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Mold Poisoning in Pets – Causes, Symptoms and Treatment

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What is Mold?

by David F. Kramer


For far longer than there have been pets and their people, there has been mold. Evidence of mold has been found in fossils from the Cretaceous period (145 to 66 million years ago), and mold is mostly likely far older than that. For as long as we animals have shared the world with plants, humidity, and the elements, we have had to deal with both the positive and negative effects of this unique microbe.


Mold is neither a plant nor an animal but a member of the fungus family. Molds cause the biodegradation of organic matter, which is a crucial function for our ecosystem. But some molds can lead to serious consequences for our pets, as well as for us, when they are inhaled or ingested.



This article was verified and edited for accuracy by Dr. Jennifer Coates, DVM

Where Does Mold Hide?

The problem with mold is that it can be found almost anywhere—both inside our homes and outside—provided there’s sufficient warmth and moisture to support it.


According to Holistic Vet Dr. Patrick Mahaney of Los Angeles, CA, mold can be found in drywall, around windows and floors, and even in wet clothing and towels that we’re about to wash—and sometimes even after they’re washed. Mold in this form can easily be inhaled or licked off of a tainted surface. That smelly towel your dog is always chewing on might be more than just smelly.


Toxic mold is of particular concern for pets and people because these organisms produce mycotoxins that can cause health problems. There are five categories of toxic mold: Cladosporium, Penicilium, Fusarium, Aspergillus, and Stachybotrys. These molds can cause anything from a sneezing or coughing fit to, in extreme cases, neurologic problems and death.


Mold can be found pretty much anywhere pets like to spend time, whether in your dog’s prime snoozing or play area, or on your cat’s favorite sunning spot on the windowsill. Once you let your pet outside, mold can be found in decaying food, rotten tree stumps, and even in the soil itself. So even in the relative safely of your own backyard, pets aren’t necessarily safe from mold.

Symptoms of Mold Poisoning

Mold poisoning in a pet basically falls into three categories: inhalation, allergic reactions, and ingestion.


If you suspect your pet may have inhaled mold, keep an eye out for the following respiratory symptoms:  respiratory distress (breathing that takes more effort or occurs more rapidly than normal), nasal discharge, coughing, wheezing, sneezing, lethargy, and in the severest of cases bleeding from the mouth and/or nose.


Physical symptoms of an allergic reaction to mold exposure might include excessive scratching, chewing, or licking, which sometimes progresses to the point of fur loss and the development of sores.


According to Dr. Mahaney, the ingestion of mold can lead to gastric symptoms such as decreased appetite, vomiting, and stool changes. In all cases, getting to the vet is crucial. If left unchecked, mold poisoning can affect the liver, kidneys, brain, spinal cord, and even the bones.


Dr. Mahaney says that if after conducting the blood work your doctor finds changes in the kidney or liver, mold exposure would be on the list of suspected causes. “If a pet has an underlying condition such as kidney or liver disease, the condition could easily worsen” due to mold toxicity, he added. Some types of mold also produce toxins that affect the nervous system, causing tremors, seizures, and sometimes death.

Treatment for Mold Poisoning

According to Dr. Mahaney, veterinary treatment for mold exposure is generally focused on supportive care, including the management of vomiting, respiratory symptoms, and the administering of IV fluids for dehydration from gastric distress. In cases of mold ingestion, your vet might opt for a detoxifying supplement such as S-Adenosyl Methionine.


The prognosis for a pet afflicted with mold poisoning is generally good, and provided the source of the mold is properly removed and treated to prevent reinfection, your pet should fully recover. As is the case with any sort of poisoning, getting your animal to the vet as soon as possible is key.

Finding and Getting Rid of Mold in the Home

If you suspect mold growth in your home, there are more than a few ways to confirm it. While there are professionals that specialize in discovering and treating household mold, there are also some do-it-yourself methods, including test kits that are available in stores and online. These products vary greatly in price (from under $10 to over $100). With such a disparity in price, however, one has to imagine that these items also vary in their effectiveness.


If you find that your pet or family is constantly battling unidentified health issues, it certainly would be a wise investment to call in a professional that guarantees their results. If you discover mold directly, you can tackle it with a mix of water and detergent, but if the affected area is larger than 10 square feet, it’s best to call in a professional to take care of it.

What Can Pet Owners do to Prevent Mold Poisoning?

Once you find mold, it’s best to keep your pet away from that area—or the entire room. If a case is particularly bad, it might be a good idea to relocate your pet to a friend or relative’s home while your house is being treated.


To discourage mold growth in your pet’s food, keep the food in an air-tight container. Choosing washable pet beds, toys, and other items your pet may use frequently can also lessen the chances of mold growth. A best practice is to keep anything your pet touches clean and dry. Water bowls, food bowls, and chew toys should be thoroughly cleaned at least once a week.


It’s also important to keep your pet from eating out of the trash or from having access to anywhere spoiled or spilled food or drink might be lurking. People often leave drink and food containers and leftover food on park grounds, so when you and your pet are out for walks, always be aware of anything on the ground they might get into. Beyond moldy foods, there is also the potential for things like chicken bones left on the ground from picnics.


“Prevent your pet from dietary indiscretions; no eating of things they shouldn’t, both inside and outside of the home,” says Mahaney. “That means not letting your pets have free rein outside, and by walking them on a leash. Inside, we need to make sure that our baseboards, drywall, and windows are not growing mold that the pets could potentially be exposed to, and keeping down the humidity in our homes to prevent the growth of mold.”

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