JAAGSIEKTEJAAGSIEKTE

Presented By

SAYAR AHMAD BEIGH

OverviewIntroductionSynonmys Organism/AetiologyHistoryPathogenesisClinical SignsLesionsDiagnosis & TreatmentPrevention & Control

IntroductionJaagsiekte is a neoplastic disease of older sheep characterised by progressive afebrile course of several months or longer, coughing, panting, profuse watery nasal discharge and moist crackles.

The name jaagsiekte is derived from Africans in which it means "driving sickness/disease.

SynonymsOvine Pulmonary Adenoma .

Ovine Pulmonary

Adenomatosis .

Pulmonary Carcinoma Of Sheep .

HistoryFirst reported in Africa in 1865 .

First mammal successfully cloned

–Dolly was euthanised after it was

confirmed that she had

Jaagsiekte .

Aetiology

Type D Oncovirus (a retrovirus )

known as Jaagsiekte sheep

retrovirus (JSRV) .

Transmission Droplet infection from respiratory secretions .

Experimentally Jaagsiekte can be transmitted to susceptible sheep by intratracheal or intrapulmonary injection of affected lung tissue .

PathogenesisVirus replicates in type II pneumocytes in

alveoli and acutely transforms lung epithelium into cancerous cells .specifically type II pneumocytes and clara cells of lung are likely target for JSRV tranformation .

The tumour so formed exhibit overactive secretory fuctions which is hallmark of Jaagsiekte .

The adenomatous ingrowths of alveolar epithelium encroach gradually upon alveolar space resulting in noxic anoxia .

Clinical Signs The disease has long incubation period of 1-3

years &is most common at 3-4 years of age .Earliest signs include occasional coughing

and some panting after exercise .Weight loss , loss of appetite, respiratory

difficulty which is associated with obvious movement of abdomen and high pitched noises .

Fluid accumulates in respiratory tract and ultimately leads to death .

Lesions Macroscopic•Pronounced thickening of alveolar wall and papillary pattern .•Partial obliteration of the alveolar spaces by small adenocarcinomas .•Peribronchial lymph nodes are hyperplastic and markedly enlarged

MicroscopicMultiple foci of neoplastic type 2 alveolar cells in

acinar and pappilary pattern .A number of mononuclear cells and lymphocytes

fill the alveoli, and along with a few neutrophils , appears as exudates in some of the bronchi .

Adenomatous foci in bronchial and mediastinal lymph nodes similar to lung .

DiagnosisA common field assesment for Jaagsiekte is

"Wheelbarrow test'' in which hind legs of animal are lifted to observe lung exudate flowing out of nose and mouth containing JSRV .

Examination of lung secretions for JSRV .