Area residents should be alert to the increased risk of blastomycosis, a fungal disease found in northern Minnesota that can be fatal in dogs.
This has been a wet year, and heavy rainfall leads to moist soil where fungi thrive.
Two veterinarians in Park Rapids have reported increased cases in dogs this year, two of them fatal.
According to the Minnesota Department of Health (MDH) website, the incidence of blastomycosis is highest in northeastern counties, although exposures have been reported throughout the state.
Outbreaks of blastomycosis have been associated with excavation, construction and outdoor recreation. However, some cases occur without any of those factors present.
Both the Ark Animal Hospital and Isaacson Veterinary Hospital have seen an increase in cases this year, while the Town and Country Animal Clinic reported no recent cases of blastomycosis.
Dr. Mia Long, who owns Ark Animal Hospital in Park Rapids, said they have seen about half a dozen cases this year in dogs from the Nevis, Menahga and Park Rapids areas.
“It is more common around lakeshores and when there has been disturbance of the soil, like excavating or a new driveway, septic system or landscaping,” she said.
One of the dogs with a severe case of the pulmonary/respiratory form of blastomycosis died.
Dr. Barb Lester of Isaacson Veterinary Hospital in Park Rapids said, “We’ve seen two cases in dogs in the last two weeks. One lives by Walker and the other has a Laporte address. Last year, we had a little dog from Akeley who doesn’t go out of town. Even a house dog who only goes out to go to the bathroom could be exposed, if they’re digging or there is excavating in the area. It does seem like there’s a higher prevalence when it’s moist outside. There is a higher incidence this year than normal. There’s an area south of Nevis where I’ve seen several dogs come in with it from the Crow Wing area.”
No cases of the illness have been seen in cats or horses this year.
Lester said one of the dogs brought in with blastomycosis died within a week, one lost an eye to the disease and one is still receiving treatment.
“We have one who has been on treatment for eight months and she’s about cleared it, but not quite,” she said. “It’s a really lengthy treatment.”
Lester said coughing and limping are two symptoms to watch for.
“It attacks the lungs,” Long said. “It can also affect the dog’s skin and eyes. Often there’s a soft, moist cough and they usually run a really high fever. In the end stages, they get pretty lethargic.” Unusual weeping sores on the legs may also accompany the disease.
Every case of blastomycosis is reported to the Minnesota Department of Health so they can track the disease.
There is no vaccine for blastomycosis.
“Owners should keep their dogs out of areas with excavation and watch for clinical signs,” Long said. “We’re thinking because it has been super moist this year the blasto is really growing.”
While the spores are not active in winter, they have seen cases as late as January. “We think the dogs are infected late fall and it’s just kind of incubating and then all of a sudden it progresses,” she said.
Lester said chest x-rays may also show changes to the dog’s lungs consistent with a fungal infection.
Testing for the disease is done by urine or blood samples, and treatment is usually by an oral antifungal medication.
“We like to get them starting treatment early,” Long said. “Once they have a negative test, we treat for another month just to make sure. Then we retest in three months. It gets pretty expensive. Sometimes we have dogs that have tested negative and we think they are in the clear, but then they test positive three months later.”
Lester said it is crucial to start treatment as soon as possible.
“Unfortunately, in most of the dogs who come in, it has spread to the point where they’re significantly sick,” she said. “If your dog is coughing and you’ve been doing excavating or building a house, get them in right away.”
Long emphasized that people cannot catch blasto from their dog. “But people are living in the same environment as their dog, so they could catch it from the same soil,” she said. “Gardeners, people digging or spending a lot of time outdoors, they should watch for that.”
Lester said the treatment process can also be extremely costly, especially in a large dog. “Sometimes we can get the generic in stock, but at times, people have had to source through Canadian pharmacies to get some of the ani-fungals,” she said.
She said there is no way to prevent the disease.
“Dogs sniff, and how are you going to keep them from that or from digging?,” she said. “I have two hound dogs, and if they were exposed hopefully I could catch it right away but it doesn’t always show up until it has spread to their lungs and done quite a bit of damage through their body. Not all of them recover, unfortunately. It’s a scary disease because it’s so aggressive.”
Human cases also increase in state
The MDH website states that an average of 33 people and 72 dogs and cats in the state are diagnosed with blastomycosis each year.
According to Wendy Gulliksrud, infection prevention coordinator at CHI St. Joseph’s Health in Park Rapids, the hospital has not seen any cases of the disease.
“I talked to our lab, and if we see a fungus growing on a culture, we would send it out for testing,” Gulliksrud said.
The incubation period for blastomycosis is from three weeks to three months. Common symptoms in people include cough, fever, shortness of breath, night sweats, chills, fatigue, weight loss, non-healing skin lesions and chest pain.
“Many patients are first diagnosed with bacterial pneumonia, and are often treated with many rounds of antibiotics before fungal infections are considered,” the MDH website states.
The MDH website goes on to state that 72 percent of cases in the state involve only the pulmonary system. Skin, soft tissue, bones or joints can also be affected and occasionally the central nervous system.
About half of the time, people exposed may not show symptoms or have a mild illness that resolves without treatment. Itraconazole is the most commonly used anti-fungal treatment. Amphotericin B is often used for severely ill patients.