Reality Bites: Fleas Can Cause Liver Failure

I recently accompanied a friend to a local veterinarian; she wanted to have her pet dog (a six-month-old cocker spaniel) treated for fleas. At the time, I didn’t think a visit to the veterinarian would have been an iconic enough event to define my day. In fact, everything went well; until I decided to ask a rhetorical question: “What’s the worst thing fleas can do outside of causing an itch?” The vet replied with a shrug: “Liver failure seems pretty bad.”

I couldn’t believe it at first. I mean I knew they could pass on some diseases (cat scratch disease, plague, and breakbone disease) that have been notorious for fatality rates, but the way she went on with her lecture was downright terrifying.

Apparently, fleas – despite their size – are large enough in comparison to other smaller parasites to serve as transport vessels from one animal to another. They are very capable of serving as a form of mothership for another lethal parasite: the tapeworm.

Flea tapeworms usually leave their eggs in an afflicted animal’s feces. If the animal is also a host to fleas, there is a good chance that the fleas’ own larvae ingest the eggs. These eggs then hatch, and as the host larvae mature into adult fleas, make a life inside them. Eventually, the adult fleas begin to suck blood from the host, causing the host’s grooming behavior to kick in. When this happens, the fleas may be ingested by the host, effectively bringing tapeworms into the digestive system.

Do you think you’re safe just because you don’t groom yourself the way your pets do? Don’t think that, fleas can get on humans. Fleas have incredibly strong back legs that allow them to accelerate thirty to fifty times faster than a space shuttle. They can close the gap between the animal’s fur and the owner’s face, and make their way into a person’s mouth unnoticed when petting an afflicted animal.

That is where the real horror begins. The flea is incapable of surviving the intense conditions of the human stomach; but the tapeworm is designed specifically for such an environment. Over time, the tapeworm grows larger, feeding on the nutrients inside its victim’s gut until it reaches a length of one to two feet. It doesn’t stop there as well. A single flea tapeworm is capable of reproducing on its own, and eventually, segments filled with eggs drop off. These can be excreted along with fecal matter, but will often hatch and grow into more tapeworms. The worst part is that when food in the gut becomes insufficient, the tapeworms can spread to other systems of the body. They tend to make their way to the liver, where they continue their life cycle of eating and reproducing; and it is here where they leave behind their gravid segments, resulting in parasitic cysts that gradually eat away at the organ, causing intense liver pain and discomfort.

An article I read documented one such case of an Armenian man in his eighties. He had contracted tapeworms from his dog, and thousands of larvae had formed cysts in his liver, to the point its texture had turned bulging and rubbery. It was so bad that although the liver is capable of repairing damage to itself even if only a quarter of its living tissues are all that remain, the parasites were winning the battle.

Thankfully, such parasitic invasions, no matter how real, can be treated and –more importantly – prevented. By treating fleas as soon as they are diagnosed, and by having your pet checked for worms immediately afterwards, the risk of contracting tapeworms from fleas is greatly reduced. Proper hygiene for both you and your pet also lower the chances of contracting tapeworms. In the event that tapeworms are contracted, Mebendazole and other drugs can be used to interfere with the natural life cycle of tapeworms (though production of Mebendazole is done by doctor’s request). Surgery may also be done to remove tapeworms that exhibit resistance to medication.

Regardless, what I learned from the vet that day still gives me a bit of chill sometimes (I can’t explain the way she described it). But at least I know how to make sure it doesn’t happen to me.