Prevalence of dental and mandibular disorders in culled sheep in Spain.

At the slaughterhouse, 1465 culled sheep heads were studied in order to identify disorders of the mandibular cheek teeth. Of these, 227 (15.5%) had evidence of osteomyelitis. The lesional profile showed that the mandible was affected in a similar proportion on both sides (46.7% on the right side vs 50.7% on the left side), mainly in the middle region (55.3%) and with most of the lesions closed without fistulisation (89.4%). In addition, swelling was palpable, with an increase in thickness in the area of the affected body (2.65 ± 0.065 cm vs 1.74 ± 0.030 cm). In 78.6% of the animals, the regional lymph nodes were enlarged. Concerning the mandibular cheek teeth, more than half of the animals lacked at least one tooth (57.0%), with the first premolar being the most frequently missing tooth (34.8%) and the third molar the least (8.2%). The impaction of food around the teeth was very common with the posterior molars being more frequently affected. In the knowledge of the authors, this is the first study that analyses the prevalence of mandibular molar and premolar disorders in sheep, and these are revealed as an important condition affecting culled sheep.

Jaagsiekte Sheep Retrovirus Can Reach Peyer's Patches and Mesenteric Lymph Nodes of Lambs Nursed by Infected Mothers.

Ovine pulmonary adenocarcinoma (OPA) is a contagious lung cancer of sheep caused by jaagsiekte sheep retrovirus (JSRV). It is generally accepted that transmission by the respiratory route occurs under natural conditions. However recent studies strongly indicate that JSRV can also be transmitted to lambs perinatally via colostrum and milk (C/M). The aim of this work was to confirm that C/M can transmit JSRV infection to lambs under natural conditions and investigate the initial events associated with this transmission route. We have analyzed the presence of JSRV in C/M samples from 22 naturally infected, asymptomatic ewes throughout a lactation period, and in various tissues collected from a group of 36 of their lambs that were fed naturally. The lambs were euthanized at 12, 24, 48, and 72 hours and at 5 and 10 days after birth. We detected JSRV-provirus by PCR in the somatic C/M cells from 10/22 ewes (45.45%). The virus was also detected in 9/36 lambs (25%). JSRV-infected cells, with lymphoreticular-like morphology, were observed by immunohistochemistry (IHC) and in situ hybridization (ISH) in Peyer's patches (PP) from the small intestine of the youngest lambs and in mesenteric lymph nodes (MLN) from lambs older than 72 hours. The virus was also detected by PCR in white blood cells (WBC) in 2/36 lambs (5.5%). These results confirm colostral transmission of JSRV to lambs under natural conditions. Infected lymphoreticular cells contained in C/M appear to be involved. These cells can cross the intestinal barrier of newborn lambs, reach the MLN and enter into circulation.

Solitary tumours associated with Jaagsiekte retrovirus in sheep are heterogeneous and contain cells expressing markers identifying progenitor cells in lung repair.

Ovine pulmonary adenocarcinoma (OPA) is a naturally occurring lung cancer of sheep caused by jaagsiekte sheep retrovirus (JSRV). This study examines immunohistochemically solitary lung nodules considered as early OPA lesions from 11 sheep infected naturally by JSRV. All 11 neoplastic nodules exhibited features of adenocarcinoma and in four of them mesenchymal growth was also observed. Both types of lesion were labelled with antibody specific for JSRV-Env. In two cases infiltrating lymphoreticular cells also contained JSRV-Env. All tumours had a high Ki67 labelling index and variably contained cells expressing CC10 (a marker of Clara cells (CCs)), SPC (a marker of type II pneumocytes), p63 and keratin 14 (markers for stem/progenitor cells of the lung airway epithelia). Tumours with mesenchymal growth had intense expression of vimentin and desmin, weak expression of smooth muscle actin and did not express pancytokeratin and p63. Both epithelial and mesenchymal proliferations did not express the stem cell markers CD90 and CD117, but some tumour infiltrating cells expressed CD133. Solitary OPA tumours can therefore be adenocarcinomas or mixed tumours and have a heterogeneous cellular composition, containing groups of cells expressing markers that characterize local progenitor cells involved in lung repair.

Chronic proliferative rhinitis associated with Salmonella enterica subspecies diarizonae serovar 61:k:1, 5, (7) in sheep in Spain.

A chronic proliferative rhinitis in sheep associated with Salmonella enterica subspecies diarizonae serovar 61:k:1, 5, (7) is described. Ten adult sheep from eight traditionally managed Rasa Aragonesa flocks located in Aragon (Spain) were studied. Clinical signs began with bilateral thick mucus nasal discharge, wheezing and snoring and progressed to partial or complete obstruction of the nostrils. Necropsy examination revealed swollen ventral nasal turbinates with a roughened mucosal surface partially covered by small polyps. Histopathology revealed chronic proliferative rhinitis with a predominant population of neutrophils that infiltrated the mucosal epithelium. Plasma cells and macrophages were present in the lamina propria. Organisms expressing Salmonella antigen immunohistochemically were detected within epithelial cells. Salmonella enterica subspecies diarizonae serovar 61:k:1, 5, (7) was isolated as a sole microorganism from nasal swabs taken from five animals. The implication of finding this bacterium in various diseases in sheep and its role as a potential zoonosis are discussed.