Why is my puppy losing weight and has diarrhea after deworming?

Hi, thanks for using Petco Pet Education Center, formerly Petcoach! Poor Bear! Diarrhea can be a sign of a vaccine reaction but since he was having abnormal stools prior to the Vet visit I think it is likely a continuation of his previous issues. I would still ask for deworming medications as adult worms do not always shed eggs that will show up in the stool sample. I would also change his food and get him on a puppy food that doesn't contain chicken. It is possible the weight loss and chronic abnormal stools are due to a food allergy. If that doesn't improve his weight and stools then I would do blood work and B12/folate/TLI/PLI testing for intestinal and pancreatic disease. Causes of poor weight gain/weight loss and diarrhea in a puppy are: intestinal parasites, food allergy/intolerance, inflammatory bowel disease, pancreatic insufficiency. Good luck!

These signs could be compatible with an inflammation infection of the gastrointestinal system and surrounding organs (like pancreas and liver). A clinical examination at your local veterinarian is immediately essential to confirm these clinical suspicions and treat appropriately. Antibiotics and possibly further investigations (like abdominal imaging as ultrasound or radiographs and fecal analysis) may be needed. Please do not hesitate to contact us again on the forum or by requesting a consultation if you have any more questions or to discuss it any further.

This diarrhea in Bear could be caused by intestinal parasites. Those would keep him from gaining weight and have diarrhea while eating, drinking, and playing. I would recommend taking Bear into the vet in the morning with a sample of his feces. The vet can do a fecal exam to diagnose intestinal worms, and can prescribe a deworming treatment for him.

Poor guy. Check his stools and make sure he doesn't still have worms. If he does then he will need a second treatment. In most situations puppies need two deworming treatments anyway, done 2 weeks apart. If he doesn't have worms and the stool is abnormally loose or soft, then talk to the vet about checking for bacteria and other parasites. In most cases of puppy weight loss it is a parasite issue. Some other uncommon causes are a malabsorption problem, endocrine disorder or pancreas problem. These disease processes would require bloodwork to be done on your pet to properly diagnose and treat. Also make sure you puppy is on a high quality dog food such as Royal Canin, Hill's science diet, Evo, Merrill, etc. And keep in mind that a few ounces difference day to day may be abnormal fluctuation for your puppy, especially after recovering from a worm infestation.

Thank you for using Petco Pet Education Center, formerly Petcoach! Intestinal parasites can be ruled out quickly with a fecal test. Once your vet determines the type of parasite, they can recommend the appropriate dewormer. I hope this helps and am happy to answer any questions you have!

Hi and thanks for using Petco Pet Education Center, formerly Petcoach! Sorry Bear is having problems. Worming puppies properly involves multiple doses to clear out as many of the parasites as possible. The wormers kill the adult worms but then over a 2-3 week period, the immature stages can migrate into the gut again, so repeated treatments are needed. So worms may be causing this problem or many other things including a food change (too rapid), dietary indiscretion (eating things he is not supposed to eat), foreign bodies, infections, etc. It's best to have your vet evaluate Bear again and decide what tests or treatment that he may need to help clear up the problem. I hope he gets better soon.

Hi,t hanks for using Petco Pet Education Center, formerly Petcoach! Dewowmers have the potential to cause an upset stomach such as vomit, diarrhea and decreased appetite. Though I am worried something else is going on since you lost a puppy recently. I worry most about parvo virus in puppies this age, especially if they are yet to be vaccinated. I would have this puppy seen today by your Vet and tested for parvo virus as it is VERY contagious and if it is the cause it will likely affect the entire litter. If it isn't parvo the Vet can at least get this puppy feeling better and prevent dehydration. Good luck!