Page 808 - The Veterinary Care of the Horse

off or removed. The dried, dead leaves and twigs are just as poisonous as the fresh plant so

they should be disposed of carefully.
VetBooks.ir Oak and acorns (Quercus spp.)

Oak leaves and acorns contain tannic acid which is poisonous to horses. Poisoning may occur

in the spring when the young leaves are eaten or due to the ingestion of acorns in the autumn.
Acorns can be addictive; some horses will actively search for them once they have acquired

the taste. Small amounts do not usually cause problems but some horses have a greater
tolerance to oak leaves and acorns than others. When it occurs, oak poisoning causes
gastroenteritis. Gastric impactions also occur. In severe cases, death is caused by kidney

failure.

CLINICAL SIGNS

These include:

• depression

• loss of appetite
• mouth ulcers

• abdominal pain (colic)

• constipation followed by diarrhoea which may contain blood

• blood in the urine

• weakness
• incoordination

• kidney damage and death.

TREATMENT

There is no antidote. The horse is treated with medication to reduce the pain and control the
diarrhoea. Fluid therapy and antibiotics may be prescribed.

PREVENTION

Fence off oak trees – either permanently or with an electric fence.

Pick up the fallen acorns daily.

How many acorns is it safe for my horse to eat?

Individual animals have different levels of tolerance. It is therefore not possible to say how