It’s been a while since dog supplements have broken through into the pet industry market.
Today, dog owners have more than enough canine dietary products to choose from. In fact, the choice is overwhelming.
Most pet parents are confused which dog supplements to buy, which ones work and which supplements are simply a potential scam.
Below, we’ll take a look at ten most popular dog supplements. We’ll talk about whether they work or not, and go through all the evidence we currently have on these products.
For pet owners who may be confused about the dog supplement terminology used here, I highly recommend referring to our Supplements for Dogs Terminology post.
Top 10 Dog Supplements: Do They Work?
The most common dog supplements’ ingredients can be determined by which supplements are most frequently purchased and the major ingredients they contain.
This list of the most common ingredients was derived from researching the best-selling dog supplements advertised on a well-known online ecommerce website.
The top 10 dog supplement ingredients discussed here (in alphabetical order) are:
- Coenzyme Q10
- Digestive enzymes
- Fish oil
- Milk thistle
- Vitamin C / Ascorbic acid
How do these dog supplements work?
Chondroitin for dogs
Chondroitin for dogs is required for the production of new cartilage in your dog’s joints and it also slows down the action of enzymes that are destructive to the joints.
Chondroitin is often added with another popular ingredient, glucosamine, because it tends to enhance the ability of both ingredients to repair cartilage and they work better together than either ingredient alone.
Chondroitin in dog supplements is usually derived from pig and cow cartilage, although shark and chicken cartilage also can be used. Algae is a non-animal source of chondroitin.
Coenzyme Q10 for dogs
Coenzyme Q10, also known as ubiquinone, is primarily recommended for dogs as treatment or prevention of heart disease and age-related cognitive dysfunction.
Coenzyme Q10 for dogs have been shown to work for certain health cases.
Creatinine for dogs
Creatinine is modified by the body to serve as a storage reservoir for quick energy.
Creatinine for dogs helps build lean body mass by allowing muscles to work longer. It is the increase in exercise that results in building muscle, not creatinine alone.
Digestive enzymes for dogs
It is thought by some owners that enzymes required for optimal digestion are destroyed by the high temperatures and some of the chemicals used when processing commercial dog food. Therefore, it is believed these may need replacing with digestive enzyme supplements for dogs.
The ingredients in digestive enzyme supplements may include pancreatic enzyme, protease (breaks down proteins into amino acids), amylase (breaks carbohydrates into manageable sugars like sucrose, lactose and maltose), lipase (breaks fats down into beneficial fatty acids) and cellulase (breaks down vegetables and fibres making them more useful to your dog).
Fish oil for dogs
A 2010 review  of the evidence for various approaches to treating canine skin allergies concluded that there was some evidence that fish oil supplements can improve coat quality and reduce the dosage of steroid medications needed to reduce itching, but generally, these effects are insubstantial and cannot substitute for other therapies.
Several published studies of fish oil supplements for dogs as a therapy for osteoarthritis in canines were reviewed by McKenzie who commented:
“The idea that fish oil supplements might have some small benefit for arthritis in dogs and cats is not out of the question.”
Glucosamine for dogs
Glucosamine is the biggest name in dog supplement ingredients by a large margin.
Glucosamine for dogs provides the building blocks of cartilage. It helps to rehabilitate cartilage and reduce the progress of dog arthritis while reducing the pain and increasing the mobility of your dog.
Supplemental glucosamine is rapidly taken up by cartilage cells and helps stimulate the synthesis of joint fluid and new cartilage. Glucosamine is very safe with no known side effects.
This supplement is sold alone or often in combination with other ingredients such as chondroitin, methylsulfonylmethane (MSM), green-lipped mussel extract, and many other ingredients. It is sold over-the-counter, through veterinarians and as an additive in commercial pet foods.
Glucosamine is ubiquitous. It is also widely believed by pet owners and veterinarians to be an effective treatment for canine osteoarthritis.
Glucosamine usually comes from the shells of crabs. It is also sold in chemical forms — something that might surprise people who think of these as “natural” products.
Milk thistle for dogs
Milk thistle is an herbal product that is widely used by both humans and their pets.
The active ingredient is a cluster of compounds called silymarin which is extracted from the Silybum marianum plant.
It appears to interfere with chemicals involved in the inflammation response, it acts as an anti-oxidant, and may interfere with the metabolism of some chemicals into toxic compounds in the liver.
When it comes to using milk thistle for dogs and cats, the primary use is for non-specific “support” of the liver.
Multivitamins for dogs
Vitamins are organic compounds and vital nutrients that your dog requires in small amounts.
These substances are termed “vitamins” when your dog cannot synthesize the compound in sufficient quantities and must therefore obtain this through his diet. This means the term “vitamin” depends on the circumstances and the individual dog.
Giving multivitamins for dogs is important for the treatment of certain health problems. However, there is little evidence of nutritional benefit when used by otherwise healthy dogs.
Many supplements advertised as multivitamins also contain other ingredients such as essential amino acids, dietary minerals or essential fatty acids. Thirteen vitamins for dogs are recognized at present.
Probiotics for dogs
Probiotics are beneficial bacteria, such as L. acidophilus, B. bifidum and L. bulgaricus, which help to keep harmful bacteria from colonizing the dog’s gut thereby causing digestive problems.
If the normal bacterial flora becomes out-of-balance or is depleted in a canine’s gut, potentially harmful (pathogenic) bacteria can increase.
Probiotics for dogs are given as live cultures. These become unstable at high temperatures (greater than 75 degrees) meaning they should be added to your pet’s food after it has been cooked, or given through direct supplementation.
Vitamin C/ascorbic acid for dogs
Vitamin C is an important nutrient needed to maintain connective tissue and collagen, the major component of skin, blood vessels, joint cartilage, tendons and teeth.
Vitamin C for dogs is also a powerful anti-oxidant that helps protect cells from damage by free radicals which is linked to canine osteoarthritis and other chronic disease states in dogs where considerable free radical damage results from long-term inflammation.