Yarmouth Veterinary Center

75 Willow Street
Yarmouth , ME 04096




Fish oils have significant anti-inflammatory effect. We see these effects at the minimum doses (the dose on the label of the veterinary products), and we see much greater effects at much higher doses:
- Minimum daily dose
- 4 times minimum daily dose for skin disease, liver disease, kidney disease, and other non-arthritis inflammatory problems
-10 times the minimum dose for arthritis
Any increase above the daily dose will be more effective than the daily dose, even if it is not a 4-times or 10-times increase.

Side effects are rarely seen. 

Fish oils can be given along with other supplements and medications.

Fish oils have to be given daily, including past the time when symptoms resolve, to be effective. They will not work if used "as needed". 

It requires up to 3 months to see the effects of fish oil supplementation.

The product you use matters; fish oil supplements vary tremendously in quality. 
- Supplementing at minimum dose: Welactin (veterinary product)
- Supplementing at high doses: Welactin, Derma-3 Twist Caps, Prescription Diet J/D, Prescription Diet Mobility and Metabolic
- Supplementing for arthritis: Prescription Diet J/D, Prescription Diet Mobility and Metabolic

You can give your pet the same fish oil supplement that you take. See our article Fish Oil Doses for help figuring out the correct dose; please ask us if you need more help. Also, please remember, these products vary significantly in quality. We strongly recommend using one of the products listed above.


- Skin problems, including allergic skin disease and ear problems
- Arthritis
- Kidney disease
- Liver disease
- Heart disease
- Respiratory disease
- Many other illnesses that have inflammation as a component

When we recommend a fish oil supplement for a pet clients often ask us two things: "Can I safely give my pet the same supplement I take myself?" (Answer: usually yes) and "Can I just buy one at the pharmacy or pet store?" (Answer: fish oil supplements vary in quality, and it is important to consider several factors in order to choose one of reliably high quality)

THE SOURCE OF THE FISH OIL  If the type of fish used for the supplement is not specified on the label or easily available from the manufacturer's product information, then there is a good chance it is a poor quality supplement.

Salmon oil is a popular version of fish oil supplement sold for human use, and acceptable for use in dogs and cats. But wild salmon have been overfished and farmed salmon may have poor quality oil due to lack of a wild diet and potentially increased PCBs and other chemicals.

Krill oil has the concern of impacting whale forage. 

Wild-caught and easily renewable small fish such as anchovies and sardines are ideal. 

Flax oil is metabolized by the pet or person into fatty acids, but it takes two to three times as much flax oil as fish oil to get the same effect.

QUALITY CONTROL  Fish oil should be purified by molecular distillation and screened for contaminants, including PCBs, heavy metals and dioxins. Standards have been set by the Council for Responsible Nutrition (CRN), World Health Organization (WHO), and International Fish Oil Standards (IFOS). 

In the US the National Animal Supplement Council (NASC) works with the FDA to establish and monitor safety and quality control standards for pet supplements, including fatty acids. Products bearing the NASC seal are subjected to quality audits every two years, follow FDA guidelines, and participate in adverse event reporting and random finished product testing. 

Some companies (for example Nutramax, producers of Welactin fish oil supplement for pets and Omegamints for people) reliably use independent third party quality testing in addition to following all Good Manufacturing Practices guidelines. 

LABELLING  Poor quality products often are labelled in a confusing, incomplete way. If the exact amounts of the EPA and DHA fatty acids are not stated on the label the product should not be used. Ideally, the label should also state the fish source, purification process, and quality control. 

DOSE FORMS  Fish oil is prone to oxidation and loss of activity, especially in non-encapsulated forms such as diets, soft chews, and bottles of liquid. It is particularly important that excellent quality control is part of the manufacturing process for these products. 

PET DIETS WITH FISH OIL / FATTY ACIDS  This is a particularly complicated area of fish oil supplementation, made confusing by many important variables. Some of the concerns and considerations:
- Pet food manufacturers can claim added fish oil on the label when only a very small amount has been added.
- The source of the oil may vary from batch to batch with some foods, and the source of the oil is often not specified.
- How the food is processed and stored by the manufacturer, shipped to and stored by the seller, and stored by the pet owner has a great impact on how much of the added fish oil is present and effective by the time it gets to the pet. An exceptionally weak link in this chain is the pet stores, where inadequate attention is often paid to proper storage and handling, and where selling points are profit-based and not nutrition-based. 
- Many Western commercial pet foods have excessive amounts of Omega 6 fatty acids, and, as a result, instead of being anti-inflammatory, these diets will create more inflammation. 
- Most good-quality fish oil-supplemented diets contain standard doses of fish oil. A few specialty diets (for example, Hill's Prescription Diet J/D) are supplemented with what qualifies as a high dose of fish oil. 
- It is our opinion that Hill's (the manufacturers of Science Diet, Presciption Diet, Healthy Advantage and Ideal Balance lines of pet food) is the only pet food company that excels at all aspects of fatty acid supplementation of their products.

Fish oils are used as a source of Omega 3 and Omega 6 fatty acids. Omega 3 fatty acids include EPA and DHA portions. Omega-3s are the anti-inflammatory fatty acids. 

Triglycerides are the most common and least costly chemical form of fish oil. They have good absorption from the digestive tract and good bioavailability. About 30% of the total fish oil content of these supplements consists of EPA and DHA. There are a number of good products; we prefer Welactin, manufactured by Nutramax. 

Free fatty acids are fatty acids that have been stripped from their triglyceride backbone and left free. The resulting product has a significantly higher concentration of EPA and DHA compared to the triglyceride form, so a lower volume of the oil is needed to provide the same fatty acid level. This may be a particularly important consideration when a larger pet is recieving high-dose fish oil therapy. There are a few good veterinary products; we prefer Derma-3 Twist Caps, manufactured by Sogeval. 

Because fish oils are nutritional supplements and not pharmaceuticals large-scale studies have not been done to establish exact doses. (These studies cost a tremendous amount of money to perform; if a manufacturer does not have to do them in order to market a product, they won't do them.) As a result, many ways of calculating a dose of fish oil for an individual pet have been suggested, and all doses, regardless of the method used, are approximate. 

There are three different doses of fish oils for dogs:
THE NRC (National Research Council, not the Nuclear Regulatory Commission) RECOMMENDED DAILY DOSE  If a fish oil product comes with a recommended dose it is approximately this one. 

THE NON-ARTHRITIS ANTI-INFLAMMATORY DOSE  Approximately 4 times the NRC dose, this is the most appropriate dose for chronic kidney disease, chronic liver disease, skin disease, heart disease, gastrointestinal disease, and other non-arthritis inflammatory problems. 

THE ARTHRITIS DOSE  Approximately 10 times the NRC dose, this is the most appropriate dose for arthritis. 

Less is known about appropriate dosing for cats and other pets. For cats, there is general agreement on a minimum dose and an anti-inflammatory dose.

For doses please see our article Fish Oil Doses.

We have seen pets benefit from the NRC dose, and we have seen them benefit more from the higher doses. Pets that are on the NRC dose or the anti-inflammatory dose can have their doses increased, and it is likely that greater benefits will be seen. Increasing above the arthritis dose is less likely to produce greater benefits.

Fish oils must be given daily, even when the pet has no symptoms, to be effective. 

It requires up to three months after starting to supplement daily with fish oils, or after increasing the dose of fish oils, to see the benefits.

Any side effects are rare. A tiny percentage of patients will have vomiting or diarrhea. Dogs that have dietary allergy to fish may have increased itchiness, but this also is very uncommon. 

Yarmouth Veterinary Center