Feline Constipation – Chronic Treatment and Prevention

(Chronic) constipation is a common problem in (older) cats. In some cases, the underlying cause is easy to identify and resolve, making treatment relatively straightforward. In other cases, however, management becomes much more challenging—either because the underlying cause cannot be eliminated, and/or because there is advanced dysfunction of the colon.

In a previous Vet Info, we discussed the treatment of the acute stage of constipation in cats. In this Vet Info, we focus on the chronic management and prevention of constipation.

Chronic treatment and prevention

If the cat has already had repeated episodes of constipation/obstipation and/or if there are
underlying causes that will persist long term, it is recommended that preventative measures are
taken.

GOAL = To achieve at least one bowel movement per day with stools that are not excessively hard or dry.

Treat underlying diseases/comorbidities/obtain and maintain a good body condition:

If an underlying cause is identified, it should be treated whenever possible—for example, correcting electrolyte imbalances, promoting weight loss, managing pain, or discontinuing medications that may contribute to constipation.

Maintain good hydration status:

• Water Fountain.
• Offer water in several places throughout the house.
• Use wide, shallow bowls to prevent the cat’s whiskers from touching the sides.
• Fresh water (change daily).
• If needed (e.g., cat with advanced chronic kidney disease): subcutaneous fluids.

Analgesia (if needed):

Constipation/obstipation can be very painful. Moreover, (chronic) pain (e.g. due to osteoarthritis) can contribute to constipation/obstipation. Adequate analgesia is therefore always indicated. It is recommended to give drugs that do not further reduce colon motility (e.g., full opioides). Possible options include:

◾ Butorphanol 0.1-0.3 mg/kg IV, IM, SC q 1-4h.

◾ Buprenorphine 10-20 mcg/kg IV, IM, SC q 6-8h.

◾ Metamizole 20-50 mg/kg IV diluted q 8-24h.

Laxatives/prokinetics and rectal suppositories:

Since the most commonly used laxatives are osmotic laxatives that draw fluid to the colon, it is important that the cat is rehydrated first.

PO = per os (= orally)? CRI = constant rate infusion                                                                                                 * May cause mild, usually not clinical, hyperkalemia with prolonged use. Monitoring of potassium levels is therefore indicated with long-term use.

Diet:

Dietary modification is not always necessary (e.g., in cases of one-time constipation and/or when there is a clear underlying cause that can be eliminated).

Adaptation of the diet is recommended in cases of chronic constipation and/or when a cat does not defecate frequently enough.

Even though there are no studies showing that canned food is more effective in preventing constipation, canned food is recommended (if the cat likes it) because it increases daily fluid intake.

In terms of diet, there are two options:

Low residue/high digestible diet:

• Contains easily digestible proteins, fats and carbohydrates.
• Is usually low in fiber content.
• Reduces the amount of stool in the colon and makes the stool softer.
• Recommended when there is marked dysfunction of the colon (e.g., megacolon, obstipation) and/or when there is mechanical obstruction (e.g., due to an old, poorly healed pelvic fracture).
• Eg. Hill’s I/D, RC or Purina Gastrointestinal, …

Diet with higher fiber content:

• This may be soluble fiber (is fermented in the colon à production of fatty acids à nutrition for colon bacteria) or insoluble fiber (is not fermented à  stimulates colon motility).
• Increases the amount of stool in the colon and, in case of insoluble fiber, makes stool drier.NOT recommended in cases of obstipation or megacolon as it might worsen the clinical signs.
• Eg. RC gastrointestinal fiber response, …
• Extra fiber can also be supplemented separately: eg. psyllium 1-4 teaspoons q 12h.

Hill’s GI biome Digestive may also be considered à modulating the gut mirobiome.

Treatment megacolon

Diagnosis of megacolon is based on:

• Presence of chronic constipation.
• Irreversible dilation of the colon with lateral radiograph of the abdomen showing a

colon diameter/length L5 > 1.48.

• When colon diameter/length L5> 1.62 often indicates that the megacolon is refractory to conservative treatment.

When conservative treatment is no longer successful, subtotal colectomy is indicated.

• Always have this surgery performed by an experienced surgeon.
• Diarrhea (usually transient) is common in the first 4-6 weeks after surgery.
• If diarrhea persists: give low residue/high digestible diet.
• Long-term results are usually favorable.