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Natural Dog Supplements – Aloe Vera Juice

by Eric Hall

April 27, 2013

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Donate This week I take a look at another supplement promoted by some websitesas a way to make your dog "healthier." Much like other supplements, it seems the advice on Aloe Vera has carried over right from the same woo peddled to humans. Is giving aloe vera juice to a dog really helpful? Is there any harm in doing so? Let's take a quick look.

In Humans

Aloe juice has been sold as an alternative therapy for humans for many years. Certainly a majority of people can attest to the nice cool feeling one gets when applying the aloe gel on sunburned skin. When looking at these benefits more scientifically, the results seem mixed at best.

Mayo Clinic has a graded list on the evidence for both topical and internal treatments using aloe. The World Health Organization also has a section on medicinal plants which includes aloe. Evidence in any cases seems limited, but if there is any consistent message, it is that aloe seems effective in treating minor burns, skin abrasions, dry skin, and evenseborrheic dermatitis. Although anecdotal, I personally use aloe as my hair gel because it does not irritate my skin like other products, thus reducingdermatitis on my scalp. In any case, the NIH states in theirNational Center for Complementary and Alternative Medicine (NCCAM) center that, "Use of topical aloe vera is not associated with significant side effects."

For taking aloe internally, the evidence is much less certain. Even the NCCAM, which is a group formed at the NIH as a result of lobbying by groups that support these mostly unscientific treatments, doesn't recommend taking aloe orally. Although it was at one time used and even sold over-the-counter as a treatment for constipation, the FDA had the treatments removed as safety data was not available. For treatment of radiation burns, evidence from early studies nearly 80 years ago showed some promise, but follow-up has not shown this to be true. Aloe also shows some promise in treating some cancers, and even has some biological plausibility because the primary sugar in aloe, "...can bind to the growth factor receptors on the surface of the fibroblasts and thereby enhance their activity." But, other studies show cancer activity can be increased by ingestion of aloe. From the NCCAM:
A 2-year National Toxicology Program (NTP) study onoralconsumption of non-decolorized whole leaf extract of aloe vera found clear evidence of carcinogenic activity in male and female rats, based on tumors of the large intestine. According to the NTP, from what is known right now there is nothing that would lead them to believe that these findings are not relevant to humans. However, more information, including how individuals use different types of aloe vera products, is needed to determine the potential risks tohumans.
Because of its laxative properties, aloe can bring ondiarrheaand abdominal cramps. Some preliminary evidence suggests aloe can lower blood sugar, which can be dangerous for those already treating their blood sugar with medication.

Overall, the evidence in humans is that aloe is mostly harmless topically. In fact, that seems to be where plausible benefits take place, and evidence points to a mild effect in abrasions and burns. Taking aloe orally has much more potential for harm, and has little benefit.

In Dogs

Promoters of using aloe for dogs use either this exact language or something very close:
...contains amino acids, folate, iron, magnesium, phosphorous, potassium, zinc, vitamin A, C and E. It has anti-bacterial, anti-inflammatory and anti-allergy agents and is an anti-oxidant. 100% pure Aloe Vera juice can also be taken internally to boost the immune system, help reduce the symptoms of allergies and to help the healing of wounds. Aloe Vera gel can be used topically to help wounds heal - 100% Aloe Vera Gel is best.
While the nutrient content is true, the amounts that would be obtained in the doses suggested by these "natural" websites would be a drop in the bucket as compared to a dog's normal diet of dog food. The next statement about its anti-everything properties is a nice standard woo statement made with no evidence. Boosting your immune system is another woo statement and has been covered by Skeptoid. While biologically it may make sense to use aloe topically on a dog as evidence in humans points to a mild effect, there hasn't been studies on dogs I could find, and keeping a dog from ingesting anything on their fur is a difficult proposition.

The ASPCA lists aloe as toxic to dogs and cats, with symptoms listed as: "Vomiting, depression, diarrhea, anorexia, tremors, change in urine color."Similarly, the Pet Poison Helpline lists aloe as a mild to moderate toxicity with similar symptoms as the ASPCA. The helpline goes further to explain how the toxicity works:
Aloes contain anthraquinone glycosides which are purgatives (medications that encourage bowel movements). When ingested, these glycosides are metabolized by intestinal bacteria forming compounds that increase mucus production and water in the colon. This can result in vomiting and diarrhea. Other clinical signs seen with aloe vera ingestion include depression, anorexia, changes in urine color, and rarely, tremors.
It would seem the anti-bacterial properties are not true at all, but instead the aloe actually feeds bacteria. Mucus is typically a sign of some sort of inflammation. Thus aloe is not doing what is claimed by promoters, but instead doing the opposite.

The website "Can I Give My Dog...?" takes a non-confrontational approach to their description of aloe. While stating small amounts are probably OK, they recommend being consistent, using small amounts, and observing the dog carefully for changes. They do conclude:
You should really resist the urge to give your dog all of these extra bells and whistles, and just keep it simple. Unless there is a pressing reason for wanting to give them things like aloe vera juice, you should just stick to the basics. Your dog is happy as can be just having the same dog food and water every day, and tinkering with this only adds inconsistency to their diet, and potentially has side effects that negate any benefits.
One other treatment some vets actually prescribe is for dogs with certain cancers. One small study seemed to show some benefit with certain cancers in dogs. However, much like the human studies, the evidence is limited, and the results have yet to be repeated. In the case of cancer for dogs, I suppose it is something to try, especially when the prognosis is poor and traditional treatments are not affordable or stand a low chance of working. I personally wouldn't do it because the evidence is not strong enough, but for those that do try it, there is at least limited evidence to support that decision.


Drinking aloe vera juice has no benefit to dogs (or humans) which cannot be obtained in a normal, healthy diet. The possible harm far outweighs any good which is obtained. Topically, make sure to ask your vet before using aloe on your dog. Steer clear of websites telling you aloe is a good idea andimportantfor your pet. It's not. Instead, feed them a consistent diet of high quality food and clean, fresh water, and your dog will do just fine.

by Eric Hall

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