Do Cats Poop Out Worms After Being Dewormed?
When a cat is treated for parasitic infections such as those caused by Capillaria worms, pet owners may wonder whether the worms will be visible in the feces afterward. While the idea can be unsettling, understanding the life cycle and treatment of Capillaria and similar parasites helps clarify what to expect post-deworming.
Understanding Capillaria Worms in Cats
Capillaria species are parasitic worms that primarily affect the bladder and urinary tract in cats. The most common ones include:
- Capillaria plica (Pearsonema plica)
- Capillaria feliscati (Pearsonema feliscati)
These are often referred to as bladder worms and are relatively rare in domestic cats. They live in the bladder wall and sometimes in the kidneys or other urinary areas, potentially causing problems like inflammation, frequent urination, or discomfort.
Life Cycle and Transmission
The life cycle of Capillaria worms is complex and involves an intermediate host—usually an earthworm. Here's how it typically progresses:
- Adult worms in the cat's bladder lay eggs.
- The eggs are excreted via urine into the environment.
- Earthworms ingest these eggs, which develop into infectious larvae inside the worm.
- Cats become infected by eating the earthworms or prey animals that have ingested them.
Cats cannot be infected directly through contact with the eggs without the earthworm intermediary.
Other Species and Symptoms
Some Capillaria species affect other areas of the body:
- Eucoleus aerophilus – affects the respiratory tract resulting in coughing or wheezing.
- Eucoleus boehmi – infects the nasal passages causing nasal discharge and sneezing.
Clinical symptoms vary depending on the infestation site:
- Urinary Tract: Blood in urine, straining to urinate, increased frequency, licking genital area.
- Respiratory Tract: Coughing, wheezing, shortness of breath.
- Nasal Infection: Sneezing, nasal discharge.
Diagnosis of Capillaria Infection
The infection is diagnosed primarily through urinalysis, checking for the presence of eggs in urine. These eggs are oval-shaped, colorless, with thick, double-walled shells and bipolar plugs. Due to intermittent egg shedding, several tests might be needed.
Respiratory Capillaria may be detected through fecal exams, radiographs, or even bronchoscopy if needed.
Treatment and Deworming Process
Cats with mild or symptom-free infections may not require treatment. However, when intervention is needed, veterinarians typically use:
- Fenbendazole (50 mg/kg orally for 4–10 days)
- Ivermectin (0.2 mg/kg by injection)
These drugs disrupt the worm’s metabolism, killing them over a course of days. Dead worms are usually broken down by the cat’s body.
Do Cats Poop Out Worms After Deworming?
No, cats typically do not pass adult Capillaria worms in their feces. Instead, the following can occur:
- Bladder worms: Eggs may be expelled in urine.
- Respiratory Capillaria: Eggs may be coughed up, swallowed, and excreted in feces.
In rare cases, dead or dying worms might be expelled if they migrate outside their usual environment or if there's a heavy infestation. However, it is more common for the body to absorb or break down the worms internally after treatment.
Follow-Up and Prognosis
Most cats recover fully with proper treatment. Follow-up diagnostics are essential to confirm the elimination of the worms. For persistent egg shedding or recurring symptoms, an extended treatment regimen may be necessary.
Prevention
To prevent Capillaria infections, follow these steps:
- Keep your cat indoors to limit exposure to earthworms and infected prey.
- Practice good hygiene and maintain a clean litter box.
- Routine deworming for outdoor or at-risk cats as advised by a vet.
Public Health and Safety
Capillaria worms in cats pose no direct risk to humans. Related worms may infect people through consuming undercooked aquatic animals but are unrelated to feline species. Still, always wash hands after handling pet waste as a precaution.
Conclusion
Seeing actual worms in a cat’s feces after deworming is uncommon, especially with Capillaria infections. Shedding usually involves eggs rather than full worms, and these are microscopic. With veterinary guidance and preventive care, Capillaria poses minimal risk to feline health.





