My dog's heartworm test: negative but faint positive line?

Hi There! Today at the vet my dog tested negative for heartworms but there was a faint line for positive? This has happened in the past when we first adopted him but came back fully negative when sending it off for further testing. Help!

Hello, sorry to hear about Saint. There are multiple potential causes for this, some of which could be test error. One could be straightforward and include an error when mixing the sample prior to depositing it into the snap test. Another can be from prolonged sit time before the test was read. Faint lines across the positive could indicate a true positive result but it is difficult to be 100% sure. Given the uncertainty and the limitations of the snap test it would be wise to confirm the negative results by sending the test out. In the interim, you should monitor Saint for any signs of coughing or exercise intolerance. My suspicion is that Saint's test is indeed negative since the line was faint. Speak with your veterinarian about resubmitting a sample or re-running another test to confirm the negative results. Hope this helps and best of luck.

Updated on September 24th, 2025

Health & Wellbeing

My dog tested weak-positive for heart worms, what does this mean? The test that was used is Snap test. It was a lower shade of blue than the solid blue positive circle. Can I keep him on preventatives or is treatment necessary? At the same time I fo

The whipworm infection would not alter the Heartworm test results. The best thing to do in this case is to have your vet send off a confirmatory Heartworm test the lab. They use a different test method that is more accurate. That way you will know. My best guess is that he is positive though. Those snap tests are pretty accurate and there is a low likelihood of a false positive even if faint. After that your vet can tell you how to proceed with Heartworm prevention or the treatment.

Updated on September 24th, 2025

Health & Wellbeing

My dogs tested light(faint) + for heartworms 4 separate times in a yr. Does this mean it's not serious or maybe the tests are wrong or he needs meds?

A Light positive is still a positive. I would ask your vet to send out test to an outside Lab to confirm the results using a different type of test. You can also have an ultrasound done to see if your dog has any adult worms at this time. Your dog should currently be a heartworm preventative every month like Heartgard. Most heartworm tests are actually looking for antibodies in the bloodstream, so when they come up positive (even light positive, this means that your dog has antibodies or that your dog has been exposed. It may be that your dog doesn't have any adult worms of his/her own at this exact moment, but that he/she has baby heartworms floating around in the bloodstream because he/she is constantly being exposed to them (be it from another dog in the area who is infected and mosquitoes are passing it around or you live in a rural area where there are a lot of coyotes who are infected?? These are very far fetched reasons.. The most likely cause is that your dog is infected but ha

Updated on September 24th, 2025

Health & Wellbeing

Hi, I adopted Edie a few days ago from a rescue. They got her from a small shelter down in south Texas. The shelter tested her for heartworms on 12/27/19 and she was negative. I took her to the vet today and she tested positive. The vet said the test

hello and thank you for your question. It is possible but very unlikly that the shelter test was a "false negative". Heartworms can take up to 6 months to mature. It is hte mature worms that breed, have babies, which spread to the bloodstream and cause an immune reponse. It is this immune response (antibodies in the bloodstream) that make a test show up positive. So your dog was already infected but not shoing a positive result yet. There was not really a mistake by the shelter, just timing. Definitely contact the shelter with the results and they may help with treatment costs. I hope your new pup feels better soon! If you have further questions please feel free to contact me for a one on one consultaion. My fees are reduced right now due to COVID-19 and I am happy to help with any concerns!

Updated on September 24th, 2025

Health & Wellbeing

I just adopted a dog 1.5 yrs old, Adoption house says he has/had heart worms and has to get injection treatment, confirmed this by the pups new vet- at time of adoption 2 months ago, pup did have "singed" like hair, very skinny. Now, he is in perfect

Thanks for using Boop by Petco and I’m so glad Carson has a new wonderful owner! You 100% need to run the test. A dog can look completely healthy and have a serious heartworm infestation that is slowly damaging the heart and major vessels. There is a very specific way of testing and treating heatworms that can be adjusted based on if there are microfilaria (baby heart worms in the blood stream) or not which is likely what they will be testing. If it is the other common test we run, you should do it because if it comes up negative, you may not need further treatment! In many cases I feel that extra testing may not be needed or may not change how I treat a problem. But heartworm disease is not one of them. Follow the protocol to the letter as best you can for the highest likelihood of success. Best of luck to you and Carson!

Updated on September 24th, 2025

Health & Wellbeing

My dog was diagnosed with ehrlichiosis by the in-house snap test which came out positive. Yet his red and white blood cell counts and platelet counts are perfect on his blood tests. Can this snap test for the disease be wrong?

