Dog and Cat


There has been public concern in Marquette County regarding Blastomycosis due to a perceived increase in diagnosis by at least one area veterinary clinic.  The following is an overview of Blastomycosis and it’s occurrence in Marquette County.

What is Blastomycosis?

  • Blastomycosis is a rare fungal disease caused by the soil fungus Blastomycetic dermatitis.  This fungus exists as a mold in the environment and as a yeast in tissue infections.
  • Blastomycosis is typically manifested as a respiratory illness, or a skin infection.

Where does Blastomycosis occur?

  • Blastomycosis occurs in wet sandy, acidic soils that are high in organic content, in close proximity to water.
  • Blastomycosis can occur almost anywhere in soil, but is most common in the Ohio and Mississippi Valley regions, in specific areas of Wisconsin, around the Great Lakes and the Province of Ontario.
  • Soil testing is very difficult and is generally unreliable as a predictor of Blastomycosis even in areas of known occurrence.

How do you get Blastomycosis?

  • Blastomycosis is contracted by inhaling fungal spores from disturbed soil, from skin contact, or through lesions while handling soil containing Blastomycetic dermatitis.
  • Risk of contracting Blastomycosis increases if you are working in areas prone to fungal growth such as, crawl spaces, old sheds, old woodpiles or debris piles that may contain rotting wood.
  • Blastomycosis is most common in men between 30 and 50 years of age.  This may be due to this population being more commonly involved in outdoor activities in woodland areas.
  • Blastomycosis is not transmitted person to person.

How do I know where I contracted Blastomycosis?

  • The origin of Blastomycosis is difficult to determine due to a long on-set of illness, which is typically weeks.  Most individuals have traveled to many locations during this incubation period.

Is there a local concern with Blastomycosis in the U.P. and Marquette County?

  • Human Blastomycosis is a mandatory reportable disease in Michigan.  This means that physicians must report the occurrence to State epidemiologists within 24 hours of diagnosis.  These disease statistics are tracked through a statewide database and are analyzed by State employed epidemiologists.
  • Although the U.P. typically sees more human cases of Blastomycosis than Lower Michigan, the average total caseload U.P. wide is only approximately 6 cases per year.
  • According to current statistics, there is no increase in the number of human cases occurring this year (2011) over previous years.
  • Marquette County typically sees far fewer cases than other U.P. counties.  The most recent confirmed human case in Marquette County was in 2006, with one case total for that year.

I have heard that dogs have contracted Blastomycosis.  Should I be concerned?

  • There have been reports from a local veterinary office that their caseload of Blastomycosis in dogs has been unusually high with 6 cases this year (2011).  These cases have been clustered in the Big Bay / Lake Independence area.  There may be an increased risk of your dog contracting Blastomycosis if roaming freely, off leash, in the Big Bay / Lake Independence area.
  • Typically, most veterinarians see 1 to 2 cases per year for dogs from various locations throughout the county.
  • Currently, most veterinary clinics have seen only one case this year, which is normal.  These cases have not been clustered with regard to geographic location.  Therefore, there does not appear to be a widespread trend.
  • Nationwide cases of Blastomycosis in dogs typically appear in large breed dogs that roam afield.
  • Dogs are 10 times more likely to contract Blastomycosis than humans.  This is due to the fact that the nose of a dog is much closer to the ground and dogs are more likely to dig into soil and inhale fungal spores if present.
  • Blastomycosis is not transferable from dogs to humans or from dog to dog.

How do I prevent myself from contracting Blastomycosis?

  • Wear a disposable NIOSH H100 approved hepa filter dust mask (available at your local home improvement store), gloves, proper footwear, long pants and a long sleeve shirt when working in moist areas, or digging in soil were fungus may grow such as crawl spaces, under porches, sheds etc.
  • If you have an organ transplant, cancer, HIV/AIDS, or are otherwise immune-suppressed, discuss with your physician regarding the advisability of avoiding activities that involve close contact with the soil in areas suspected to have Blastomycosis present.
  • Avoid allowing piles of rotten wood to accumulate under, or in close proximity to, your home or camp.