Serological and necropsy findings for rams infected with Brucella ovis which were not identified by the complement fixation test.

The eradication of Brucella ovis from a commercial flock of 36 Romney rams was complicated by four infected rams remaining undetected despite four successive flock examinations using the complement fixation test. These four rams were subsequently tested using an enzyme-linked immunosorbent assay and a gel diffusion test and shown to be infected by semen culture. All four rams could have been identified as infected at the initial test if the enzyme-linked immunosorbent assay had been used in addition to the complement fixation test. Although gross evidence of epididymitis was found in only one ram at necropsy, three had histological lesions of epididymitis and all four had a seminal vesiculitis.

Vetch toxicosis in cattle grazing Vicia villosa ssp dasycarpa and V benghalensis.

The epidemiological, clinical and pathological features of a disease syndrome in adult cattle grazing woolly-pod vetch (Vicia villosa ssp dasycarpa) or popany vetch (V benghalensis) are reported. Outbreaks of toxicosis occurred between midwinter and midsummer in 3 dairy and 6 beef herds on the north coast of New South Wales, between 1982 and 1992. Friesian, Angus, Murray Grey, Guernsey and Hereford breeds were affected. Mean morbidity and case fatality rates in affected herds were 7% (65 of 889) and 69%, respectively. Signs of pruritic dermatitis, illthrift and death were associated with an eosinophilic granulomatous inflammation of many organs, particularly involving the renal cortex, dermis, myocardium, adrenal glands, lymph nodes and hepatic portal triads.

Chondrodystrophy in calves associated with manganese deficiency.

A severe congenital chondrodystrophy in Charolais calves is described. Thirty-two calves were born on the same farm with shortened limbs and enlarged joints. Histologically, there was poor cartilage maturation with excessive amounts of rarefied cartilage matrix. There were degenerative changes in the chondrocytes and a severe reduction in the mucopolysaccharide content of all body hyaline cartilage. The cartilage matrix, when examined ultrastructurally, showed loose, disorganised fibres in a rarefied matrix, and extensive vacuolation of the chondrocytes. A low level of manganese was found in the liver of an affected calf. The pregnant cows were fed on apple pulp and corn silage, both of which are low in manganese.

Jugular thrombophlebitis resulting from an anaesthetic induction technique in the horse.

Forty-eight hours after general anaesthesia was induced by glycerol guaiacolate and thiopentone sodium in 10 horses, the jugular veins were dissected out at post-mortem and examined visually and histologically. All veins showed a marked thrombophlebitis involving the media and intima at the site of injection. The influence of catheter composition, catheter placement and chemical composition on the occurrence of the thrombophlebitis is discussed. It is concluded that the thrombophlebitis was chemically induced.

Familial progressive nephropathy in young Bull Terriers.

The clinical, clinicopathological and pathological findings are described in three Bull Terrier bitches with advanced renal disease. The bitches were less than four years old and showed variable presenting signs but anorexia, lethargy and polydipsia were the most frequent. All three dogs were azotaemic and isosthenuric. Urinary protein was measured in two of the three cases. Both were proteinuric. At necropsy all dogs had shrunken kidneys. Histological examination revealed nephron loss, atrophy of glomerular tufts, interstitial fibrosis, and mineralisation of basement membranes. The progressive renal disease in these dogs was similar to the condition reported in Bull Terriers in Australia, and is probably familial and inherited.

An unusual incidence of neurological disease affecting horses during a drought.

The clinical, pathological and epidemiological factors were investigated in 12 horses presenting with severe neurological signs. Although the cases involved differing central (n = 1), spinal cord (n = 4) and peripheral nerve (n = 7) deficits in a number of instances, there were similar pathological findings. The possibility of a unifying aetiological factor, such as a toxicosis, is discussed because of the pathological similarities and as the cases appeared during an unusually long dry period.