Hepatozoonosis in Dogs: 2025 Veterinary Guide to Diagnosis, Symptoms & Tick-Borne Prevention 🐶🦠

Hello, I’m Dr Duncan Houston BVSc. Hepatozoonosis is a serious and often devastating parasitic disease in dogs caused by ingesting infected ticks. Though uncommon, this disease can be fatal—especially without early diagnosis and ongoing management. In this 2025 guide, I’ll explain how Hepatozoonosis spreads, how to recognize it, and how to support your dog through it. 🩺

🧬 What Is Hepatozoonosis?

Hepatozoonosis is caused by two species of protozoan parasites:

• Hepatozoon canis – typically causes milder illness
• Hepatozoon americanum – causes a more severe, often fatal condition

Both are spread by ingesting infected ticks, not by tick bites. That’s what makes this illness unique and so challenging to prevent. 🦟

⚠️ How Dogs Become Infected

• 🐕 Dogs eat infected ticks by grooming, chewing fur, or eating infected prey
• 🦠 Protozoa develop inside the tick before becoming infective
• 🐭 Eating rodents or birds with ticks may also lead to infection
• 🚫 Dogs are not contagious to other dogs or humans

Young dogs and those with suppressed immune systems are most at risk. ❗

🩺 Signs of Hepatozoonosis

H. canis (Milder Form)

• 🤒 Occasional fever
• 😴 Lethargy or reluctance to move
• 🩸 Pale gums
• 🧬 Enlarged lymph nodes or spleen
• 🧒 Most common in dogs under 18 months

H. americanum (Severe Form)

• 🥵 Muscle, bone, or joint pain
• 🚶‍♂️ Limping or inability to walk
• ⚖️ Weight loss, fever, sensitivity to touch
• 💔 Chronic wasting or collapse

Once symptoms appear, untreated dogs typically decline rapidly—often passing within a year. ☠️

🔬 Diagnosis

• 🩺 Physical exam + history
• 🧪 Blood work (checks for inflammation and organ function)
• 🔍 Microscopic exam for parasite stages
• 🧫 Muscle biopsy may be required to confirm H. americanum
• 🖥️ X-rays to rule out other issues

💊 Treatment Options

There is no cure for either form. Treatment focuses on symptom control and improving quality of life.

• 💊 Antibiotics (e.g., clindamycin, TMS) for temporary relief
• 🔥 Anti-inflammatory drugs for pain
• 💉 Supportive care: fluids, nutrition, syringe feeding
• 🩸 Blood transfusions in severe cases

Relapse is common. Long-term care often includes intermittent treatment when symptoms flare. 💉📆

🛡️ Prevention

No vaccine is available—so prevention focuses on avoiding tick exposure:

• 🧴 Use monthly tick preventives year-round
• 🌿 Keep grass trimmed, remove brush piles
• 🦟 Treat your yard, especially in warm climates
• 🚫 Prevent dogs from eating rodents, birds, or ticks
• 🧽 Remove ticks promptly—before your dog can swallow them

📱 Ask A Vet: Ongoing Support for Tick-Borne Disease

• 🔍 Help interpreting biopsy or blood test results
• 💊 Guidance on long-term symptom management
• 🩺 Adjustments for chronic pain or nutritional care
• 📅 Prevention schedules for multi-pet households

Download the app or visit AskAVet.com for 24/7 support and peace of mind. 🐾

✅ Summary: Hepatozoonosis in Dogs

• 🦟 Caused by eating infected ticks—not from tick bites
• ⚠️ H. americanum causes more severe, often fatal disease
• 🐶 Symptoms range from mild fever to severe pain & wasting
• 🧬 Diagnosis often requires bloodwork and biopsy
• 💉 No cure—long-term management is key
• 🛡️ Prevent with year-round tick control & prey avoidance

Hepatozoonosis is rare but deadly. Staying vigilant with tick prevention is your best defense. 🛡️🐶

— Dr Duncan Houston BVSc