Petco Text Logo
Petco Pet Logo

  • Two Easy Ways to Start Earning Rewards!

My puppy has diarrhea. Is it safe to deworm her again for worms?

Updated On September 23rd, 2025

Pet's info: Dog | Mixed Breed Medium (23 - 60lb) | Female | spayed | 3 months and 16 days old | 30 lbs

I suspect that my puppy has worms. She has had diarrhea for nearly a week, but is otherwise normal (eating well, plenty of energy). She has been dewormed twice (most recently a month ago) and has has a fecal test done that came back negative (1 month ago). She also received her final vaccinations last week. Is it safe to de-worm her now? If so, what medicine do you recommend? Again, she seems completely healthy otherwise.

2 Answers

Most Helpful Answer

Image profile

Answered By Shaneez Wallani, DVM

Veterinarian

Published on May 16th, 2017

Diarrhea in a puppy could be caused by parasites, change in diet, toxin ingestion, infectious viral diseases, blockage in the intestines caused by ingestion of a foreign body, or a mass/growth in the gastrointestinal tract. Sometimes worms can be present in the intestinal tract even if they are not noted in the stool, and multiple types of worms can be present at one time. Please make an appointment to have Jo seen by a veterinarian as diarrhea can lead to dehydration, which can be very dangerous, particularly in a young puppy, and should be addressed asap. Puppies often need to be dewormed monthly for the first few months, as many are either born with worms or can get them during nursing if their mothers were not dewormed appropriately during pregnancy. Deworming medication does not kill all stages of a worm’s life cycle at once, so repeating treatment can help to treat the worms by killing them off in the susceptible stage of their life cycle. Speak to your vet about dispensing an appropriate medication for Jo and to schedule an appointment if there is no improvement.

Vote icon

1Pet Parents found this answer helpful

Other Answers

  • Image profile

    Answered By Jessica Keay, DVM

    Veterinarian

    Published on

    I am sorry to hear about Jo. I would recommend dropping a stool sample off for your vet to check again, as there are other possible causes for diarrhea they may find (infections with Giardia or Coccidia) that won't be treated by a dewormer. They may also carry a probiotic to start your pup on to help with the diarrhea. The dewomer I prefer is Fenbendazole, and is given three days in a row, and then three weeks later it is repeated. Your vet carries it and you can sometimes find it at a feed store/pet store (though often it is cheaper at the vet's office). If she becomes lethargic, vomits, or has decreased appetite, the diarrhea worsens or has blood in the stool then an exam at the vet is needed.

    Vote icon

    1Pet Parents found this answer helpful

See More Answers

Related Questions

Petco Pet Education Center
Health & Wellbeing
Why is my mouse's eye swollen, cloudy, and has pus?
Is your mouse's eye swollen, cloudy, and pussy? Dr. Melanie, a certified vet, discusses severe eye issues like infection or abscess, urging an immediate visit.
Updated on December 04, 2025
Petco Pet Education Center
Health & Wellbeing
Can I use human contact lens solution as eye drops for my mouse?
Can you use contact lens saline for your mouse's eye drops? A certified vet discusses ingredients like boric acid and potassium chloride. Find safe solutions for your pet!
Updated on December 04, 2025
Petco Pet Education Center
Health & Wellbeing
What fish dog food helps dry skin if my dog eats Science Diet?
Is your dog's dry skin a concern? A certified vet offers expert advice on finding the best fish-based dog food alternatives to Science Diet for essential oils.
Updated on February 04, 2026
Petco Pet Education Center
Food & Nutrition
What's the best way to feed my hamster when I'm going on a trip?
Planning a trip to Chicago and need to feed your Syrian hamster? A certified vet offers expert advice on feeding options for short and long trips, plus finding trusted pet sitters.
Updated on December 04, 2025
Petco Pet Education Center
Food & Nutrition
Can chickens eat bell peppers daily and what about veggie salads?
Can your chickens eat bell peppers and salads? Veterinarian Dr. Elizabeth offers expert advice on safe feeding, frequency, and how fresh veggies boost vibrant yolks.
Updated on December 04, 2025
Petco Pet Education Center
Food & Nutrition
My newly adopted pet won't eat hay. What can I do to encourage it?
Adopted a pet not eating hay? Dr. Stafford, a certified vet, offers expert guidance on encouraging hay consumption, including adjusting pellets and trying fresh types.
Updated on December 04, 2025
image
Have A Vet Question?

Book an appointment with the pros – our expert vets are here to help.

Book Now

Sponsored