Having an active dog at home can be a joy and a challenge, especially when you have to deal with your furry friends unpredictably getting sick. This is particularly the case if your pet develops an illness many pet owners are unfamiliar with, such as blastomycosis.

Discover more about the symptoms which are associated with this rare and potentially life-threatening fungal infection, the treatment options and if there are any ways that your dog can avoid catching it.

Table of Contents:

• What is blastomycosis in dogs?
• Are all breeds at risk?
• Can humans catch blastomycosis from their dogs?
• Blastomycosis symptoms in dogs
• How is blastomycosis diagnosed?
• Blastomycosis treatment in dogs
• Prognosis, management, and recovery
• Can you prevent blastomycosis in dogs?
• Key Takeaways

Key Takeaways

Pro Tip: Pet insurance offers peace of mind knowing your fur baby can get the gold standard in vet care without the stress of worrying over whether or not you can afford treatment if they do become ill with something like blastomycosis.

What is blastomycosis in dogs?

Blastomycosis is a fungal infection caused by Blastomyces dermatitidis, a fungus that is found in the soil and in decomposng organic matter (e.g. rotting vegetation). Dogs are generally infected by inhaling fungal spores in the environment.

Blastomycosis primarily involves the lungs, eyes, and skin. But other organs and body systems are also susceptible, such as the heart, bones, lymph system and nervous system. The illness can be fatal if left untreated.

In the United States, Blastomycosis is most common in the mid-Atlantic states, particularly the warm and damp river valleys of Ohio, Mississippi Missouri and Tennessee. And it is happening in Southern states, in the Pacific Northwest and in areas around the Great Lakes.

Aerohematogenous infection is the most frequent route in which dogs become infected with Blastomyces, once the infective particles of the fungus, known as conidia, become aerosolized. Some weather phenomena, like rain or fog or dew is believed to spark these particles, then they are inhaled or absorbed into the dogs skin. The majority of blastomycosis infections in dogs occur in early fall or late summer.

Are all breeds at risk?

Blastomycosis can occur in dogs, cats, and humans, among these animals, dogs seem to be more susceptible to the disease. Dogs are about 10 times more likely to become infected than humans are, and 100 times more likely than cats are, according to VCA Animal Hospitals.

Any breed, age or sex of dog can become infected. Yet, as a disease of habitats of damp soil with the presence of decomposing vegetation (e.g., marshes), birding dogs and trail partners of all sorts are thought to put themselves at particularly higher risk by living in an area where BLastomyces is endemic. Even large-breed males are reported to be more frequently infected.

Is it possible for humans to catch blastomycosis from their dogs?

Usually, the disease is not pass through animal-to-animal or animal-to-human. However, since the fungus is present in the common environment, even non infested family members, other animals, and the humans are at risk of developing an infection from spores present in the environment.

As noted previously, human blastomycosis is thought to be relatively rare. If a human’s open wound comes into contact with an open, draining wound on a dog, there is a chance for the bacteria to be transmitted to the human. So, so if your dog is positive, also follow strict hygiene rules when dealing with their lesions. Always use rubber gloves and wash your hands thoroughly after handling the infected pet. In many instances, no special separation is required for the infected dog from other dogs or human members of the household.

If you’re worried about possible exposure to blastomycosis and whether or not your dog is infected, get in touch with your doctor. This is particularly important if anyone in your household is a young child, senior citizen, chemo patient, or has a weakened immune system.

Blastomycosis symptoms in dogs

Symptoms of Blastomycosis in Dogs Depending on the system that is involved, dogs with blastomycosis may also present with:

Fever

Poor appetite

Depression

Weight loss

Coughing

Difficulty breathing

Swelling of the lymph nodes

Limping

Eye inflammation

Eye discharge

Skin lesions

Orchitis (testicular inflammation)

Seizures

The disease involves several organs in many animals. 65%-85% of affected dogs have respiratory problems (DVM360). Cutaneous lesions (ulcerative, draining sores located on the nose, mouth, or pads of the paws, papules and/or rash-like lesions) are seen in 30% to 50% of affected dogs. Eye signs (blindness, red eye, squinting) are also frequently present, occurring in approximately 50% of infected animals.

If you dog has recently been in a Blastomyces endemic area during the 6 weeks prior to the onset of signs, contact your veterinarian immediately if your dog has been to this geographical location.

