Bluetongue, Biology

Bluetongue

Bluetongue (BT) is a non-contagious and arboviral disease of both domestic and wild ruminants. The disease is enzootic in areas where reservoirs (cattle and wild ruminants) and vectors exist for the BT virus (BTV). The disease in sheep is characterized by stomatitis, rhinitis, enteritis and lameness.

Clinical signs: Initially, the affected animals show high rise of body tempera­ture followed by excessive salivation, nasal discharge and reddening of buccal and nasal mucous membranes. Later on saliva and nasal discharge becomes blood mixed and there is bad smell from mouth. Lips, gums, dental pad and tongue are swollen. Purple coloured necrotic lesions are noticed on the lateral aspect of tongue resulting in difficulty in swallowing. Laminitis, coronitis, lameness, occasional diarrhoea, breaking of wool and rapid loss of condition are also noticed and younger animals die within one week. However, recovered animals suffer from convulsions, abortions, and cracking of hooves and skin.

Affected cows usually show rise in body temperature, stiffness, laminitis affecting all the four limbs, excessive salivation, edema of lips, inappetance, nasal discharge, and ulceration on tongue, dental pad and muzzle, and congenital abnormalities.

On postmortem examination reveals generalized edema, aspiratory pneumonia, hyperemia, haemorrhages, necrosis of skeletal and cardiac muscles, haemorrhages at the base of pulmonary artery and lesions on tongue.

Diagnosis: It is diagnosed by clinical sign and postmortem lesions in dead sheep. Blood examination reveals high activity of creatinine phosphokinase enzyme due to muscular degeneration. Disease can be confirmed by inoculating blood of suspected animal into unweaned white mice or hamster. Complement fixation or ELISA tests are also employed for its confirmatory diagnosis.

Treatment: There is no specific treatment for the disease but oral lesions can be washed with mild antiseptic solutions like 3% alum or weak KMnO4 solution. Lesions can be painted by 2% gentian violet to check secondary bacterial infection for which broad-spectrum antibiotics like streptopenicilin, tetracycline, erythromycin, ciprofloxacin or gentamycin may also be used.

Control: Adoption of strict hygienic and proper vector control measures can reduce the occurrence of disease. Prophylactic immunization of sheep against BT is the most practical and effective control measure to combat BT infection. At present, attenuated vaccines are used in the Republic of South Africa, the USA and other countries. However, EU countries were using attenuated vaccines, only recently shifting to inactivated vaccines owing to their safety and efficacy. In India, inactivated vaccines are in experimental stages and are expected to be on the market shortly. Inactivated vaccines generate serotype-specific long-lasting protective immunity after two injections, and may help in controlling epidemics. Attenuated live vaccines are efficacious but safety issues are of great concern. Recombinant vaccines, which generate cross-protection against multiple BTV serotypes, have great potential in BT vaccine regimens.

Posted Date: 9/20/2012 1:11:42 AM | Location : United States







Related Discussions:- Bluetongue, Assignment Help, Ask Question on Bluetongue, Get Answer, Expert's Help, Bluetongue Discussions

Write discussion on Bluetongue
Your posts are moderated
Related Questions
Discuss the refractive and response to wound functions of cornea. Refractive Function: Cornea, through its interaction with the tear film, forms a smooth refractive functi

classifying kingdom of organisms

How can we increase of total peripheral resistance?   A.  A decrease in the diameter of every arteriole.   B.  An increase of sympathetic discharge to all the smooth muscles

Honeybees are unusual in that male bees (drones) have only one copy of each gene, while female bees have two copies of their genes. That is because drones develop from eggs that ha

Explain saturated fatty acids Some of the more significant saturated fatty acids with their systematic and common names are listed in table, and some of the unsaturated fatty a

What is heterospermy?also give its significance?

List four possible after-effects of solvent abuse (glue-sniffing). Possible after-effects of solvent abuse are headache, nausea, vomiting, convulsions, runny nose, a rash round

An impermeable membrane separates one liter of a 0.01 M glucose solution in water in the left compartment from one liter of a 0.1 M glucose solution in water in the right compartme

ESR and CRP are elevated in almost all patients of arthritis and carditis and rarely in patients with chorea. ESR should be repeated periodically as it is useful in following the c

Define Sample Titration for Estimation of Vitamin c in Lemon Juice? Cut the lemon into two halves with a stainless steel knife. Remove the seeds. Squeeze the juice from half a