Brewers Yeast good for long term use alongside other supplements?

Question
QUESTION: I have been giving my dogs Excel 8-in-1 Brewers Yeast with Garlic tabs. I
have been following the recommended dosage of 1 tab for every 10 pounds.
Is it safe to give to my dogs on a long-term basis? Like throughout their
entire lifetime? Or will that eventually lead to kidney/liver failure?

Also, I have recently acquired some shark liver oil and garlic oil soft gels
which I also plan to give to them..would that be overkill? I am planning to
either alternate the shark liver oil soft gels with the brewers yeast and give
the garlic oil on a daily basis. My concern though, is that the brewers yeast
already contains garlic and the garlic oil might be too much..

Should I stick to just one supplement? Or alternate the three on a daily basis?
Or stop with the supplements altogether?

ANSWER: I do not know what your goal is with these supplements.

Brewers Yeast provides B-vitamin complex and minerals like zinc and chromium, and it is fine as long as the dog has no allergies to it.  

I would not add the garlic oil softgels.  There is really no reason to, especially since there is already garlic in the Brewer's Yeast tabs.  Garlics benefits are anecdotal, and it has not been proven to ward off fleas.  A small amount of garlic is fine for dogs, but too much can cause anemia.

The concern with feeding liver oils (rather than fish body oils) is the amount of vitamin A in liver, and the fact that overdoses can be toxic long-term.  Cod liver oil does not have a dangerous amount of vitamin A, but other liver sources can.  This is in addition to the amount of vitamin in their dog food.

I am not sure if shark liver oil is dangerous for dogs in the amount of vitamin A it contains, but as a comparison, I found one serving of Cod Oil for a large-sized dog containing 700 IUs, and 1 shark liver oil pill to contain 10,000 IUs (IU is a potency measurement of vitamins).  A large-breed dog might need only 3,000-6,000 IUs of Vitamin A a day.  

So this may be something to ask your vet about to make sure.

---------- FOLLOW-UP ----------

QUESTION: Thanks for getting back to me so quickly.

I checked the literature included in the Shark Liver Oil soft gels, one soft gel
contains 625 IU of Vit A and 62.5 IU of Vit E. Would that be ok then? I've
heard that these liver oils will help improve a dog's skin & coat condition,
which is why I decided to try them out. Incidentally though, this is also what
Brewers Yeast does although the vitamin contents are not the same.

On another note, is brewers yeast safe to give throughout the lifetime of my
dogs? Or is this something unnecessary and to be stopped after I've used up
my bottle? Have there been cases of long-term brewers yeast use causing
liver/kidney failure in dogs?

ANSWER: I think it would be fine then with those levels of vitamin A.  To improve skin and coat, I would rather give fish body oils that are high in omega-3 fatty acids, such as salmon oil, or any fish oil pill.  I would also question what is the main diet for the dogs, since all the supplements in the world are not going to give you full benefits if the main diet is not quality.  I have not heard of any long-term problems with brewers yeast.

---------- FOLLOW-UP ----------

QUESTION: My adult dogs are currently on Eagle Pack Holistic Recipe Lamb Meal & Rice while my 4-month-old husky pup is on Eagle Pack Small & Medium Breed Puppy Formula; I am about to put her on the Large Breed Formula as I think she has been growing too fast.

So would you suggest giving the Shark Liver Oil together with the Brewers Yeast on a daily basis? Presently I am just alternating between the two but if it's ok to give them together daily, I will just give the Shark Liver Oil until I finish my supply, then go back to plain Brewers Yeast.

By the way, all my dogs including the puppy weigh between 23 - 26 pounds so I give them 2.5 tabs of Brewers Yeast and just 1 soft gel of Shark Liver Oil.

Thanks again.

Answer
I am not too familiar with giving dogs virgin coconut oil, but I have heard of it's benefits to humans.  I believe coconut oil is not high in omega-3 like fish oil is, but it does contain lauric acid (its the only vegetable oil that contains it) and has benefits to health internally (metabolism, strengthening immune system) and also benefits when applied to the skin and hair.

I think it is fine to give the shark liver oil and the brewer's yeast together.