How to read this page
The summaries below describe research on dog health in general. They explain why these topics matter and how much is known about them. They are not claims about Carevia Pets products. A study of a specific ingredient, dose or diet cannot be assumed to apply to any other product, and no product on this website is presented as a treatment for any disease.
When you read any health claim, it helps to ask four questions: Was the study done in dogs? Was it a controlled trial or only an observation? Was the product, ingredient and dose the same as the one being sold? Did the dogs have a diagnosed condition, or were they healthy? The answers change what a result can tell you.
Joints and mobility
Osteoarthritis is common, but estimates of how common vary widely. A frequently quoted figure holds that about one in five dogs over one year of age in North America has osteoarthritis. A 2020 systematic review reports that this figure is based on data collected from 200 veterinarians in North America, while recent estimates from United Kingdom primary-care practices range from about 2.5% to 6.6% of dogs of any age. Its authors caution that the United Kingdom figures are likely underestimates because of how cases are recorded.[2]
The largest single study of this kind analysed the electronic records of 455,557 dogs attending United Kingdom primary-care practices in 2013. It examined how often osteoarthritis was diagnosed and which factors, including age, bodyweight, sex, neuter status and breed, were associated with a diagnosis.[1] The wide range between studies reflects different methods and populations: a diagnosis recorded in a clinic is not the same as joint changes found on an X-ray survey.
Osteoarthritis often develops after another joint problem. The 2020 review describes secondary osteoarthritis, which follows an underlying joint disorder or injury, as the most common form in dogs.[2] This is one reason veterinarians pay attention to joint development in young dogs and to injury history in older ones.
What this means in practice. Stiffness, reluctance to climb stairs, or slowing on walks can have many causes. Only a veterinary examination can tell which. Body condition and controlled exercise are discussed in the veterinary literature as part of day-to-day joint care, and any supplement should be considered an addition to veterinary guidance, not a replacement for it.
Digestion and the gut microbiome
The gut hosts a complex community of microorganisms. A 2020 review describes the canine gut microbiome as a community of bacteria, archaea, viruses and other organisms that contributes to metabolism, helps protect against pathogens and helps train the immune system. Most bacterial sequences found in the canine gut belong to five major groups (phyla).[3]
Disruption is associated with disease. The same review reports that age, diet and other environmental factors influence the microbiome, but that the changes seen in dogs with gastrointestinal disease are far larger. It also notes that strategies to influence the microbiome may be useful in gastrointestinal disease, and that laboratories can now measure a “dysbiosis index” to help veterinarians monitor treatment.[3]
Limits of the evidence. Much of the published work describes how the microbiome differs in dogs that are ill. Fewer studies test whether a particular supplement changes health outcomes, and results for one product do not transfer automatically to another. Persistent vomiting, diarrhea, weight loss or blood in the stool should always be assessed by a veterinarian rather than managed with supplements alone.
Skin and coat
Skin disease in dogs is often multifactorial. Canine atopic dermatitis is a genetically predisposed, inflammatory and itchy skin condition. International veterinary guidelines describe its management as multifaceted, combining identification of flare factors, skin and coat hygiene, and other measures. For chronic skin lesions, the guidelines mention more frequent bathing and increasing essential fatty acid intake among the options.[5]
What controlled trials found. A systematic review of 49 randomized controlled trials involving 2,126 dogs found some evidence for several medicines used to reduce itch and skin lesions. It also reported one high-quality trial in which an oral essential fatty acid supplement reduced the dogs’ need for the steroid prednisolone by roughly half.[4]
Limits of the evidence. These findings concern dogs with diagnosed atopic dermatitis who were under veterinary care, and the supplement acted as an add-on to medical treatment. They do not show that a supplement improves skin or coat in healthy dogs. Itching, hair loss, redness or recurring ear infections should be examined by a veterinarian, because food allergy, parasites and infection can look similar to one another.
