Quebec has reported its first case of Rocky Mountain spotted fever, a tick-borne disease that can be deadly. The case was shared on social media by Dr. Alex Carignan, who posted a photo of the rash associated with the illness. The disease has also been identified in dogs in Ontario, raising concerns about its spread.

Rocky Mountain spotted fever is caused by the bacteria _Rickettsia rickettsii_. Symptoms in humans can include fever, headache, nausea, vomiting, stomach pain, muscle pain, and loss of appetite. A distinctive red rash typically appears two to four days after the onset of fever, ranging from small dots to larger splotches. Treatment with the antibiotic doxycycline is effective, and most patients recover fully. However, the disease can be fatal in 5 to 10 percent of cases in the U.S., and without treatment, the mortality rate can reach 25 percent.

The American dog tick is the primary vector for this disease, found from eastern Alberta to Nova Scotia, particularly in southern regions. Dr. Scott Weese, a veterinary expert, noted that while the disease is named after a specific region, it affects various large mammals, including humans. Previously, American dog ticks were not a major concern as they were not known to carry Lyme disease, which is transmitted by blacklegged ticks. Weese stated, "Now we're having to change our tune a little bit, realizing that this tick might not be as benign as we thought around here."

In Canada, Rocky Mountain spotted fever was previously rare, with only one case per 500,000 people reported in British Columbia in 2019. However, a 73-year-old woman diagnosed with the disease in 2023 had traveled from Saskatchewan to Ontario, where she was in contact with her son's dogs. This case, along with a cluster of dog infections linked to Long Point Provincial Park in Ontario, suggests that the disease may be becoming more established in Canada.

Dr. Isaac Bogoch, an infectious disease specialist, emphasized the importance of understanding the geographic distribution of the disease. He noted that other tick-borne illnesses, such as Lyme disease, have also expanded their range due to climate change, which has led to milder winters and hotter summers.

To protect themselves and their pets, experts recommend several precautions. People should stay on trails, avoid long grass and leaf litter, and wear long sleeves and pants when in tick-prone areas. Checking for ticks after outdoor activities is crucial, as is promptly removing any ticks found. Weese highlighted that dog owners are at a higher risk of tick exposure, as dogs can carry ticks into homes.

Preventive medications for dogs can reduce the risk of tick-borne illnesses, but they should not replace other protective measures. Bogoch advised healthcare workers to be vigilant for tick-transmitted diseases beyond Lyme disease to ensure timely treatment for suspected cases of Rocky Mountain spotted fever.

While awareness of these diseases is increasing, experts stress that they remain rare in Canada. Weese concluded, "Canada hasn't been the hot spot for any of these ticks or their diseases in the past, and they won't be the hot spot compared to the U.S. But we're a hotter spot than we were."