Protothecal enteritis as a cause of protein-losing enteropathy in a bull

Prototheca spp are achlorophyllic saprophytic algae found in wastewater, sewage, agricultural waste, and possibly elsewhere in the environment. Infections with these organisms have been reported in cattle, humans, and dogs; affected cattle commonly develop mastitis. A 5-year-old Brahman-cross bull was evaluated because of a history of diarrhea and weight loss. The history and physical examination and clinicopathologic findings were similar to those associated with granulomatous enteritis caused by Mycobacterium avium subsp paratuberculosis (Johne's disease), which is the most common protein-losing enteropathy of cattle. However, diagnostic tests for paratuberculosis yielded negative results. Biopsy specimens from the ileum, jejunum, and ileocecal lymph node were collected for histologic examination and preparation of tissue impression smears; Prototheca-like organisms were identified. Because of the poor prognosis associated with this infection and the lack of safe and economical therapeutic agents for cattle, the owner decided to euthanatize the bull. Infection with Prototheca organisms was confirmed postmortem. As this case illustrates, protothecosis may be a cause of granulomatous enteritis in cattle.     

Bluetongue virus as a cause of hydranencephaly in cattle.

Hydranencephaly was produced in a foetus and a calf by intra-uterine infection with an attenuated Type 10 bluetongue virus. Laparotomy was performed on the respective dams and the foetuses, respectively 126 days and 138 days old, were inoculated intramuscularly through the uterine wall with 1 ml of a virus suspension containing 5 x 103 tissue culture infective doese. The younger feotus was aborted on Day 262, while the other one was born alive on Day 273. Both foetuses showed marked hydranencephaly.     

Haemorrhagic enteritis in a dog associated with Clostridium sp.

Shortly after a dietary change to milk, a 4-year-old female Chihuahua commenced vomiting, developed diarrhoea and subsequently passed blood. Despite treatment with amoxicillin, this dog died 7 hours after the commencement of the clinical signs.     

Hemorrhagic enteritis caused by Clostridium perfringens type C in a foal

A 4-day-old foal died with bloody diarrhea. Using a mouse neutralization test, Clostridium perfringens type C was isolated from intestinal contents, and alpha and beta toxins were identified. About 4 m of the jejunum had severe necrohemorrhagic enteritis. Microscopically, large, rod-shaped, gram-positive bacteria were seen on necrotic intestinal villi by use of Brown and Hopp's stains.     

Hemorrhagic enteritis associated with Clostridium perfringens type A in a dog

A female Shetland sheep dog died suddenly with hemorrhagic diarrhea and vomitting, and was examined pathologically and microbiologically. Gross pathological change was restricted to the intestinal tract. The intestine contained watery, blood-stained fluid. Histopathologically, the principal intestinal lesion was superficial mucosal hemorrhagic necrosis at the jejunoileum. Many Gram-positive bacilli were found adhering to the necrotic mucosal surface in parts of the intestinal tract. Clostridium perfringens in pure culture were isolated from jejunal contents by anaerobic culture. These results suggested that the typical lesion of this case coincided with canine hemorrhagic enteritis and enterotoxemia due to C. perfringens infection could be the cause of sudden death.     

Neospora-like protozoan infection as a major cause of abortion in California dairy cattle

Ninety-five aborted bovine fetuses received from California dairies over a 4.5-year period had histologic lesions of focal encephalitis. Protozoa that reacted with Neospora caninum antiserum were detected in the brain of 88 of these fetuses and in the heart of 1 fetus. Sarcocystis spp schizonts were seen in the vascular endothelium of 1 fetus. It was concluded that a Neospora-like cyst-forming coccidian may be a major cause of abortion in California dairy cattle.     

山羊源第三梭菌的分离鉴定及耐药性分析

为确定导致山羊严重腹泻的病原菌,从病死山羊肠道内分离到的1株优势菌并命名为CT-1,根据其形态特征、培养特性、生化特性及16SrDNA分子鉴定结果确定分离菌株为第三梭菌。随后对分离菌株进行了动物回归致病性试验及药敏试验。动物回归致病性试验表明,该分离株能够导致山羊严重腹泻。药敏结果显示,该菌对氯霉素,红霉素,庆大霉素,阿米卡星敏感;对恩诺沙星,环丙沙星,阿奇霉素,强力霉素,氟苯尼考,阿莫西林,磺胺间甲氧嘧啶耐药。     

Malignant peripheral nerve sheath tumor as a cause of chronic cardiac insufficiency in cattle

Chronic cardiac insufficiency was associated with a malignant peripheral nerve sheath tumor in a cow. An eight-year-old cow developed a progressive condition (over a period of three months) characterized by an enhanced abdominal volume, reluctance to move, a positive jugular pulse, watery diarrhea and death. At necropsy, moderate subcutaneous edema and an enhanced hepatic lobular pattern were observed. A 23x20x11 cm firm, grayish-white mass adhered to and infiltrated the right atrium. Multiple firm, yellowish-white nodules of 0.5 to 12 cm in diameter were diffusely scattered in the epicardium and parietal pericardium. Histologically, the tumor was poorly circumscribed with foci of infiltration of the myocardium. The neoplastic cells had two major histologic patterns, Antoni types A and B. Within occasional foci, pleomorphic cells with an epithelioid appearance were present in addition to multinucleated cells with periodic acid Schiff (PAS)-positive cytoplasmic globules. Foci of cartilaginous and granular differentiations were interspersed among the neoplastic cells. Multiple vessels presented wall hyalinization and tumoral embolus. Large necrotic foci with mineralization and cholesterol clefts were also observed. Immunohistochemically, the tumor was positive for S100 protein, vimentin and neuron-specific enolase labeling.     

Dissecting aneurysm of the carotid artery as a cause of respiratory distress in adult cattle

A two-and-a-half-year-old Friesian cow and a five-year-old Charolais cow developed severe respiratory distress and palpable swellings to the left of the larynx as a result of a dissecting aneurysm of the common carotid artery. Neither cow responded to medical treatment. The underlying pathogenesis of the condition was uncertain, but direct trauma to the carotid artery was a possible contributory factor. Aneurysms of the common carotid artery should be considered when swelling occurs in the region of the larynx or when respiratory distress is due to laryngeal compression.     

Haemorrhagic necrotising enteritis in foals associated with Clostridium perfringens

Two foals aged 35 and 48 h from 2 Thoroughbred studs died several hours after developing clinical signs of depression, severe haemorrhagic diarrhoea and dehydration. Both foals had an acute haemorrhagic enteritis extending from the anterior jejunum to the terminal ileum which was characterised histologically by villus necrosis. Necrotic villi were surrounded by large numbers of rod-shaped Gram positive bacteria. Clostridium perfringens was recovered from the intestines of both foals and the isolates were considered to be C. perfringens type C. Other cases of diarrhoea were also observed in foals of the same age on these 2 studs, but the aetiology of these was not determined.