How pet supplements are regulated in the United States
Dietary supplements for people are governed by a specific law, the Dietary Supplement Health and Education Act of 1994. The Food and Drug Administration’s Center for Veterinary Medicine (FDA-CVM) has taken the position that this law does not apply to animal products. Supplements for dogs and cats are therefore regulated as animal food, in cooperation with state agencies, and many claims that are permitted for human supplements are not permitted for animal products.[6][8]
In 2001, animal-health companies formed the National Animal Supplement Council (NASC), an industry body that operates an adverse-event reporting system that FDA-CVM can access.[8] A National Research Council committee later reviewed the safety of supplements for dogs, cats and horses. Its task was limited to safety. It did not assess whether the products work.[7]
What this means for you. There is no pre-market approval of efficacy for pet supplements, so labels, ingredient quality and dosing differ between brands. Read the label, ask your veterinarian, and report any adverse reaction to the seller and your veterinarian.
Summary of the evidence
| Topic | What the research reports | Limits to keep in mind | Source |
|---|---|---|---|
| Joint health | Osteoarthritis is common; recorded prevalence ranges from about 2.5% to well above 20% depending on method and population. | Figures depend on how cases were found. Studies of prevalence do not show that any product helps. | [1][2] |
| Digestion | The gut microbiome supports metabolism and immune function; imbalance is associated with gastrointestinal disease. | Many studies describe disease states rather than testing supplements. | [3] |
| Skin and coat | Guidelines list essential fatty acids among the options for chronic atopic dermatitis; one high-quality trial showed a steroid-sparing effect. | Results apply to dogs with diagnosed disease under veterinary care. | [4][5] |
| Regulation | Animal supplements are regulated as animal food; human supplement law does not apply. | There is no efficacy approval process. Quality varies by brand. | [6][7][8] |
Questions to ask your veterinarian
- Is my dog’s weight and body condition where it should be, and how does that affect joints and digestion?
- Could the signs I have noticed have a cause that needs diagnosis or treatment first?
- Is it safe to add a supplement to my dog’s current food and medicines?
- How will we judge whether it is helping, and when should we stop?
- Which signs should make me stop giving it and call you?
References
- Anderson KL, O’Neill DG, Brodbelt DC, et al. Prevalence, duration and risk factors for appendicular osteoarthritis in a UK dog population under primary veterinary care. Scientific Reports. 2018;8:5641. doi:10.1038/s41598-018-23940-z
- Anderson KL, Zulch H, O’Neill DG, Meeson RL, Collins LM. Risk factors for canine osteoarthritis and its predisposing arthropathies: a systematic review. Frontiers in Veterinary Science. 2020;7:220. doi:10.3389/fvets.2020.00220
- Pilla R, Suchodolski JS. The role of the canine gut microbiome and metabolome in health and gastrointestinal disease. Frontiers in Veterinary Science. 2020;6:498. doi:10.3389/fvets.2019.00498
- Olivry T, Foster AP, Mueller RS, McEwan NA, Chesney C, Williams HC. Interventions for atopic dermatitis in dogs: a systematic review of randomized controlled trials. Veterinary Dermatology. 2010;21(1):4–22. doi:10.1111/j.1365-3164.2009.00784.x
- Olivry T, DeBoer DJ, Favrot C, et al. Treatment of canine atopic dermatitis: 2015 updated guidelines from the International Committee on Allergic Diseases of Animals (ICADA). BMC Veterinary Research. 2015;11:210. doi:10.1186/s12917-015-0514-6
- U.S. Food and Drug Administration, Center for Veterinary Medicine. Compliance Policy Guide Sec. 690.100, Nutritional Supplements for Companion Animals.
- National Research Council, Committee on Examining the Safety of Dietary Supplements for Horses, Dogs, and Cats. Safety of Dietary Supplements for Horses, Dogs, and Cats. Washington, DC: The National Academies Press; 2009.
- National Animal Supplement Council. Regulation of animal health supplements: a historical summary. nasc.cc/historical-summary
Links lead to the publishers’ pages. Summaries are written in our own words, and we encourage you to read the original sources. Citations were last checked on March 18, 2025.