Polioencephalomalacia: Vit B1 deficiency in Angora Goats

Tuesday, 14th November 2017

Polioencephalomalacia (PEM) - caused by Vit B1 (Thiamine) deficiency simply literally means softening of the brain.

It is a disease that is seen more commonly in Angora kids grazing lucerne lands or fed concentrates especially if containing molasses.


Below photo Angora kids unable to stand or raise their hindquarters

Polioencephalomalacia on histopathologyThe disease can be seen under the following conditions:
  • Goat kids are very prone to thiamine deficiency as the rumen is not fully functional for the first year. Kids who have just begun consuming high concentrate rations or grazing lush pasture are most susceptible.
  • High levels of sulphates (Sulpher) in the diet such as goats grazing lucerne or concentrate diets that contain molasses.

Some water sources are also high in sulphur.

  • Any illness or condition that leads to a goat not eating can cause the rumen to function poorly, resulting in a drop in B vitamin production.
  • Any change in diet may also lead to rumen function issues as it takes the rumen 7 to 10 days to adapt to the diet change
  • Mouldy hay or feed also leads to poor rumen function
  • Deworming with levamisole may predispose the goats
  • Presence of thiaminase producing bacteria in the rumen such as clostridia (which is often associated with carbohydrate rich diets) will also result in reduced thiamine production.

How do goats get Vit B1 (Thiamine)? Do I need to supplement?

 B vitamins are not necessary supplements in the diet of a healthy goat. In fact, B vitamins are not obtained by ingestion of feeds at all. Goats manufacture B vitamins in the rumen through micro-organisms during the digestion process which they absorb. The bacteria in the rumen produce enough thiamine for an animal’s needs. However, under certain conditions thiamine production may decrease or available thiamine may be destroyed leading to a deficiency and the appearance of clinical signs.

Keep in mind the predisposing factors mentioned above as there may be times when you do need to supplement Vit B1.


What clinical signs can be seen?

  • Weak back legs
  • Staggering
  • Short choppy hindquarter gait
  • Depression
  • Aimless wandering
  • Able to raise front legs but not hind legs. Sits with front end raised as in photo above.
  • Grinding teeth
  • Head pressing
  • Star gazing
  • Muscle tremors
  • Circling
  • Blindness
  • Nystagmus – flickering of eye.
  • Collapse, unable to stand and death

Video of early clinical signs of Thiamine deficiency.  Note short choppy HQ gait and twitching tail

Video of more advance signs


The signs may be confused with the:

  • ‘Weak and hypothermic kid’ or
  • the ‘Floppy kid syndrome’

More information on these can be found on our website


  • Make sure you treat with Vit B1 (Thiamine) as the other Vit B’s will not help!
  • Vit B1 (thiamine) intramuscular injection (10 – 20 mg/kg body weight)  given every three hours for a total of five doses. Early cases respond within 6 to 8 hours with complete recovery in 24 hours. Goats not recovered by 72 hours will never fully recover.
  • A goat will not overdose on an injection of B vitamins. The excess is expelled through urination.
  • The administration of probiotics assists with proper micro-organism balance in the rumen.



The video below shows the effectiveness of Vitamin B treatment in an angora goat kid.



Dr Mackie Hobson (SAMGA vet)

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