How is blastomycosis diagnosed?

Blastomycosis can be challenging to diagnose as the symptoms are frequently non-specific. Lung infections can resemble cancer on imaging tests, and skin lesions can mimic a skin infection.

The most effective ways to diagnose it are:

Cytology from fluids exuded from skin lesions

Microscopic evaluation of lymph node cells and lung tissue by cytology or biopsy

The tracheal wash (collection of fluid from the windpipe)

Samples of tissue may also be removed to test for the presence of the fungus. Other tests that may be useful in making a final diagnosis include a urinalysis and an X-ray of the lungs or the leg (if the dog is limping). Newer specialty tests are also available to demonstrate the fungal organism in the blood and urine.

Blastomycosis treatment in dogs

The treatment of Blastomycosis is with anti-fungal oral medicine (typically fluconazole or itraconazole), which is often expensive due to the long course of treatment. You have to take the medicine for at least 6-8 weeks. There are some treatments that can take more than about a year to get the infection cleared up.

The affected dog may take a longer hospitalization, if they developed severe respiratory signs. Oxygen supplementation may be necessary for dogs with dyspnea (difficulty in breathing).

Eye infections can be challenging for your vet to treat and you may be referred to a veterinary ophthalmologist (eye specialist). Topical eye medications can help reduce discomfort and pain, but we don’t typically use them to help eradicate the infection.

Removal of the affected organs may be required to get rid of the fungal organism (castration may be necessary for male dogs with orchitis). In the ocular form, vision is lost in the eyes, the blind eyes may need to be removed to rid the infection. Most dogs recover from enucleation (eye removal) splendidly, particularly if they were already blind. For more serious bone infections, your pet may require a leg amputation.

Blastomycosis dogs are discharged after hospitalization to the owner initially applying ophthalmic or oral agents. Skin lesions may also need topical treatment.

Pro Tip: The price for diagnosing and treating blastomycosis can be awfully steep. X-rays, lab work and a biopsy can run from $500 to $1500, and the long-term antifungal medication can cost between $150 and $750 a month. With the right pet insurance plan, you can be reimbursed for up to 90% of your vet bills for unexpected illnesses and accidents.

Prognosis, management, and recovery

The prognosis for dogs with blastomycosis is fair to guarded and depends on the response to therapy. About 70% of dogs are reported to achieve a clinical cure, according to the Merck Veterinary Manual. Patients with mild diseases at the age of diagnosis share a better prognosis.

The majority of these are in relation to the first 24-72 hours of initiation when the drug is having the intended effect. Sometimes there can be quite an intense form of an immune response as the medication starts to kill off these fungus things, so you can then get a respiratory distress type situation when suddenly all these organisms are suddenly going.

Apart from the relape of infection months or years after the initial infection the cure may sometimes seem successful. Relapse may occur in up to 20% of recovered dogs. Patients with ocular, nervous system and testicular involvement may be at increased risk of relapse.

The urine is typically retested with a urine antigen test to see if the treatment plan is effective. Chest X-rays may also be used to assist in assessing response to treatment, and in demonstrating any permanent scarring of the lungs that may have occurred as the result of treatment.

Is blastomycosis preventable?

There is no dog vaccine for blastomycosis. The only thing pet dog owners can do is to keep their canine companions away from marshy lands, streams and lakes where the risk of exposure is greatest. If you live in or venture into high-risk areas, that’s probably going to be hard, but you should, at the very least, try to avoid dark, moist, dense areas where the fungus flourishes, especially if your pet’s immune system is already compromised.

Key Takeaways

It is quite a lethal fungal disease. Dogs that live in or spend time around a body of water, such as hunting and sporting dogs, as well as large breeds that live or spend time in or around wet areas in endemic areas in the US are most commonly affected.

The most frequent clinical manifestations of blastomycosis are respiratory tract involvement, cutaneous lesions, ophthalmic changes (with the occasional consequence of blindness), anorexia and depression. But the disease manifested in a variety of ways.

Oral antifungal agents are the treatment of choice, given for a least 2 months.

Quick identification and aggressive therapy are essential to successful cure of Canine Blastomycosis. If your dog has been diagnosed with this condition, make sure to follow your vet’s instructions and follow up with all necessary visits to keep the disease and treatment in check.