3.2 Pathological observations:
Out of 66 clinical cases, 46 cattle (69.7%) showed generalized skin
nodules and papules of various sizes ranged from 0.5 cm to 6.5 cm
located all over the body particularly, neck, head, face, nose, tail,
perineum and udder (Fig. 1A). Twenty showed few small patchy
nodules at the neck region, lumbar and face region. The number of
nodules varied from few to more than a hundred based on the severity of
the disease. These subcutaneous nodules were round, circumscribed, firm
and raised above the skin and diffusely present on the body
(Fig. 1B) . In severe cases, these nodules were ruptured, and
whitish-grey serous fluid was oozing out of lesions. In few cases,
nodules at the vulva, perineum and hindquarters were ruptured leading to
ulcers and suppurative wounds (Fig. 1C) . The prescapular lymph
nodes were enlarged in nineteen cases (19/66, 38%). Edema of the
ventral body parts of the body (brisket edema) and legs was consistent
in some cases. Nasal and ocular discharge, conjunctivitis and salivation
were noticed in all the animals. Lameness was observed due to severe
edema and pustular lesions on the feet of affected animals (Fig.
1D) .
Microscopic lesions observed in the skin nodules includes hyperkeratosis
(46, 69.7%), diffuse granulomatous reaction in dermis and epidermis
(39, 59%) (Fig. 1E) , focal to diffuse vasculitis and
lymphangitis in dermis and epidermis (39, 59%) (Fig. 1F) ,
spongiosis (34, 51.5%), vacuolar degeneration of epithelial cells (15,
22.7%) and acanthosis (12, 18%) (Fig. 1G) . The inflammatory
cell types were mainly comprised of macrophages, neutrophils,
lymphocytes and eosinophils along with diffuse coagulative necrosis and
infarction in blood vessels in the dermis (15.1%) (Fig. 1H) .
The characteristic eosinophilic intracytoplasmic viral inclusions in
keratinocytes and epithelial cells were observed in 2 (3.03%) cases
which were a pathognomonic feature of LSDV infection (Table 3) .