Giardia in dogs and cats

Giardia is a small intestinal parasite that occurs worldwide and can cause diarrhea in dogs and cats. Young animals are particularly sensitive, but older animals can also become infected. Giardia is contagious and can sometimes even be transmitted to humans.

What is Giardia?

The Giardia parasite moves using flagella in the intestines of your dog or cat. Outside the animal, the parasite survives in a cyst, which remains infectious for a long time, especially in a wet and cold environment. In dry and warm conditions, the cyst dries out more quickly.

Infection

Giardia is mainly spread through feces. Each cyst contains two parasites, which can multiply in the intestine and form new cysts. Infection mainly occurs through:

• Contaminated drinking water or food

• Contact with infected animals

• Contaminated surfaces or environment

Giardia is common in shelters because many animals live close together and the parasite is highly contagious.

Symptoms of Giardia

Not every infected animal gets sick. About half of the animals show symptoms, usually young animals:

• Abdominal pain or cramps

• Diarrhea, sometimes slimy, greasy, or with blood

• Weight loss with long-term infection

• Sickly appearance and a dull coat

Fever usually does not occur.

Diagnosis

A veterinarian may suspect Giardia in cases of diarrhea, but a stool sample test is needed for certainty. Feces are often collected over several days to reliably detect the parasite. Tests may include:

• Rapid test

• Microscopy

• PCR test (measures Giardia DNA)

Treatment of Giardia

Treatment is necessary because an infection usually does not go away on its own. All animals in the same household must be treated at the same time to prevent reinfection. Treatment options:

• Medications that kill the parasite

• Fiber-rich food to regulate diarrhea

• Stool-thickening agents

• IV fluids for dehydrated or young animals

The environment must also be thoroughly cleaned and disinfected, including rugs, beds, food and water bowls, and litter boxes.

Prognosis

Most animals recover fully. Some animals remain carriers of Giardia without symptoms. Carriers can still infect other animals. After three months of correct treatment and hygiene, the chance of reinfection is minimal.

Prevention

Complete prevention is difficult, but you can reduce risks by:

• No outdoor water or communal water bowls for your dog

• Cleaning up feces immediately

• Treating promptly in case of infection

• Good hygiene in the home

Giardia and humans

Humans have their own species of Giardia, but sometimes dogs or cats can transmit an infection. Therefore, always wash your hands after contact with infected animals or feces.