Avoid Them Like The Plague
No murder hornets here, but a recent diagnosis of the plague in a human in Colorado merits visiting some of the bugs of summer. None are limited to the summer, but with more of us outside getting through these pandemic times due to warm weather, risks are higher.
So, back to the plague. This is the same plague that you remember from history class, caused by a tiny bacterium called Yersinia pestis. The plague is endemic to the world, but seen with more frequency in some areas, including the Rocky Mountain or Four Corners region. Due to better parasite preventatives targeting fleas, the rate of human cases has markedly decreased.
The recent case diagnosed in a person in southwestern Colorado is the first since 2015, but be aware that does not mean that plague is not active in our area. As recently as last summer, the Rocky Mountain Arsenal was closed, and restrictions were placed on cars entering the Dick Sporting Goods to prevent parking in areas without asphalt due to high level of plague being diagnosed in the area prairie dogs.
Yersinia pestis is transmitted by the bite of a flea to mammals after the flea has fed on another infected animal. The most common routes of infection for humans are 1) direct bite from a flea that has been feeding on an infected animal; 2) handling of sick animals where bacteria in their blood stream can enter humans through cuts or abrasions in the skin or from contact with the mucus membranes (mouth, nose, eyes); or 3) from our pets either bringing in infected fleas or from being sick themselves. Dogs are typically resistant to the plague, but cats are very susceptible and can easily spread the plague via the respiratory form, pneumonic plague, by coughing and sneezing.
Human clinical signs of plague include fever, swollen and painful lymph nodes, chills and extreme exhaustion. In our pandemic times, with the vagueness of these symptoms, flea prevention is the simplest of ways to keep pets and humans safe. Commonsense also dictates keeping dogs on leash and away from prairie dog colonies, never handling sick rodents and the COVID-19 tenets of not touching your face and washing your hands.
Now for more bugs – or rather worms. With increased road trips, outdoor time and open dog parks, intestinal parasites are a greater risk. A recent study (DoGPaRCS) by veterinarians Susan E. Little and William G. Ryan et al surveyed fecal samples from over 3,000 dogs at dog parks in 30 metropolitan areas, including Denver. The pet owners were also surveyed on their parasite control practices and dogs’ history of intestinal parasites. Intestinal parasites were detected in one in five dogs at 85 percent of dog parks. Giardia was the most common parasite found followed by hookworms and whipworms. Giardia does not have a preventative, but hookworms and whipworms are easily prevented by having your dog on heartworm preventative.
Beyond dog parks, in the Denver area I would extrapolate the risks also to our heavily used open spaces, hiking trails and area city parks and green spaces. Hookworms are the source of the human diseases of cutaneous and visceral larval migrans – which are just as bad as they sound and to which children are most at risk.
The DoGPaRCS study also highlighted the role of veterinarians in detecting intestinal parasites. Proper testing of fecal samples, including a centrifugal floatation with fecal antigen assays, is essential. Passive fecal floatation, commonly used in many veterinary practices, fails to identify many parasitic infections and cannot detect antigens that are still shed into the stool even when the parasites are not producing eggs.
Takeaways today: Keep yourselves and pets away from animals that could be sick from or carry fleas infected with the plague. Prevent fleas and ticks with appropriate once monthly preventatives. Make sure your dog is on heartworm preventative to be protected against hookworms. And, lastly, have stools fully analyzed by your veterinarian annually.
Dr. Margot Vahrenwald is the owner of Park Hill Veterinary Medical Center at 2255 Oneida St. For more information, visit parkhillvet.com