Cryptosporidium infection as a cause of calf diarrhea

Cryptosporidiosis is a self-limiting protozoal disease of the intestinal tract. Although identified as possible agents of calf diarrhea less than 15 years ago, Cryptosporidium spp. are now believed to be common in calves and in many other host animal species worldwide. Recent literature on all aspects of cryptosporidiosis in calves is reviewed, predicaments in diagnosis and management are discussed, and public health concerns are raised.     

Arteriovenous fistula in the orbit of a calf

An Ayrshire calf with a protruding left eye and a fluctuant swelling dorsal to the orbit was examined. A diagnosis of arteriovenous fistula was made based on the findings of pulsation, a palpable thrill and a machinery-like bruit on auscultation over the swelling. Arteriography failed to outline the full extent of the fistula. The calf was euthanized and the fistula dissected. An enlarged superficial temporal artery communicated with a branch of the maxillary vein by way of a tortuous mass of vessels. The frontal bone was eroded by this plexus.     

Congenital mastocytomas in a Holstein calf

Congenital defects occur infrequently in cattle. In this report, a stillborn Holstein calf was presented for unusual nodules in the skin. Necropsy and histopathologic findings aided in the diagnosis of systemic mastocytoma, or mast cell tumor. The diagnosis of congenital mastocytoma in this case is extremely rare and unique.     

Congenital sporozoan encephalomyelitis in a calf

Protozoan encephalomyelitis was diagnosed post mortem in a five-day-old Friesian calf which had shown nervous signs from birth. The lesion was a subacute necrotising multifocal encephalomyelitis associated with protozoan bodies (6 X 6 microns to 16 X 30 microns). Ultrastructurally these bodies corresponded to apicomplexan meronts composed of eight to 89 merozoites which reproduced by internal budding to form paired daughter cells (endodyogeny). The merozoites were indistinguishable from Toxoplasma gondii; they reacted weakly with anti-Sarcocystis species serum and did not cross react with anti-T gondii serum. The generic identity of the sporozoan was not established, but it is unlikely to have been either Sarcocystis species or T gondii.     

East coast fever as a cause of calf mortality in zanzibar

Crossbred and zebu calves at 4 to 5 months of age in an area where tick control was carried out showed little difference in mortality. Crossbred calves at 10 months of age had a mortality rate of 20% from all causes, 14% from East Coast fever. Serological results plus mortality studies showed that the survival rate of crossbred calves known to have been exposed to ECF was 57%. Serological results further showed that, in spite of tick exposure, only 26% of the crossbreds had seroconverted at 10.3 months of age while 15% zebus had positive titres.     

Congenital hepatic fibrosis in a newborn calf

Congenital hepatic fibrosis was observed in a newborn calf. Light microscopy revealed that periportal areas were linked via connective tissue to the central vein regions and to other periportal areas. Hyperplastic fibers were positive for type I collagen. A remarkable increase in the number of myofibroblasts that were positive for alpha-smooth muscle actin and vimentin was observed in the inner wall of the sinusoids, indicating the occurrence of various fibrogenesis. Ultrastractually, foci of cells resembling cholangiole epithelium cells were observed within the sinusoids, thereby suggesting either ductal plate dysplasia or a bile duct anomaly.     

Congenital erythropoietic protoporphyria in a Limousin calf

Bovine congenital erythropoietic protoporphyria is an uncommon genetic defect in Limousin and Blonde d'Aquitaine cattle that is characterized by severe photosensitization. Clinical signs include intense pruritus and exudative dermatitis involving the face, pinnae, and dorsal aspect of the thorax. Affected cattle have hematologic and serum biochemical values within reference ranges, and their teeth are normochromic. Definitive diagnosis of bovine congenital erythropoietic protoporphyria is accomplished by genetic testing. Affected cattle should be sent to a terminal market.     

Congenital duodenocolic fistula in a dog

A one‐year‐old female cocker spaniel presented with a 6‐month history of persistent diarrhoea. Abdominal ultrasonographic examination revealed mild diffuse thickening of the intestinal wall coupled with mesenteric lymphadenopathy. A connection between the duodenum and the colon was observed during an endoscopic procedure and confirmed by computed tomography. Surgical resection of the communication allowed remission of the diarrhoea. Histology showed a normal duodenal epithelium and muscular layer. A duodenocolic fistula is an abnormal connection within the digestive tract, which in humans is usually considered a complication of a local pathological condition. Due to the absence of a predisposing cause and, in view of the dog's age and histological results, a congenital origin was suspected.     

Congenital enlargement of the suburethral diverticulum in a Holstein calf

A 3-month-old, female Holstein calf was examined because of marked perineal swelling and tenesmus of 4-days duration. A congenitally enlarged urethral diverticulum was diagnosed using fluoroscopic and ultrasonographic imaging techniques. The urethral diverticulum was surgically resected and the perineal area was reconstructed.     

Congenital nutritional muscular dystrophy in a beef calf

A 13-hour-old Aberdeen-Angus was involuntarily recumbent since birth. Congenital nutritional muscular dystrophy was suspected based on clinical findings, increased serum creatine kinase, and decreased serum vitamin E and selenium levels. Recovery followed after supportive therapy and parenteral vitamin E and selenium. Reports of this disease in newborn calves are unusual.     

Congenital thymic aplasia in a Holstein-Israeli female calf

An unusual case of congenital thymic aplasia in a Holstein-Israeli female calf is described. The most prominent clinical findings were diarrhoea and weakness. At necropsy, the only significant pathological finding was the marked decrease in thymus size. Histologically, this organ was composed of loose connective tissue in which a few lymphocytes were scattered randomly.