This is when food material causes a blockage in the intestines or, in some case, the stomach. This often occurs when horses suddenly move onto drier food, e.g. when they become stabled for the winter or placed on box rest.
Pelvic flexure impaction
The pelvic flexure is a sharp bend in the large intestine and is the most common site for impactions due to the narrowing of the large intestine.
Signs
Affected animals will usually have mild colic signs with a normal heart rate and mucous membrane colour. There may be a reduction in the volume of the gut sounds and the number of droppings (these may also be firmer). The impaction is diagnosed by palpating it on rectal exam.
Treatment
Horses should be starved until the impaction has cleared and given plenty of water. The vet will pass a stomach to give large volumes of fluid to soften the impaction, laxatives such as liquid paraffin can be included (this often has to repeated). Pain killers are used to keep the horse settled. In persistent cases intra-venous fluids are also given.
Caecal impaction
Impaction of the caecum can occur after a general anaesthetic or exercise has been reduced suddenly.
Signs
Affected animals will usually have mild to moderate colic signs with a normal heart rate and mucous membrane colour. There may be a reduction in the volume of the gut sounds and the number of droppings (these may also be firmer). The impaction is diagnosed by palpating it on rectal exam.
Treatment
Horses should be starved until the impaction has cleared and given plenty of water. The vet will pass a stomach to give large volumes of fluid to soften the impaction, laxatives such as liquid paraffin can be included (this often has to repeated). Pain killers are used to keep the horse settled. Intra-venous fluids are given routinely and drugs to help increase gut motility are often used. Surgery must be performed if the impaction is not responding to treatment as there is a risk of the caecum rupturing. If this occurs the animal must be put to sleep immediately.
Small colon impaction
A small colon impaction can be seen following salmonella infection.
Signs
Affected animals will usually have mild colic signs with a normal heart rate and mucous membrane colour. There may be a reduction in the volume of the gut sounds and the number of droppings (these may also be firmer). The impaction is diagnosed by palpating it on rectal exam.
Treatment
Horses should be starved until the impaction has cleared and given plenty of water. The vet will pass a stomach to give large volumes of fluid to soften the impaction, laxatives such as liquid paraffin can be included (this often has to repeated). Pain killers are used to keep the horse settled. In persistent cases intra-venous fluids are also given.
Stomach impaction
A stomach impaction can occur after eating a large amount of straw or unsoaked sugar beet.
Signs
Affected animals will usually have mild to moderate colic signs with a normal heart rate and mucous membrane colour. There may be a reduction in the volume of the gut sounds and the number of droppings (these may also be firmer). Diagnosis is made by visualising the impaction using an endoscope.
Treatment
Horses should be starved until the impaction has cleared and given plenty of water. The vet will pass a stomach to give large volumes of fluid to soften the impaction, laxatives such as liquid paraffin can be included (this often has to repeated). Pain killers are used to keep the horse settled. Intra-venous fluids are given routinely and drugs to help increase gut motility are often used. Surgery must be performed if the impaction is not responding to treatment as there is a risk of the caecum rupturing. If this occurs the animal must be put to sleep immediately.