Rocky Mountain Spotty Fever
Tick's are prevalent in the San Francisco Bay Area. If you are a regular hiker or dog owner you likely have first-hand experience with these creepy arachnids. The purpose of this article is to remind our clients of the potential dangers of the infectious diseases transmitted by ticks. One of our canine patients at Vision Care For Animals recently presented for eye redness, pupil dilation, and vision decline. Subsequent investigation at our Palo Alto veterinary ophthalmology practice revealed ocular findings consistent with Rocky Mountain Spotted Fever. Rocky Mountain spotted fever (RMSF) is a tick-borne disease caused by R. rickettsii in North and South America. Domestic dogs are susceptible to infection and canine RMSF can be fatal without appropriate treatment .
Symptoms of RMSF infection can include fever, lethargy, petechia, and uveitis (ocular inflammation). When a patient presents with uveitis to our ophthalmology clinic we consider their relevant risk factors including travel history and lifestyle to determine the appropriate screening blood test that may be necessary to exclude infectious diseases including those transmitted by ticks. While the majority of our patients develop uveitis from an immune mediated or idiopathic cause, a small fraction will have a specific infection or neoplasia (cancer) identified as the trigger.
Fortunately specific antimicrobial therapy is effective in treating RMSF. Doxycycline is considered the drug of choice for both humans and canines to clear the infection. Appropriate and prompt treatment of ocular inflammation and close monitoring of patients by a veterinary ophthalmologist is critical to prevent blindness and to improve patient comfort.
For our veterinary referral community... did you know RMSF is a reportable disease in California under Title 17? While I was aware of the potential serious health consequences of RMSF I was surprised to discover that its on the list of reportable diseases . For those in the profession its worth review and to become familiar with the reporting process to the appropriate health authority. We reported our case to the Santa Clara County Public Health Department last week. I was surprised to learn our report was the first filed by a veterinarian in Santa Clara for any reportable disease. This sounds incredible (not sure of the accuracy) , regardless its important to stay vigilant and report our cases according.
1) Michael L. Levin et al "Clinical Presentation, Convalescence, and Relapse of Rocky Mountain Spotted Fever in Dogs Experimentally Infected via Tick Bite" PLOS ONE | DOI:10.1371/journal.pone.0115105 December 26, 2014