Common Internal Parasites in Cats
Even strictly indoor cats are at risk of internal parasite infection. According to CAPC (Companion Animal Parasite Council) data, the following are the most common intestinal parasites in cats:
| Parasite | Transmission Route | Common Symptoms | Zoonotic |
|---|---|---|---|
| Roundworm | Fecal-oral, vertical transmission (mother to kitten), hunting | Abdominal distension, vomiting (may vomit worms), diarrhea, weight loss | Yes |
| Tapeworm | Ingesting fleas or prey containing larvae | Rice-grain-like segments visible around the anus, may be asymptomatic | Yes (rare) |
| Hookworm | Fecal-oral, skin penetration | Bloody stool, anemia, weight loss | Yes |
| Toxoplasma | Hunting, raw meat | Usually asymptomatic (may cause illness in immunocompromised individuals) | Yes |
| Coccidia | Fecal-oral | Diarrhea (more severe in kittens) | No |
| Giardia | Contaminated water, fecal-oral | Chronic soft stool, diarrhea | Debated |
Recommended Deworming Schedule
According to CAPC and ESCCAP (European Scientific Counsel Companion Animal Parasites) recommendations:
Kittens
- Starting at 2 weeks of age: Deworm every 2 weeks until 2 months old
- 2 to 6 months of age: Deworm monthly
- After 6 months: Based on risk assessment, at least every 3 months
Adult Cats
- Strictly indoor cats: Every 6 to 12 months, or regular fecal testing
- Cats with outdoor access: Every 1 to 3 months
- Cats that hunt: Monthly
How to Know If Your Cat Has Parasites
- Fecal examination: The most basic screening method. A veterinarian examines the stool under a microscope for parasite eggs. A single fecal test has a detection rate of about 70 to 80%, so consecutive samples over 2 to 3 days may sometimes be needed
- Visual observation: Roundworms may be visible in vomit or stool (resembling thin noodles), and tapeworm segments may be seen around the anus (resembling white grains of rice)
- Clinical signs: Abnormally distended abdomen in kittens, chronic diarrhea or soft stool, weight loss, dull coat
Important Deworming Considerations
- Use veterinary-prescribed deworming medication: Different parasites require different drugs, and over-the-counter "broad-spectrum dewormers" may not cover all types
- Dose accurately by weight: Underdosing is ineffective, while overdosing may cause side effects
- Flea control in tandem: Fleas are the intermediate host for tapeworms — without flea control, tapeworms cannot be eradicated
- Environmental cleaning: After deworming, clean all feces from litter boxes to reduce the risk of reinfection
- Deworm all cats in multi-cat households simultaneously: To prevent cross-infection
Zoonotic Considerations
According to CDC data, some cat parasites can be transmitted to humans:
- Toxoplasma: Infection during pregnancy can affect fetal development. Cleaning the litter box daily (Toxoplasma oocysts need 1-5 days to become infectious) can greatly reduce the risk
- Roundworm: Young children may become infected through contact with contaminated soil in sandboxes or gardens
- Basic precautions: Wash hands after cleaning the litter box, keep young children away from cat feces, and deworm cats regularly
References
- Companion Animal Parasite Council (CAPC). Parasite Prevalence Maps and Guidelines.
- ESCCAP (European Scientific Counsel Companion Animal Parasites). Worm Control in Dogs and Cats Guidelines.
- CDC (Centers for Disease Control and Prevention). Parasites and Health: Toxoplasmosis, Roundworms.