Sheep - AgRIS

weight. Hyperimmune serum is similarly effective. Vaccination of sheep with Haemorrhagic
septicaomia adjuvant vaccine is recommended. The dose of the vaccine is 3 ml
intramuscularly. The vaccine is expected to give protection against disease for a period of one
year. A slight swelling may occur at the site of inoculation and a slight rise in temperature
which may persist for 2-3 days. The animals should not be sent out for grazing for 2 to 3 days
following vaccination.
v) Paratuberculosis : (Jonhe’s Disease)
Paratuberculosis is a chronic wasting disease,Characterised by progressive emaciation and
a thickening and corrugation of the wall of the intestine. The morbidity rate is difficult to
estimate because of uncertainty of dioagnosis but the animal mortality rate in infected flocks
may be as high as 10 percent. The disease may cause severe economic embarrassment in
infected flocks. The reclamation value of clinically affected animals is usually negligible
because of severe emaciation. The causative organism is Mybacterium paratuberculosis, an
acid fast organism. The progress of the disease is always slow. For this reason, it is most often
observed in older animals. The incubation period may be as much as a year. Progressive loss
of weight results in extreme emaciation, Lesions include thickining of intestinal mucosa,
enlargement of lymph nodes. Diognosis is made on the isolation of organism. Infected sheep
react to intradermal injection of Johnin which is useful as an aid in diagnosis of clinical
shedders. A complement fixation test has also been used as a diagnostic tool. No treatment is
successful Vaccine from iceland may be of great value.
vi) Sheep Pox
Sheep Pox is highly contagious. Although in most cases spread appears to occur by contact
with infected animals and contaminated articles, spread by inhalation may also occur. It is
characterised by development of vesicles and pustules on the skin and internal lesions. It is the
most serious of all the pox diseases in animals, often causing death in 50% of affected animals.
Major losses may occur in each new crop of lambs.
The etiological agent is a filterable virus. The virus is quite resistant, having been known
to remain viable for 2 years in sealed tubes. The incubation period is of 2 to 14 days. In lambs
the malignant form is quite common. There is high rise of fever, eyelids are swollen,
discharge from the eyes and nose. anorexia, by the second day eruption appears. There is a
formation of papules with a depressed centre later vesicles develop and finally pustules. These
may develop on the wooly and on non wooled areas. The pustules become dry with the
course of time and fall off, excessive salivation occurs due the lesions in the mouth. There is a
fluctuation in the temperature due to invasion of the pustules by secondary organisms. The
course of the disease is 3 to 4 weeks, during which time the sheep become emaciated and may
shed their wool. In fatal cases, death occurs in about 1 week after the first sysmtoms appear.
In the malignant form pox lesions extend into mouth, pharynx, larynx and vagina. Lesions may
also appear in the trachea with an accompanying Catarrh & Pneumonia. Lesions occassionally
reach the abomasum and are accompained by a haemorrhagic enteritis. The disease can be
diagnosed on the clinical picture and with immunodiffusion technique. Vaccination at the
proper time is the best control.
vii) Foot and Mouth disease
It is an extremely contagious acute disease by a virus. It is characterised by the
development of vesicles in the oral cavity and in the interdigital space. The mortality is usually
low (3%). The economic loss is chiefly due to loss of condition of the affected animal. When
the disease breaks out in susceptible animal, it spread very rapidly. There are seven
immunologically distinct types of foot and mouth disease virus. Type O,A and C. widely
distrubuted, and found in Europe and South America. Type S,A.T. 1, 2 and 3 are found only in
Africa and Type Asia I is widely distributed in Asia. The disease is transmitted by contact with
diseased animal. The incubation period is short and less than 24 hours. There is high rise of
temperature with acute painful stomatitis. Affected sheep show only small lesions in the mouth
but all four feet may be badly affected with severe lameness. The field diagnosis of disease in
sheep is based on the presence of vesicular lesions on the mucosa of the mouth and on the skin
of the interdigital area of the feet. The lesions are found in the mouth, pharynx, oesophagus
and forestomach. Antibiotics are recommended to check the secondary infection. As a
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