My cat has diarrhea. Can I give him his HeartGard heartworm preventative?

As long as he’s eating and feeling fine then go ahead and give the Heartgard. Wait another day to give the Nexguard just incase giving both at the same time could upset his stomach. Thanks for using Petco Pet Education Center, formerly Petcoach to help you care for Charlie.

Hello, & thank you for using Petco Pet Education Center, formerly Petcoach. I do not think you have anything to worry about. The stool could look this way more from the stress of the veterinary visit, than from the Heartgard. It can take approximately 8 hours from the time a substance is swallowed to the time it is passed back out, so I very much doubt that the medication caused this. Now, if Max had vomited within 30 minutes or so of swallowing the Heartgard, then I would say this is the probable cause. So, as long as he is eating & drinking regular, & his stool does not get looser, then he will be perfectly fine.

Hello. Heartguard is generally considered very safe, even in a dog with a current heart worm infection. If there was a reaction due to the presence of heartworms, it is almost always some kind of pulmonary event. So, it is possible that he has just developed a sensitivity or had a one off reaction to the Heartguard. Do think about having Buster tested before giving another pill, & do try to remember to give it every 30 days. All heartworm medications do a great job, but only if doses are not skipped, especially for dogs living in warmer climates. And if he does not seem better tomorrow, please make an appointment with your vet to have things checked out. Thanks for using Petco Pet Education Center, formerly Petcoach.

A heavy parasite load can cause some GI upset such as diarrhea as the worms die off and are expelled from the body. In some cases, multiple dewormings are needed to clear them all. However, if you suspect there is something else going on, such as an allergic reaction to the medication, the worms, or another underlying illness, it would be best to seek veterinary care ASAP for further examination and workup.

Diarrhea can be normal after Immiticide injections, especially if he is also currently on steroids (often used concurrently to reduce inflammation and chances of embolisms). You should worry if you see signs of coughing, extreme lethargy, pale gums, not eating, or any random bleeding episodes. Other than that a little loose stool is not very concerning for a severe reaction. You can try a bland diet of boiled plain chicken and rice or cottage cheese tonight to help settle the stomach. If the diarrhea continues past 12-24 hrs then antibiotics +/- probiotics may be prescribed by your vet to help get the intestinal flora back to normal status.

I would check with your vet first to make sure it does not interfere with any other medications Kyah is on if she is still on a treatment for another stomach issue. If you don't know what type of worms Kyah has, you can bring a sample of her stool to your vet for testing so they can provide you with the correct deworming medication. If she is still having diarrhea even after a course of stomach medications, a recheck with your vet to rule out any other health issues such as food allergies, illnesses, GI problems, etc is also a good idea in addition.

I would talk to you veterinarian next week about gastrointestinal disease. With a continuously vomiting and diarrhea cat my concerns are Irritable bowel disease or even lymphoma. I would be less inclined it be intestinal parasites if Opie has been an indoor cat. I would not give the drontal today. I would recommend seeing a different veterinarian for a second opinion but Opie may need an abdominal ultrasound. If he is really have bad diarrhea and is still vomiting a lot a specialty hospital may be worth going to because the internist can perform the ultrasound. Thank you for using Petco Pet Education Center, formerly Petcoach.