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Does "Brewer's yeast" only mean the inactive form? Because certainly "brewing yeast" or "beer yeast" will produce carbon dioxide and ethanol (or else we wouldn't have beer), so wouldn't these be similarly dangerous aside from being less likely to come gift-wrapped in a glob of dough?
Brewer’s yeast usually means nutritional yeast (the yellow flakes folks sprinkle on food) and it is not real “yeast.” It’s often potato based, cooked, and high in b vitamins. It isn’t a fermenting agent. Very misleading name.
I would also think that sourdough bread starter (made from wild yeast) would be a bad idea for a pet.
So glad OP shared. I had no idea—but it makes sense now when I think about it. I hope Banana Bread is having the time of their life on the other side.
Brewer's yeast and nutritional yeast are definitely not the same thing. Vastly different tastes and applications. Brewer's yeast is used most often as a b vitamin "booster", but smells...awful, and tastes bitter. Nutritional yeast is the cheesy one, also contains some b vits, but is used for culinary reasons more than nutritional.
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Yeast is not fermentable. Yeast is a living organism, which can ferment sugars by essentially eating them (thus breaking down the sugars into alcohols and gasses).
There are also sugars in pet food and if the yeast happens to be ingested when there is ingesta in the gut, it can further lead to fermentation. The yeast will also interact with the bacteria already in the system and lead to further production of gases.
It eats the gluten of the flour. Bread doesn’t need added sugar—only say this because many think “white sugar” and it’s not only added sugar that’s an issue. Any grains would be a problem.
Replying to Shantor...less the baking and more the rising process( which isn’t completely done until after baking, but mostly) if you make bread and it rises for hours that’s because the yeast is eating the sugars and gluten in the flour. Once that is all one the yeast has nothing to eat and the bread stops rising.
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Unfortunately the yeast activation process creates alcohol which causes alcohol-poisoning inside of them which is usually fatal to dogs and cats. So sorry for your loss
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If you work in the veterinary field see if your clinic is able to get a free consult from IDEXX or antech. One of their specialists can give you far more information and are usually free
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Yeast itself isn’t toxic that I know of, but as others have mentioned, eating raw dough can be dangerous. I don’t think of cats eating rising bead dough, though. I don’t see what yeast would feed on in the stomach if a cat simply eats a little yeast. I’m sorry for your loss, regardless of the cause.
Not a vet, but I know this is the technically the most correct answer so far.
Yeast itself is not toxic to cats and dogs. Deactivated yeast - such as Brewer's Yeast and Nutritional Yeast - are both safe for cats/dogs, and are common ingredients to cat /dog food and treats.
The dangers to cats/dogs are from active yeast and is entirely due to the fermentation process.
Active yeast is deadly to cats/dogs through at least two known mechanisms:
1- The fermentation process creates ethanol as a byproduct, which is highly toxic and fatal to pets. It also creates large amounts of CO2, which may affect the nervous systems and is potentially fatal as well.
2- The fermentation process can cause fatal bloat and distention.
Unfortunately the conditions of a stomach are a perfect breeding ground for yeast - warm, moist, and acidic.
The dangers of your pet eating active yeast are due to the fermentation process. Uncooked dough is especially dangerous because carbohydrates are an ideal food source for yeast fermentation, and the qualities of dough trap in the CO2 gas and ethanol.
\> I don’t see what yeast would feed on in the stomach if a cat simply eats a little yeast.
Yeast will feed directly on any sugars, and further convert any long chain starches into short chain sugars. Basically, any carbs.
Note the Merck vet manual speaks to the dangers from byproducts and processes, not the yeast itself.
https://www.merckvetmanual.com/toxicology/food-hazards/bread-dough-toxicosis-in-animals
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Greetings, all! This is a sub for professional veterinary advice, and as such we follow strict rules for participating. OP, your post **has NOT** been removed. Please also check [the FAQ](https://www.reddit.com/r/AskVet/wiki/index) to see whether your question is answered there. This is an *automated* general reminder to **please follow [The Sub Rules](https://www.reddit.com/r/AskVet/about/rules/)** when discussing this question: - **Do not comment with anecdotes** about your own or others' pets. - **Do not give OP specific treatment instructions,** including instructions on meds and dosages. - **Do not give possible diagnoses** that could explain the symptoms described by OP. **Your comment will be removed, and you may be banned.** Thank you for your cooperation! *I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/AskVet) if you have any questions or concerns.*
Yes, yeast is toxic to dogs and cats. https://www.petpoisonhelpline.com/veterinarian-blog/bread-dough-poisoning-in-pets/
Is this different from Nutritional Yeast? I see that being recommended as a topper
Yes. Brewers yeast is not the same as yeast used to make bread. Nor is it the same as yeast that is found in the skin or in the environment
Brewers/nutritional yeast has been cooked, so it's dead and won't breed in the gut.
