Can Mold Make Your Dog Sick?

Whether your dog ate mold or you’re simply preparing for possible problems in the future, you have come to the right place. Can mold make your dog sick? Yes. But, are dog mold allergy symptoms too difficult or expensive to treat? No.

There is hope for your furry friend and I’d like to share that hope with you today.

Mold Exposure and Immune Response

Mold exposure comes in three forms for both dogs and humans. There is the inhalation of mold spores, the skin-contact of mold, and the ingestion of mold. All three types of exposure can either be benign or dangerous, depending on the type of mold and the body’s immune function. A sensitive immune system can overreact to the most benign exposure and the least dangerous mold. A well-functioning immune system will handle most exposures effortlessly and the dog or person will show little to no symptoms at all.

The good news about a dog’s immune system is that it was designed to handle some of life’s grittiest encounters. Dogs are able to heal from the nastiest and dirtiest (bacterial) animal bites, recover from the filthiest and most toxic foods (think: garbage), and handle some of the most polluted habitats known on the planet (Chernobyl, anyone?). In other words, it is very unlikely that a one-time exposure to mold will cause your dog anything long-lasting. That said, it would still be beneficial if you knew a few worse-case scenarios and how to manage them if your dog’s mold exposure was severe or he has an overly-sensitive immune response to mold.

Molds Dogs Are Most Commonly Exposed To:

• Alternaria–common during Spring and Fall
• Aspergillus–vegetation, basements
• Fusarium—cereal crops (dog food), plants
• Helminthosporium—soil in Summer
• Hormodendrum—both living and decaying leaves
• Penicillium—vegetation, stored food products
• Phoma—quick-growing after Autumn rains
• Spondylocladium—plants, building air ducts

Some of these molds produce mildly-irritating mycotoxins (which the body can adapt to and fight easily), while others produce the most dangerous mycotoxins, known as aflatoxins. Aflatoxins are both carcinogens (cancer-causing) and mutagens (DNA-altering). With aflatoxic molds, a one-time exposure is enough to disrupt the health of your dog for long periods of time or cause their immune system to be overly responsive (think: self-destructive inflammation) or less responsive (think: extreme vulnerability to weak microbes), which can result in chronic and devastating sickness and possible death. There is even evidence to suggest that aflatoxins are responsible for liver disease in dogs, as well (See: “Can mold cause liver disease in dogs?”).

If you suspect your dog has been exposed in a dangerous way to mold, you will need to know what symptoms to look out for. It may not be enough to remove the dog from the mold-infested habitat, bathe him, or change his diet; you may need to take him in to a veterinarian.

Some of the less worrisome dog mold allergy symptoms will include temporary sneezing, coughing, and itching that improve upon removal from a habitat, the cleaning of a habitat, or a bath with hypoallergenic shampoo. Such symptoms are only a concern if they persist for several days. Other more immediate and severe symptoms will not always include respiratory indicators like symptoms of black mold poisoning in humans. Instead, severe dog mold allergy symptoms will often manifest themselves in a dog’s skin, as later mentioned, despite whether the mold was breathed in, touched, or consumed.

Your Dog Breathed in Mold

If you suspect your dog has inhaled large quantities of mold spores or has persistently been in a habitat contaminated by mold, there is good news and bad news.

The good news: A dog’s lungs—much like a person’s—is a very inhospitable environment for microbes. This is because there is no nutrition available in the lungs to both bacteria and fungi, which reduces the chance of long-term residence should such microbes get past the carina (where the airways branch off into the lungs). Most importantly, however, the respiratory system itself is under constant surveillance by the immune system.

It should be noted that an immediate sneeze or cough response to mold exposure is actually a good sign that the respiratory line of defense is working properly. A persistent cough lasting for several days, however, is a sign that inflammation and infection have taken hold of your beloved pooch and he needs medical attention.

The bad news: For centuries, dog breeding has custom-tailored a subjective preference on dog behavior and appearance. This has caused not only a great variety of dog breeds, but a vast watering-down of certain breeds’ capacity for good health and longevity. In other words, some dog breeds are more susceptible to respiratory issues. We may feel a fierce cute-aggression response to squished pug and bulldog faces, but the truth of the matter is that the adorable shape and size of their snout makes them weak and vulnerable to respiratory strife and disease.

