What is Capillaria aerophila?
Capillaria aerophila is a respiratory parasite that primarily affects foxes, dogs, and cats. The adult worms live in the trachea and bronchi, although they can also infest the nasal passages and sinuses in some cases.
- Males measure 16–18 mm
- Females reach 18–20 mm
What are the clinical signs of Capillaria in Pets?
Some animals show no symptoms despite being infected. When signs do appear, they may include:
- Persistent coughing
- Frequent sneezing
- Nasal discharge
- Inflammation of the respiratory tract (tracheitis, bronchitis, sinusitis, or rhinitis)
Good to know: These symptoms are usually mild and rarely serious.
How is Capillaria in Pets transmitted?
Cats and dogs become infected by ingesting parasite eggs, either:
- Directly from a contaminated environment
- Indirectly by eating earthworms, which act as intermediate hosts
Life cycle of the parasite
Once ingested, the parasite’s eggs hatch into larvae in the digestive tract. These larvae then migrate through the bloodstream and lymphatic system to reach the respiratory tract, where they mature into adult worms.
- The female worms lay eggs that are swallowed and eliminated via the feces, continuing the cycle
- Life cycle duration: 25 to 40 days between ingestion and egg production
How is Capillaria diagnosed?
Diagnosis is made by identifying parasite eggs under a microscope from:
- Fecal samples
- Tracheal or nasal mucus
Capillaria eggs are distinctive, with:
- A rough outer surface
- Polar plugs at both ends
What is the treatment for Capillaria?
Several veterinary-prescribed antiparasitic medications are effective and safe when properly administered. Treatment is usually successful with the correct dosage and duration.
Prevention and recommendations
To help prevent Capillaria infection:
- Prevent pets from eating earthworms
- Pick up feces quickly to reduce environmental contamination
- Monitor for respiratory symptoms and consult a vet if signs appear
