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Duralactin

What is Duralactin®? 

Duralactin® is a nutritional supplement that contains MicroLactin®, a dried milk protein that comes from hyperimmunized cows. It is designed to help manage inflammation and support joint health in dogs, cats, and horses.

Duralactin® is a natural, non-prescription alternative to traditional anti-inflammatory drugs like NSAIDs, and can be used for long-term management of inflammatory conditions such as arthritis and other joint problems. The paste product designed for cats contains L-lysine and is used in the management of eye and respiratory health.

MicroLactin® is sold as a non-prescription supplement for humans and is sometimes used in animals off-label as a substitute for Duralactin®.

The U.S. Food and Drug Administration (FDA) does not review non-drug health supplements (e.g., herbals, nutraceuticals, shampoos, and other supplements) for safety or effectiveness before they are sold to the public. Manufacturers of non-drug health supplements must ensure their supplements are safe and labeled accurately. The FDA requires that these non-pharmaceuticals contain a disclaimer that says, “This supplement is not intended to diagnose, treat, cure or prevent any disease.” Health Canada licenses “veterinary health supplements” after reviewing safety, efficacy, and manufacturing information provided by the manufacturer. These supplements are not tested by Health Canada.

Your veterinarian is the best source of information about the safety of non-drug health supplements in pets. Just because a supplement is natural does not mean it is safe. All medicines and medicinal plants are potentially toxic if used inappropriately or given at high doses. Supplements can also have side effects, like pharmaceuticals. Few supplements and herbs have been subjected to rigorous scientific trials to determine their efficacy.

Many supplements and drugs are commonly prescribed for off-label use in veterinary medicine. “Off label” means the drug is being used in a way that has not been reviewed or approved by the U.S. Food and Drug Administration (FDA) or Health Canada. In these instances, follow your veterinarian’s directions and cautions carefully, as they may be significantly different from those on the label.

Although the information in this handout may be helpful, it may also be incomplete and may not represent the full range of effects the supplement could have on your pet.

How do I give my pet Duralactin®?

  • Duralactin® is given orally (by mouth). It comes in several formats, including chewable tablets and soft chews (dogs); soft chews, capsules and paste (cats); and pellets (horses).
  • This supplement may be given with or without food.
  • Ideally, take this supplement at the same time every day.

This supplement may take several days to have effect within the body and visible signs of improvements are not always noted.

What if I miss giving my pet the supplement?

If you miss a dose, give it as soon as you remember. However, if it is almost time for the next scheduled dose, skip the missed dose and resume the regular dosing schedule. Do not give the pet two doses at once.

Are there any potential side effects from Duralactin®?

Duralactin® may cause the following side effects:

  • Vomiting, diarrhea and nausea in animals with a dairy sensitivity

Sensitivities can develop over time, with repeated exposure. Your pet may have no reaction after the first few doses but may develop a sensitivity later. It is important to watch for signs of an allergic reaction over the entire course of treatment (e.g., irregular breathing, rash, fever, puffiness and swelling around the face). This supplement should stop working within 24 hours, although effects can be longer in pets with liver or kidney disease.

Are there any risk factors for this supplement?

DO NOT USE in:

  • Patients who are allergic to the product or any of the ingredients in this product

USE WITH CAUTION in:

  • Pets that are pregnant or intended for breeding (safety is not known)

Are there any drug interactions I should be aware of?

There are no documented drug interactions for Duralactin®. Make sure your veterinarian is aware of any medications (including vitamins, supplements or herbal therapies) that your pet is taking before starting any new treatment, due to risk of overdosing and toxicities when giving multiple supplements.

Is any monitoring needed with this supplement?

  • Follow your veterinarian’s recommendations regarding when your pet needs to be rechecked and what tests may need to be performed before and during treatment with this supplement.
  • At home, monitor for any abnormal changes. If any occur, discontinue the supplement and contact your veterinarian.

How do I store Duralactin®?

  • Store at room temperature.
  • Ensure bottles are tightly sealed and secured inside a cabinet to prevent accidental ingestion.
  • Store in a cool dry place away from sunlight.
  • Keep out of the reach of children

What should I do in case of emergency?

If you suspect an overdose or an adverse reaction to the supplement, call your veterinary office immediately. If they are not available, follow their directions in contacting an emergency facility. Be prepared to provide information about the product and your pet’s weight and symptoms. Adverse effects should also be reported to the FDA or Health Canada.

© Copyright 2025 LifeLearn Inc. Used and/or modified with permission under license. This content written by LifeLearn Animal Health (LifeLearn Inc.) is licensed to this practice for the personal use of our clients. Any copying, printing or further distribution is prohibited without the express written consent of LifeLearn. This content does not contain all available information for any referenced medications and has not been reviewed by the FDA Center for Veterinary Medicine, or Health Canada Veterinary Drugs Directorate. This content may help answer commonly asked questions, but is not a substitute for medical advice, or a proper consultation and/or clinical examination of your pet by a veterinarian. Please contact your veterinarian if you have any questions or concerns about your pet’s health. Last updated on Jul 25, 2025.