The Symptoms, Diagnosis, and Treatment for Puppies With Giardia

Keeping Your Puppy Free of Parasites

Dog Relaxing On Wet Mud At Field

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Giardia in puppies can cause devastating health problems. Giardiasis is an illness caused by a protozoan, a single cell organism that parasitizes the small intestine. Similar to the protozoan coccidia, canine Giardia infection typically affects younger dogs. Puppies are prone to diseases that older dogs can fight off. Older dogs have a more developed immune system that is better at fighting diseases. Up to half of young puppies will get giardiasis. These intestinal parasites can cause significant trouble given a puppy’s susceptible immune system.

Know the Signs of Giardiasis

The organism compromises the puppy's ability to properly process food. Signs of infection in a puppy are diarrhea, which is sometimes mixed with mucus and blood. Other times the stool may simply be soft and light colored, or it can even appear normal. The dog often develops a poor hair coat and the tummy swells from gas and looks bloated. Infected puppies may have trouble gaining or maintaining weight. While the illness can be asymptomatic, symptoms show most often among puppies.

Transmission, Diagnosis, and Treatment

The infective cyst stage of the organism lives in the environment, most usually in standing water. Puppies tend to contract the parasite by drinking from mud puddles or other contaminated water sources. The disease is also spread through contact with infected feces. The puppy can ingest infected feces which will then transmit the parasite to the puppy's body.

Diagnosis is made with a stool sample at the veterinarian's office. Using a microscopic examination, the veterinarian will look for the protozoan in the sample. Diagnosis can be tricky because infected dogs pass the organism only intermittently, and a fresh stool sample may be negative even when Giardia is present. Repeated tests are often necessary before the tiny parasite is detected. Some dogs may not show signs of illness themselves, yet are infected and spread the parasite.

Giardia can be treated with the prescription drug fenbendazole. The veterinarian will prescribe it and it will effectively remove Giardia cysts from the feces of dogs. (Technically, however, no drugs are actually approved for specifically treating giardiasis in animals.) No side effects from this treatment course are reported and it is safe for pregnant and lactating animals. Repeated fecal exams will need to be done in a few weeks following the medication. The veterinarian will confirm if any organisms are still present and make sure the medication is working. Because one sample is not always accurate, your veterinarian may require multiple confirmations at regular intervals following the prescription treatment. In addition to medication, bathe puppies with shampoo to remove fecal material and associated cysts.


To help prevent the chance of infection, keep the yard clean of feces. Restrict your dog's access to unsanitary water to help prevent the chance of infection. (Giardia is one of the most common waterborne diseases in the U.S.) Environmental areas like grass and standing water are tough to decontaminate, but you can sanitize surfaces by steam-cleaning and cleaning with disinfectants. Allow surfaces to dry completely after cleaning. If your dog was infected, it can be helpful to clean any outdoor surfaces where they may frequently defecate with a bleach-based cleaning supply. If it's possible to remove and replace any rocks or other outdoor items, that is recommended. The more items that may have been contaminated that you can remove or thoroughly clean, the better. Also, if you are on a walk and see your dog sniffing near other feces or drinking from standing water, stop the behavior immediately.

Giardia also commonly occurs in kennels and boarding facilities where the disease spreads rapidly due to the crowded conditions. Don't board your dog until your dog it's about a year old.

Giardia and Humans

Giardia is also zoonotic, meaning there is a risk it can be transferred to humans. If your puppy has it, other people in your family can be carrying the parasite as well, so it's important to treat other family members who are infected. The symptoms in humans are similar to canines and include diarrhea, gas, greasy stool, and other digestive issues. It is also diagnosed with a stool sample. Speak to your doctor if your pet has been diagnosed with giardia, especially if you or a family member is showing symptoms or has a compromised immune system.