What the heck is empiric deworming?
It sounds like a bad torture scene from the next fantasy series, where the empire gets angry at its subjects and sends down millions of worms to eat them alive (shudder).
Actually, nature can be an evil empire if it strikes your pet with intestinal parasites. Empiric deworming means you give your pet a safe deworming medication if you suspect intestinal parasites (worms), even if your vet hasn’t found actual evidence of the worms in a stool sample.
What Vets Do With the Poop
Let’s start with the all-important fecal sample — the bag of poop you bring to your vet for the annual physical.
A small amount is all you need to bring. Think sample size — no super-sizing of the poop sample, please. You may be asked to scoop the poop at other times too and bring us a small sample, particularly when your pet is having diarrhea.
Now let’s take a refresher course in Poop 101. Here’s what happens when we delve into the details of the doo-doo. Your pet’s stool sample is analyzed to detect parasites (worms) in the GI tract.
Some folks think we can tell a lot else from the stool, like whether or not their dog ate poison or if their pet is allergic to the food they’re feeding. We can’t tell these things from a stool sample. We do look at the color and consistency, which can give us some information, and that’s all you need to know about that. I don’t want this post to carry a gross-out alert.
In a routine stool sample, we float the poop in a solution that allows the parasite eggs to float to the top. Then we mount a drop of the sample on a slide and look for the eggs under a microscope.
Parasites can be identified by the shape of their eggs. With the parasite identified, we can prescribe the proper drug and “deworm” the pet. There are other more esoteric tests we can run on poop if we suspect uncommon parasites or pathogens, but that is saved for Poop 201.
Empiric Deworming With a Negative Stool Sample
What happens if we suspect worms but can’t find them? Say a dog or cat has intractable diarrhea, is not responding to diet trials and various medications, and has negative stool samples. In these cases, it’s not only acceptable but recommended to empirically deworm the pet.
Deworming puppies, kittens, stray animals and pets who spend a great amount of time outdoors roaming is also suggested.
People often ask why I couldn’t find worms in their pet. The simplest answer is that parasites are sneaky pests that don’t always read the course literature for Poop 101 — in other words, they don’t show up in all samples. Parasites don’t like:
- Old poop (rock poop)
- Frozen poop (poopsicles)
- Icky poop (watery poop)
Veterinarians must pay attention to the shelf life and quality of your pet’s poop. Some parasites shed intermittently, so your vet might ask you to collect stool samples 3 days in a row.
Your pet may be suffering from explosive, watery diarrhea, but eggs are more difficult to find or are not present in very sick poop.
Why Vets Use Stool Samples
We get better treatment results and can give a person guidelines on how to avoid reinfection if we can identify parasites in a stool sample. Some people don’t want to empirically deworm their pet for these reasons:
Some folks just don’t want to give a medicine if they don’t think there is a good reason to do so. Some people are very holistic and distrust many medications. I often hear, “I don’t want to give that poison to my pet.”
If a dog or cat shows no evidence of GI problems or if the person thinks they have a low exposure to contracting intestinal parasites, such as the lap dog or the cat who goes outside on a limited basis, they just don’t want to give deworming medication on spec.
Good prescription dewormers can be a bit pricey, particularly for a large dog or in the case of multiple-pet households.
We have a higher success rate if we identify the parasite. There are different dewormers for different parasites, some being less expensive than others.
Parasites also have different life cycles, requiring dewormers be given at different intervals to kill all the stages of the parasite. Lastly, some worms can be transferred from pet to pet, so better to know what you’re dealing with before going home with a bag full of medicine for each critter.
Learn more about deworming in this video:
This ends our refresher course in Poop 101. This is what will be on the test:
- Fresh stool samples should be analyzed at least once a year and more often if your pet is experiencing GI symptoms.
- Based on your pet’s exposure and lifestyle, you may want to deworm your pet empirically. A great example of this is the outside cat who hunts, dines frequently out of the home and poops outside of the home as well. Pups and kittens, particularly those who may have had a rough start in life, should also be dewormed.
- If your pet is having recurrent diarrhea and stool samples are negative, empiric deworming is a sound idea and a good medical practice.
Happy hunting for perfect poop samples. And remember: Your vet has nice little plastic containers if you just can’t find the perfect receptacle at home to ruin with a sack of poop. Veterinary technicians do not appreciate being asked to wash out these containers and return them to you.
Our goal is to complete the task of poop collection with the least amount of gross-out moments for everyone involved — promise.
This pet health content was written by a veterinarian, Dr. Debora Lichtenberg, VMD. It was last reviewed Oct. 4, 2017.