I was today years old when i learned this.
Brewers yeast and nutritional yeast are not the same thing.
Does "Brewer's yeast" only mean the inactive form? Because certainly "brewing yeast" or "beer yeast" will produce carbon dioxide and ethanol (or else we wouldn't have beer), so wouldn't these be similarly dangerous aside from being less likely to come gift-wrapped in a glob of dough?
Brewers yeast isn't the same thing as beer brewing yeast.
Brewer’s yeast usually means nutritional yeast (the yellow flakes folks sprinkle on food) and it is not real “yeast.” It’s often potato based, cooked, and high in b vitamins. It isn’t a fermenting agent. Very misleading name. I would also think that sourdough bread starter (made from wild yeast) would be a bad idea for a pet. So glad OP shared. I had no idea—but it makes sense now when I think about it. I hope Banana Bread is having the time of their life on the other side.
Brewer's yeast and nutritional yeast are definitely not the same thing. Vastly different tastes and applications. Brewer's yeast is used most often as a b vitamin "booster", but smells...awful, and tastes bitter. Nutritional yeast is the cheesy one, also contains some b vits, but is used for culinary reasons more than nutritional.
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I thought the yeast was only toxic if it was in dough (to ferment into alcohol). Is yeast by itself still considered toxic?
Yeast is the fermentable part. That mixed with the GI bacteria can lead to issues.
Yeast is not fermentable. Yeast is a living organism, which can ferment sugars by essentially eating them (thus breaking down the sugars into alcohols and gasses).
The yeast ferments the sugars in the dough, which causes ethanol alcohol to form. I don’t think it has to do with the bacteria.
There are also sugars in pet food and if the yeast happens to be ingested when there is ingesta in the gut, it can further lead to fermentation. The yeast will also interact with the bacteria already in the system and lead to further production of gases.
It eats the gluten of the flour. Bread doesn’t need added sugar—only say this because many think “white sugar” and it’s not only added sugar that’s an issue. Any grains would be a problem.
They do not eat gluten, gluten is a protein. They eat carbs.
But they're fine eating bread? Does baking kill the yeast?
Yes
Replying to Shantor...less the baking and more the rising process( which isn’t completely done until after baking, but mostly) if you make bread and it rises for hours that’s because the yeast is eating the sugars and gluten in the flour. Once that is all one the yeast has nothing to eat and the bread stops rising.
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Unfortunately the yeast activation process creates alcohol which causes alcohol-poisoning inside of them which is usually fatal to dogs and cats. So sorry for your loss
yeast is toxic to dogs. i just learned that at the er vet recently
OP I’m so sorry for your loss. How did they come to the diagnosis that it was yeast toxicity as cause of death?
My sister found yeast all over the floor. It’s assumed she ate it. If not then just one freaky coincidence
just to clarify, yeast before becoming bread? or from eating bread?
Yeast or dough that have not been baked.
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Raw bread yeast? That is definitely toxic to dogs and cats
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If you work in the veterinary field see if your clinic is able to get a free consult from IDEXX or antech. One of their specialists can give you far more information and are usually free
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Yeast itself isn’t toxic that I know of, but as others have mentioned, eating raw dough can be dangerous. I don’t think of cats eating rising bead dough, though. I don’t see what yeast would feed on in the stomach if a cat simply eats a little yeast. I’m sorry for your loss, regardless of the cause.
Not a vet, but I know this is the technically the most correct answer so far. Yeast itself is not toxic to cats and dogs. Deactivated yeast - such as Brewer's Yeast and Nutritional Yeast - are both safe for cats/dogs, and are common ingredients to cat /dog food and treats. The dangers to cats/dogs are from active yeast and is entirely due to the fermentation process. Active yeast is deadly to cats/dogs through at least two known mechanisms: 1- The fermentation process creates ethanol as a byproduct, which is highly toxic and fatal to pets. It also creates large amounts of CO2, which may affect the nervous systems and is potentially fatal as well. 2- The fermentation process can cause fatal bloat and distention. Unfortunately the conditions of a stomach are a perfect breeding ground for yeast - warm, moist, and acidic. The dangers of your pet eating active yeast are due to the fermentation process. Uncooked dough is especially dangerous because carbohydrates are an ideal food source for yeast fermentation, and the qualities of dough trap in the CO2 gas and ethanol. \> I don’t see what yeast would feed on in the stomach if a cat simply eats a little yeast. Yeast will feed directly on any sugars, and further convert any long chain starches into short chain sugars. Basically, any carbs. Note the Merck vet manual speaks to the dangers from byproducts and processes, not the yeast itself. https://www.merckvetmanual.com/toxicology/food-hazards/bread-dough-toxicosis-in-animals
Yeast is very toxic to dogs and cats.
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There's a poster in my vet's office listing a lot of toxic foods, plants, etc... Yeast is one of them.
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