Scientists conducted a literature review of research on the use of nutraceuticals on immune-mediated inflammatory diseases (IMIDs) affecting dogs’ skin. Most dermatological IMIDs affecting dogs require the use of immunosuppressive drugs which can have adverse side effects. Veterinarians have looked to nutraceuticals as an alternative to these drugs.
Nutraceuticals lack a firm definition in pet food. In general, nutraceutical ingredients in pet food go beyond providing basic nutrition and have some value to health and wellness of the pet. Turmeric, green tea extracts, Yucca schidigera and collagen appear as nutraceuticals in Petfood Industry’s Ingredient Issues archive. Formulations using these pet food ingredients may fall under federal oversight as dog, cat and other pet supplements, especially if certain labeling claims are made.
In the journal Veterinary Dermatology, researchers reviewed 64 scientific publications. The collected body of literature contained minor evidence for the beneficial use of several nutraceuticals, including essential fatty acids, niacinamide and probiotics, to treatment of specific IMIDs affecting dogs’ skin.
“These nutraceuticals may improve clinical signs or reduce the required dose of concurrent medication (e.g. drug-sparing effect) in some dogs,” the researchers wrote. “Some nutraceuticals also may be used for long-term maintenance therapy.”
However, the researchers ultimately found limited evidence for the efficacy of nutraceuticals to treat dermatological IMIDs.
About immune-mediated inflammatory diseases in dogs
IMIDs in dogs occur due to the abnormal immune response of a dog's body to its own tissues or external agents, such as allergens, bacteria or viruses. IMIDs can affect various organs and systems in a dog's body, including the skin, joints, eyes and blood vessels. These conditions are chronic and often require lifelong management and treatment.
Some examples of IMIDs in dogs include:
- Canine atopic dermatitis - This is a skin disorder caused by an allergic reaction to various environmental allergens, such as dust mites, pollen, and mold spores. Dogs with canine atopic dermatitis experience itching, hair loss, and skin infections.
- Immune-mediated hemolytic anemia - This is a condition in which a dog's immune system attacks and destroys its own red blood cells, leading to anemia. Symptoms include lethargy, pale gums, and rapid breathing.
- Immune-mediated polyarthritis - This is a type of arthritis in which the immune system attacks the joints, causing pain, stiffness, and lameness. Immune-mediated polyarthritis can affect one or multiple joints.
- Immune-mediated thrombocytopenia - This is a condition in which the immune system attacks and destroys the platelets, leading to abnormal bleeding and bruising.
- Systemic lupus erythematosus - This is a complex autoimmune disorder that can affect various organs and systems in a dog's body, including the skin, joints, kidneys, and blood vessels. Symptoms include fever, joint pain, and skin rashes.
The treatment of IMIDs in dogs usually involves a combination of medications, such as immunosuppressive drugs and steroids, and supportive care, such as blood transfusions and nutritional therapy.
Nutraceuticals in pet food
Regulation of pet supplements has a complex history. The passage of the Dietary Supplement Health and Education Act of 1994 (DSHEA) fundamentally changed how FDA could regulate dietary supplements for human consumption, as the new law provided for both the use of ingredients that normally would not be allowed in foods in conventional form as well as for label claims that would otherwise render a food product to be a "drug." Not surprisingly, the supplement industry flourished as a result, and notwithstanding FDA's formal notice in 1996 that DSHEA did not apply to animal products, that category grew substantially as well. This caused a great conundrum for both the industry and regulators, as many supplement products for animals simply could not fit within the AAFCO rubric.
Eventually, an amenable albeit tenuous solution was reached through the efforts of the National Animal Supplement Council (NASC). Animal supplements that supply only AAFCO-acceptable ingredients (e.g., vitamins, minerals, fatty acids) remain squarely within AAFCO's purview. For those that include ingredients that are not approved for use in feeds (e.g., herbs, metabolites), NASC developed a novel scheme for labeling of "dosage-form animal health products" that more closely emulated the labeling as required by DSHEA. Regulatory concerns regarding safe use of products containing unapproved ingredients were placated by NASC's commitments to self-regulate through mandatory audits of its members and implementation of an adverse effect reporting system.
Makers of these products must abide by conditions set by FDA and states that enforce "animal remedy" laws as "unapproved drugs of low regulatory priority." However, for the most part these products escape the scrutiny of state feed control officials, because as labeled they are no longer "feeds" per se. As viewed by the typical purchaser of animal supplements, though, the distinction between products subject to the feed regulations and those that are not may not be readily apparent.