Quick Answer
After being dewormed, most dogs will pass dead worms in their stool within 24-48 hours. In some cases it can take up to 2 weeks for all of the worms to be completely cleared from your dog’s system. The exact timeline depends on the type of dewormer used, the severity of your dog’s worm infestation, and how their body responds to treatment. Monitor your dog’s stools for the presence of live worms or segments of worms for at least 2 weeks after deworming. Contact your vet if you still see evidence of an active worm infection.
When Do Dogs Normally Pass Worms After Deworming?
Most deworming medications work by paralyzing or killing the worms in your dog’s intestines, causing them to loosen their grip on the intestinal wall. The dead or dying worms are then passed out through your dog’s feces, which is why you may see evidence of worms in the days following deworming treatment.
Here is a general timeline for when you can expect to see worms after administering common dewormers:
Fenbendazole (Panacur, Safeguard)
– Works slowly, often taking 3-5 days to fully kill all worms
– Dead worms may pass for up to 2 weeks after treatment
Pyrantel Pamoate (Nemex, Strongid)
– Works quickly, starting to paralyze/kill worms within hours
– Most worms passed within 24-48 hours
– Some worm segments can still pass for up to 1 week
Praziquantel (Bayer Tapeworm Dewormer)
– Works very quickly, tapeworms often dead within 30 mins
– Full tapeworms containing egg packets visible in stool within 24 hours
– May continue to see dead segments for up to 2 weeks
Ivermectin (Heartgard)
– Begins working within 6 hours
– Most worms passed within 24-48 hours
– Occasional worm fragments visible for 5-7 days
Milbemycin Oxime (Interceptor, Sentinel)
– Kills worms slowly over 2-5 days
– Most worms passed 1-2 weeks after dosing
– Some dogs continue passing dead worms for up to 3 weeks
So in most cases, you can expect your dog to pass the bulk of the dead worms within the first 1-3 days after deworming. However, it’s not unusual to see some worm parts or segments continue to pass for up to 2 weeks, especially if your dog had a heavy parasite load.
How Long Should I Monitor My Dog’s Stool After Deworming?
It’s recommended to monitor your dog’s stools for at least 2 weeks after deworming to check for any signs that live worms are still present. Here are some things to look for:
– Whole live worms or parts of worms passing in the stool
– Active worm segments moving in the stool
– Worm eggs visible under a microscope when a fecal sample is tested
– Evidence of reinfection such as increased scooting, licking, or new worms segments passing after initial die-off period
You should contact your vet if at any point within the 2 weeks after deworming you see evidence of live worms or new worm segments being passed. This could indicate an incomplete kill of the worms, or a reinfection from your dog’s environment. Your vet may recommend a second deworming, stronger medication, or prescribe a monthly preventative.
Some dogs may continue to pass dead worm fragments for up to 3 weeks after deworming, which is normal die-off and not necessarily indicative of an active infection. But to be safe, bring a fresh stool sample to your vet if you are ever uncertain whether worms are alive or dead.
What Factors Influence How Long Worms Are Passed After Deworming?
Several factors play a role in determining how quickly your dog will pass worms after being dewormed:
Type of Dewormer Used
Some dewormers work more quickly than others. For example, praziquantel starts killing tapeworms within 30 minutes, while fenbendazole can take 3-5 days to fully eliminate some worms. Faster-acting dewormers usually cause worms to pass sooner.
Severity of Infestation
Dogs with mild worm burdens may pass all worms within 24 hours. Dogs with heavy infestations often take longer to fully pass all worms, as there are more parasites killed off by the dewormer.
| Worm Severity | Time to Pass Worms |
|---|---|
| Mild | 24-48 hours |
| Moderate | 3-7 days |
| Severe | Up to 2 weeks |
Individual Response
Every dog responds differently to deworming. Factors like metabolism, bowel motility, immune response, and overall health impact how quickly worms are passed from the body post-treatment. Healthier dogs tend to pass worms faster.
Reinfection Risk
Dogs at high risk for reinfection due to contaminated environment or flea exposure may continue to pick up new worms, extending the timeline. Using preventatives is important for these dogs.
Proper Dosing
Following your vet’s instructions for proper dosing and administration is key. Under-dosing dewormers can lead to incomplete worm removal and longer die-off period.
What Are Signs My Dog Still Has Worms After Deworming?
If your dog still has an active worm infection after deworming treatment, you may notice these signs:
– Live worms visible in vomit or stool
– Parts of worms moving in stool
– Bloody stool or diarrhea
– Continued weight loss
– Pot belly appearance
– Vomiting or coughing
– Worm eggs seen under microscope in stool
– Lethargy, poor appetite
– Increased licking or scooting
– Rope-like proglottids around anus (tapeworms)
Contact your vet immediately if your dog shows any of these symptoms post-deworming so they can determine if additional treatment is required. Make sure to bring a fresh fecal sample for analysis.
Tips for an Effective Deworming Experience
Follow these tips to help ensure a successful worm removal when deworming your dog:
– Get an accurate diagnosis through fecal testing before deworming
– Follow re-testing recommendations, usually 2-4 weeks post treatment
– Give all doses as prescribed by your vet
– Confine dog for 12-24 hours after giving dewormer to prevent reinfection
– Pick up all stools promptly and dispose of sealed bag for 2 weeks
– Bathe and clean bedding right after deworming
– Repeat treatment if live worms seen after initial round
– Give monthly heartworm/parasite preventative as prescribed
When to Take Your Dog to the Vet After Deworming
You should make an appointment with your vet if:
– You see evidence of live worms more than 2 days after deworming
– Significant worm segments are still passing 2 weeks after treatment
– There is no decrease in passed worms or egg counts after treatment
– Your dog has vomiting, diarrhea, lethargy, or other symptoms
– Your dog seems to have reinfection from environmental exposure
Immediate vet care is needed if your dog shows any symptoms of intestinal blockage, trouble breathing, or worm migration after deworming. Some swelling, lethargy, vomiting, or diarrhea can be normal side effects of treatment, but severe reactions warrant an exam.
Conclusion
To summarize, most dogs will pass dead worms within 24-48 hours of deworming treatment. However, it can take up to 2 weeks for all worm parts and segments to clear your dog’s system after being killed off by medication. Carefully monitor stool for at least 14 days, and contact your vet if you see any evidence of live worms still being passed after the initial die-off period. Stick to prescription retesting and prevention to ensure your dog is fully dewormed and free of intestinal parasites long-term.