Aflatoxin in Dog Food: What You Need to Know

If you’ve ever heard of aflatoxin in dog food prompting a dog food recall, you might be wondering what aflatoxins are and why they may prompt a pet food brand to issue a safety warning to consumers. More importantly—you may want to know just how worried you should be. 

The truth is that aflatoxins have been found in many commercial pet foods, and they can be fatal. We’re going to look at what aflatoxins are, how aflatoxin poisoning might happen in dogs, and what to do if you’re worried.

What is Aflatoxin?

Aflatoxin is a type of mycotoxin—a name given to natural toxins produced by mold (fungi) (1). These molds grow on certain foods in particular conditions—mostly in warm and humid climates. In fact, it’s estimated that 25 percent of the world’s food crops are contaminated with mycotoxins (2). 

Aflatoxin B₁ is one of the most common and most poisonous mycotoxins. It’s usually produced by Aspergillus molds, which usually grow on crops such as rice, wheat and corn, and some nuts and seeds. 

Dogs are particularly susceptible to aflatoxins, tolerating less than 50 parts per billion before symptoms of aflatoxin poisoning start (3). This makes dogs at least four times more susceptible than pigs and more than six times more susceptible than cattle. 

Once eaten, the aflatoxin is absorbed into the bloodstream and makes its way to the liver, where it is transformed to an epoxide that binds to DNA (4). This not only damages the liver, but tiny, non-fatal doses over a long period can cause growth problems, immunosuppression, and cancer (3). A recent study found a correlation between low-level aflatoxin exposure and mammary (breast) cancer in dogs (5).

Causes of Aflatoxin Poisoning in Dogs

Dogs generally get aflatoxin poisoning through eating contaminated foods. This can be caused by homemade foods (6), commercial pet foods (7), or even something that a dog has scavenged on a walk. Aflatoxin poisonings often occur in outbreaks, because one moldy batch of food can be eaten by many pets. However, aflatoxin poisoning doesn’t generally spread from pet to pet. 

Aflatoxin in Dog Food

Aflatoxins are mainly produced by mold from the Aspergillus family. These molds are common in tropical and subtropical parts of the world (4) and tend to grow on:

• Corn
• Wheat
• Rice
• Peanuts
• Sunflower seeds
• Nuts (Brazil nuts, walnuts, pistachio nuts, pine nuts)
• Pumpkin seeds
• Lentils
• Dairy products and eggs (Aflatoxin M₁)
• Potatoes and sweet potatoes
• Herbs and spices
• Dried fruits

These toxins can grow in the field or in storage, but growth is more likely at certain temperatures and humidity. Because of this, particular times of the year or storage conditions can be riskier for aflatoxin growth. 

Moldy food almost certainly contains mycotoxins, including aflatoxins, and should never be fed to dogs. However, aflatoxins can survive food preparation conditions, and can therefore be present in invisible amounts in the finished product. This can be true for commercial foods (4) or even for snacks like peanut butter. 

While dog food contamination with aflatoxin is rare (8), it can be extremely serious. Keeping an eye on dog food recalls is always a sensible precaution.

Aflatoxin Dog Food Recall: What to Do

The dog food industry tries very hard to ensure that aflatoxins are not present in pet foods. First, they have stringent ingredient quality checks, and they conduct sorting to ensure damaged grains don’t enter the food. Heat and pressure kill any fungus remaining, but cannot destroy any toxin they have already produced. Binding ingredients can also be added to the dog food to reduce the absorption of any aflatoxins in the feed (9). Good storage and testing protocols developed by specialists ensure that contamination is rare, and any problems are usually caught (and acted upon) at an early stage (10, 11). 

Despite all this, pet food recalls due to aflatoxin contamination do occur, on average less than one per year (9). A recall usually covers a batch, or several batches that were known to be produced at the same time, and it doesn’t necessarily mean that every bag in the batch will be affected. Sometimes, like in the recent Sunshine Mills recall, a single affected bag is found on routine testing, and the decision is made to recall the batch just in case other bags are affected. 

If your dog food brand issues an aflatoxin dog food recall, check the information carefully to make sure it’s the same flavor, range, and composition as the one your dog eats. If you have the packaging, you should check the lot number against those in the recall to confirm you have an affected batch (12).

If your dog food is part of a aflatoxin recall:

1. Stop feeding the food immediately.
2. Contact your veterinarian and arrange for all animals that have eaten the food to be examined.
3. Contact the company to return the food, or throw away the food in such a way that pets, humans, and wildlife cannot access it. 
4. Wash storage tubs, scoops, pet bowls and anything else that has been in contact with the food in hot, soapy water, then sanitize with bleach. Rinse well and allow to dry thoroughly.
5. Wash your hands after handling dog food, regardless of whether it’s been recalled.

