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Fleas and ticks have been a nuisance since time immemorial.  Fleas can make you all itchy and ticks, they can carry the bacterium that causes Lyme disease, which can cause fevers and a rash, even if it's quickly treated.  Especially if you like spending time outdoors, it can be hard to avoid these parasites, and it doesn't help that the animals we keep as pets make good hosts to these bloodsuckers.  

The good news is there are some tick and flea repellents available for humans, but then again, they just aren't as convenient or long-lasting as the medicines you give your dog or cat.  So some days, it seems like life would be easier if you could just slap on your animal's tick or flea collar and hike into the woods worry free, but you definitely shouldn't.  Here's why.

Flea and tick collars work by slowly releasing chemicals like deltamethrin or pyriproxifen.  They dissolve in the natural oils of a pet's fur and can repel and/or kill pests.  Many do this by preventing their targets from growing or by totally shutting down their nervous systems.  This is the same method used by those topical gels you might put on your dog's back once a month, and it's generally pretty effective, but there are reasons you should never use these things on yourself.  

When you apply this kind of treatment to your pet, the medicine is absorbed into the animal's oil glands and then is slowly released into their fur from there.  This means the toxins will never be present in large quantities, so they don't pose a significant danger, but if you try to wear one of those colors or slather on some gel, for one, they can seriously irritate your skin and cause feelings of tingling or burning, but also, unlike cats and dogs, you sweat basically everywhere and for flea collars, that's a big deal, because that sweat can cause a bunch of chemicals to come out of the collar at once, so not only would you be absorbing a bunch of neurotoxins, but you'd also be using up a huge portion of the treatment in one go, which means you'd have much less protection against those parasites.

Of course, pets have other pest-repellant options, too, like oral medications which work roughly the same way, but you really shouldn't try those either.  That's because these medications can also contain neurotoxins.  Pets can usually handle small doses of them, though, and they're helpful because the treatments can last a while once the chemicals are secreted into their fur.  Humans are another story.  For one, it's not clear if an oral pesticide like this would even work for us, but even if it did, we don't have fur and we bathe a lot more, so those chemicals wouldn't stick around for long, so even though flea and tick treatments for pets are convenient and long-lasting, they're not worth trying on ourselves.

If you want to fight off those parasites, you're better off sticking with treatments made for humans, like permethrin.  Although it is a nerve agent, it's considered safe as long as you don't ingest it.  Normally, it's just applied to clothes.  It might not last as long as a collar and it might not be as powerful as what your dog takes, but it will keep you safe and that's what matters.

Oh, and on a small note, there's a reason dogs and cats have different flea and tick medications.  Dog treatments are strong enough to be dangerous for cats, so make sure your animals are only getting the treatments aimed at them, too.

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