Do Cats Poop Out Worms After Being Dewormed?
Understanding how cats respond to deworming treatments can be both reassuring and enlightening—especially when it comes to parasitic infections like those caused by Capillaria. These worms rarely affect cats, but when they do, it's vital for pet owners to know what to expect before, during, and after treatment.
What Are Capillaria Worms?
Capillaria worms, also known as Pearsonema, are small parasites that can infect a cat’s urinary tract or respiratory system. The two most common species that affect cats are:
- Capillaria plica (Pearsonema plica)
- Capillaria feliscati (Pearsonema feliscati)
These are often referred to as bladder worms due to their preferred location in the bladder wall, kidneys, or parts of the urinary tract. Other types, such as Eucoleus aerophilus, affect the lungs and airway rather than the urinary system.
Will Cats Pass Worms in Their Stool After Deworming?
Unlike intestinal worms, Capillaria species do not live in the gastrointestinal tract. Therefore, it's uncommon for cats to poop out adult Capillaria worms after deworming. Instead, these worms may be eliminated from the bladder or respiratory system gradually through natural processes post-treatment.
However, depending on the type of worm and infestation site:
- Cats may shed eggs in their urine, not feces, especially with bladder involvement.
- When the respiratory tract is infected, eggs may be coughed, swallowed, and finally excreted in the feces.
- Visible adult worms in stool are rare and usually occur with intestinal parasites—which Capillaria typically is not.
Life Cycle and Transmission
The Capillaria life cycle necessitates an intermediate host—usually an earthworm. Here's how the infection spreads:
- Worms release eggs into a cat’s urine.
- Eggs must be ingested by an earthworm where they develop into an infectious stage.
- Cats become infected by consuming earthworms or animals that have eaten earthworms.
Importantly, the infected earthworm is required for the parasite's life cycle. Immature worms cannot infect cats directly without this step.
Symptoms of Capillaria Infection
Many cats show no symptoms. However, if the infestation is heavy, certain signs may emerge:
Urinary Tract Capillaria (P. plica, P. feliscati)
- Bloody urine
- Frequent urination or straining
- Urinating outside the litter box
- Abdominal pain
- Fever or urinary blockage in rare cases
Respiratory Tract Capillaria (E. aerophilus)
- Coughing
- Wheezing
- Labored breathing
Diagnosis and Deworming
Veterinarians typically diagnose Capillaria through urinalysis (for bladder worms) or fecal exams and imaging like chest x-rays (for respiratory types). The challenge lies in intermittent egg shedding, which may necessitate multiple samples.
Once diagnosed, the vet may prescribe effective antiparasitic medications:
- Fenbendazole: Often given orally at 50 mg/kg for 4–10 days
- Ivermectin: Typically administered by injection at 0.2 mg/kg
These treatments kill the worms, allowing the body to eliminate them over time. In most urinary cases, the immune system and excreting urine assist in the cleanup rather than fecal elimination. Therefore, while some eggs may appear in feces, full worms are seldom observed in stool.
What to Expect After Deworming
Post-treatment, you may or may not notice a change in your cat’s output:
- If treating bladder worms, improvements appear in urine analysis and clinical symptoms, but there’s no visible worms in poop.
- If dealing with respiratory Capillaria, eggs may be eliminated through feces, especially if coughed and swallowed.
- In rare cases of mixed or heavy infection, dead worm remnants could be passed, albeit rarely.
Recovery and Follow-Up
The prognosis for Capillaria infections is usually very good. Most cats recover fully with proper medication and care. A recheck urinalysis or fecal exam is often advised to confirm the effectiveness of treatment.
Prevention Tips
To significantly reduce the odds of reinfestation:
- Keep cats indoors.
- Avoid allowing them to hunt small animals or ingest earthworms.
- Maintain hygiene and clean litter boxes often.
- Discuss a routine deworming schedule for outdoor cats with your vet.
Public Health and Safety
Capillaria worms in cats pose minimal risk to humans. Related species can infect humans through consumption of undercooked fish or frogs, but the ones that affect cats are not zoonotic. Regardless, always use good hygiene when handling litter or pet waste.
Conclusion
Cats with Capillaria rarely pass visible worms in their stool after deworming. If the infection is bladder-based, worm eggs will show in urine; if respiratory, eggs may be coughed and excreted in feces. Adult worms are almost never seen. Proper treatment, cleanliness, and prevention are key to keeping your feline healthy and worm-free.
