Sheep - AgRIS

17. Diseases and their Control
Morbidity and mortality are the two important factors resulting in heavy losses in sheep
production and improvement programmes. Prevention is always better than cure as it is a lot
cheaper. This has a special significance with sheep as they seem to respond less to treatment
when sick than other livestock species. Disease is sheep can be broadly categorised as non -
infectious and infectious.
17.1 Non-Infectious Diseases
80.2 per cent deaths in lamb carcasses have been estimated due to non-infectious causes.
Starvation primarily from mis-mothering and behaviour, nutritional and environmental stress,
reproductive problems and predation are the major causes reported.
1) Pneumonia
It is one of the most common and important pathological conditions in sheep. It is
characterised clinically by increased respiration, coughing and abdominal breathing. A toll of
20-40 per cent of the mortality at central Sheep & Wool Research Institute, Avikanagar have
been due to this conditions, although mainly due to bacterial or viral causes but occasionally
one can come across with ―aspiration‖ or ―drenching‖ pneumonia during mass drenching
operation. The best remedy is to aviod force drenching and allow the animal to deglutinate the
drench itself. If some fluid has entered in respiratory tract, lower the animal‘s head
immediately and slap few times on its head.
2) Ruminal tympany
―Bloat‖ or over-distension of left flank either due to gas alone or with froth. This is also
generally encountered in ―greedy feeders‖ either when lush pasture is available or in farms
where concentrate feed is offfered. Tying a ―stick‖ in the mouth as a bit is most practical and
can be done immediately. Oral administration of sweet oil with turpentine oil or at times with
formaline is advised.
3) Acute Impaction of the Rumen
The ingestion of large amounts of highly fermentable carbohydrate feeds causes an acute
illness due to the excess production of lactic acid in the rumen. Clinically the disease is
manifested by dehydration, blindness, recumbency, complete ruminal stasis and a high
mortality rate.
Antihistamine such as Avil, Normal saline solution 500 ml. I/V,sodaabicarbonate 4 gms.
orally is advised.
4) Intussusception
It is a common occurence in sheep due to several reasons such as nodular worms, change
in feed and local intestinal problems.
The animal look dull, off feed, kicking at the belly with no rise of temperature and frequent
straining with no defecation, an excitment with symptoms of colic at later stages and the
animals become recumbent and dies.No rational treatment except surgery is possible. Mild
purgatives with astringants may be of little avail.
5) Deficiency diseases
Young sheep grazing on drought stricken pasture can suffer serious depletion of reserves
of the minerals and vitamins. In adult sheep on a deficient diet for few months before hepatic
stores are depleted and disease becomes evident. Copper and cobalt deficiency in sheep are
characterised by anorexia and wasting. Growth and wool production are severaly retarded.
Wool may be tender or broken. Fine wool becomes limp and glossy and loses crimp
developing straight steely appearance. Anaemic, diarrhoea and unthriftiness occurs in
conditions of extreme cases. Required dosage of copper or cobalt sulphate treatment causes
rapid disappearance of the symptoms.
i) Diseases caused by the deficiency of Phosphorus, Calcium and Vitamin D
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