Veterinary Partner

Veterinary Partner: Understanding Giardia Infection in Dogs

Fred Bahnson 


In addition to ticks, fleas, and heartworm, dogs can also be affected by another parasitic organism known as Giardia. Giardia, or giardiasis, is an intestinal infection caused by a parasite that can impact dogs, cats, and even humans. This comprehensive guide will provide you with all the information you need to know about Giardia in dogs, including prevention, symptoms, testing, treatment, and more.

What is Giardia in Dogs?

Giardia is a common infection that affects the intestines of dogs, leading to severe diarrhea. Dr. Kathleen Chiu, D.V.M., a veterinarian and partner doctor at Hometown Veterinary Partners in Myrtle Beach, South Carolina, explains that dogs contract Giardia by ingesting infectious cysts found in the feces of other dogs. The parasite has two forms: trophozoites, which live in the intestines of infected dogs, and cysts, which are protected by an outer shell and shed in the infected dog’s stool. Unfortunately, cysts are resilient and can survive in the environment for months, particularly in colder weather.

Prevention of Giardia in Dogs

There are several measures dog owners can take to prevent Giardia infection:

  1. Wash your hands frequently.
  2. Disinfect areas that may contain Giardia.
  3. Dispose of feces properly.
  4. Prevent dogs from ingesting potentially contaminated water, food, or soil.

Life Expectancy of Dogs with Giardia

With proper care and treatment, most dogs will recover from a Giardia infection. Dr. Anna Massey, V.M.D., an emergency veterinarian and director of critical care at Red Bank Veterinary Hospitals in Tinton Falls, New Jersey, explains that some dogs may not show any symptoms, and the infection may be discovered incidentally. However, untreated diarrhea caused by Giardia can lead to severe dehydration and pose a life-threatening risk. The prognosis depends on factors such as the dog’s overall health, the severity of the infection, and any potential complications.

Symptoms and Behaviors of Dogs with Giardia

One of the challenges with treating and preventing the spread of Giardia is that dogs often do not exhibit symptoms. Dogs infected with Giardia usually maintain their normal appetite and energy levels. However, some signs and symptoms may include:

  • Acute or sudden onset of diarrhea
  • Soft or watery stool with mucus
  • Abdominal discomfort
  • Excessive, foul-smelling gas
  • Poor coat condition

In severe cases, dogs may experience lethargy due to dehydration, weight loss, decreased appetite, and vomiting.

Testing for Giardia in Dogs

To accurately determine if your dog has Giardia, it is highly recommended to have your veterinarian conduct a fecal test. While some at-home tests are available, a veterinarian can perform more reliable and precise tests. These may include fecal flotation, fecal wet slide, fecal sample stain, rapid ELISA test, or PCR test. Regular fecal analysis every six months is also advisable to screen for asymptomatic dogs and prevent further contamination.

Treatment and Costs for Dogs with Giardia

The cost of treating Giardia in dogs can vary based on factors such as your location, the severity of the infection, and the required testing. Outpatient treatment, which includes medication, diagnostic tests, and follow-up visits, typically ranges from $100 to $300. If the dog is severely dehydrated or unwilling to eat or drink, hospitalization with intravenous fluids and medications may be necessary, increasing the costs to $1,000 to $4,000.

Stages of Giardia in Dogs

The stages of Giardia infection can vary, but generally follow this path:

  1. Stage 1: The dog ingests Giardia cysts from feces, contaminated water, or soil.
  2. Stage 2: The cysts release trophozoites in the small intestine, which multiply through binary fission.
  3. Stage 3: Trophozoites become free-swimming and attach to the dog’s intestine, causing severe diarrhea and dehydration.
  4. Stage 4: The trophozoites encyst again and leave the colon in feces, contaminating the environment.

Is Giardia Covered by Pet Insurance?

Coverage for Giardia treatment depends on your specific pet insurance plan. Acute infections are often covered, but if your pet had recurring Giardia before obtaining insurance, it may be considered a pre-existing condition and not covered. Review your policy’s terms and conditions or contact your insurance provider directly for clarification.


Understanding Giardia infection in dogs is crucial for prevention, early detection, and effective treatment. By implementing preventive measures, conducting regular fecal tests, and seeking veterinary care, you can protect your dog’s health and well-being. Remember to consult with your veterinarian to develop an appropriate treatment plan tailored to your dog’s specific needs. Stay informed, be proactive, and ensure the best care for your beloved canine companion.