Vet Guide to Coccidiosis in Dogs 2025 🐶🩺

By Dr. Duncan Houston BVSc

Coccidiosis is a gastrointestinal infection caused by microscopic protozoa (Cystoisospora spp.) that invade the intestinal lining. While often harmless in healthy adult dogs, it can cause severe illness in puppies and immunocompromised pets. Here’s an in‑depth vet guide on its causes, clinical signs, diagnosis, treatment, and environmental prevention. 💊

📍 What Is Coccidiosis?

• • Caused by single‑celled parasites—most commonly *Cystoisospora canis* and *C. ohioensis*.
  • These protozoa invade intestinal cells, leading to cell damage and diarrhea.
  • Healthy adult dogs often carry the parasite without symptoms; puppies and stressed dogs are at higher risk.

⚠️ Causes & Risk Factors

• • Infection occurs via ingestion of infective oocysts from feces or contaminated environments.
  • Oocysts must sporulate in the environment (12–26 hrs) before becoming infective.
  • Puppies in kennels, shelters, or with poor hygiene are particularly susceptible.

⚠️ Clinical Signs

• • Often asymptomatic in adults, but symptomatic puppies may develop:
  • 💩 Watery or bloody diarrhea
  • 🤢 Vomiting, nausea
  • ⚠️ Weight loss, dehydration, weakness
  • Severe cases may lead to lethargy, fever, or even death.

🔬 How Is It Diagnosed?

• • Fecal flotation/crudex: Detects oocysts microscopically; may require repeated testing due to intermittent shedding.
  • Fecal antigen or PCR: More sensitive detection methods used in some labs.
  • Clinical context—diarrhea, young age, stress or kennel living—guides suspicion.

💊 Treatment Options

• • Sulfadimethoxine (Albon): First-line, FDA-approved treatment—50–60 mg/kg daily for 5–20 days.
  • Ponazuril or Toltrazuril: Effective off-label alternatives, useful in resistant cases.
  • Other sulfa-based regimens: sulfaguanidine, diclazuril, furazolidone as per guidelines.
  • Supportive Care: Treat dehydration with fluids, provide antidiarrheals, nutrition, and monitor closely.
  • Retest feces 2 weeks post-treatment to confirm clearance.

🧼 Environmental Control & Prevention

• • Remove feces daily—oocysts sporulate quickly in yards/kennels.
  • Steam-clean or use ammonia-based disinfectants—oocysts resist most cleaning agents.
  • Prevent coprophagia, control rodent/insect vectors.
  • Test and treat all in-contact animals in group living environments.

📈 Prognosis

• • Puppies typically recover within 2–4 weeks with treatment.
  • Healthy adults often carry without illness, needing no treatment.
  • Severe, untreated disease can cause growth delays or fatality.

📊 Quick Reference Table

✅ Vet Tips by Dr Duncan Houston BVSc

• • 🐾 Treat all dogs in the environment, not just those showing symptoms.
  • 🧽 Clean daily with steam or ammonia-based agents to eliminate oocysts.
  • 💊 Re-check fecal samples 2 weeks post-treatment to confirm cure.
  • 🚫 Prevent feces ingestion and minimize environmental contamination.

If your puppy has diarrhea, weight loss, or appears unwell, connect through the AskAVet.com app for prompt advice.🐾❤️