Aflatoxin Symptoms in Dogs

If your dog is unlucky enough to eat some aflatoxin-contaminated foods, they can experience a range of symptoms including lethargy, vomiting, and appetite loss. On examination, they may have jaundice, seen as a yellowish tint to the gums and eyes. 

You may also notice these symptoms of aflatoxin poisoning in dogs:

• Bruising and unexplained bleeding
• Weakness
• Diarrhea
• Vomiting
• Lethargy
• Jaundice
• Appetite loss
• Increased thirst
• Dark urine
• Collapse

While some of these aflatoxin symptoms are obvious and sudden, smaller doses of aflatoxin can build up over time, causing subtle signs that are easy to miss. This unfortunately means that several weeks may have passed since the exposure, making diagnosis difficult.

Tiny doses over a long period of time can cause longer-term health problems such as cancer and immunosuppression (3).

Unfortunately, dogs that are exposed to aflatoxins or experience aflatoxin poisoning are at risk of death or euthanasia due to the severity of the condition. 

Diagnosing Aflatoxin Poisoning in Dogs

If your dog is showing symptoms, or they’ve had known contact with a recalled batch of dog food, they should see a vet immediately. The liver damage caused by aflatoxins doesn’t always show straight away, meaning a veterinary examination and blood tests are required to determine if an animal is affected.

Blood tests check for several liver enzymes, which may be raised in cases of liver damage. A clotting profile also indicates whether liver damage may be affecting your dog’s ability to clot blood. 

Liver biopsies may also be required (13), which is the best way to confirm the diagnosis. However, this procedure cannot be performed on a severely ill dog—especially one with clotting problems. 

Urine tests are being developed that can help to diagnose aflatoxins in dog urine (14).

The dog’s food can also be tested, but it’s important to realize that a negative result doesn’t necessarily rule out aflatoxin toxicity as the cause for the symptoms. The dog could still have eaten the aflatoxins at the end of an old batch of food or while scavenging out on a walk.

Aflatoxin Poisoning in Dogs: Treatment

There is no specific treatment or antidote for suspected aflatoxin poisoning, so most veterinarians or emergency hospitals will support your dog’s liver in hope that it can heal. This requires intensive care at a veterinary hospital to allow regular medications and monitoring. 

However, it’s important to realize that the prognosis for aflatoxin poisoning, especially in dogs showing symptoms, is poor, and euthanasia is a common choice for these dogs.

Medications for Aflatoxin Poisoning

Since dogs are often not eating and may have had vomiting or diarrhea, hospitalization for a drip (intravenous fluids) is usually necessary. Anti-vomiting medication and antibiotics will usually also be given, alongside a suitable liver-safe balanced diet. N-acetylcysteine may also help the liver to produce the enzymes it needs to get rid of aflatoxin from the body (15).

Dogs that survive the initial poisoning may often have ongoing liver problems. Silymarin (Milk Thistle) and SAMe are two liver-supporting nutrients that may be given to dogs with aflatoxin poisoning, and may also be used alongside Vitamin E and zinc. Dogs may have to have these supplements for life. 

General Cost to Treat Aflatoxin Poisoning in Dogs 

Because it needs intensive treatment, aflatoxin poisoning costs are high. In dogs presenting to the vet with symptoms, the care is likely to cost $3,000 or more if they survive and are discharged. It’s also likely that dogs will need continual medication and regular checkups for life, which will further add to the cost of treatment and care.

If the aflatoxin is found to be related to a diet, the food manufacturer may help with costs in some cases. Pet insurance will also often cover these costs, so it’s worth exploring your financing options when making a decision about your pet’s treatment. 

Aflatoxin in Dogs Prevention

Since aflatoxin poisoning is serious, you might be wondering how to avoid aflatoxin in dog food. There’s no definitive way to prevent your pet from aflatoxin poisoning, but there are some things you can do to help reduce their risk. 

Seek out quality dog food brands. Buy food from reputable manufacturers with proper testing and recall procedures in place.

Consult pet nutritionists. If you are home-making food, consult with a veterinary nutritionist for advice on reducing the risk of using contaminated ingredients.

Practice proper storage. Store purchased pet food in its original container – this keeps it fresher as well as means you have the lot number to check against batch recalls.

Hold on to lot numbers. Save lot numbers and UPC labels for at least 3 months after a bag of food is finished – an envelope in a drawer works well.

Stay informed about recalls. Keep an eye out for dog food recalls so that you are aware as soon as possible of any problems with your chosen food.

Check your dog food stash. Dry kibble dog foods are usually too dry to grow molds, but you should throw away food that gets damp or stale, as this can lead to mold growth and production of mycotoxins.

Practice good food hygiene at home. Refrigerate wet food after opening, use the food by the best before date, don’t feed food that looks moldy or smells off, and regularly clean your dog’s bowls to reduce their risk of food-borne illness.