Heartworm Medication Reactions

[Ellie May]

Look at this:
Heartgard Fails [Archive] - HomeVet

I think, even though any of them can fail occasionally, Interceptor might be the better choice for us.

[navygirl76]

i use heartguard. i have also noted that i cannot give Teddy his heartguard AND give him his flea and tick (frontline) treatment on the same day. he will have diarrhea-i think its too much meds for his 7 lb body.. so ill stagger them a few days apart..

besides that, he has never had any problems with any meds.

[Yorkieluv]

It looks like the issues one of the posters has on that site is with the chewable Heartgard, not the pill. The pill supposedly has a more uniform distribution of the heartworm preventative, and it does not need to be chewed.

Later another poster says that Heartgard makes heartworms sterile and that because of that, the Knotts test may be negative. According to Heartgard tablet product information, heartgard eliminates the tissue stage of heartworm larvae. It says nothing about making heartworm sterile.
Also, the most common test for heartworm is not the Knotts test, it is actually the Antigen Test which looks for the presence of a protein given of by sexually mature female worms producing microfilaria.
The following link is very informative:
Heartworm Disease In Dogs and Cats... Diagnosis, Prevention and Treatment for Heartworm Disease In ThePetCenter.com

The following info comes from Heartgard tablet product information:
http://heartgard.us.merial.com/downl...nformation.pdf
PRECAUTIONS: All dogs should be tested for existing heartworm infection before
starting treatment with HEARTGARD, which is not effective against adult D. immitis.
Infected dogs must be treated to remove adult heartworms and microfilariae prior to
initiating a program with HEARTGARD.
While some microfilariae may be killed by the ivermectin in HEARTGARD at the
recommended dose level. HEARTGARD is not effective for microfilariae clearance. A
mild hypersensitivity-type reaction, presumably due to dead or dying microfilariae and
particularly involving a transient diarrhea, has been observed in clinical trials with
ivermectin after treatment of some dogs that have circulating microfilariae.

This comes from INTERCEPTOR® Flavor Tabs® Product Information - Novartis Animal Health US, Inc. :
Precautions
Do not use in puppies less than four weeks of age and less than two pounds of body weight. Prior to initiation of the INTERCEPTOR Flavor Tabs treatment program, dogs should be tested for existing heartworm infections. Infected dogs should be treated to remove adult heartworms (which are D. immitis) and microfilariae prior to initiating treatment with INTERCEPTOR Flavor Tabs. Mild, transient hypersensitivity reactions manifested as labored respiration, vomiting, salivation and lethargy, have been noted in some treated dogs carrying a high num-ber of circulating microfilariae. These reactions are presumably caused by release of protein from dead or dying microfilariae.

The info in red came from websites, the info in black is mine.

[Ellie May]

Yup, it was the chewable.
Something is just bothering me about it though (don't really know what).
It seems like there are more reactions with Heartgard but maybe I'm missing something.

I had never heard of Heartgard causes testing to show up as false negative and I don't know if I believe the person who wrote that. I think Ellie's vet does the antigen test.

Originally Posted by Yorkieluv

It looks like the issues one of the posters has on that site is with the chewable Heartgard, not the pill. The pill supposedly has a more uniform distribution of the heartworm preventative, and it does not need to be chewed.

Later another poster says that Heartgard makes heartworms sterile and that because of that, the Knotts test may be negative. According to Heartgard tablet product information, heartgard eliminates the tissue stage of heartworm larvae. It says nothing about making heartworm sterile.
Also, the most common test for heartworm is not the Knotts test, it is actually the Antigen Test which looks for the presence of a protein given of by sexually mature female worms producing microfilaria.
The following link is very informative:
Heartworm Disease In Dogs and Cats... Diagnosis, Prevention and Treatment for Heartworm Disease In ThePetCenter.com

The following info comes from Heartgard tablet product information:
http://heartgard.us.merial.com/downl...nformation.pdf
PRECAUTIONS: All dogs should be tested for existing heartworm infection before
starting treatment with HEARTGARD, which is not effective against adult D. immitis.
Infected dogs must be treated to remove adult heartworms and microfilariae prior to
initiating a program with HEARTGARD.
While some microfilariae may be killed by the ivermectin in HEARTGARD at the
recommended dose level. HEARTGARD is not effective for microfilariae clearance. A
mild hypersensitivity-type reaction, presumably due to dead or dying microfilariae and
particularly involving a transient diarrhea, has been observed in clinical trials with
ivermectin after treatment of some dogs that have circulating microfilariae.

This comes from INTERCEPTOR® Flavor Tabs® Product Information - Novartis Animal Health US, Inc. :
Precautions
Do not use in puppies less than four weeks of age and less than two pounds of body weight. Prior to initiation of the INTERCEPTOR Flavor Tabs treatment program, dogs should be tested for existing heartworm infections. Infected dogs should be treated to remove adult heartworms (which are D. immitis) and microfilariae prior to initiating treatment with INTERCEPTOR Flavor Tabs. Mild, transient hypersensitivity reactions manifested as labored respiration, vomiting, salivation and lethargy, have been noted in some treated dogs carrying a high num-ber of circulating microfilariae. These reactions are presumably caused by release of protein from dead or dying microfilariae.

The info in red came from websites, the info in black is mine.

[TLC]

Interceptor for mine. No issues

I now give it every 45 days

[Ellie May]

Originally Posted by TLC

Interceptor for mine. No issues

I now give it every 45 days

Nicole, did you talk to your vet about this?
I would like to give it less often but didn't think it was okay.

I know Heartgard is okay every 42 or so days, but I thought Interceptor needed to be given every 30.

[TLC]

Originally Posted by Ellie May

Nicole, did you talk to your vet about this?
I would like to give it less often but didn't think it was okay.

I know Heartgard is okay every 42 or so days, but I thought Interceptor needed to be given every 30.

hmmm....No I didn't talk with my Vet recently, but when I was on the Yahoo Group, others there gave Intercepter every 45 days, and I thought I read that they (company/vet) say 30 b/c it is easier for the general ppl to remember and give every 30 days.

Although, I do remember, way back when, I told my Vet I was late (passed 30 days) and he said that ok, I think he said within the 10 days or 14 days after the time suppose to give (I can't remember) is fine.

[Ellie May]

Ellie is going on Interceptor.
Of course her vet office doesn't carry it anymore.
So we have to get a prescription for it.

[TLC]

Originally Posted by Ellie May

Ellie is going on Interceptor.
Of course her vet office doesn't carry it anymore.
So we have to get a prescription for it.

Did you find out about the 45 or 30 days?

[Ellie May]

Originally Posted by TLC

Did you find out about the 45 or 30 days?

Lol, no.
I had an index card full of questions for her and I didn't even get to all of them.

I am going to give it every 30 days until I find out.
I think she would need to call the company and I really don't want to have her do that because she is already calling Nutramax to see if they will give us samples of Cosequin.

[Yorkieluv]

You can call the company yourself. I've called places like Nutramax to ask a load of questions before, and they're typically pretty nice and will put you in contact with the right people to answer your questions.

[Ellie May]

Originally Posted by Yorkieluv

You can call the company yourself. I've called places like Nutramax to ask a load of questions before, and they're typically pretty nice and will put you in contact with the right people to answer your questions.

I'm will if she forgets.
She offered, so I figured I'd let her.

I have called Merial and Novartis before and they gave me the info I needed but one of the companies wasn't too helpful.

Someone could call Novartis and ask what the grace period is if a dose is missed.
That would be how long extra we could wait between doses.
I'm not sure they'd be much help though.