It is possible but very rare for the test to be wrong (false positive) - repeat testing in 2-3weeks would provide more information. The test looks for antibodies (made by the dogs immune system in response to infection), some dogs become what is termed 'sub-clinical' - infected but without any clinical signs or alterations in blood cells, a phase which can last months or years before signs of disease are detected; regular blood counts should be considered to monitor for changes in such cases

Updated on September 24th, 2025

Health & Wellbeing

Hello do they test for heart worms

Yes. Testing for heartworms is simple with a blood sample taken by your vet. We do a screening snap test that gives results in 8-10 mins. I hope this helps and thanks for visiting Boop by Petco. Take care. : )

Updated on September 24th, 2025

Health & Wellbeing

He was diagnosed with border line positive for heartworm our vet too a micro test that showed negative he has him on sentinel pills he wants to redo the regular heart work test again would it show negative if he is on heartworm pills

Yes, it would show up even if on prevention. The test is only checking for the presence of the adult heartworms in the heart. It takes approximately 6 months from the time the dog is bitten by a positive mosquito to the time they would show up positive on a test. I suggest you not wait and get a confirmatory test now. If Shiloh truly is heartworm positive you should have him treated. The prevention is only going to keep him from getting more worms. It does nothing for treatment. Hope this helps. Best wishes.

Updated on September 24th, 2025

Health & Wellbeing

Last yr in May dog came positive with babesia Gibsoni symptom shown was fever and lethargy then vet run a medicine course for month he become ok and active then in September I went for blood work again and it came positive again with babesia Gibsoni

Babesia, just like all the other tick borne diseases, can show up positive on the snap test, because the snap test confirms exposure and not always current infection. As long as Danny's bloodwork does not show current low platelets or anemia, then he is likely free of infection. Just expect him to be positive on the screening test for a while, and monitor him for any recurring symptoms, which would indicate a repeat infection. The fact that he is clinically ok now, is a good sign that he is free from true infection. : ) I would also make a point to keep him on a tick/flea preventative to help protect him from future infections. Best wishes with your pet Danny moving forward! Take care.

Updated on September 24th, 2025

Health & Wellbeing

Good day! I just wanted to ask about test..what test can be perform to check if a dog has a heartworm? and if positive what can i do about it? Thank you so much!:)

Hello, & thank you for using Boop by Petco. We usually do a test where the antigen to heartworms can be quantified using a very small amount of blood. There are many companies that make these tests & they usually are less than $40 to run. The test only takes 10 minutes & shows either positive or negative. If a dog has a significant number of heartworms, sometimes you can see them directly in a drop of blood under a microscope. If the test comes back positive, depending on the overall health of your pet, we start therapy first with a round of the antibiotic Doxycycline, then we use a form of medical grade arsenic, injected into a muscle, either 2 or 3 times over a short course of time. This will kill any adult heartworm that are in the heart & in the vasculature in the lungs. It sounds pretty intense, but most dogs come through very, very nicely. I hope this helps. Take care.

Updated on September 24th, 2025

My dog's heartworm test was negative but showed a faint positive line?

Most Helpful Answer

Related Answers from Veterinarians

My dog's heartworm test was negative but showed a faint positive line?

Most Helpful Answer

Related Answers from Veterinarians

Related Questions

Hi There! Today at the vet my dog tested negative for heartworms but there was a faint line for positive? This has happened in the past when we first adopted him but came back fully negative when sending it off for further testing. Help!

My dog tested weak-positive for heart worms, what does this mean? The test that was used is Snap test. It was a lower shade of blue than the solid blue positive circle. Can I keep him on preventatives or is treatment necessary? At the same time I fo

My dogs tested light(faint) + for heartworms 4 separate times in a yr. Does this mean it's not serious or maybe the tests are wrong or he needs meds?

Hi, I adopted Edie a few days ago from a rescue. They got her from a small shelter down in south Texas. The shelter tested her for heartworms on 12/27/19 and she was negative. I took her to the vet today and she tested positive. The vet said the test

I just adopted a dog 1.5 yrs old, Adoption house says he has/had heart worms and has to get injection treatment, confirmed this by the pups new vet- at time of adoption 2 months ago, pup did have "singed" like hair, very skinny. Now, he is in perfect

My dog was diagnosed with ehrlichiosis by the in-house snap test which came out positive. Yet his red and white blood cell counts and platelet counts are perfect on his blood tests. Can this snap test for the disease be wrong?

Hello do they test for heart worms

He was diagnosed with border line positive for heartworm our vet too a micro test that showed negative he has him on sentinel pills he wants to redo the regular heart work test again would it show negative if he is on heartworm pills

Last yr in May dog came positive with babesia Gibsoni symptom shown was fever and lethargy then vet run a medicine course for month he become ok and active then in September I went for blood work again and it came positive again with babesia Gibsoni

Good day! I just wanted to ask about test..what test can be perform to check if a dog has a heartworm? and if positive what can i do about it? Thank you so much!:)

Share