It’s an automatic reaction for many people – “I’m taking Bella to the vet, so I better bring some of her poop too.” But why is it important to bring your furry friend’s feces to the vet? The answer: disease screening for both your pet and you. Dogs, cats, and all animals for that matter have an assortment of parasites that they can become infected with, and many of these can also infect humans.
The most common parasites of dogs and cats are roundworms and hookworms. Dogs can also be parasitized by whipworms. These parasites can cause diarrhea and weight loss, most commonly in young animals. Hookworms can also cause anemia, or low red blood cells, because they attach themselves to the intestinal wall where they suck blood. Virtually all puppies and kittens are born infected through placental migration or quickly become infected by roundworms and/or hookworms from their mothers’ milk. Even when properly dewormed, the mother dogs and cats can still have worms inside their muscles that do not wake up from their state of arrested development until the puppies or kittens are nearly ready to be born. Once the worms grow to adulthood inside the dog’s or cat’s intestinal tracts, they mate and release eggs. These eggs are passed in our pets’ feces, where they contaminate the ground. Sometimes the eggs are picked up by smaller animals like rodents and birds, and then are passed to our pets when they eat that animal. Most commonly, dogs and cats get infected by ingesting the eggs either directly from feces or indirectly by eating something that the eggs have contaminated, such as dirt or plant materials.
People can become infected the same way as pets, which is termed fecal-oral transmission. Most commonly, it is children who contract these parasites because they put many inanimate objects in their mouths that may be contaminated, and also have a less-developed immune system to destroy the parasites if they manage to make it inside their bodies. Once inside a human, roundworms often get lost since they are not in the correct host species and end up in abnormal areas such as the muscles, brain, organs, or eyes. This is called visceral larva migrans. Hookworms can also be transmitted by the fecal-oral route, but they can also burrow through the skin of a dog, cat, or human – most commonly through bare feet. While they will find their ways to the intestines in most dogs and cats, they will also get lost inside human skin, causing cutaneous larva migrans.
Another very common parasite is the tapeworm. These are classically seen as “grains of rice” in the animal’s stool. They can cause diarrhea and weight loss occasionally, but again more so in young animals. The most common way a dog or cat contracts tapeworms is by ingesting fleas. The juvenile tapeworm lives inside the flea, and when a dog or cat bites the flea off, it is swallowed along with the tapeworm. Tapeworms can also be transmitted when dogs and cats eat rodents or rabbits. Children can again be infected by eating fleas but this is not common. The most relevant piece of information to have is that if you see tapeworm segments in your pet’s stool, your pet probably has fleas.
Fortunately, all of the aforementioned parasites can be prevented. Using a monthly heartworm preventative to protect against infection of deadly heartworms through mosquito bites has the added benefit of controlling many intestinal parasites. Most heartworm preventatives will control roundworms and hookworms. Some will also control whipworms and tapeworms. Since tapeworms usually are a result of a flea infestation, the best way to control against those are with veterinarian-recommended flea preventatives. Fortunately, all of these common parasites are treatable if your pet contracts them.
However, there are other parasites that we screen for in your pet’s stool that cannot be prevented with medication. Examples of these are Giardia, Coccidia (also known as Isospora), Capillaria, Strongyloides, Toxoplasma, and Neospora. Many of these can cause serious disease, while others may only cause mild diarrhea. Regardless, it is very important to have your pet’s stool sample checked at least annually to ensure the chance for harm to you and your loved ones, furry and non-furry, is minimal.
Author: Dr. Jeffrey Haymaker