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Constipation in Dogs and Cats


Constipation in dogs, cats, and other pets and small animals, is a condition in which the animal shows difficulty defecating, or defecates infrequently, or not at all. Constipation, or chronic constipation may involve moisture from the fecal matter being absorbed, often leaving the defecation dry or hard. Prolonged constipation may lead to a condition known as megacolon.

sad dog with constipationMegacolon, a more severe complication associated with constipation, exists when the large bowel of an animal is permanently enlarged, and in most cases, normal functioning of the colon is impaired. Mostly found in dogs and cats, it is known to be more common in cats. Although congenital megacolon has been well-documented since 1988, it is not convincingly described, and diagnosis can be questionable. Therefore, diagnosis is often idiopathic, which means that the cause may be unknown and indeterminable. Megacolon is more often categorized as an acquired condition.

Whether it leads to megacolon conditions or “severe constipation” or not, constipation in animals can be a serious issue. Dogs and cats generally have bowel movements at least once a day. Hence, if they appear to be struggling in the process of defecating, or “pooping,” and possibly leave hard, dry movements, or if they try and fail, a veterinarian should be consulted as soon as possible. Obstruction or impaction can lead to additional problems for the animal, such as the aforementioned megacolon.

What causes constipation?

As simple as it sounds, constipation is often the result of diet. However, it may not be as simple as that. It could be that your animal’s diet, especially with cats, needs more fiber, paralleling a common issue with humans. But fiber should be prescribed, and not be assumed as a solution. Or, it could be that other matter inconsistent with a healthy diet is consumed, which could point to gravel, dirt, grass, plants, plastic, or any number of things. Obstruction may develop from all sorts of things, from eating toys or bones, over grooming and ingestion of hair, or finicky cats that don’t like their cat boxes for assorted reasons. Even lack of exercise may be attributed as the cause.

In addition to typical consumption and processing issues, constipation could be the result of a number of medical issues. Dehydration due to other illness, side effects of medication, hernias, tumors, and neurological disorders are all possibilities. Hence, proper evaluation and diagnosis of your pet is critical.

hormone replacement therapy questions?If you would like to talk to one of our licensed pharmacists about dog or cat constipation, call us Toll Free: 855-559-5200

Symptoms and Signs:

One of the most common ways to detect constipation in pets is to recognize when their excrement changes. It is easy to tell when your animal has diarrhea, which is not indicative of constipation. But the signs to watch for are dry or hard stool deposits, which can indicate that the animal is having more trouble passing this matter. Dogs with this condition may appear to be straining more than usual, and also there may be some passing of mucus, or presence of blood. Cats may show signs of straining as well, or possibly leave nothing behind in the litter box after unsuccessful attempts.

Here are some indications that can be noticeable…

  • No defecation for a day or two
  • Small, dry, and/or hard stools, possibly accompanied by mucus or blood
  • Straining, whimpering, or crying while trying to defecate.
  • Lethargy, dehydration, or reluctance to eat
  • Vomiting, visible discomfort, or “hunched up” appearance
  • Lack of grooming

Cats and dogs of any age can develop these conditions. It must be noted that conditions of constipation can be similar or identical to those of other diseases. Medical tradition suggests always getting to the root of the problem, and the causes behind the condition. Hence, accurate diagnosis and treatment can be critical, and should always be taken seriously.


It is always best to seek professional help when your pet has a problem. Even if constipation seems to go away, the condition may return in a few days, indicating that there may be a more complex problem.

Although it is more common in elderly pets, constipation may occur in any age of a dog or cat, and is not gender or breed specific.

A vet will take blood samples, and possibly urine and stool samples if available. An analysis of diet will follow, with an assessment of fiber content, and other components. X-rays are sometimes needed to better determine the condition of your pet. The consultation, which will probably include a hands on examination, will convey helpful information.


The Irvine Compounding Pharmacy has a preferred treatment for appropriate cases of constipation, which requires a veterinarian’s prescription for a medication called “Cisapride,” which has proven to be very effective in correcting constipation issues. But, first and foremost, it should be understood that non-professional diagnosis should never be taken for granted, nor be followed by non-professional prescription. We sometimes forget that, especially in the cases of dogs and cats, these animals are carnivores, and designed to consume meat. Hence, although fiber added to their diets may be a solution, knowing when the problem calls for it, and when it does not, is very crucial. Likewise, other potential options, such as stool softeners, suppositories, enemas, etc., should only be administered after professional consultation and direction.

hormone replacement therapy questions?Our licensed pharmacists are trained to help with dog or cat constipation, call us Toll Free: 855-559-5200

If caught early enough, constipation can be treated with diet adjustments only. Increasing water intake is always recommended. As well, more exercise can assist in your dog or cat’s overall body functions. Even after the initial problem is relieved, diet adjustments may be a major part of ongoing treatment. However, if severe constipation, or megacolon is the diagnosis, the situation may require more advanced treatment. In some cases, surgery, or other manual procedures may be required to relieve the animal of its obstruction. Controlled rehydration, application of enemas, or manual extrication of the obstruction may be needed.


Just to save a trip to the vet, and/or the cost of the visit, please do not attempt these things…

Home enemas – Some commercial products are actually highly toxic to pets. This includes some suppositories. Always get a vet’s guidance and help first.

Mineral oil – Not proven to be effective, and can be inhaled, causing bigger issues, and potentially permanent damage.

High fiber grains meant for human consumption– As stated earlier, your dog or cat, being a carnivore, does not have grains as part of its natural diet, and adding them could actually make conditions worse. A consultation with a vet may result in a prescription for fiber, but it will be the right type.

Laxatives meant for human consumption – While “some” laxatives or stool softeners may be safe for dogs or cats, others are not, and guessing at which ones are acceptable could prove devastating. Always seek consultation with a veterinarian first, and follow prescribed directions.


By now, it must be clear that if you suspect your pet of having constipation issues, it’s best not to wait too long to seek help. Waiting and observing while our pet suffers, and possibly gets worse, is just a bad idea. The sooner we achieve a proper diagnosis, and start the right treatment, the sooner we’ll have our furry friend adding its love to the household.

hormone replacement therapy questions?If you would like to talk to one of our licensed pharmacists about dog or cat constipation, call us Toll Free: 855-559-5200