Do cats need fiber?

As part of their natural prey diet, the cat does not ingest dietary plant fiber, nor does her digestion require a substrate or medium for food fermenting bacteria to live on. Fiber plays an important role in the diet of omnivores, and is essential in the diet of herbivores, but the cat as a carnivore has no natural need for fiber. Not only does the cat not rely on bacterial fermentation as part of the digestion process, fiber also does not necessarily promote stool volume and regular bowel movements in the cat.

From our studies we have learned, that food volume creates stool volume. However, bulking up food with inedible fiber to create stool volume often results in:

• the fiber being expelled as part of hair balls.
• the fiber causing irritation of the intestine, leading to loose stool with mucus and sometimes blood.
• the fiber being visibly expelled in dry feces without the desired softening effect.
• the fiber bulk taking the place of essential nutrients.

Physically, the cat has retained attributes of its desert dwelling ancestors. This includes the ability to extract as much water from fecal matter in the colon as possible, in order to preserve water and retain bodily fluids. Cat feces are naturally dry, and an adult cat consuming a natural diet to meet her caloric need will often evacuate feces only every other day. Kittens eating more food to meet their caloric needs of growth will subsequently have more frequent bowl movements.

Attempting to increase frequency in bowel movements in a group of adult cats eating a raw meat diet by adding a plant based fiber resulted in:

• regurgitation of the food
• regurgitation of the fiber as part of hair balls
• irritation of the intestine, observed by loose stool with mucus and blood
• no changes in bowl movement frequency

Adding more water also has little effect on texture or frequency of bowl movements, because moisture is naturally extracted from feces by the colon. Instead, the cat will urinate more.

After a six months study (September 2008 – March 2009) to determine the necessity of fiber in the cat’s diet, we conclude, that healthy adult cats and kittens do not draw a benefit from dietary fiber. When fed regularly and according to their caloric need with a proper raw meat food for cats, they will have consistent bowl movement as is expected from a creature adapted to living in a dry climate. Feces are often very solid, dry, in small “nuggets”, and not every day.

Fecal samples of individual cats eating a diet without fiber.

Lisa A. Pierson, DVM, who has been independently applying, researching, and in some aspects adjusting our recipe for the past six years, concurs with fiber being an unnecessary part in the cat’s diet. In her own information she writes:
“Dietary fiber is a bit of a controversial subject among raw feeders. Many cats, including my own, do just fine without additional fiber added to their diet. I have experimented with adding different amounts of Psyllium and then started leaving the Psyllium out of the diet completely.”

Cats with a tendency to regurgitate their food should not be given fiber. They should be fed several small meals throughout the day of highly digestible food, as it is the volume of food ingested at one meal which, in most cases, triggers the regurgitation. These cats should not have essential nutrients and calories replaced by bulk in their diet, as it is already a challenge to get enough food into these cats due to their peculiarity. Once these cats receive consistent, small meals throughout the day without the urge to purge, regular bowel movements will follow – which may have been absent, because the cats were simply not eating enough food or keeping it down to begin with. (Read more about Regurgitation)

Veterinary advice should be sought, if dietary fiber is in any way recommended and appears beneficial for certain cats. A Veterinarian may recommend a food stuff or fiber supplement known to be useful in these cases. Cats who do not have a confirmed bowl movement in four days and lack appetite should be brought to a Veterinarian for examination, as they may be constipated – a condition which must be resolved promptly and professionally.

Psyllium Husk – a source of soluble fiber – had been a part of our InstinctsTC formula in the past, and some customers/cats may see a need to keep including it in the homemade diet. Psyllium Husk is available at health food stores as whole husks or as powder. Please do not confuse Psyllium seed for Psyllium husk.

Psyllium husk can be added to the premix in the following ratio:

Per each 1 kg (2.2 lbs.) of cat food add:

• 1 tsp. Psyllium husk powder mixed with ½ cup (125 ml) cold water or
• 2 tsp. Psyllium husks whole mixed with ½ cup (125 ml) cold water.
  If desired, you can double this recommendation, but do not exceed beyond that.

Another source of fiber, which is commonly used, is canned pumpkin or cooked squash, yam, or sweet potato. (Do not use regular potato). Olive oil, or another vegetable oil, can also be useful as a mild laxative.

Why we have taken the Psyllium Husks out of our Formula:

• Psyllium husks cause many cats to regurgitate the food. This is a well observed fact in our own study group. Maybe the food gets too slimy/mucousy to stay down. Also, the Psyllium husks with water create much unnecessary, non-nutritive food volume. Maybe, some of the regurgitation is due to cereal intolerance, as Psyllium Husk surely has some seed/cereal residue. Cereal intolerance, resulting in dramatic regurgitation of food, is also well observed in our group.
• While observing and photographing a lot of cat scat, we often see no difference between stool resulting from eating food with Psyllium husk, without Psyllium husk, plain meat, or mice. Stool bulking qualities of Psyllium may be overrated in cats. A theory is, that maybe cats get used to it over time, and the mucilage looses its effect. I have, however, observed loose, mucousy, sometimes even bloody stool when re-introducing Psyllium to the group. Often, We had this type of stool while the group was fed a Psyllium-containing food consistently. We do no longer observe any mucous or rubber-stool since feeding our formula without Psyllium.
• Psyllium can cause constipation, especially when clients choose not to follow instructions - which we know happens more than we think. This, combined with the occurrence of mucousy, sometimes bloody stool, as well as a higher incident of regurgitation, makes Psyllium no longer a great thing to add.
• Cats do not require dietary fiber as PRE-biotic to sustain and/or nurture digestive flora, as their intestinal tract is not colonized by food digesting bacteria, largely due to the fact, that cats to not ingest plant based nutrients looked in cellulose. Some bacterial fermentation does occur in the cat’s colon, and it is believed that bacteria synthesize some vitamins which the cat benefits from.
• Dietary fiber - particularely mucilage - can decrease mineral absorption - especially zinc, calcium, and iron. This is a fact and has been raised as a concern by customers
• Last, but not least, Psyllium does not taste good.