Toxoplasmosis in Dogs

Toxoplasmosis is a parasitic infection caused by Toxoplasma gondii. The disease may be transmitted from cats or dogs and may also be contracted by humans. Toxoplasmosis is particularly dangerous for pregnant women.

Causes of Toxoplasmosis

Toxoplasmosis is an infection that is caused by the presence of a parasite known as Toxompasma gondii. The parasite may infect the dog if he consumes raw meat or insufficiently cooked meat that contain toxoplasma cysts. Dogs that have a weak immune system are more likely to develop the disease.


Toxoplasmosis may be transmitted from other canines or felines that are infected with the parasite. The disease may also be transmitted from:

  • Mother to puppies through the placenta
  • Infected birds or rodents
  • Water infested with the parasite
  • Food infested with the parasite

Symptoms of Toxoplasmosis

Toxoplasmosis will rarely show symptoms. If symptoms are present, these may include:

  • Fever
  • Lack of appetite
  • Weight loss
  • Lethargy

The infection may develop and affect internal organs, most commonly the lungs, brain, eyes or the central nervous system. The dog may display a few specific symptoms depending on the organ that is affected:

  • Seizures
  • Confusion
  • Coughing
  • Panting
  • Exercise resistance
  • Secondary eye infections
  • Excessive blinking
  • Photophobia (sensitivity to light)
  • Jaundice (yellowing of eye whites)
  • Pot bellied appearance

Detection of Toxoplasmosis

Toxoplasmosis may be detected through a blood test. The blood should contain antibodies to the Toxoplasma gondii parasite. The vet may also choose to run a few additional tests such as:

  • Feces analysis
  • Urinalysis
  • Eye exam (if the eyes are affected by the infection)
  • X-rays (if suspecting that the lungs are affected)

Toxoplasmosis Treatment Options

The treatment of toxoplasmosis may vary, depending on how severe the infection is. The vet may prescribe:

  • Oral antibiotics such as clindamycin
  • Sulfonamides
  • Anticonvulsants such as phenobarbital, if the dog displays seizures 
  • IV fluids, if the condition is severe and the dog is dehydrated and severely anemic

If the dog's eyes are affected, the vet may prescribe different topical ointments. For respiratory symptoms, the vet may indicate a few antitussives. If the central nervous system is affected, the prognosis is poor. Toxoplasmosis may be fatal in immunocompromised dogs.

Toxoplasmosis Prevention

Toxoplasmosis may be prevented by feeding your pet only dog food and avoiding raw meats or meats from dubious sources. If you feed meat to your pet, always make sure it is sufficiently cooked. Uncooked meat may contain toxoplasma cysts, which will cause the infection. Prevent your dog from coming into contact with pets that are infected with toxoplasmosis.

Toxoplasmosis is a zoonotic disease, so it may be transmitted to humans as well. Even though the parasite is not dangerous for humans, pregnant women that haven't been in contact with the parasite before may be at risk, as the parasite may affect the baby.