Disease Guide

Toxoplasmosis in Dogs & Cats: Symptoms, Diagnosis & PCR Testing [2025]

A parasitic infection caused by Toxoplasma gondii, with cats as the primary host; can cause multi-organ damage and requires antibiotic treatment

Last updated: 2025/12/16
Pethealthmap Editorial Team
Sources: AVMA, CDC, National Taiwan University Veterinary School

When to See a Vet

Seek Emergency Care Immediately

  • Unable to stand on their own or persistently and severely lethargic
  • Repeated vomiting episodes with inability to stay hydrated
  • Rapid breathing or obvious difficulty breathing

Schedule a Clinic Visit Soon (within 24–72 hours)

  • Noticeably reduced activity level lasting more than two days
  • Significantly decreased appetite or persistent refusal to eat for more than one day
  • Diarrhea or vomiting lasting more than forty-eight hours

01What Symptoms Indicate Something Is Wrong?

Toxoplasmosis in dogs and cats typically presents as generalised malaise and gastrointestinal signs; some cases may also show respiratory or neurological changes.

  • Lethargy or noticeably reduced activity
  • Persistent weakness, excessive sleepiness, or sluggish responses
  • Loss of appetite accompanied by weight loss
  • Frequent vomiting or persistent diarrhoea
  • Occasional rapid breathing or neurological signs such as unsteady gait

Seek emergency care immediately if you notice the following symptoms:

  • ⚠️ Seek veterinary care if symptoms have not improved within 48 hours

02How to Monitor at Home: Key Observations & When to Go to the Emergency Vet

Observing and recording key details at home helps your vet quickly understand the progression of the condition and evaluate treatment response.

  • Note the date and time symptoms first appeared and how they have progressed
  • Track daily appetite, food intake, and any refusal to eat
  • Log the number of vomiting episodes, what was vomited, and when
  • Observe bowel movement frequency, consistency, and any presence of blood or mucus
  • Weigh your pet weekly and record any changes for your vet to compare
  • Record videos or photos of concerning signs (e.g. vomiting, abnormal gait) to share with your vet

03How Will the Vet Diagnose It? Common Diagnostic Tests

The vet will begin with a physical examination and, where necessary, combine blood tests, imaging, and specific diagnostics to confirm infection or rule out other conditions.

Physical examination

assessing temperature, mucous membranes, neurological reflexes, and respiratory status

Blood work

evaluating inflammatory markers and organ function (liver, kidneys)

PCR testing

detecting Toxoplasma gondii DNA at a specialist or reference laboratory (referral may be required)

Cytology or faecal examination

microscopic search for the organism or inflammatory cells

Imaging (X-ray / CT scan)

assessing involvement of the thorax, abdomen, or nervous system

04Post-Diagnosis Care: Medications, Diet Adjustments & Home Care Guide

Treatment is guided by test results and disease severity, and requires regular follow-up visits with any necessary monitoring tests.

  • Medication type and duration are determined and monitored by your vet
  • Maintain hydration and electrolyte balance; provide easily digestible, nutritious food
  • Home care focuses on a low-stress environment and regular feeding schedules
  • Schedule follow-up visits for blood work or imaging to assess treatment response
  • If symptoms do not improve or worsen, referral to a specialist hospital may be recommended

05What to Prepare Before the Vet Visit: Key Information to Help Your Vet

1
Note when symptoms started, how they have changed, and any history of eating raw meat or hunting
2
Compile a record of appetite, vomiting, and bowel movements over the past few days
3
Prepare a list of current medications, supplements, and vaccination records
4
Bring videos or photos of any concerning signs (vomiting, abnormal gait, or breathing difficulties)
5
Bring any previous test results or imaging for comparison, if available
6
Prepare a list of questions for your vet and note the urgency of your concerns
7
Consider booking a clinic that can perform PCR testing or specialist diagnostics

This content is for reference only and cannot replace a professional veterinary diagnosis. If your pet shows signs of illness, please seek veterinary care promptly.

Frequently Asked Questions (FAQ)