Enzootic nasal adenocarcinoma in a dairy sheep flock

In a herd of dairy sheep several losses occurred due to a respiratory syndrome in combination with progressive wasting. Clinical and pathomorphological diagnostics of 3 sheep revealed the presence of cancerous masses in the nasal cavities. These neoplasms were identified as adenocarcinomas originating from the nasal mucosa. Etiologically, they were attributed to JRSV (Jaagsiekte Sheep Retrovirus) by detection of capsid protein 24 in western blot. The significance of the disease in Switzerland is discussed, also in the context of lung adenomatosis.     

Pregnancy toxemia in a flock of sheep

A high prevalence of metabolic disease was evident in a large flock of sheep early in the lambing season. Pregnancy toxemia and secondary hypocalcemia were diagnosed on the basis of history, physical examination findings, and results of serum biochemical analyses. To decrease costs to the owner, pooled serum samples were used to determine the metabolic health status of the flock. Ewes close to the time of lambing were found to be in severe negative energy balance, which resulted in excessive fat mobilization as well as clinical signs associated with pregnancy toxemia and hepatic lipidosis. By nutrient analysis, it was determined that the ewes had an inadequate amount of fermentable carbohydrates, which provide glucose to support the additional nutrition required during late gestation. The diet provided to sheep during late gestation should contain sufficient glucose precursors to maintain adequate glucose availability to maternal and fetal tissues. To minimize the physiologic decline in dry-matter intake during late gestation (which results in accentuation of negative energy balance), high-quality feed ingredients should be fed to ewes during this period.     

Aldicarb toxicosis in a flock of sheep.

Aldicarb toxicosis was diagnosed in 200 sheep that died suddenly. Carbamate insecticide toxicosis was suspected based on observed clinical signs (hypersalivation, diarrhea, urination, paddling, seizures, miosis, and deaths occurring within 1 hour). Tissue samples were submitted from 4 Columbian ewes for pathologic and analytical evaluation. Severe diffuse pulmonary edema was observed on gross and histologic examination. Inhibition of cholinesterase activity in retina (21.2-68.1% of normal activity, n = 3), brain (40.6-45.6% of normal activity, n = 3), and whole blood (27% of normal activity, n = 1) supported a diagnosis of carbamate toxicosis. Reversal of brain and whole blood cholinesterase activities (reactivation factor greater than 1.4) following an in vitro 1 hour incubation at 37 C was also consistent with carbamate poisoning. Aldicarb toxicosis was confirmed following its detection in rumen contents at 1.5, 5.5, and 334 ppm using both high-pressure liquid chromatography with UV detection and gas chromatography with nitrogen/phosphorus detection.     

Enzootic pneumonia of sheep in New Zealand

Extract

Enzootic pneumonia of sheep is a specific condition confined to southern Otago and the Southland district and is commonly referred to as “Southland Pneumonia.” It has been recognized as a distinct clinical entity for many years in that area, heavy losses being reported in the Gore district of Southland in 1924.     

Enzootic nasal adenocarcinoma of sheep in Slovenia

SUMMARY Clinicopathological and electron microscopical findings of eight cases of enzootic nasal adenocarcinoma of sheep, diagnosed solely in one big flock in Slovenia between years 2001 and 2003 are described. All affected sheep were female, their mean age was 4.5 +/- 1.5 years and they either belonged to the Istrian pramenka breed (five sheep) or were crossbreeds (three sheep). Tumours that arose from the ethmoid area of the nasal cavity were unilateral in six cases (75%) and bilateral in two cases (25%). All tumours were classified as adenocarcinomas by histopathological examination and they displayed either a combination of tubular and papillary growth or less often solely tubular proliferation. No metastases were detected in regional lymph nodes, brain or other organs. Electron microscopical studies performed on the reprocessed paraffin-embedded tissues revealed the presence of the virus-like particles with an average diameter between 70 and 90 nm.     

Enzootic nasal adenocarcinoma of sheep in Canada

A survey of veterinary diagnostic laboratories revealed that intranasal tumors occur in sheep in most provinces of Canada. Tumors were diagnosed in 44 sheep of several breeds including Polled Dorset, Suffolk, Cheviot, Rambouillet and various crossbreeds. Twenty-seven percent of tumors occurred in sheep that were less than two years old. Most tumors were sporadic but 33% of cases occurred in six related flocks, indicating that this disease can be an enzootic problem. The clinical signs were persistent serous, mucous or mucopurulent nasal discharge and stridor. Affected sheep progressively developed anorexia, dyspnea and mouth breathing and most died from effects of asphyxia and inanition within 90 days of the onset of clinical signs. Tumors originated unilaterally or occasionally bilaterally in the olfactory mucosa of the ethmoid turbinates. They were expansive and sometimes locally invasive but metastases were not found. Histologically, the tumors were classified as adenomas or, more frequently, adenocarcinomas. The etiology was not established but retrovirus like particles were observed in tumor tissue from one affected sheep.