Thiamine (Vitamin B1) is naturally produced in the rumen of the goat, by the rumen microorganisms. Thiamine deficiency, or Polioencephalomalacia, occurs when thiamine production is decreased in the rumen. More frequently found in goats kept under intensive management conditions, it results from changes in microbes resulting from diets that are high in energy without sufficient levels of fiber.
Goats with a properly functioning rumen do not require a dietary thiamine supplement.
Frequently seen in goats kept under more intensive management conditions, it most often occurs in 2 to 3-year-olds. Because immature kids do not have a functioning rumen, they are susceptible if they are not fed a thiamine enriched product such as Purina Kid Milk Replacer. Other possible causes include sudden feed changes, moldy hay, dietary weaning stress, deworming with anthelmintics, eating some types of ferns, and overdoses of some anticoccidial medications.
First signs include depression, anorexia and/or diarrhea which may appear suddenly or over a period of several days. Other signs include head elevation while standing, excitability, drowsiness, circling, muscular tremors and apparent loss of vision which causes goats to walk in circles. If symptoms occur, contact your veterinarian immediately. Rigidity and convulsions occur in later stages of the disease.
TREATMENT / PREVENTION
Adding thiamine to the diet is not a treatment for this condition. Because thiamine is destroyed in the rumen, it is not available to the goat. Therefore, if your goat shows any signs of thiamine deficiency, call your veterinarian immediately. Left untreated, goats will die within 24-72 hours of disease onset. Treatment may consist of thiamine therapy in combination with a lower energy diet and more good quality forage. Animals severely affected by the disease for more than 24 hours usually don’t respond to treatment.
As usual, the best cure for thiamine deficiency is prevention. Always feed your goats sufficient fiber, proper fiber to starch ratio — especially with concentrated feeds intended to stimulate rapid growth and increased production. Changes in diet should be made slowly, usually over 7-10 days, to give the rumen microbes time to adjust.