fibrinonecrotizing enterocolitis with thrombosis was observed. Salmonella Manhattan was isolated. Salmonella spp. is a common cause of colitis in both foals and adult horses.

Pigs

Odontogenic cysts were diagnosed in a 1-year-old kunekune pig with a history of swollen face and dyspnea. On necropsy, the pig had large cavities in the mandible packed with feed. The cause of these cysts is not fully known, but a genetic predisposition is suspected.

Small Ruminants

Cysticercosis was the cause of death of a 1-year-old female Alpine goat experiencing fever and reduced milk production prior to death. The postmortem examination revealed extensive cysts containing larvae throughout the liver, lung, and peritoneal cavity. This condition was caused by Cysticercus tenuicollis, the intermediate stage for the tapeworm Taenia hydatigena. Dogs, wolves, lynx, foxes, raccoons, bears, and cats act as definitive hosts of this cestode.

Bibersteinia trehalosi septicemia was the cause of death in a 3-month-old show lamb that was off-feed and hypothermic with marked leukopenia, metabolic acidosis, and hypoglycemia. The lamb died within 24 hours of onset of illness despite antibiotic and IV fluids treatment.

Histologically, embolic pneumonia and hepatitis, both with thrombosis and accompanied by bacterial colonies, were noted.  B. trehalosi was isolated in pure culture from the lung and liver.