Human multivitamins, also including prenatal vitamins, should never be given to dogs. They contain too many vitamins in different quantities for accurate canine dosage to be achieved. Multivitamins that include IRON can cause DAMAGE to a dog’s digestive system, kidneys and liver.
Glucosamine and certain other human joint supplements may be fed to dogs, if provided you choose a brand without additives. Compare the list of ingredients and the dose per tablet to a joint supplement for dogs before buying. ALWAYS consult with a veterinarian before adding a supplement to your dog’s diet.
As a occasional remedy for upset tummy, human acidophilus capsules can be given to your dog. If prolonged daily supplementation is necessary, purchase a probiotic supplement formulated for dogs, or choose commercial dog food that contains a probiotics. (Yogurt has natural acidophilus in it, and can be given to your dog… provided it’s a Plain Yogurt, and without additive chemical sugars (such as nutria-sweet or xylitol (which is toxic to dogs)
Fish oil supplements for humans are suitable for dogs, as long as they contain pure fish oil, preferably wild Alaskan salmon oil, with no additives. Talk to your vet in order to calculate the proper dosage. You may need to buy a jar of liquid oil, rather than capsules, in order to achieve a low enough dose for small dogs.
Never give human prescription medication to dogs, unless it is prescribed to your dog by a veterinarian. Prescription medications, like antibiotics and pain relievers, may be safe for humans but harmful to dogs.
Some vitamins can simply be added to your dog's diet through whole food sources. For example, probiotics are found in live-culture yogurt. Omega fatty acids are found in fish such as salmon and other fish.
This was given to me by my Veterinarian when I asked about adding a vitamin to my dog’s diet. I have given her Omega 3, and Joint Supplements. But, as for a multivitamin, her food diet has enough of a daily vitamin. I also have given her live-active acidophilus yogurt, usually a plain organic yogurt I mix it with her food if we are changing her diet. She’s also fed a non-grain diet. But, as in anything always consult with your Veterinarian if you want to add supplements to your dog’s diet.