Hi all -

My girl Shadow was just diagnosed with a lower than normal resting heart rate. A normal resting heart rate for dogs should be between 60-140, and hers ranges 35-50 when at rest. It was of concern because she sleeps so much, and when she plays she gets tuckered out pretty quick. Doctor said that she most likely will need a pace maker., and wrote a prescription for low dosage of trubataline to help her in the meantime.

We just had extensive bloodwork done to rule out any other problems she may have, and this is the results...

Kidneys, electrolytes, thyroid, and all blood cell counts were normal. The liver values were also generally good, though two (ALT and AST) were slightly below normal. The only test that was of most concern was the heartworm test -  ELISA test.  This is an antibody-based test, and her results came back positive for heartworm. The big question we have to tackle is whether heartworm disease can cause the slow heart rate - doc says technically, yes, it could cause problems with the pacemaker in the heart. Although he hasn't seen this, but won't rule it out 100%.

The next step is a second heartworm test, and then also a trip to the cardiologist to figure out what we need to do. Our pocketbooks are shedding like crazy, but there's no way I will stop until she is better.

I was hoping that there may be someone out there who has dealt or is dealing with something similar - Does anybody out there have any experience with this or advice?

*When we got her she had missed 1 month of heartguard, and we were told to start right away - gave her a dose on 6/30. Doctor said this may have killed the larvae, but that adult female heartworm can still be in her. Other than lethargic behavior, no other noticeable physical signs.

I can't address the heart problems, I have zilch experience there. As for the heartworms, you're on the right track with more testing. At her age (2yrs+/-, yes?) she should be in the very early stages and, depending on your vets diagnosis, may require nothing more than the monthly preventive to kill the young.

I'll tag Amy (@amymeme) whose husband is a human doctor but general experience with "mammals" in general he seems to be quite knowledgeable.

My boy is still testing negative for heartworms with basic blood testing but there is still a good chance that he has them so I have been doing a lot of research. Right now his heart rate is good but a large infestation can drag the pace down, more than likely though if your vet thinks this is a recent heartworm gain then your dog may have an abnormal/weak heart and the heartworms are making it worse. My boy has allergies and those allergies are potentially being made worse by the heartworms causing us to see symptoms earlier than one normally would, which is actually a good thing. Ivermec will kill young heartworms. The slow kill heartworm method used by many shelters if Ivermectin and doxycycline over the course of several months. It is easier on the dog than the old method. (Old method used melarsomine which would cause mass die-off of worms that would clog the heart valves and arteries and essentially give dogs a stroke) I would find out what is up with the heart. Heartworm treatments are hard on an animal, even the slow kill method, and if the heart is abnormal you may have to do something with it before treatment. Not sure how many tests you really need. When your vet goes to check the heart for abnormalities I would think that if there was a heavy infestation that it would be capable of being spotted when looking for tears to the heart. Ask about radiographs and xrays that could potentially do double duty to help with costs. Adult heartworms can show up on some types of soft tissue xrays.

Other than the slow heartrate and positive test, does she have any other symptoms?

It takes 6 months of having the worms before they show up on the average heartworm test that most vets do. By 6 months you are usually dealing with adults which are harder to get rid of. Also, was she on heartworm preventative at all? If she was on a preventative when she got the worms many larger heartworm preventative brands will help with the costs of treating the condition.