Petco Text Logo
Petco Pet Logo

  • Two Easy Ways to Start Earning Rewards!

Senior dog with heart murmur panting after Frontline. What to do?

Updated On September 23rd, 2025

Pet's info: Dog | Mixed Breed Small (up to 22lb) | Male | neutered | 18 lbs

my dog is a pom mix, he's 15, has a heart murmur and fleas. my vet said to give him frontline. i did a few hours ago and now he has a rapid heart rate and is panting hard. any suggestions? it is humid here and he has long hair which doesn't help.

2 Answers

Most Helpful Answer

Image profile

Answered By Daniel Fonza, DVM

Veterinarian

Published on September 19th, 2017

Hello there and thank you for your post! I have not seen these symptoms with Frontline before. The temperature may be a factor so I would make sure that the temperature is cool enough for him and place a fan on him. I am concerned that he may be having a reaction to the front line. If this is a reaction it could potentially become much worse. I would suggest getting him examined by a veterinarian to ensure everything is okay. Especially with a heart murmur, I would want to make sure that these are not symptoms of congestive heart failure. I hope this helps and I hope that he is okay. Please feel free to contact me if you have any other questions or concerns. I am also available by phone or text based consultation if needed

Vote icon

1Pet Parents found this answer helpful

Other Answers

  • Image profile

    Answered By David Darvishian

    Veterinarian

    Published on

    Hi and thanks for using Petco Pet Education Center, formerly Petcoach! So sorry to hear about Rommel. Just based on this information, I would have to advise that you get Rommel seen as soon as you can. Small breed dogs with acquired heart murmurs (I'm assuming here) can go into congestive heart failure while on medicines for this condition and especially if not on any medicines for this heart problem. You can try getting him more comfortable in a cooler environment with less humidity and see if that helps but if that doesn't help rather quickly, then I would advise calling your veterinarian or your local emergency vet if it's after hours. Rommel may be developing some fluid in his lungs which can happen when in congestive heart failure. Your vet would most likely advise bloodwork, urinalysis, xrays, and ultrasound to assess his heart. Other tests include EKG and possibly a measurement of blood pressure. He may need to be put on a diuretic and some heart medicines to help his heart and prevent fluid accumulation in his lungs. Good luck with Rommel

    Vote icon

    1Pet Parents found this answer helpful

See More Answers

Related Questions

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
Health & Wellbeing
My degu has a white bump in its fur. Should I take my pet to the vet?
Worried about your pet degu's white pustule? A certified vet discusses this potential skin infection, explains why not to pop it, and guides your next steps.
Updated on December 04, 2025
Petco Pet Education Center
Health & Wellbeing
My pet's ear mite treatment isn't working. What else could it be?
Pet still itching after treatment? A Petco vet clarifies it may not be ear mites. Discover effective solutions like Revolution or consulting an exotic vet.
Updated on December 04, 2025
Petco Pet Education Center
Health & Wellbeing
My rat is losing weight and has breathing issues. What should I do?
Dambo's weight loss, rough breathing, and mucus worry you? A Petco veterinarian addresses these concerning symptoms and recommends urgent professional care.
Updated on December 04, 2025
Petco Pet Education Center
Health & Wellbeing
My pet has worsening sores and scratches. Could it be an infection?
Nike's worsening sores and constant scratching worry his owner. A certified Petco veterinarian offers expert guidance on potential causes like bacterial infections and next steps.
Updated on December 04, 2025
Petco Pet Education Center
Health & Wellbeing
My dog's matted fur bled after cutting. Should I take him to the vet?
Did your pet bleed after matted fur removal? A trusted vet explains potential infection, wound care, and why immediate veterinary attention is crucial for healing.
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