Constipation

Constipation in Cats

What is constipation?
Constipation can be defined as an abnormal accumulation of faeces resulting in a difficulty in passing motions. This may result in reduced frequency or absence of defecation, and/or excessive straining to defecate. The faeces are retained in the large intestine which is called the colon. Since one of the functions of this part of the bowel is water absorption, the retained faeces become hard and dry which makes passage of these even more difficult. Constipated cats strain in an attempt to defecate and this is often painful. Paradoxically, some constipated cats may pass small amounts of liquid faeces. Constipation is a condition seen most commonly in middle-aged and older cats.

What causes constipation?

Factors associated with causing constipation include:-

	Excessive hair in the stool, especially in long-haired cats, and cats with flea allergy.
	Ingestion of foreign bodies.
	Obstruction caused by tumours, strictures or masses compressing the large intestine.
	Pelvic injuries, most commonly after a road accident, resulting in a narrowed pelvic canal.
	Damage of the nerves which cause the colon to contract. This may arise following traumatic damage such as a road accident or may be seen as part of a more generalised neurological disease.
	In some cases, there is no obvious cause identified.

What is megacolon?
This term refers to a dilated and poorly mobile colon. Megacolon may be seen as a primary entity or arise following long-term constipation. When the colon becomes distended with faecal material over a prolonged period of time its ability to contract may be reduced or lost resulting in megacolon.

How are constipation and megacolon diagnosed?
In most cases, a diagnosis of constipation can be made on the basis of the clinical signs that the cat is showing. Affected cats usually strain unsuccessfully to defecate and may cry in pain when doing this. Any faeces passed are hard and dry. The cat may also show signs of lethargy, reluctance to eat and vomiting.

Further tests may be needed in order to diagnose the cause of the constipation and these may include x-rays of the abdomen and pelvis in order to look for pelvic injuries, colonic strictures or tumours. X-rays are also required for the diagnosis of megacolon.

How can constipation and megacolon be treated?
This varies depending on the cause of the problem. If an obstruction is present, such as a colonic tumour, surgical treatment may be required.

Initial treatment of a cat with constipation may involve administration of enemas and manual extraction of faeces by a veterinary surgeon. The latter of these may necessitate an anaesthetic or sedative. Treatment of dehydration with intravenous fluids may also be needed in severely affected cats. If the constipation recurs or becomes a long-term problem then continuous therapy may be needed to prevent recurrence. A wide variety of treatments are available and the aims of these are to enable regular defecation of soft faeces. Altering the diet so that this contains more fibre (e.g. Metamucil) may be helpful and lubricating laxatives or stool softeners may also be used in mildly affected cats. Those more severely affected may need drugs that stimulate contraction of the colon. The doses of all of these drugs may need to be altered to produce the desired effect. Ideally, cats should defecate at least once every other day. (Most normal cats defecate once or twice a day depending on their diet.) Over a period of time, resistance to the treatment may be found necessitating an increase in the drug dosage or a change to another therapy. No changes to the treatment protocol should be made without consulting your veterinary surgeon.

In long-haired cats, regular grooming may reduce hair ingestion by the cat and therefore reduce the likelihood of hairballs causing constipation. Likewise treating any concurrent allergic skin disease, e.g. by flea control, is vital also.

It is important to ensure that there is always access to a clean litter tray so that frequent defecation is encouraged.

If megacolon develops or if the constipation is severe and medical treatment is unsuccessful at controlling this, surgery may be advised by your vet. Surgical treatment involves removal of most of the colon which initially will result in diarrhoea since the colon is responsible for water removal from faeces. Over a period of time, this usually improves. The surgery should not result in loss of bowel control.

What is the long-term outlook for a cat with this problem?
The long-term outlook varies tremendously according to the cause of the constipation, however, most cats can be adequately managed without having to resort to surgery, especially if medical therapy is implemented early in the course of the problem.