My Pet Doesn't Have Worms!

Warning, potentially disturbing photo in post.


I hear it all of the time, my pet doesn't have worms.  "How do you know?", I ask.

He had a stool check when he was a puppy.

Well, that's a start but the last test was two years ago, so how do you know he doesn't have worms now?

I never see worms in her stool.

That's good, worms in the stool are often signs of a serious infestation.  But the test we do checks for evidence of parasites in the stool that are too small to see with the naked eye.  Or, we look for microscopic eggs being passed into the stool.  New tests are even more sensitive and look for DNA from the parasites, present before these parasites can cause disease in our pets or our family.

My cat never goes outside.

OK, now we have to have some serious discussions, because even indoor cats can have parasites.  Parasites that can cause disease in our pets and in us as well. (this is not the disturbing photo)

This little guy is only a few months old.  Rescued from the street and actually headed to a good home this week.  (sorry, not for adoption).  He was tested for feline leukemia, feline aids, intestinal parasites, treated and vaccinated.  So good to go for life right?  WRONG!

Here's the thing about worms, at least the most common ones that we see (round worms, hook worms, and whip worms) they are all well adapted to their hosts, and some are not very picky about their hosts.  They can survive very well in their hosts or the environment and pass their traits on to future generations of worms without making their host very sick, sometimes.  The sometimes is the important part.  If the host does not have a good immune system (young, old or sick pets), or, if the host is not the preferred host (dog or cat round worms in people), the parasites can cause serious diseases. Here is a photo of a child with a round worm in his eye.

Not only that, but they are tricky.  Our deworming medications will kill the adult worms present in our pets.  Not the immature ones, just the adult ones.  That is why we need to treat multiple times, killing the parasites as they mature.  The interval between treatments and the medication that we use, will depend on the type of parasite that is present.

To make matters even worse, some parasites, especially the round worms and toxoplasmosis in cats (subject of another blog post) will form cysts in the host.  These cysts can become activated during times of stress, hormonal changes, illness, or just about any reason that you can think of.  Then your indoor pet will be shedding infective eggs into your environment and re infecting themselves and posing a risk to you and your family. (especially children and immune compromised individuals)

Here's a little story that a parasitologist from Colorado State University shared with me and I want to share it with you.

What does your indoor cat do when it sees a fly?  Mine catches it, plays with it, and eventually eats it.  Now, where was that fly before it was in your home?  In many cases it was on a pile of dog poop outside, picking up roundworm eggs.  In fact many critters that find their way into our homes (OK other people's homes) like mice, roaches and the aforementioned flies, can bring in parasite eggs.  

After becoming infected what do most cats do?  They wander around the house, they dig in the litter box contaminating their little paws with feces and parasite eggs, and they jump on our tables and counters... need I say more?

Wait, don't kill the cat.  It's much easier to prevent parasites than you think.  The CDC recommends twice a year fecal tests for all pets, we agree.  They also recommend periodic (quarterly) deworming for all pets.  We have a better answer for now.

Put all pets on a regular parasite control product.  Monthly heart worm protection will prevent the more common zoonotic (contagious to people) parasites.  Every pet, every month.  For cats, we recommend the topical application of either Revolution or Advantage Multi once a month.  This will also prevent fleas and heart worm.  (I know the cat never goes out.  I can't tell you how many indoor cats I see with fleas every year).  If you have a dog, it goes out and can bring fleas in.  

In addition, have stools checked twice a year.  Bring a small sample to your veterinarian.  We send our out to a lab that does a very good job of checking for parasites.

Detection and prevention will decrease the likelihood that you will have parasite issues in your family, both 2 and 4 footed.