Fats are often considered unhealthy for people and dogs, but some fats are in fact essential for normal body functions. The most important of these include the omega-3 fatty acids docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA) and alpha-linolenic acid (ALA). ALA is primarily found in certain plant oils, such as flaxseed oil, while EPA and DHA are more concentrated in fish oil.
The Health Benefits of Fish Oil
DHA is essential for the development of the brain and retina in human babies and is also needed for the maintenance of normal brain function in adults. Humans who are deprived of dietary DHA in the last third of gestation and the first eighteen months of life suffer from decreased retinal function and impaired learning. Studies also show that continued fish oil supplementation in children and teenagers might continue to have a positive effect on the eye and brain.
Puppies are likely to obtain enough DHA from their mothers while they are nursing, but when they are weaned, they are dependent on DHA in their diet. But how much DHA is enough and can additional supplementation of DHA above minimum requirements be beneficial?
A study conducted by Hill’s Pet Nutrition separated 48 Beagle puppies into three groups, and supplemented them with different levels of DHA in the diet after weaning. The pups were put through a series of cognitive and learning tests, as well as testing of retinal function up until twelve months of age. The puppies supplemented with high DHA demonstrated improved learning and memory compared to pups on a low DHA diet. These pups also had increased activity in the inner layer of the retina, indicating an increased ability to see in low light. It appears that DHA is as important for brain and eye development in puppies as it is in humans.
DHA supplementation can be of benefit in certain adult conditions as well. One human study found that supplementing DHA for six months improved learning and memory in people aged 55 years or older. Therefore, DHA may have a beneficial effect in elderly dogs suffering from age-related brain deterioration. Due to its anti-inflammatory properties, omega-3 fatty acid supplementation has also shown to be helpful in the treatment of canine arthritis and skin diseases such as atopic dermatitis.
It’s not clear how much dietary DHA to give a puppy or adult dog. The Association of American Feed Control Officials (AAFCO) has set the minimum requirement for puppies as a combined amount of EPA plus DHA of 0.05% per kg of dry matter. The minimum value for adult dogs is expected to be less but has not been set by AAFCO. Dose requirements for DHA plus EPA for specific medical conditions vary widely, between fifty to 220 mg/kg body weight per day.
Too much omega-3 fatty acids in your dog’s diet may cause problems. According to the National Research Council (America), the safe upper limit for DHA plus EPA is up to 208 mg/kg body weight per day. The most common side effects of consuming excessive amounts are diarrhea and vomiting. The best way to avoid these side effects is to transition your dog slowly onto the new food or supplement and split the daily dose between feeds. Theoretically, very high levels of DHA could also cause blood-clotting problems, pancreatitis, and heavy metal toxicity, but there are no clinical reports of these having occurred.
Fish oil can be beneficial to dogs at several life stages and to those with a number of medical conditions. Commercial puppy foods are now being advertised as having extra DHA. Similarly, there are therapeutic foods for dogs that contain increased omega fatty acids to support the brain, skin and joints. Chat to your vet before adding any fish oil supplements to your dog’s diet, about whether they are likely to help their condition and what amount would be safe to give.