Rinderpest
It is also known as cattle plague resulting in high fever, diarrhoea and high mortality rates. In year 2006, OIE has declared that India is free from rinerpaste infection and disease. This status could be achieved because of sustained effort though National Programme for Rinderpest Eradication (NPRE).
Etiology: It is caused by rinderpest virus (a morbillivirus) in cattle and buffaloes of any age group. The virus is excreted in the urine, faeces and nasal discharge of infected animal and transmission occurs through ingestion of contaminated feed or by inhalation. Sheep, goats and wild ruminants serve as reservoirs of the infection.
Pathogenesis: After gaining entry through inhalation, the organisms penetrate epithelium of upper respiratory tract and multiply in the regional lymphnodes. From there, organisms are disseminated to other lymph nodes, lungs and epithelial cells of mucous membranes, and destroy the lymphocytes and produce enteritis resulting in diarrhea.
Clinical signs: Initially, the affected animals reveal high rise of body temperature followed by anorexia, reduction in milk yield, lacrymation and rough hair coat. Nasal, oral and conjunctival mucous membranes are inflammed and vulva is swollen. At this stage, lacrymation and salivation are pronounced. Discrete necrotic lesions develop on the dorsum of tongue in the oral cavity which become extensive and coalesce later on to form pseudomembranes. When these are removed, raw reddened ulcers are left. Afterwards, the animals reveal severe diarrhoea or dysentery with tenesmus. Skin in perineum, scrotum, flank and inner aspect of thigh becomes moist and red. Abortions occur in pregnant animals whereas death occurs in affected animals in few days after onset of diarrhoea. In sheep and goat, similar symptoms of less intensity develop but spread of disease is slow.
The postmortem lesions are noticed in the mucosae of mouth, abomasum and small intestine. The oral mucosae are congested and lips and ventral surface of tongue have yellowish grey necrotic patches and erosive ulcers. Mucosa of abomasum is highly congested and has small flat caseous deposits and ulcers. Mucosa of colon has transverse zones of haemorrhage and erythema giving "zebra strips".
D ia g no s is : It is diagnosed by clinical sign, postmortem findings and histopathological lesions in dead animals. Blood examination reveals lymphopenia and leukopenia. It is confirmed by serological tests like agar gel precipitation, counter immunoelectrophoresis, complement fixation, immunofluorescence and haemagglutination tests.
The disease should be differentiated from FMD. Diarrhoea is not seen in FMD and lesions are seen feet. In haemorrhagic septicaemia, swellings are seen around neck and there is dyspnoea. Bovine malignant catarrhal fever has eye lesions and nervous signs and bovine viral diarrhoea occurs sporadically with low mortality rate.
Treatm ent: T here is no specific treatment and symptomatic treatment is administered. However, the fluid lost during diarrhoea should be replaced by saline or lactated ringers solution intravenously.
Control: Virus cannot survive outside the host for a long period and various strains of virus have the same immunological identity. The tissue culture vaccine given @ 1 ml/dose subcutaneously provides immunity for long period. Wild ruminants which serve as reservoir should not be allowed to come in contact of domestic animals for proper control of the disease. Separation of sheep and goat from cows and buffaloes is also important in preventing the disease.