Voss: Parasite prevention

The signs of spring are impossible to miss in Aspen: Skis get tucked away, trail rides replace powder days and the first hints of green return to our beloved Aspen trees. There is a collective exhale in town as the pace softens and locals reclaim a bit of quiet. Spring may be short and often messy, but it feels like a reset. Our pets feel it, too. Dogs trade snowbanks for trails, rivers and long sunny afternoons outside. With that seasonal shift comes a less visible change that deserves just as much attention.

Warmer temperatures wake up more than just wildflowers. They also bring back ectoparasites — organisms that live on the outside of the body, feeding off skin and blood. Fleas, ticks and lice are the usual suspects here in the Roaring Fork Valley, and while they may be small, they can come with large consequences. 

Ticks are the classic mountain hitchhiker. Even though Colorado has fewer tick-borne diseases (infectious bacteria or parasites transmitted to mammals via tick bites) than many parts of the country, the risk is not zero. A dog running through tall grass can easily pick one up, and once attached, ticks are difficult to spot unless you are actively looking. Beyond the potential for disease, they are simply unpleasant. They embed, feed and linger longer than anyone would like. Preventative medications for our pets keeps them from ever entering your home. 

Fleas tend to have a reputation as more of a nuisance here, but they, too, can cause serious health risks. Fleas can carry and transmit diseases, including plague and tapeworms. While the plague may sound like something from a history textbook, it still exists in the western United States. Dogs are less likely to show clinical signs than cats but can present with swollen lymph nodes, fever and lethargy. Cats are far more likely to become sick, especially if they hunt or interact with rodents. Left undetected, this is a fatal disease and even scarier is that all of our pets are capable of bringing infected fleas into our homes, which puts every family member (two- and four-legged) at risk. Most cases in Colorado are seen between May and October, right when pets and people are spending the most time outside. 

Then there are lice, less dramatic but still unwelcome. They tend to show up as persistent itchiness or a dull, scruffy haircoat. The good news is that dog lice are species-specific and will not infect a human host, but that does not make them any more appealing to have around (especially for those of us who share beds with our furry housemates). Many of the same preventatives used for fleas and ticks will take care of lice as well, making protection fairly straightforward. These should be given year round, as lice can remain active through cold temperatures.

Heartworm disease is a different kind of threat, one that arrives through a bite from an infected mosquito. Aspen’s elevation and climate reduce the overall risk to our dogs, but it does not eliminate it. It only takes a single bite from an infected mosquito to transmit heartworm larvae, and the species of mosquitos that carry heartworm are present in our valley. After transmission, larvae mature slowly over several months into large worms that live in pulmonary arteries and right heart chambers. By the time symptoms appear, the disease is already well-established. Treatment exists, but is far more difficult than prevention. 

The good news is that prevention for all of these pesky bugs has become remarkably simple. Many modern prescription medications provide protection against fleas, ticks, lice, heartworm and intestinal parasites into a single monthly dose. There is even a long-acting injection we can give to protect dogs from heartworm for up to a year. What used to require multiple products and careful scheduling can now be streamlined into something manageable. 

Spring in the mountains is full of new growth, longer days and more adventures. Making sure our pets are current on parasite prevention is an important step to ensure worry-free adventures outside.

Dr. Kelly Voss is a veterinarian at Aspen Animal Hospital, where she practices small animal medicine and surgery. She has a background in emergency and critical care and is passionate about bringing high-quality veterinary care to the mountains. Have a question for the column? Email her at dr.kellyvoss@gmail.com.