Trying to find out if this is a rare incident or a more prevalent concern. Dog has not missed any dosage by more then a day or two.

Any help greatly appreciated.

From what I know, Sentinel works well on heartworms.

FWIW, I also know is that every single heartworm positive dog we've x-rayed for our local shelter has been a rescue from hurricane Katrina. It wouldn't surprise me at all if that event didn't push heartworm meds beyond their ability to be effective. Just a thought as to why your dog may have tested positive.

You've done a great service by posting this...it's a good example of why heartworm blood tests are important.

Wow, sorry to hear this. I just posted above how much I like Sentinel.

How long have you had the dog? What dose of Sentinel had you been giving and how much does the dog weigh? Was the dog always fed in conjunction with the pill?

I have been told by a couple of vets that the way Sentinel works allows it to be given even well past the 30 day benchmark without a problem, although that practice is not recommended.

One more thing to mention. Most, if not all, of these companies offer a guarantee if you show your dog has been on the medication. Novartis may pick up most or all of the vet bill for treatment. It's worth calling the company and asking.

If you get nowhere with customer service then ask your vet to contact his Novartis rep and get him/her on the case. Reps can pull strings and get you what you want.

 Quote: Butch Crabtree

Trying to find out if this is a rare incident or a more prevalent concern. Dog has not missed any dosage by more then a day or two.

Any help greatly appreciated.

Was he tested before he started the Sentinel?

P.S. I'm so sorry this happened.

Treatment for heartworm has improved a *lot* in the last decade, and has a high success rate now.
http://www.heartwormsociety.org/article.asp?id=11

Fanni has been on Sentinal since she was 6 months old. At present she weighs 60 pounds, the dosage is for dogs 51 pounds to 100 puonds.

The reason for her being given the medication a day or two late is because of feeding her around training sessions, sometimes fed early before traveling. She would be given the medication at feeding the next day.

I have three other dogs and they will be tested this coming week.

I've talked to my vet and he says that his office has sent all of her health records to the manufacture for review. 42 pages of health records.

That's kinda like asking a child if he or she did anything wrong. Let's hope that they will work with me on this concern.

If not there are other options that I will try.

Thanks for the reply

It's true that a day or two late is more than built into the dosage instructions. The thirty-day dose is meant to last 40+ days to allow for late dosing.

At least, my vet tells me that.

here is the American Heartworm Association's view on missing a dosage: This came off their website, not a question from me.

QUESTION:
I have missed two months of heartworm prevention for my dog. Should I worry?

ANSWER:
Monthly heartworm preventives kill the heartworm larvae that accumulate in the dog's body during the month prior to dosing. In addition, these formulations have an additional month of safety-net (reach-back, retroactive) efficacy when dosing is resumed. The extended efficacy of these preventives is a safeguard in the event of inadvertent delay or omission of a regularly scheduled dose and does not justify lengthening the recommended interval of administration. If the lapse in administration of a monthly formulation or the injectable product is three to six months, dosing should resume immediately and the dog should be tested for possible infection seven to 12 months later. The reason for testing seven months later is that heartworms must be about seven months old before the infection can be diagnosed.
With daily heartworm preventives, if the gap in administration is less than two months, one to two doses of a monthly preventive should restore protection. If the lapse in administration is three to six months, switch to a monthly preventive immediately and test the dog seven to 12 months later.
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I'm hoping that the manfacture will contact me soon.

We must supply the link when we copy and paste text from another site into a message here.

Here's the link for the above text:
http://www.heartwormsociety.org/article.asp?ID=14#q36

Connie, Thanks for posting the link. I was unaware of this policy. Again, thanks for helping.