Moving on in my talks about re-emerging diseases, I will talk about one that affects people as well as pets. While we are not sure of why they are coming back, hookworm infection is on the rise. This is another one of those worms where folks feel they don’t need good preventive protocols because their dog “doesn’t eat things off the ground”. What they don’t realize is that this is the exact same hookworm that humans (kids especially) get in their skin from walking or playing in dirt.
Hookworms start their lifecycle in an animal’s gut where adult worms shed eggs that are pooped into the environment. Unlike other worms whose eggs are immediately infective, the hookworm will go through 3 life stage changes before becoming an active, motile, and burrowing little larval worm. Since worms are less hardy in the environment, meaning they die in cold weather, this sounds like a good thing. Unfortunately, this also means that, unlike eggs, they don’t need to be ingested by the next host to get into their body. Instead, they can get into the skin as folks walk/jog through contaminated areas and the worms will burrow their way inside the body. They will then continue to burrow through the body tissues until they find the gut. So, if you are one of those barefoot runners, now is the time to look into those “barefoot” athletic shoes….
Because the larvae are also found throughout the tissue, hookworms are also one of those parasites that can get passed from mothers into nursing puppies and kittens. This is why we check multiple stool samples and deworm puppies as part of their pediatric regimen. Once the worms reach the gut, they will latch onto the tissue there with their “hooks”, sharp teeth that also slice into the tissue. They then feed off of blood until they are mature enough to make their own eggs.
Luckily, many hookworm infections are preventable with use of standard “heartworm” medications prescribed by your vet. There are two major species seen in dogs and cats. Unfortunately, no one preventive covers both. This is why will still recommend regular fecal screenings, especially since hookworms can be passed onto pets’ owners. Even more unfortunate is that there seem to be resistant strains of hookworms making their way into the environment thanks to overtreatment at puppy mills and greyhound tracks. So, there may be a shift in how we use preventives in the future.
Once infected, pets will need to be treated with more potent medications than those found in the preventives. However, thanks to these new resistant worms, we may not eliminate it with the first or even third round of treatment. Try not to get frustrated. Trust me, your vet is JUST as frustrated. This still does not mean that preventives are not necessary. Not only do they prevent other parasites, but there is strong evidence that they will at least slow infection with resistant worms. Considering this can get passed onto our family members, the importance of prevention cannot be overstressed.