Yeast is often used as a supplement for dogs. What does it do?
Yeast is a high energy food that is extremely rich in the vitamin B group. Its beauty is that it occurs naturally and hopefully the vitamins are contained in a useful proportion, rather than some arbitrary decided laboratory combination that may or may not contain some of the lesser components and may or may not be balanced for the benefit of the dog rather than the financial benefit of the manufacturing drug company.
Yeast has a high proportion of digestible protein, which contain many of the essential amino acids. But it does not contain sufficient calcium. If you are not already using a calcium supplement and you decide to use a supplement of yeast, you will need to use a calcium supplement, and cod liver oil to provide vitamins A and D to allow for the proper absorption and use of calcium and phosphorus.

There are two sorts of yeast generally available. These are Brewers and Torula. They are grown from two separate species of yeast, and although not as different as tomatoes and potatoes, there are distinct advantages of using one or the other for various effects.
Dogs like yeast, so there is no worry about choosing the one which Fido will eat without trouble. There are yeast tablets specially manufactured for dogs as well as being tablets for human use which are also suitable for dogs. Dogs are quite happy to eat yeast powder too, which may be sprinkled on their food.
The key to which form to use, tablet or powder will depend upon the economics of the situation. The main dog yeast tablet is made from Brewers yeast, for knowing which yeast the human tablets are made from you will need to check out the label. The powder is usually the cheapest way to buy the yeast. It is available from health food stores and some supermarkets as well. The tablets (human type) are available from health food stores and supermarkets. The dog tablets are available from specialty dog shops.
Which yeast will be the best supplement for my dog?
Growing puppies who receive a plethora of supplements including a multivitamin preparation will do best on Torula yeast which is rich in zinc, the lesser members of the vitamin B group and an excellent selection of essential amino acids. It is richer in iron, potassium, and manganese as well as the zinc already mentioned than Brewers yeast.
It is less rich in thiamine and choline than Brewers yeast. But the choline content is more than adequate. It also contains a greater amount of vitamin B12, than does Brewers yeast.
It is therefore the yeast of choice for puppies, show dogs and those that require a feeling of well being at all times.
On the other hand Brewers yeast contains more thiamine (Vitamin B1) than does Torula yeast. It also contains chromium and selenium; both of which are essential to life, but which in even small quantities are deadly poisons. In Brewers yeast, the amounts are useful for the dog, but quite safe to avoid overdosage. Selenium is essential with vitamin E for proper muscle development of both the external muscles as well as those of the heart and digestive system. Chromium is a vital part of the glucose tolerance factor which assists in maintaining the blood glucose level, converting body fats back to glucose in times of need and may assist in the prevention of diabetes. Not much work has been done on dogs.
So Brewers yeast is probably the yeast of choice for very active, working dogs, racing dogs, agility and advanced obedience dogs as well as the fat, lazy, slothful dog needing to lose a bit or a lot of weight. It would also be the yeast of choice for dogs under other forms of stress in which a multivitamin preparation was not included in the diet.
As with Torula yeast, Brewers yeast requires a calcium supplement to balance its excess of phosphorus. Cod liver oil as a source of Vitamin A and D should also be fed to ensure the correct interaction of the calcium and phosphorus in the general diet.
Yeast, in one form or another, is a good supplement for many dogs. However, it is wise to use the right yeast for the right result. A few of the important differences have been explained. To be sure, you are using the right yeast for the right reason, a canine nutritionist should be consulted.= .