Microsoft word - blastomycosis in dogs.docx

Blastomycosis in Dogs: Symptoms, Treatment and Prevention
Blastomycosis, called blasto for short, is caused by fungus blastomyces dermatitidis. Simply put, blastomycosis
is a very serious and potentially deadly illness that's caused by a fungus typically found in the soil near water ways or
swampy areas. The spore that causes the infection is airborne, so soil that has been disturbed or dug up is most
likely the source of airborne spores. Once inhaled, the spores turn into a yeast that rapidly infests the lungs.
Because blastomycosis can have multiple symptoms,
Difficulty breathing (e.g., coughing, wheezing and other unusual breathing sounds) Skin sores or lesions, which are frequently filled with pus and do not heal Reluctance to walk, loss of coordination It's unlikely to be quickly diagnosed unless you or your veterinarian are already aware blasto is in your area.
As a result, the illness has usually progressed beyond the point of treatment and recovery by the time other illnesses
or disease are ruled out and blastomycosis is diagnosed. Blasto is not communicable from dog to dog, or dog to
human, although humans, cats, and other mammals can become sick if they inhale the spores.
Blasto can affect virtually every system in a dog's body, so observation and a physical exam, including blood tests,
are unlikely to point a veterinarian in the direction of a blastomycosis diagnosis. Three dogs recently stricken in
southwest Minnesota exhibited an array of symptoms:
seizures, raspy breath, trouble breathing fever, chills, depression, and sores that wouldn't heal. It wasn't until the veterinarian did a microscopic examination of a scraping from the unhealed sore on one of the
dogs that the yeast cells were discovered, making the blasto diagnosis possible. In speaking with a local veterinarian,
I'm aware of other dogs in Minnesota whose eyes and eyesight were affected and who experienced paralysis in their
hind legs. Blastomycosis is also suspected to have been the cause of some dogs who exhibited:
Once diagnosed, blasto is most often treated with Itraconzole, an antifungal agent. Even then, symptoms of
blastomycosis can get worse before they get better if there are massive amounts of dead yeast in the dog's system
that the body must expel. Treatment of blasto usually lasts several months, and you can expect costs to run into the
thousands of dollars. The good news is that the vets I've spoken with believe that if blasto is caught early, before it
can spread too far, most dogs can be effectively treated. The key is early detection, and that usually happens only if
you or your vet keep blasto in the backs of your minds when presented with a sick dog.
To date, there are no known blastomycosis preventative medicines or vaccines. If your dog does become sick, let your veterinarian know if you suspect blasto. Being aware of any cases in your area, knowing symptoms to look for, and being proactive if your dog should fall ill is the best approach. Blastomycosis is not a reported disease, so information on the numbers and frequency of cases is limited; this also adds to delays in diagnosing blasto. Diagnosis
A dog must be properly tested for a definitive diagnosis. This condition is commonly mistaken for cancer or
pneumonia. If mistaken and treated as a bacterial infection, it will be treated with antibiotics, which can actually
exacerbate the illness. From Kim McFarlane’s personnel experience, her dog was treated with Amoxicylin for
a prostate infection that he was NOT tested for--the vet just assumed that was the problem.
If your pet has been in an environment where the Blastomyces fungus may have been present at any time in the six
weeks previous to the onset of symptoms, you will want to ask your veterinarian to test for a fungal infection.
There are several methods to diagnose blastomycosis:
Analysis of fluid drained from any skin lesions Sputnum culture (if dog coughing up fluid) Tracheal wash for collecting trachea (windpipe) fluids Chest x-rays (which shows a 'snowstorm' pattern if the fungus is growing as a budding yeast) Blood and urine analysis (in the form of a diagnositc antigen test) Examination of the cells in the lymph nodes Tissue samples may be taken to check for the presence of fungal organisms, especially if a dog is coughing, but there is no sputnum or fluids to test on. Treatment
Blastomycosis is treated with anti-fungal medication. It is usually easier to treat, the earlier it is detected.
Anti-fungal therapy is challenging for veterinarians because prolonged treatment is needed and the fungus is difficult to eradicate. There are a limited number of anti-fungal drugs that can be used, which tend to be expensive and can pose significant toxicity problems. One preferred treatment of canine blasto is with the triazole drug itraconazole. Other clinicians have reported
success using fluconazole (a different triazole), ketoconazole with amphotericin-B, or amphotericin-B alone.
Amphotericin-B presents risks because of its toxicity for the kidney.
For life-threatening Blasto, Amphotericin B (Amp B) is usually the treatment of choice, although as noted,
Amphotericin B can have serious side effects.
At the commencement of treatment, many dogs seem to get worse for 5 to 8 days after treatment starts. This is probably because of a "die off" effect, where a dog's body is purging itself of tens of thousands of dead yeast organisms. Despite extensive treatments, some dogs may not entirely rid their body of the yeast, and relapses can occur. Prevention
Being around infected soil is the key risk factor for a dog contracting blastomycosis. Knowing if blastomycosis has
occurred in your area, recognizing the symptoms of the disease, and getting your dog diagnosed early are the best
defenses in preventing your dog of contracting the disease.
Currently, there is no vaccine to guard against getting the illness. The fungus is often isolated to a small area and therefore is often very difficult to trace back to a source. Also there is no convenient or reliable means of detecting B. dermatitidis in the soil, and there is no way for it to be eliminated from the soil. Therefore, the best prevention is limiting a dog's possible exposure to the spores by being aware of your surroundings. This is not always practical, given the amount of time dog spend in wooded areas or near lakes and streams. But just as with other fungi - such as mushrooms - the spores are probably only present for a short period of time, in specific environments and conditions. Avoid letting your dog forage in areas with rotting vegetation at water's edges or in dark dense forest where fungi can
thrive, especially in an area known to have had cases of blastomycosis in previous years.
Also avoid letting your dog play in excavation sites that have a lot of dust or loose dirt (like landscaping a backyard, draining a pond, etc).

Source: http://www.cardunaldogtraining.com/uploads/Blastomycosis_in_Dogs.pdf