Live Near Water? Be Aware of This Deadly Fungus

Analysis by Dr. Karen Shaw Becker


Story at-a-glance -

  • Recently, a yellow Lab in Wisconsin named Nud succumbed to a blastomycosis infection
  • Blastomycosis is a systemic fungal infection, and large breed male dogs, especially hunting and sporting breeds, are most often affected
  • Symptoms of infection include loss of appetite, fever, weight loss, coughing, and skin lesions
  • Conventional treatment for a blastomycosis infection is an antifungal drug; complimentary non-toxic protocols include hyperbaric oxygen and ozone therapy
  • If you live where fungi are prevalent, learn about the types of organisms your dog may encounter and take steps to prevent exposure

In early June in Wisconsin, a yellow Labrador Retriever named Nud (short for Nudder-Budder) developed breathing problems and began throwing up blood. His mom, Sara, took him to the veterinarian where it was discovered he had a collapsed lung. Diagnostic tests were ordered. Tragically, Nud died 8 days later of a disease that plagues Central Wisconsin: blastomycosis.

Blastomycosis is Seen Most Often in Large Breed Male Dogs

Blastomycosis is a systemic fungal infection caused by Blastomyces dermatitidis, an organism that grows in rotting wood and wet soil. The fungus thrives in wet environments like swamps, lakes, and on riverbanks where damp soil and lack of direct sunlight encourage its growth.

The fungus is also found in locations that harbor decaying organic matter like wooded areas, forests, and farms. Blastomycosis infections are prevalent in locations near water, including the Mississippi, Ohio, Missouri, and Tennessee River basins.

The infection is seen most often in large breed male dogs like Nud, and especially in hunting dogs, sporting breeds, and dogs that spend a lot of time in environments where the blastomyces organism exists. All dogs are susceptible, and occasionally, cats acquire the infection as well.

Studies indicate most dogs who develop a blastomycosis infection live within a quarter mile of a body of water. Nud’s mom Sara told a local news station that she had taken her dog swimming just once this year before he became ill.1

How to Avoid Human Blastomycosis Infections

The fungus releases airborne spores into the environment that can be inhaled by people and animals. This is the most frequent method of transmission, though the spores can also enter through the skin. In fact, just digging in the soil can release the spores. Once inhaled, the spores travel through the lungs and become large, thick-walled, yeast-like organisms that multiply within the lungs and other tissues of the body.

Blasto is a dimorphic pathogen, meaning it occurs in two distinct forms: it grows as a mold in the environment, and as yeast in tissue. Blastomycosis has the potential to cause significant pulmonary disease. The yeast also tends to travel to other sites in the body, especially the skin, eyes, and joints.

If your dog has a blastomycosis infection, he can't directly infect other members of the family — humans or pets. However, care should be taken when handling any secretions. For example, in draining lesions, you should use protective gloves and wash your hands thoroughly after you've had contact with your infected pet's sores.

There's no need to isolate infected pets from other family members. However, you should take care to avoid the area where your dog likely picked up the Blastomyces spores. This is particularly important for infants and toddlers, elderly family members, and anyone who is immunocompromised.

Symptoms and Diagnosis

Symptoms of blastomycosis infection in dogs include loss of appetite, fever, weight loss, depression, inflammation of the iris of the eye and discharge from the eyes, coughing, wheezing, and pus-filled skin lesions. More serious symptoms can include sudden blindness, lameness, inflammation of the testicles, enlarged lymph nodes, and seizures.

Unfortunately, blastomycosis is often misdiagnosed, sometimes as cancer and sometimes as a bacterial lung infection. Needless to say, treatments for cancer and antibiotics for bacterial infections will not address the fungal infection and can lead to permanent damage or even death, if your pet doesn't get an accurate diagnosis.

If your dog has been showing any of the above symptoms for six weeks or more with no noticeable improvement, or if like Nud he suddenly develops breathing difficulties and he has or may have been in an environment that harbored the Blastomyces fungus, your veterinarian should test for a fungal infection.

Blastomycosis is best diagnosed through examination of a lymph node, examining fluid from skin lesions (cytology), by a transtracheal wash, or by examining lung tissue. Tissue samples may be taken to check for fungal organisms. There's also a blood test called an AGID test or antigen ID test for exposure to blasto. But a positive result doesn't mean your dog necessarily has the infection, only that he's been exposed.

Chest X-rays of a dog with blastomycosis often reveal a sort of snowstorm-type pattern. Urine screening tests can also be very beneficial for diagnosis.

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Treatment Options

Blastomycosis is a serious, often fatal fungal infection, so the sooner you seek treatment, the better chance your dog has to fully recover.

Conventional treatment is oral administration of an antifungal drug. These medications require long-term treatment, sometimes for many months. They are very expensive. And of course, all of them carry potentially serious side effects.

The preferred antifungal at the moment for dogs diagnosed with this infection is Itraconazole, which is better tolerated and has fewer side effects than older antifungal drugs. I also recommend a nutraceutical called quantum nucleotide, which helps to stimulate an immediate immune system reaction, as well as oil of oregano in capsule form, which is excellent support for a body fighting a fungal infection.

For many dogs, the critical period during treatment is the first 24 to 72 hours, as the antifungal drug begins to kick in and kill off the fungi. Since there are typically a large number of organisms in the lungs, there can be an overwhelming inflammatory response that can result as the fungi die off. Respiratory distress can be a big problem during the first few days of treatment.

Whatever drug is used, it must be given for a full month past all signs of infection. Dogs with severe breathing difficulties may require supplemental oxygen until their lungs return to normal function.

In addition to conventional therapy for fungal infections, intravenous (IV) vitamin C, hyperbaric oxygen2 and ozone therapy have all been used to shorten infection time and enhance standard treatment protocols. Especially if your pet isn’t responding adequately to conventional treatment, I recommend you seek out these nontoxic, systemic immune-enhancing treatments as soon as possible after diagnosis.

Prevention is Always the Best Treatment

Since fungal infections in dogs can be life-threatening and often require long-term treatment with powerful, expensive antifungal drugs, obviously, every attempt should be made to avoid exposure in the first place. If you live where fungi are prevalent and your furry family member spends a lot of time outdoors, learn about the types of organisms he may encounter in your local area, as well as the symptoms of infection.

If you see signs he may have been exposed to fungi, get him to your veterinarian right away. The earlier a fungal infection is identified and treated, the more likely your dog will make a full recovery.