Moldy Food (Mycotoxins) Poisoning in Dogs
Written By hannah hollinger
Published: 06/24/2016Updated: 10/21/2021
Veterinary reviewed by Dr. Linda Simon, MVB MRCVS
Moldy Food (Mycotoxins) Poisonings in Dogs - Symptoms, Causes, Diagnosis, Treatment, Recovery, Management, Cost
What is Moldy Food (Mycotoxins) Poisoning?
Mycotoxins are poisonous substances produced by fungi and molds that grow on spoiled food. These substances are toxic to dogs as well as humans and can pose a problem for pets that like to eat food out of the trash. There are many different kinds of mycotoxins which are divided into several families. The most common group are tremorgenic, meaning that they contain a neurotoxin which causes tremors or seizures in dogs. 
Tremorgenic mycotoxins are produced by various Penicillium species of bacteria, with penitrem-A being the substance that most frequently causes poisoning in dogs. Penitrem-A is found on many types of spoiled food, including, bread, dairy products, and nuts. This type of poisoning is relatively common in dogs, with immediate symptoms of vomiting, tremors, and fever. Without treatment, high doses can cause fatal seizures.
Other toxic mycotoxins can also be present including aflatoxins produced by aspergillus fungi. These mycotoxins are metabolized in the liver and may cause hepatocellular necrosis (liver cell death) which will affect liver function giving dogs a yellowish, jaundiced appearance. Fusarium mold containing trichothecene mycotoxins can also sometimes be found on old or contaminated pet food. This will cause vomiting, diarrhea and abdominal pain. Severe mycotoxin poisoning can result in death and even non-fatal doses may be symptomatic for up to five days. Veterinary treatment can reduce the symptoms and help to eliminate the toxins faster, greatly increasing the dog’s chances of recovery.
Moldy food can contain mycotoxins that are poisonous to your dog. If ingested, the syndrome that can occur is called mycotoxin intoxication or mycotoxin toxicosis. Seizures and tremors are the most common symptoms. Severe cases can be fatal without treatment.
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Symptoms of Moldy Food (Mycotoxins) Poisoning in Dogs
These symptoms could indicate mycotoxin poisoning.
  • Vomiting
  • Diarrhea
  • Restlessness
  • Disorientation
  • Tremors
  • Seizures
  • High fever (hyperthermia)
  • Jaundiced appearance (icterus)
  • Abdominal pain
Types
These are some of the mycotoxins found frequently in moldy food.
Penitrem-A
  • The most common type of tremorgenic mycotoxin associated with poisoning in dogs, frequently found in mold growing on bread, nuts, cheese and other spoiled products
Aflatoxins
  • Produced by aspergillus fungi this can also be a component in many types of mold
  • In dogs, it can affect liver function and may cause icterus (jaundice)
Vomitoxin
  • A trichothecene mycotoxin produced by Fusarium mold that grows on grains such as those found in bread or dog food
  • This is an infrequent cause of poisoning in dogs that is mainly caused by contaminated dog food
Roquefortine
  • Another tremorgenic mycotoxin frequently found with penitrem-A
Causes of Moldy Food (Mycotoxins) Poisoning in Dogs
These are some of the causes and risk factors for mycotoxin poisoning.
  • Spoiled food left in an open trashcan
  • Compost heap
  • Feeding spoiled food to a dog
Diagnosis of Moldy Food (Mycotoxins) Poisoning in Dogs
A history of moldy food ingestion is the easiest way of identifying a likely mycotoxin poisoning in your dog. Whenever possible, you should bring a sample of the suspected substance with you so the veterinarian will be able to better identify the mycotoxin that is causing the problem. If aflatoxins are present, a blood test will show reduced liver function, but other mycotoxins rarely have obvious diagnostic markers. 
Lab testing of the spoiled food or the contents of your dog’s stomach will be necessary to definitively diagnose mycotoxin toxicosis and identify the substance that is causing your dog’s symptoms. The veterinarian will also need to test for alternative causes since ingestion of other toxic substances like ethylene glycol, hydrocarbons or amphetamines could cause similar symptoms. A history of your dog’s recent activities may be helpful, especially if you didn’t see the incident.
Treatment of Moldy Food (Mycotoxins) Poisoning in Dogs
Initial treatment will focus on eliminating the toxic substance. Vomiting may be induced or gastric lavage may be done under anesthesia. Activated charcoal may be given to reduce absorption in the stomach as well as a cathartic medication to initiate bowel movements. Intravenous fluids usually form part of the therapy too.
More advanced cases will require medication to control symptoms. Diazepam is often prescribed to control seizures with tremorgenic mycotoxins. Intravenous methocarbamol may be necessary with very severe seizures. For aflatoxin poisoning, intravenous fluids and electrolytes will be necessary to support liver function and blood transfusions might be required in severe cases. Corticosteroids may be prescribed if your dog is in shock as well as other medications to regulate body temperature.
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Recovery of Moldy Food (Mycotoxins) Poisoning in Dogs
Most dogs will survive mycotoxin poisoning with aggressive treatment. It is important to get treatment however, since this type of toxicity can be fatal. Finding and removing the cause of poisoning will be necessary to prevent a recurrence. You should buy fresh dog food and throw away the old food in a sealed container or a dog-proof garbage can. Buying dog food in smaller quantities can reduce the risk of contamination. 
Spoiled food should be disposed of in a garbage disposal whenever possible. Rinse out old milk cartons or bottles before recycling them. Keep sealed lids on all your garbage cans and try to train your dog not to go through trash; teaching a 'leave it' command can come in very useful, especially when out and about. Avoid feeding any spoiled food to your dog. Food that is not fit for human consumption will likely be toxic for your dog also.
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Moldy Food (Mycotoxins) Poisoning Average Cost
From 79 quotes ranging from $200 - $3,000
Average Cost
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Moldy Food (Mycotoxins) Poisoning Questions and Advice from Veterinary Professionals
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mastiff mix
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One Year
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27 found this helpful

