CLA for Dogs

CLA in Dog Foods and CLA Supplements

So you've read about CLA for dogs and the potential health benefits of conjugated linoleic acid (CLA). Are you wondering if your dog gets enough CLA in her diet or if CLA is something you should be supplementing?

Can dogs produce their own CLA or must they obtain it from dietary sources or supplements? What types of CLA supplements are available? How much CLA is present in commercial dog foods? And how much CLA do dogs need? Those are some the questions I will address in CLA for Dogs.

Can Dogs Produce CLA?

If you read What Is CLA?, you know that probiotic microorganisms convert linoleic acid (LA) and alpha linoleic acid (ALA) to conjugated linoleic acid (CLA) in the rumen of cattle, sheep, deer, goats, and other cud-chewing mammals.

But what about non-ruminant animals such as dogs?

Dogs as well as humans possess the probiotic bacteria necessary to transform LA into CLA via biohydrogenation, as was demonstrated by a Japanese study that incubated canine feces with LA. However, the researchers point out that the numbers of LA-hydrogenating intestinal bacteria decrease greatly as dogs get older.

Moreover, since the bacteria in question predominate in the large intestines, while fat digestion occurs primarily in the small intestines, the "ability of intestinal bacteria to produce CLA is probably low." This hypothesis was confirmed in a human study that found that increasing consumption of LA had no effect on CLA levels in the body.

Humans, dogs and other animals that possess the delta-9-desaturase enzyme do have the ability to convert trans vaccenic acid (TVA), a naturally occurring trans fat, to CLA. Studies confirm that TVA is converted to CLA at a rate of 19% to 30%. However, since TVA is found primarily in the meat and dairy products of ruminants, diets low in CLA will also be low in TVA.

Do Dogs Need CLA?

According to the most recent dietary guidelines for dogs issued by the National Research Council (NRC) in 2006, dogs have no known dietary requirement for CLA.

The NRC notes that preliminary studies suggest that CLA may produce numerous effects that are beneficial to dogs but that more research is necessary before specific recommendations can be made.

While your dog may not need CLA, there is evidence to suggest that he or she may nonetheless be able to benefit from this fatty acid. Unfortunately we don't yet know how much CLA may be required for cancer prevention or anti-inflammatory benefits.

We do know that the CLA needed for fat reduction or lean body mass gains cannot be obtained from dietary sources. There are two reasons for this: First, the CLA isomer primarily responsible for the effects on body composition is t10,c12-CLA isomer, and this isomer is present in food only in very small amounts. And second, the amount of CLA necessary to propel changes in body composition is much higher than what can realistically be obtained from food. See CLA and Weight Loss for details.

But what about the amount needed for the other health benefits of CLA?

Unfortunately there are currently no recommendations using CLA for dogs, and recommendations for humans vary widely.

Some researchers believe as little as 95 mg a day may be sufficient to lower the risk of certain cancers. That's an amount obtainable by moderate consumption of red meat or dairy products. In fact, this recommendation is based not on a clinical trial, but a population study indicating that women consuming whole milk dairy products (a potent source of CLA) have a reduced risk of breast cancer.

A number of researchers recommend higher doses of CLA for cancer prevention and other health benefits.

Suggested amounts range from 441 mg of CLA for women and 620 mg for men to a recommended minimum of 3 grams daily. The latter recommendation is based on the amounts of CLA used in most clinical trials (i.e., at least 0.5% of the diet).

The canine equivalent of this dose would be a minimum of 0.08 grams per kilogram of body weight. This means a 60 pound (30kg) dog would receive about 2.2 grams daily.

CLA in Dog Food

At this time, I'm aware of only one commercial dog food that specifically mentions its naturally high CLA content (that would be Addiction's Wild Kangaroo and Apples dry dog food). There are, however, a number of dog foods--mostly in the weight management category--that contain CLA supplements.

Royal Canin is a company that includes CLA in many of their mini breed, diabetic and weight control formulas.

Unfortunately virtually all dog foods specifically touting their CLA content are very high in carbohydrates, and high carb foods are probably far from ideal for most dogs.

So, how can you select a dog food with an at least moderate amount of CLA that does not consist of 50% or more cereal grain?

Given what we know about dietary sources of CLA, it makes sense that dog foods consisting primarily of ruminant meat would have the highest CLA levels. And since CLA is a fat, red meat-based foods with moderate to high fat content are most likely the best bets.

For instance, the dehydrated dog foods from ZiwiPeak would be good choices. Not only are their lamb and venison formulas almost entirely meat (except for a few supplements), but this meat is from grass-fed ruminants.

If you recall, CLA levels are two to five times higher in grass-fed meats than in grain-fattened meats.

EVO Red Meat formula is likely also a good source of CLA as it contains fresh meat from four different ruminants as well as cottage cheese.

One thing to keep in mind when evaluating kibble for potential CLA content is that meat meals have much of their fat removed during the rendering process. Because many dry dog foods consist primarily of meat meals, not fresh meats, dog food manufacturers typically add a separate fat source such as chicken fat (not a good source of CLA) to their kibbles. So, while lamb is a good source of CLA, lamb meal is not.

If you are feeding a homemade diet, including more meats and dairy products from grass-fed ruminants is a simple way to ensure that your dog receives a healthy amount of CLA. Remember that fattier meats and dairy products will contain more CLA than reduced fat versions. Of course high fat consumption is recommended only for lean, active dogs.

CLA Supplements

If moderately high to high fat levels aren't appropriate for your dog due to weight or health issues, or if you and your vet have determined that your dog may be able to benefit from a higher dose of CLA than can realistically be obtained from dietary sources, CLA supplements are an option.

CLA supplements typically come in gel capsule form and derive from safflower oil or, to a lesser extent, sunflower oil.

These vegetable oils contain 78% and 68% linoleic acid respectively.

A patented process is then used to convert the linoleic acid to conjugated linoleic acid. It's recommended that you purchase Tonalin™ or Clarinol™ brand CLA, because these are the type of CLA supplements used in most of the more promising clinical trials.

Many different supplement manufacturers are now using the patented Tonalin™ or Clarinol™ branded process in their CLA, so locating these supplements shouldn't be a problem.

Most CLA capsules contain 80% conjugated linoleic acid, so a 1000 mg to 1300 mg capsule provides 780 mg to 1040 mg CLA, typically consisting of equal amounts of the cis-9, trans-11 and trans-10, cis-12 isomers plus traces of other CLA isomers.

Should You Supplement CLA?

At this point, there are too few canine studies demonstrating the effectiveness of CLA for dogs to make a general recommendation for CLA supplementation. That said, CLA has a solid safety record in dogs, so supplementing with CLA is unlikely to hurt and may help.

I feel older dogs may be most likely to benefit from additional CLA because they often have a tendency to gain unwanted fat, while losing lean muscle mass.

Older female dogs that weren't spayed before their first heat (in other words, female dogs with an increased risk of mammary tumors) may also be able to benefit from CLA's potential breast cancer preventive benefits.

Since supplementing with polyunsaturated fatty acids (PUFAs) such as CLA increases lipid peroxidation, it's important to supplement vitamin E whenever additional PUFAs are included in the diet.

I suggest adding 10-20 IU of natural vitamin E (that's d-alpha-tocopherol; the synthetic form you'll want to avoid is called dl-alpha-tocopherol) for every gram of CLA or other PUFA fed as a dietary supplement.

Although clinical trials show dogs tolerating CLA very well, even at high doses, I strongly recommend you consult your veterinarian before starting your dog on CLA for dogs or any other supplement.