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Powerpoint presentation about PEM in goats for Undergraduate BVSc students
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POLIOENCEPHALOMALACIA
Dr. UMESH C G,Assistant Professor,
Department of Veterinary Clinical Medicine, Ethics and Jurisprudence,
College of Veterinary and Animal Sciences, Pookode,
Wayanad, Kerala
Affects cattle, sheep, and goats. Affect an individual or appear as a herd problem
Affecting calves ages 6-12 months and lambs and kids ages 2-6 months.
Less common in adults, and it is more sporadic in small ruminants.
Etiology.
Thiamine deficiency Decreased thiamine synthesis Increased thiamine destruction by thiaminase
Bracken fern, horsetail Rumen microbial destruction of thiamine
Bacillus thiaminolyricus or Clostridium sporogenes Thiamine antimetabolites
Amprolium
Predisposing factors.
Feeding high concentrate, low-roughage diets High-sulfate dietary or water sources. Major management changes in feeding
Pathogenesis
Neccessary for the production of erythrocyte transketolase enzyme
Increase in blood pyruvate and suppression of pentose phosphate pathway
Reduction of –CHO metabolism of cerebral cortex and ATP production
Intracellular oedema Degeneration and necrosis
Clinical finding
Cortical blindness (i.e., absent menace with intact palpebral and papillary light reflex) occurs early in the course of disease.
Dorsomedial strabismus and nystagmus are also common findings with PEM.
Clinical signs
Other neurologic signs Incoordination Aimless walking Circling Muscle tremors Head pressing Convulsions and depression Hyperexcitability leading to recumbency, Opisthotonus, and paddling with extensor rigidity.
Clinical signs
Vital signs can be normal or elevated because of exertion.
The rumen usually remains active
Clinical pathology
Low blood thiamine (Normal range:75-180 nmol/L; below 50 nmol/L
chance of PEM)
Decreased erythrocyte transketolase activity.
CSF analysis The protein level can be normal to highly elevated
Pleocytosis.
The CSF pressure is increased to 200-350 mm of saline (normal pressure is 120-160 mm saline).
Necropsy findings
Diffuse cerebral edema with compression
Yellow discoloration of the dorsal cortical gyri
Laminar necrosis of cerebrocortical grey matter.
Autofluorescence of a freshly cut surface of brain cortex when placed under ultraviolet light
Laminar necrosis
Gyral contraction
Autofluorescence of a freshly cut surface of brain cortex
Differential diagnoses.
Lead toxicity Pregnancy toxemia in sheep Nervous ketosis in dairy cattle.
Therapeutic plan
Thiamine 10 mg/kg intravenously early in the course of clinical
signs. Followed by intramuscular or subcutaneous dosing
every 3 hours for 5 treatments.
Treatment
Corticosteroids, mannitol, or DMSO may be indicated for animals with possible cerebral edema.
Tranquilizers Supportive care: Soft, dry bedding while recumbent and
parenteral or oral fluid administration. Diet: Only roughage for several days before being
reintroduced to concentrates. Euthanasia. If no response to treatment is seen within 3 days
Prevention.
Thiamine can be added @ 3mg/kg DM of the feed.
If the diets associated with thiamine inadequacy 5-10 mg/kg DM of thiamin can be added.
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