Vitamin B1 (Thiamine) Deficiency
Vitamin B1 (Thiamine) Deficiency is also called and cause Polioencephalomalacia and Cerebrocortical necrosis.
Etiology
- Primary: Diet deficiency
- Secondary: Thiaminase enzyme – Prevent utilization of thiamine.
- Thiaminase enzyme is produced in the rumen by Clastridium sporogenes and certain Bacillus sp.
- High dose of Amprolium for coccidian infection
- Molasses toxicity
Pathogenesis
- Young animals are more susceptible (lambs, kid, calf) especially 6-9 months of age than older animals.
- Usually required thiamine is absorbed from rumen micro flora.
- The free thiamine is readily absorbed and actively phosphorylated to thiamine pyrophosphate (TPP).
- The brain is critically dependent on carbohydrate for energy. Thiamine is an essential component of several enzyme (like TPP) used in glycolysis in the brain. TPP has a coenzyme role in decarboxylation of alpha ketoacid (pyruvate) for entry in to TCA cycle.
- Deficiency in the thiamine cause low TPP in the body which leads increased blood pyruvate level and decrease lactate: pyruvate ratio and depressed erythrocyte transketolase (ETK) activity. It interferes with normal carbohydrate metabolism which leads to cerebral cortical damage by oxidative damage. There by increased cerebral oxidative stress results inflammation followed by cerebral edema and necrosis cause increases intracranial pressure.
Clinical Signs
In early stage:
- Diarrhea
- Dull and isolate themselves from group
- Elevated head with staggering gait
- Blindness
- Bilateral absence of mance reflex ( but palpebral and PLR may be present)
- Hyperaesthesia to tactile and auditory stimuli
Disease progress:
- Frequent Bruxism
- Head pressing
- Twitching, Muscle termer
- Opisthotonus, nystagmus followed by recumbency and clonic convulsion with intermittent spastic and terminal flaccidity. If untreated death within 2-3 days
Diagnosis
- History and Clinical signs
- Elevated blood pyruvate and lactate level
- Increased Urine pyruvate concentration
- Reduced erythrocytetransketolase activity
- Increased Pyruvate kinase level
- Increased CPK
- Increased Thiaminase level in rumen liquor and feces (Thiaminase level may be normal
- in blood, RBCs and Plasma)
- Increased CSF pressure
Differential Diagnosis
- Listeriosis
- Lead poisoning
- Coenuriasis
- Molasses poisoning
- Amprolium toxicity
Treatment
- Thiamine Hydrochloride injection at 10mg/kg body weight repeated every 4-6 hours respond within 24 hours by IV followed by IM administration.
- Dexamethasone at 1 mg/kg body weight IV.
Prevention and Control
- Daily requirement of thiamine for mono gastric at 30-60 µg/kg.
- Addition of yeast, cereals, grains, liver and meat meal in the dietary ration provided thiamine.
- Provide adequate amount of roughage at 1.5 kg/100 kg body weight.
