Do Dogs and Cats Really Need Supplements?

From omega-3s to probiotics, the pet supplement market is booming. But do our furry companions actually need them — and if so, which ones matter most? Here is what every pet parent should know.

When a complete diet is enough

If your dog or cat is eating a high-quality, commercially prepared pet food that is labelled “complete and balanced,” they are likely getting all the essential nutrients they need. Reputable pet food brands formulate their recipes to meet strict nutritional guidelines, which means supplementing on top of a complete diet may not always be necessary — and in some cases, can actually cause harm by creating nutrient imbalances.

When supplements become important

Supplements become valuable in specific situations — when a pet has a diagnosed deficiency, a chronic health condition, is on a homemade diet, is a senior pet, is recovering from illness or surgery, or has breed-specific health vulnerabilities. In these cases, the right supplement can make a meaningful difference to your pet’s quality of life.

Key supplements and what they do

Omega-3 fatty acids: Supports skin, coat, joints and heart health. Found in fish oil.

Glucosamine & chondroitin: Supports joint health and mobility, especially in senior pets.

Probiotics: Supports gut health and digestion. Helpful after antibiotics.

Vitamin D: Important for bone health. Deficiency is common in indoor pets.

Taurine: Essential for cats — supports heart and eye health. Cats cannot produce it naturally.

Antioxidants: Vitamins C and E help combat cell damage and support immune health.

Cats vs Dogs – Key differences

What cats need

Cats are obligate carnivores, meaning they have very specific nutritional needs that differ greatly from dogs. Taurine is non-negotiable — without it, cats develop serious heart and eye conditions. Cats also cannot produce certain fatty acids on their own, making dietary sources essential. Never give cats supplements formulated for dogs, as some ingredients safe for dogs can be toxic to cats.

What dogs need

Dogs are omnivores and generally more flexible in their nutritional needs. Joint supplements such as glucosamine are among the most commonly recommended for dogs, particularly larger breeds prone to hip dysplasia. Omega-3 supplements are also widely used for skin, coat, and inflammatory conditions. Senior dogs often benefit from a broader supplement routine tailored to their age-related changes.

Senior Pets – extra care for older pets

As pets age, their ability to absorb certain nutrients decreases and their health needs change. Senior dogs and cats often benefit from joint support, supplements, antioxidants to combat cellular ageing, probiotics for digestive health, and omega-3s for cognitive function and inflammation. If your pet is over seven years old, a conversation with your vet about a tailored supplement is well worth having.

What to watch out for – not all supplements are created equal

The pet supplement market is largely unregulated in many countries, which means quality varies significantly between brands. Always look for supplements that have been independently tested, carry a veterinary recommendation, and list clear, transparent ingredients. Avoid supplements with vague ingredient lists, excessive fillers, or artificial additives. More is not always better – over-supplementing can lead to toxicity, particularly with fat-soluble vitamins such as A and D.

Always consult your vet first

Before starting any supplement, speak to your veterinarian. They can assess your pet’s specific needs through blood tests and health checks, recommend the right supplement and dosage, and identify any potential interactions with existing medications. What works well for one pet may not be appropriate for another — your vet is always the best starting point.