Capillariasis in Cats: A Vet’s 2025 Guide to Capillaria Worms 🐾🩺

Capillariasis in Cats: A Vet’s 2025 Guide to Capillaria Worms 🐾🩺

By Dr Duncan Houston, BVSc

🔍 What Is Capillariasis?

Capillariasis is caused by small parasitic nematodes of the genus Capillaria (also called Pearsonema or Eucoleus), which can infect the urinary bladder and, less commonly, the respiratory or nasal tract in cats.

🐾 Common Species & Infection Sites

• Capillaria plica/feliscati (Pearsonema): bladder worms in cats and dogs.
• Capillaria aerophila (Eucoleus): respiratory tract—lungs & bronchi.
• Capillaria boehmi: nasal passages/sinuses; rare but possible.

⚠️ Who’s at Risk?

All cats can be affected, but indoor cats with no exposure to intermediate hosts are at lower risk. Outdoor cats that hunt, drink from soil or contaminated water may ingest infected earthworms or other hosts.

⚠️ Signs & Symptoms to Watch For

🩺 Urinary (bladder) Capillaria

• Often no signs unless heavily infested
• Frequent urination, straining, painful urination (dysuria)
• Blood in urine (hematuria), accidents outside the litter box
• Rarely, bladder inflammation, occasional obstruction, or secondary urinary infections

🌬️ Respiratory Capillaria

• Coughing, wheezing, sneezing, nasal discharge
• Difficulty breathing, especially in heavy infestations

👃 Nasal Capillaria

• Possible sneezing, nasal discharge from sinus infections

🔬 How Cats Get Infected

Different species have slightly varied life cycles:

• Bladder worms: eggs shed in urine → embryonate in soil → earthworm eats eggs → cat eats worm and becomes infected ~8 weeks later.
• Lung worms: eggs coughed up/swallowed → passed in feces → ingested directly or via earthworm → larvae develop in airways.
• Nasal worms: similar cycle, lodge in nasal tissue.

🩺 Diagnosis

• Urinalysis: bladder infections—detect barrel-shaped, bipolar eggs.
• Fecal exam or nasal/tracheal wash: identify respiratory or nasal worm eggs.
• Repeat samples may be needed—eggs shed intermittently.
• Imaging (ultrasound/X‑ray): assess complications like bladder wall thickening or lung changes.
• Bloodwork: generally normal but useful to evaluate overall health.

💊 Treatment Options

• Fenbendazole (commonly 20–25 mg/kg daily for 7–10 days)—effective for urinary and respiratory Capillaria.
• Ivermectin, levamisole, or milbemycin: alternatives or in combo, depending on availability.
• Anti-inflammatories: e.g., prednisolone for bladder inflammation if painful.
• Supportive care: manage pain, encourage hydration, and treat secondary infections.
• Follow-up testing: 2–4 weeks after treatment to confirm clearance.

📅 Prognosis & Outcome

• Bladder infections: prognosis excellent—cats recover fully once dewormed.
• Respiratory/nasal infections: generally mild; severe cases may require longer treatment or hospitalization.
• Heavy bladder infestations can rarely cause blockages or renal complications—but typically resolve.

🛡️ Prevention Strategies

• Keep cats indoors to reduce hunting and earthworm ingestion.
• Avoid feeding raw prey or allowing cats access to soil and puddles.
• Maintain clean litter boxes and environment.
• Include Capillaria-effective dewormers in routine parasite control.
• Annual vet well‑checks with urine/fecal testing for early detection.

🐾 Home Care & Owner Tips

• Monitor urination habits, behavior and breathing.
• Complete the full medication course and follow treatment instructions.
• Provide hydration—wet food or fresh water.
• Ease respiratory distress with a steamy bathroom or nebulizer if advised.
• Keep calm, warm environments and use comfort aids from Ask A Vet, Woopf & Purrz.
• Use the Ask A Vet app for advice between visits—expert support anytime.

📝 Summary Comparison

🐾 Keep your feline healthy and worm‑free with reliable advice from Ask A Vet—download the app for guidance anytime. Enhance recovery with soothing products from Woopf and Purrz. You’re doing great! ❤️

📢 Always consult your veterinarian for accurate diagnosis and treatment plans.

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