Leptospirosis, frequently shortened to lepto, is a bacterial disease that, if you’ve heard of it, it’s likely been from your veterinarian. Transmissible between humans and animals (to use the fancy medical adjective, “zoonotic”), leptospirosis is one of those eerily under-discussed diseases whose pathology can be so insidious that education on its prevalence and prevention should not be glossed over by any veterinarian or any pet owner.
We live in a city with large numbers of wild animals and public spaces trafficked by countless domestic dogs – the volume of which can be easily visualized on early summer mornings. Our melange of mice, rats, raccoons, opossums and even deer makes our 68 square miles of city home to lots of lepto-susceptible mammals in close quarters.
The Leptospira bacterium is primarily hosted by mice, rats and their relatives, but the pathogen, excreted in these infected animals’ urine, can find its way into our waterways with ease. And who among us hasn’t had to pull our dogs away from doing the usual Dog Things: trying to lick up puddles after a DC-trademarked summer downfall, roll in hot doggie bliss in muddy creeks, dig into the carcasses of small wildlife or otherwise investigate – either intentionally with their mouths or simply via the exposed maw of panting faces – all of the new routines, water-adjacent excursions and vacation spots that often accompany our summertime leisure?
That’s where your vet comes in. While the American Animal Hospital Association (AAHA) – one of the field’s paramount research-minded organizations – does not yet nationally recommend immunization with the leptospirosis vaccine as part of a “core” vaccination protocol for dogs, it does suggest that pet owners follow the advice of their veterinarian, whose vaccine recommendations are based on local disease burdens in addition to their canine patients’ lifestyles. AAHA also names leptospirosis as one of the most common zoonotic disease in the world, with infection rates in the US increasing in recent decades.
Leptospirosis is here. It’s in the city! I don’t have much of a backyard but I have a muddy back alley with roaming dogs, raccoons and opossums, a summer vegetable garden and plenty of mice. While some veterinarians around here may downplay the benefits of leptospirosis immunization in area dogs, it’s worth mentioning that in local emergency animal hospitals, cases of leptospirosis in dogs are often so severe that patients must be transported to even more specialized hospitals for intensive treatment, such as hemodialysis, in order to fight for survival, costing their owners well into the five digits, when all is said and done.
Sometimes known as the “great pretender,” leptospirosis in dogs can manifest with nonspecific clinical signs, such as loss of appetite, vomiting or lethargy, which is perhaps the reason why many cases are diagnosed only once the disease has progressed so severely that many dogs are unable to rally.
Traditionally, leptospirosis has been infamous for attacking the vital organs of our pups; the liver and kidneys are particularly vulnerable. However, cases can also cause muscle disease, bleeding disorders and severe respiratory compromise. Dogs can contract the illness by eating or drinking from contaminated soil or waterways, being bitten by other infected mammals (over 150 species of animals have been found capable of hosting the pathogen), ingesting the carcasses of infected animals and in some cases by breeding. Even dogs that spend most of their time indoors can be infected by mice or other pests that set up shop inside buildings, showing that any dog, not just active, outdoorsy ones, can potentially develop leptospirosis.
As with dogs, humans generally pick up the disease through inadvertent exposure to the urine of infected animals, such as through unsuspecting ingestion ( the vegetable garden that I mentioned?) or absorption into the body through mucous membranes or broken skin. It is more common in warmer climates. In our area, the humidity, potential for flooding and spastic bouts of heavy rainfall common in the summer months – not even counting the population density and lifestyles of humans and their dogs here – can result in an uptick of leptospirosis cases this time of year.
The disease in humans usually presents mildly, with vague symptoms such as fever, muscle aches and nausea that generally respond to antibiotics and any needed corrections in electrolyte balances. However, much as in dogs, rarer, more severe cases, often involving the liver, lungs, kidneys or even the heart or brain usually require hospitalization and advanced procedures in order to stabilize these unlucky human patients.
Many variants of the Leptospira bacterium exist, but the canine vaccine covers most of the prevalent serovars transmissible to dogs. Most local veterinarians recommend the annual leptospirosis vaccine to all healthy dogs, due to the prevalence of the disease in our area. Humans are advised to use proper protective equipment when swimming or indulging in other water-based recreation, and the American Veterinary Medical Association (AVMA) recommends always practicing good hygiene, consulting with your veterinarian about leptospirosis prevention for your dog and ing your physician if you have any concerns about your own health.
Dr. Dan Teich is the medical director for District Veterinary Hospitals in Navy Yard, Eastern Market and Brookland. Visit www.districtvet.com for more information.