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27 found this helpful

My pet has the following symptoms:
Not Eating
Took a piece of Moldy food out if my dogs mouth on a walk last night. Don't think she swallowed any but she's not eating today. She did go on her walk, her poop was normal, and she drank water
March 7, 2021
Answered by Dr. Linda S. MVB MRCVS
27 Recommendations
Most dogs tolerate moldy food well, especially large breeds. The fact she likely didn't eat much bodes well and the lack of appetite could be unrelated. Monitor for further signs such as vomiting, diarrhoea or lethargy and consider offering tasty food such as warm warm today. If she doesn't improve soon, a vet visit is best.
March 7, 2021
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Black Mouth Cur
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Three Years
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26 found this helpful

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26 found this helpful

My pet has the following symptoms:
My dog may have eaten a small amount of mold from a bite of old canned dog food. Noticed small mold on the can cover afterward. Does he require treatment if no symptoms are present? Also, would it better to give him more (fresh) food and water or is it better for him to have less in his stomach?
Jan. 6, 2021
Answered by Dr. Linda S. MVB MRCVS
26 Recommendations
Hi there, thank you for your question. Most dogs have very strong stomach acid and robust gastrointestinal systems so they can typically tolerate gone off food better than us and won'y necessarily suffer ill effects from a little mold. Monitor for signs such as vomiting, diarrhoea or a reduced appetite but we wouldn't be likely to see them. I would probably let his stomach rest and not feed too much just in case.
Jan. 6, 2021
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Maltese
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Twelve Years
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9 found this helpful

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9 found this helpful

My pet has the following symptoms:
Vomiting
My dog ate old lettuce from Monday and isn't feeling well and throwing up. I'm worried about her and will make an appointment with the vet, what should I do to help her?
Dec. 6, 2020
Answered by Dr. Linda S. MVB MRCVS
9 Recommendations
I agree a vet visit is best. Try to get her to keep something down to avoid dehydration. Bland small meals of chicken and rice with water are best. Allow her to rest and keep her on a comfortable bed in a room that isn't too hot or cold. Avoid dog food, treats and chews which may be too rich. Hopefully she is feeling better very soon.
Dec. 6, 2020
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Great Pyrenees
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Five Years
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22 found this helpful

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My pet has the following symptoms:
None
My dog ate a backache of moldy sargento cheese slices from the garbage about 2 hours ago
Sept. 28, 2020
Answered by Dr. Michele K. DVM
22 Recommendations
Thank you for your question. Cheese mold can be quite toxic, and it would be best to monitor your dog very closely over the next 24 hours for signs of vomiting or diarrhea, or lethargy or a decreased appetite. If any of those things are occurring, then having him seen by a veterinarian would be a good idea. I hope that all goes well!
Oct. 4, 2020
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Australian Shepherd
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Two Years
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1 found this helpful

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1 found this helpful

My pet has the following symptoms:
Tarry Stool
Hey my dog ate 5 day old moldy dog food is he gonna be ok he isn’t showing any signs
Sept. 24, 2020
Answered by Dr. Michele K. DVM
1 Recommendations
Thank you for your question. I apologize for the delay, this venue is not set up for urgent emails. I hope that your pet is feeling better. If they are still having problems, It would be best to have your pet seen by a veterinarian, as they can examine them, see what might be going on, and get any testing or treatment taken care of that might be needed.
Oct. 23, 2020
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Doberman Pinscher
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Maple
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8 Years
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My pet has the following symptoms:
Shaking
Jaundice
Fever
Vomiting
Ataxia
High Liver Enzymes
My dog ate very old pasta sauce that didn't look moldy at first. It smelled good and I only saw the mold in it after it was too late. She puked for 2 days and was shaking constantly, had a hard time walking and refused to eat since. It's been 2 weeks now and she's still refusing to eat. She has mild jaundice with high liver enzymes. Her mood and energy is much better now, she runs and plays and goes for walks but the jaundice is still there (2 weeks) still refusing to eat. If she drinks a lot of water she pukes. She took meds for vomiting and appetite stimulator but she still won't eat. Shaking was controlled with Clonazepam, very low dose. I give her subcutaneous fluids everyday to keep her hydrated. She's taking herbs and supplements like SAMe, milk thistle and vitamins to help her heal and function. How long will it take for her liver function to return back to normal? I read it takes 30 days in humans for new cells to generate. When will she start eating on her own? Will she recover completely from this?
Moldy Food (Mycotoxins) Poisoning Average Cost
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Average Cost
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