Association of Klebsiella organisms with pulmonary lesions in sheep.

Small nodules were seen on chest wall and in the lungs of sheep slaughtered in Al-Ahsa abattoir, Saudi Arabia. Klebsiella pneumoniae subspecies ozaenae was isolated and characterized. The histopathology of the nodules was described.     

Brain lesions of naturally occurring pregnancy toxemia of sheep.

The neuropathology and biochemical features of 17 sheep with clinical signs and gross necropsy features of naturally occurring pregnancy toxemia were retrospectively evaluated. The sheep ranged in age from 3 to 6 years and were of seven different breeds and three breed crosses. Thirteen sheep (case Nos. 1-4, 6-9, 11-14, 16) showed astrocytic nuclear swelling, hypertrophy and proliferation, and cerebrocortical neuronal necrosis. Seven of these sheep had Purkinje cell necrosis (case Nos. 2, 3, 6, 11, 12, 14, 16), and seven had vacuolation of cerebral and cerebellar sub-cortical white matter (case Nos. 1-4, 9, 12, 13). The neuropathologic features were similar to those of naturally occurring hypoglycemia of human beings and experimentally induced hypoglycemia of primates and the rat. The lesions seen in the sheep studied may have been caused by cerebral hypoglycemia, but data for blood or cerebral glucose concentrations were not available.     

Injection site lesions of footrot vaccines in sheep

Three trials were conducted to assess the size and frequency of lesions induced by an oil-based and an alum-precipitated aqueous B. nodosus commercial footrot vaccine at two injection sites (neck and brisket) with or without prior skin swabbing with methanol. Animals used were previously unvaccinated and clean and dry at time of vaccination. Trial 1 contained 57 2-tooth Booroola Merino x Coopworth ewes, trial 2 contained 60 mixed-age Corriedale ewes, and trial 3 contained 39 rams of mixed age and sex. Firm nodules or plaques with indurated edges and with a maximum dimension of 1cm or more appeared soon after vaccination and were still very common (50-100% of sheep vaccinated) 5-6 weeks after injection. A variable proportion exhibited a liquefied central area of necrosis and later discharged necrotic material. The oil-based vaccine produced significantly larger lesions than the alum-precipitated aqueous vaccine. Lesion size at the brisket site was significantly larger than the neck site in ewes but not in rams. Skin preparation with methanol had no effect on lesion frequency or size.     

Cervical scoliosis and kidney lesions in sheep following dosage with vitamin D.

A case of cervical deformity of lambs following dosage with vitamin D was investigated. The lesions of a scoliosis are described together with the kidney lesions. It is suggested that doses of vitamin D normally considered to be non-toxic to sheep may prove to be so under certain conditions.     

Bacteriologic and pathologic studies of hepatic lesions in sheep

At an abattoir, lesion specimens from 140 condemned sheep livers were collected for bacteriologic culture and for pathologic examination. Grossly, 23 lesions were abscesses; from 9 of which, Fusobacterium necrophorum biovar A (3 in pure culture and 6 in mixed culture) was isolated and from 14 of which, biovar B (6 in pure culture and 8 in mixed culture) was isolated. Escherichia coli was the predominant facultative anaerobic bacterium and Clostridium perfringens was the predominant obligate anaerobic bacterium isolated from the 14 lesions with mixed bacterial infection. Histologically, these lesions had a core of coagulation necrosis, encircled by a zone of necrotic phagocytic cells and bacteria with cellular characteristics of F necrophorum biovars A or B, and a connective tissue capsule. Of the 117 lesions without F necrophorum, 49 were culture-positive (for other organisms) and 69 were culture-negative. These 117 lesions were fibrous and were smaller than the 23 abscesses. A variety of gram-positive and gram-negative facultative anaerobic and obligate anaerobic bacteria was isolated from the culture-positive lesions, but always in low numbers. Eleven culture-negative and 18 culture-positive lesions were examined and had histologic characteristics of parasite-induced granulomas, with numerous eosinophils and epithelioid giant cells. Results of the study indicated that the histologic appearance of ovine hepatic lesions with F necrophorum was similar to bovine liver abscesses caused by F necrophorum, but unlike bovine liver abscesses, F necrophorum biovar B was isolated more frequently than was biovar A and often in pure culture. Most of the lesions in the condemned livers were parasite-induced granulomas.     

Detection of papillomaviral-like DNA sequences in premalignant and malignant perineal lesions of sheep.

Small hyperkeratotic and ulcerated lesions and clinical cancers were isolated from the perineal region of sheep and examined for evidence of papillomavirus infection by various criteria including gross morphology, histology, immunohistochemistry and DNA hybridisation. No specific diagnostic features of papillomaviral infection by immunohistochemistry were found, although some lesions showed gross morphological and histological features similar to papillomaviral effect in other species. DNA hybridisation analysis, using human papillomaviral type 11, 13, 16 and 18 DNA probes under conditions of reduced stringency (Tm-40 degrees C), detected homologous sequences in two thirds of the biopsies examined. These homologous sequences occurred in benign hyperkeratosis as well as invasive squamous cell carcinomas but were much more frequently isolated from carcinomas. This finding suggests that a papillomavirus is associated with the development of squamous cell carcinomas of the perineum of sheep.