Constipation

Constipation is a tricky problem in any pet, since most solutions cause problems of their own. But since diabetic cats are forced to be careful with their diet, they (or the cats who eat with them) may easily react to the new diet with constipation.

Chronic constipation is a serious problem that can lead to Megacolon, a potentially fatal complication. Consult your vet about any cat or dog who is always constipated.

Water first

Chronic low-level dehydration is a very common cause for constipation, especially among diabetics. Always begin by increasing hydration, either by adding a bit to the food, or putting out more and fresher water, or by injecting small amounts of subcutaneous fluids if you are trained on this. Keep those sub-q doses small unless talking with your vet.

In Cats

According to Jack J. Broadhurst, DVM, felines need to eat large, well-spaced high-protein meals to have regular bowel movements. Both dry food and free-feeding small meals may cause constipation in cats.

Diabetic cats may suffer from neuropathy, and low bowel motility may also be a symptom of that. Wikipedia discusses the possibility of "Autonomic neuropathy" from diabetes which can lead to low bowel motility or gastroparesis. Methyl-B12 is said to help in these cases.

Symptoms of constipation in cats include irritability, painful abdomen, lethargy, and poor appetite or even loss of appetite, painful defecation, complaints from the litterbox or unwillingness to enter it, pooping outside the litterbox, small hard stool, or simply no litterbox activity for more than a day.

Know the cause first

In general, the remedy used should take into account the cause of the constipation! If you don't know the cause, please consult a vet, since using the wrong remedy can make things worse. Keep in mind that all the remedies to follow can make things worse in some cases -- there's no best or worst cure for everyone, and a vet should be in the loop.

Example: Obstipation or blockage

constipation from an intestinal blockage or obstipation is a medical emergency, and is not always obvious. Constipation remedies containing lots of fiber/bulk can make a blockage worse very quickly, leading to intestinal damage or death. Before starting any treatment for a cat with no output, it would be best to have a vet check by x-ray for any possible obstructions. Note:

Low motility + low intestinal hydration + fiber/bulk 
= severe constipation and/or obstipation. 

Example: Osmotic laxatives

Osmotic laxatives work by bringing water from the body into the intestine. This is not a good idea if the constipation was caused by dehydration! That water has to come from somewhere. Always give extra water (in food or subcutaneously) with osmotic laxatives.

Also note: No osmotic laxative will work on stool that is already in the intestine. Any dry, hard, or excessively large stool should be completely removed before using an osmotic laxative.

Remedies List

Constipation remedies are classified as hydrating, bulk-forming, lubricant, emollient, osmotic, or stimulant.

Please read as much as possible about constipation and consult your vet before trying to treat it. Good links include:

• Pet Care Tips
• Little Big Cat
• Marvistavet
• Merck Vet Manual
• fabcats on constipation
• Vetinfo4cats: questions and answers on constipation
• Columbia Animal Hospital

Suggested remedies and their mechanisms and cautions include:

Remedy	Mechanism	Cautions
Extra water in food	Hydration, lubrication
Subcutaneous fluids	Hydration, lubrication	Can overhydrate with bad effects, vet only.
Enema (various possibilities: water, or K-Y, or mineral oil, or soapy water)	Flushing, lubrication	Don't try this at home unless vet recommends it.
Canned pumpkin	Fiber and bulk	Don't use if possibility of intestinal blockage
Soaked flax seed	Fiber and bulk	Don't use if possibility of intestinal blockage
Psyllium husks	Fiber and bulk	Don't use if possibility of intestinal blockage
Lax-Eze	Fiber and bulk	Don't use if possibility of intestinal blockage
Slippery Elm	Fiber and emollient	Don't use if possibility of intestinal blockage
Vaseline/petroleum jelly	Lubrication	retards or blocks food absorption
Olive oil/butter/animal fat/tuna in vegetable oil	Lubrication	Not a regular diet.
Children's glycerin suppositories	Lubrication	administered anally
Lactulose	Osmotic stool softener, Lubrication	Pulls water into the intestines osmotically -- can dehydrate -- give extra water with this, don't use long term. It is a form of sugar (and is quite sticky in solution!), and is not digested. It does not affect blood glucose level in most cases. It may be ineffective against existing blockages.
Docusate sodium/DSS	Osmotic stool softener, Lubrication	Pulls water into the intestines osmotically -- can dehydrate -- give extra water with this, don't use long term.
Miralax (Polyethylene glycol)	Osmotic stool softener, Lubrication	Pulls water into the intestines osmotically -- can dehydrate -- give extra water with this, don't use long term.
Exercise	Prokinetic: increases intestinal contractions	Likely to either raise or lower Blood glucose level, depends on individual.
Aloe Vera juice[2]	Stimulant, astringent, purgative	Controversial: Some swear by it, others say may be poisonous to cats[3][4]
Cisapride/Propulsid	Prokinetic: increases intestinal contractions	Works best with stool softeners. Addictive. Causes cardiac arrythmia in some humans.
Sodium Picosulfate/Dulcolax	Prokinetic: increases intestinal contractions	Addictive, can cause bowel irritation.
Acidophilus yogurt	Probiotic: rebalances intestinal flora	May be irritating to lactose-intolerant pets.

Further Reading

• Feline Constipation, Obstipation, and Megacolon-Prevension, Diagnosis & Treatment-WSAVA 2001
• Feline Megacolon-WSAVA 2003

• Gastrointestinal Signs in Endocrine Diseases-Cats & Dogs-Provet UK
• Merck Veterinary Manual-Cathartic and Laxative Drugs
• Merck Veterinary Manual-Drugs-Cathartic and Laxative
• Fiber in Pet Foods-Pet Education.com-Drs. Foster & Smith