PhD

A study on polio encephalomalacia in goats was conducted in the
department of Clinical Medicine College of Veterinary and Animal Sciences
during the period 1999 to 2002. The occurrence of the disease in Kerala was
studied. The study revealed that the disease was reported throughout Kerala with
maximum occurrence in the post-monsoon period. The disease was prevalent in
all the age groups. Feeding of carbohydrate rich diet was one of the probable
predisposing causesfor the development ofPEM.
Six apparently healthy goats maintained under identical conditions were
utilized for recording normal values. Twenty one confirmed cases of PEM were
equally divided into three groups at random. Detailed clinical examination,
sampling and analysis of rumen liquor and blood were done before initiation of
therapy, 48 and 96 h of study. Therapeutic management of group 1 was by
administering thiamine hydrochloride for four days @ 50 mg/kg body weight.
(half of the dose intravenously and the other half intra muscularly) whereas in
group 11 and III it was supported with oral administration of 500 mg
oxytetracycline/animal once (on the day of admission) and 1 gm of thiamine
hydrochloride / animal once (on the day of admission) respectively.
The characteristic clinical signs were head tilt, lateral deviation of head,
nystagmus. circling, staggering gait, pressing of head and lying only on one side.
All the symptoms mentioned above were not present in all the animals. Rumen
liquor study did not reveal any significant change in pH, physical characters, total
volatile fatty acids, copper, cobalt and sulphate levels. Rumen liquor thiamine
level was significantly low on the day of admission in all the groups, but became
normal by 48 h in group III and by 96 h in other groups.
Normal level 'of serum copper, cobalt, magnesium and sulphate confirmed
that these electrolytes were not involved in the etiopathogenesis of PEM in
Kerala. Significant increase in glucose, lactate, and pyruvate levels were observed
on the first day in all the diseased animals. The values decreased steadily after the

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initiation of the treatment and the decrease was more marked in group Ill.
Decrea?ed level of serum thiamine, TK value with increase in per cent TPP effect
were observed at zero hour in all the groups and were comparable to normal value
after 48 h of treatment.
Two severely affected animals were utilized for the post-mortem studies.
Brain on gross examination showed extensive meningeal congestion. Whole brain
was soft, swollen with yellowish discolouration of cerebral grey matter.
Histopathology of the brain of succumbed goats revealed necrosis of neurons of
the pyramidal and fusiform cell layers of cerebral cortex with neuronophagia,
satellitosis, perivascular edema, perivascular cuffing and neovascularisation of
grey matter in certain gyri.
Ultrastructural lesions were characterized by neuronal swelling, membrane
lysis, condensation of component of nucleolus, neuropil spongiosis, spiltting and
ballooning of myelin at the intra-period line.
All the animals responded to the treatments adopted. More than 50 per
cent of the animals in group III recovered by third day of treatment when
compared to 14.28 per cent in group Il and none in group I.
Therefore oral administration of 1 g of thiamine once on the day of
admission along with parentral thiamine @ 50 mglkg body weight is
recommended for efficient and speedy recovery.