The nasal passages are a dog’s respiratory system’s first defense against mold. The shorter the snout, the less likely it can stop mold spores from entering the lungs. It isn’t just the snout of these types of breeds—their lungs are naturally weak from centuries of inbreeding, as well. Some long-snouted dogs have the same inbred lung weaknesses as the severely short-snouted dogs. The most mold-vulnerable breeds will be short-snouted and/or small breeds. The least mold-vulnerable breeds will be mutts and large breeds with a less narrow ancestry of breeding. Ages of greatest susceptibility will be newborn puppies and geriatric dogs of all breeds.

Breeds with weak respiratory function or individual dogs with compromised immune systems, can easily develop a fungal infection of the respiratory system called pneumocystis carinii. P. carinii infiltrates the body’s weakened defenses, multiplying and growing to critical levels in the lungs.

Symptoms of P. carinii include the following:

• coughing
• diarrhea
• difficulty in regular exercises
• gradual weight loss
• cachexia—physical wasting (muscle loss and weakness)

Regardless of your dog’s breed, please be aware that an inhalation of large quantities of mold or a recurring inhalation of mold is not something to take lightly, even if you have a so-called “healthy” breed. 

Your Dog Touched Mold

The skin of both humans and dogs is the greatest barrier and defense against mold. Rarely will skin contact with mold cause a noteworthy reaction. However, this only applies to dry and well-groomed dogs (and people). Long-haired dogs and dogs that are kept outdoors are more likely to experience mold-induced rashes or mold infections because the fur is not clean or dry, which traps moisture, decaying organic material, and heat—mold’s favorite habitat. In addition, open wounds and mucus membranes (i.e. eyes, genitals, nose) are more susceptible to fungal infiltration and infection.

If your dog and his living conditions are kept clean and dry and his wounds from all his daily adventures are cleaned and treated quickly, mold on dog skin is no danger, but you will still need to take precautions against mold contact.

Dog mold allergy symptoms in the skin will reveal themselves by the following indicators:

• chewing of the paws
• chronic ear infections
• excessive licking
• hair loss
• hot spots
• pruritus (excessive itching and scratching)
• pustules (pus-filled zit-like bumps, usually within a hair follicle—causes hair to fall out)
• redness and scaliness of the skin
• secondary skin infections
• shaking of the head and ears
• thickened and odorous skin

Your Dog Ate Mold

If you’re certain your dog ate mold, you can also be relatively certain that his body is equipped to remedy and resolve the issue rather quickly.

A dog’s gut—the stomach and intestines—is very acidic, which is typical of any carnivore. Their digestive system is designed to process large quantities and great varieties of meat and bone, as well as manage dangerous microbes from decaying flesh. During digestion, a dog’s stomach acid can reach a pH level well below 1.0. For comparison’s sake, a human’s stomach pH generally stays between 2.0 and 3.5, which allows for many types of bacteria and fungi to sneak through unscathed. A vulture, for example, has probably the most corrosive stomach acid on the planet because it was designed to clean up rotting carcasses, which are jam-packed full of biotoxins. Your dog’s stomach acid is nearly on the same level as the vulture’s, which means only the most cantankerous molds will have a fighting chance of survival and colonization throughout the dog’s digestive tract.

In addition to a well-fortified digestive system, your dog also has a very sensitive and reactive gag-reflex when the gut detects a health risk in its food. Many an owner can attest to this, as most dogs throw up at least once a year. (The trick is keeping them from eating it again, am I right?)

Dog mold allergy symptoms from the consumption of mold will include the following:

• foul-smelling or chronic gas
• diarrhea
• retching (dry heaving or productive throwing up)


The truth is that every dog consumes mold on a daily basis. This is because mold is present in all grain-based foods. Most dogs have a high tolerance for molds, and others—like those with compromised immune systems—will react badly with the aforementioned symptoms. Still, it is possible for even the most healthy dogs to have bad reactions if they encounter a particularly dangerous mold in their food—such as aflatoxins.

If you find that your dog does not respond well to his food, try adjusting his diet before taking him to the veterinarian. Grain is not a necessary component of a dog’s diet—it is merely filler put into dog food to make it more affordable for the owner and tastier and more filling to the dog. Grain food is also the reason a lot of pets become obese. Therefore, switching to another brand or type of dog food might be beneficial in more ways than one.

