Bluetongue Disease in Sheep and Goats:
About this disease
- This is acute infectious but not contagious disease of sheep characterized by fever, inflammation and ulceration of buccal mucosa and tongue.
- This disease mostly affects sheep and goat and cattle are very rarely affected.
- Blue tongue is endemic in India.
- It is basically a disease of sheep and young sheep within the age group of one year are more prone to infection.
- Suckling lambs are relatively resistant due to their acquired passive immunity through colostrum.
- The disease occurs mainly during the rainy season particularly in the months of October, November and December.
What Causes Bluetongue Disease?
- It is caused by Arthropod-borne orbi virus in the family of Reoviridae.
- Biting insect of the genus of the Culicoides transmits the virus during the rainy season while blood sucking.
- Mosquitoes and other ectoparasites like sheep ked, Melophagus ovinusmay transmit the disease mechanically.
- The disease is more prevalent in late summer and early autumn which makes conducive environment for the multiplication of the vectors.
- Transmission through semen and placental route is possible.
- The virus is resistant to decomposition, desiccation and against antiseptic agents.
What are the symptoms of BT ?
- Depressed attitude and off feed.
- Reddening and swelling of nose and oral mucosa,
- Profuse nasal and oral discharge,
- Inflammation and ulceration of lips, gums, buccal mucosa and tongue,
- Cyanotic (bluish) appearance of tongue,
- Tilting of neck towards one side (wry neck)
- Lameness, reddening and swelling of coronary band of the limbs.
- Congestion of conjunctival mucous membranes and matting of eyelids,
- Foul smelling diarrhoea.
- Dyspnoea, snoring and Pneumonia may be observed.
- Death due to respiratory failure.
First aid for Bluetongue Disease in Sheep and Goats:-
- Separation of sick animals should be made.
- Affected animals should be kept away from solar exposure.
- Adequate rest to the affected animal.
- Affected animals should be fed with porridge made of rice, ragi and kambu.
- Apply glycerin or animal fat on the ulcers.
- Immediate consultation should be made to the nearest qualified veterinary doctor for treatment.
- Animals should not be allowed for grazing.
- Ulcers in the mouth can be treated with saline water or dissolve 1g of
Potassium permanganate in 1 liter of water and wash the mouth 2 to 3 times a day with this solution.
- Contact your nearest Veterinary Assistant Surgeons for further advice regarding the antibiotic administration or symptomatic treatment to be given to the affected sheep.
- Contact nearest Veterinary Assistant Surgeons for ring vaccination in the event of outbreak of disease.
General prevention and control measures
- Proper Vaccination of animals with regular intervals.
- Vaccination schedule:
First vaccination at
Next vaccination at
Month of vaccination
3 months of age
Once in a year
- Attempt should be made to control the vector (culicoides) population with fly repellants.
- Use of ectoparasiticides injections should be suggested in the areas more prone to vector population.
- Grazing of the animals should be avoided in areas where there is lot of vectors.
- Cattle may act as carrier. Viraemic stage remains in them for more than 5 weeks. So movements of cattle should be restricted.
- Importation of animals from the areas prevailing the disease should be avoided.
- Strict regulation is to be followed to prevent entry of diseased animals from endemic zones.
- The spread of the disease can be controlled by the use of insect repellents, external application of fly repellents and spraying of butox (1ml in 1 liter of water) in the breeding places of the insects.
- The sheep can be housed in insect proof sheds.
- Cloud of smoke with dried leaves / wood during 6 – 8 P.M. might help to keep off Culicoides from sheep sheds.
Courtesy By Tamil Nadu Agricultural University @ www.agritech.tnau.ac.in/