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My dog coughs & sneezes a week after heartworm treatment. Normal?

Updated on September 23rd, 2025

Pet's info: Dog | Mixed Breed Small (up to 22lb) | Male | neutered | 9 years and 7 months old | 11 lbs

My dog has been coughing trying to release phlegm but I haven’t seen any come out and he also sniffles and sneezes a bit I was wondering if that’s normal for him since it has been a week since his first round of heartworm treatment shots. He doesn’t sneeze or cough like crazy but occasionally he does do it

3 Answers

Most Helpful Answer

Answered By Megan, DVM, CVA

Veterinarian

Published on April 17th, 2018

This can be normal after the first round of heart worm treatment. As the adult heartworms die, they cause an inflammatory reaction in the lungs. It is VITAL to keep Charlie under strict confinement during this time. This means he needs to stay in a confined area or crate and then only to be taken outside on a least to go to the bathroom a few days per day. If they are too active the cough will only get worse. You can try to give him some Benadryl twice a day to help with the sniffles/sneezes. See link below. I would also contact your vet just to tell them what is going on to make sure they don't want to add any meds or change any meds for him. Of course, if he stops eating, the cough gets worse, you notice labored breathing, or he is coughing up blood then I would have your vet take a look at him immediately. I hope this helps!

https://www.petcoach.co/canigive/dog/benadryl/#!

4Pet Parents found this answer helpful

Related Answers from Veterinarians

Answered By Kevin Sanada, DVM
Veterinarian
Published on April 15th, 2018
Treatment for heartworm is difficult, because the worms are dying and dissolving slowly in the heart. The first place the dead worms and/or pieces of worms go is to the lungs. Depending on the size of the piece that goes to the lungs, they can have varying degrees of lung problems.

A cough could indicate a problem, but as long as he's breathing OK, this would not be an emergency. In this case I'd recommend you contact Charlie's vet sometime in the next 24 hours. They can give medication for the cough and help determine how serious this is. If Charlie is having trouble breathing, then this is an emergency, because it can indicate a severe thromboembolism in the lung.

I hope that helps and Charlie gets better soon.
1Pet Parents found this answer helpful
Answered By Dr. Melanie, BVSc MS
Veterinarian
Published on April 21st, 2018
Good on you for keeping Rebel as calm as possible, but sometimes large amounts of worms die at once, leading to problems. One of these problems is coughing, and because things can quickly get worse, I do think it's best that he is seen by an ER vet right away. Other things that can happen include difficulty breathing, panting excessively, the dog becomes weak and lethargic, the dog can collapse, and a decrease in appetite. You want to avoid any severe side effects, and when a cough does develop in a dog who is getting heartworm treatment, it's best to have them seen by a vet as soon as possible. Please take him into an ER vet. Best of luck with Rebel!
1Pet Parents found this answer helpful

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Related Questions

Why is my dog gagging and reverse sneezing after heartworm treatment?

What you are describing sounds like a reverse sneeze. Typically, we are concerned with patients developing respiratory distress associated with heartworm treatment secondary to worm die off and blood clot formation. It does not sound like a that is the case here. Nonetheless, contact your veterinarian and let them know. He may need to be evaluated if the sneezing and gagging continue.

Updated on September 23rd, 2025

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My dog is making a nose sound after heartworm shots. Is it serious?

What you are seeing is not typically a side effect I've ever seen in a dog receiving this treatment. It may be that Charlie is fighting an upper respiratory infection or has irritation in the sinuses. If this does not resolve on its own, I would recommend having a veterinarian examine Charlie so that the most appropriate diagnostic and treatment recommendations can be made. I hope this helps! Please let me know if you have any other questions or concerns and I would be more than happy to help you further.

Updated on September 23rd, 2025

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Is coughing common for dogs after slow kill heartworm treatment?

Coughing can occur from the damage the worms are doing to the lungs. It could also be caused by the worms dying off and causing inflammation, although I'm not sure how likely that is with the slow kill method. I would recommend keeping him crated and resting (no walks, no running, no excitement -- basically no getting his heart rate up) until he can get to the vet for evaluation, which will likely include chest x-rays and a discussion of if he needs anti-inflammatory medication and cage rest to get through this treatment. Wishing you and Bug (love his name!) the best of luck.

Updated on September 23rd, 2025

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What normal side effects should I expect after dog heartworm shots?

Side effects can be common after heartworm treatment shots. You can see soreness and swelling at the site of the injection, and abscesses can form over time in this spot. Definitely let your vet know of Charlie is very uncomfortable or if his condition appears to be worsening over time. The most severe problems are related to the sudden death of large amounts of heartworms. Get Charlie into a vet right away if you notice a cough or a pre-existing cough becomes worse, he has difficulty breathing, pants excessively, becomes weak or lethargic, collapses, he has a significant drop in exercise, he starts vomiting, drools a lot, or has diarrhea. Best of luck, I hope this helps!

Updated on September 23rd, 2025

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My dog's shallow breathing after heartworm treatment: should I worry?

Any change in breathing warrants a trip to the vet for a recheck. While it’s possible that there’s nothing wrong, you could also be noticing the beginning of a complication of heartworm treatment. Pulmonary thromboembolism can occur when dying worms become lodged in the small blood vessels of the lungs. Your vet might want to take a chest x-ray.

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Is puppy reverse sneezing after shots and heartworm meds normal?

Reverse sneezing isn't particularly linked to vaccinations or to heartworm medication. It is simply irritation of the throat (larynx) due to possible allergies or irritation of the throat from a foreign object. I would recommend monitoring her today to see if the reverse sneezing resolves on its own within 24 hrs. As long as she isn't acting ill, eating, drinking well then its ok to monitor. If the sneezing fits don't seem to be resolving on their own, then its best to contact your vet who will likely recommend a short course of antihistamines to try next. In rare instances, a nasal mite is the underlying cause for unresolved reverse sneezing. I hope that Kona's reverse sneezing fits resolve soon! Best wishes and take care.

Updated on September 23rd, 2025

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My dog has a wet cough. Is it heartworm? Should they be active?

Hello, there are multiple causes for a cough like the one you are describing. One potential cause may include heartworm disease, however, this can be checked with a snap test. If it returns positive for heartworm, then there are medications you can try at home to treat this disease. Other causes may include heart disease and lung disease. Some primary lung diseases such as bronchitis and pneumonia can cause this. To fully explore this causes for your dog's cough, he may need x-rays, a cardiology consultation, and a heart worm test. The other cause in smaller dogs include a collapsing trachea. Ideally your coughing dog should not live an fast or active lifestyle to prevent exacerbation of her cough and from her going into respiratory distress. Please see your veterinarian soon if your dog continues to cough. Hope this helps and best of luck.

Updated on September 23rd, 2025

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