There are more grain-free dry, wet, and raw versions of dog food available today than ever before. To start your journey, read about the grain-free dog food brands praised by DogFoodAdvisor.

How Do You Treat a Dog with Mold?

Mold detox for dogs begins with their environment or habitat. Check the home and yard for an abundance of moisture and decaying organic material (mold’s nourishment). Find the point of exposure, entry, and/or growth. The faster you remedy the point of mold exposure, the faster your dog will experience relief of symptoms.

Second, wash your dog and/or change his diet. The best shampoos for mold on dog skin will not only be anti-microbial but soothing with ingredients like oatmeal and aloe vera. Most itch-relief shampoos will have the ingredients necessary to give your dog relief from mold.

If your dog continues to suffer long after the bath and you’re willing to move forward without a vet’s advice, try an over-the-counter antihistamine and/or a steroid cream—be sure your dog does not lick where you apply it. (Any gentle anti-fungal cream that you would use on yourself is generally safe for dogs, as long as they do not lick it or get it in their eyes.) As for an antihistamine, Benadryl is a safe histamine blocker for dogs, but be certain your dog does not have the following conditions before administering it:

• cardiac conditions
• currently pregnant
• glaucoma
• low blood pressure

If you know your dog does not have these conditions and you are willing to move forward without a vet’s advice and take full responsibility for any results, you may administer 1mg per pound of body weight, 2-3 times a day to your dog until symptoms subside completely. Most Benadryl tablets are only 25mg, which is the perfect dose for a 25-lb. dog.

Third, if necessary, take your dog to a veterinarian and explain your concerns of mold exposure. If your vet sees recurring or severe dog mold allergy symptoms, he or she may introduce inflammation therapy or hyposensitization techniques. Inflammation therapy involves the use of corticosteroids and antihistamines. Coupled with Omega-3 supplements, these medications can boost the dog’s recovery. Hyposensitization techniques usually involve incremental doses of allergen injections that may eventually desensitize your dog to unavoidable mold exposure.

Fourth, commit to a routine—in the home and performed on the dog—that lowers the chances of mold exposure and mold infection in the future, such as:

• frequent bathing and brushing (make sure the dog’s fur is dry before bed or outside play)
• frequent habitat cleaning (including dog beds, dog houses, and keeping the yard and house as dry as possible)
• grain-free dog food
• Omega-3 supplements

Concluding Thoughts

By far—for both people and dogs—the most dangerous type of mold exposure is prolonged exposure. A one-time encounter will rarely, if ever, have devastating consequences for your dog—unless they have a compromised immune system to begin with. It is the prolonged exposure to mold that can facilitate a compromised immune system or cause an overly-reactive immune response. Consider it your dog’s body’s way of saying, “Enough is enough! Help me already!”

Lastly, remember that if your dog has been exposed to mold, so have you. Be mindful of changes in your own body and do not delay in remedying any mold-encouraging conditions in your home or among your daily habits.

All things considered, the dog is a resilient creature with an impressive immune system that has survived some of the grossest and most dangerous things on the planet. Not only do they tend to recover quickly from mold exposure in most cases, they also have a knack for sniffing out and avoiding mold altogether. Dogs aren’t just used to detect drugs or bombs, well-trained mold detection dogs are also quite adept at detecting and differentiating between over 18 different types of mold, which has saved countless human lives over the past few decades. Just think, if they’re able to point out mold for praise or a treat, then it’s safe to assume that most dogs are aware enough to avoid dangerous molds for their own safety. Then again, they do like to roll in corpses and fecal matter and lap up their own vomit. Still, one can hope…

If your dog has experienced dog mold allergy symptoms, we would appreciate you sharing his or her story with us down in the comments below. What was the first sign of mold exposure that you noticed? How long did the symptoms last? What mold treatment worked best? Don’t be shy! Your fuzzy friend’s experience could help others identify and alleviate their own dog’s mold problems.

For more information regarding mold, mold prevention, and mold solutions, please check out the rest of MoldBlogger.com.


About the Author: Amanda Demsky is the mother and personal chef of two boys, the domestic technician of a desert home, and occasionally, a freelance writer and editor. If you have questions regarding this topic or suggestions for related topics, please feel free to comment below to receive a direct response from the author herself.