Our GSD pup is 7 months old. Last month she had her first heart worm tablet, and within 24 hours she was horribly sick. Diarrhea and vomiting. Spent the day on IV fluids at the clinic. We did not make a connection.
Yesterday I gave her the second tab. Tonight she is horribly sick again. Explosive diarrhea and projectile vomiting.
Possibly the heart worm meds? Ivermectin / pyrantel. If she can’t take the heart worm meds, what do we do about heart worm prevention?
Stupid question, but are you sure she is heart worm negative? I know that reaction can happen if you give it to a dog who is actually affected.
Would be very difficult for her to have heart worms. She was born in the fall and really not outside at all until after mosquito season. She started Heartgard In March.
Many German Shepherds carry the MDR1 gene ( stands for multiple drug resistance) which can cause a reaction to ivermectin and other drugs. Genetic testing is available to verify your dog has the gene. I would talk to your vet. It can be pretty serious to expose these dogs to heartguard. There can be neurologic symptoms.
Not sure if this will work but here is a link to a Washington State university article about MDR1.
Oops…that’s a link to testing info…lemme see if I can find the darn article…
Been researching online. Could be the flavorings in the chewable tabs. Lots of people are reporting this as a problem.
I’ll check with the vet tomorrow.
What brand? Maybe try a different brand?
[QUOTE=Raincityrider;8628095]
Many German Shepherds carry the MDR1 gene ( stands for multiple drug resistance) which can cause a reaction to ivermectin and other drugs. Genetic testing is available to verify your dog has the gene. I would talk to your vet. It can be pretty serious to expose these dogs to heartguard. There can be neurologic symptoms.[/QUOTE]
This.
GSDs should be genetic tested for the MDR1 gene before ever having Ivermectin. Some vets may not know,though they should, about the link between the gene and Ivermectin toxicity. If the dog has the gene and is given Ivermectin, the dog could die. Get the dog tested.
[QUOTE=King’s Ransom;8628142]
Been researching online. Could be the flavorings in the chewable tabs. Lots of people are reporting this as a problem.
I’ll check with the vet tomorrow.[/QUOTE]
Get the dog tested for the gene. It’s nothing to fool around with.
[QUOTE=pezk;8628222]
This.
GSDs should be genetic tested for the MDR1 gene before ever having Ivermectin. Some vets may not know,though they should, about the link between the gene and Ivermectin toxicity. If the dog has the gene and is given Ivermectin, the dog could die. Get the dog tested.[/QUOTE]
So, the levels in Heartgard and your other prescription ivermectin based heart worm preventives are SO far below the toxic dose level of causing symptoms due to the MDR1 gene. They are safe to give once monthly in the microgram dosages they are available in. You run into ivermectin problems when doseing for things such as mange. It would not hurt to test the dog for the gene as there are other medications that may need to be given down the road that can also causes problems due to the MDR1 gene.
Regardless the GI symptoms you are seeing can be ‘normal’ for certain heart worm and flea medications for the first couple of doses. I would change products and perhaps even go topical preventive such as Revolution or Advantage Multi if you are seeing constant GI upset from oral products. There are other oral formulations available as well that contain different ingredients and both active and not active. Have you tried giving the medication with food?
[QUOTE=Justmyluck;8628281]
So, the levels in Heartgard and your other prescription ivermectin based heart worm preventives are SO far below the toxic dose level of causing symptoms due to the MDR1 gene. They are safe to give once monthly in the microgram dosages they are available in. You run into ivermectin problems when doseing for things such as mange. It would not hurt to test the dog for the gene as there are other medications that may need to be given down the road that can also causes problems due to the MDR1 gene.
Regardless the GI symptoms you are seeing can be ‘normal’ for certain heart worm and flea medications for the first couple of doses. I would change products and perhaps even go topical preventive such as Revolution or Advantage Multi if you are seeing constant GI upset from oral products. There are other oral formulations available as well that contain different ingredients and both active and not active. Have you tried giving the medication with food?[/QUOTE]
I was told by a canine dermatologist that a dog with that gene could never have ivermectin even in a small dose. I owned a female GSD with that gene. Lucky for her we lived in a place where heart worm was exceedingly rare though many vets recommended it anyway. Makes me wonder if the vets there were just selling drugs, not necessary for the dog in its current environment.
I checked with the breeder and pup already had genetic testing to check for MDR1 and other known genetic anomalies. She is clear on that.
Plus it’s true that dose in heart worm med is too low to cause the MDR1 reaction.
We are looking at the product formulation as the culprit. Breeder asked me to call her today to discuss (I say “I spoke” to her, but mean I chatted with her online).
[QUOTE=pezk;8628341]
I was told by a canine dermatologist that a dog with that gene could never have ivermectin even in a small dose. I owned a female GSD with that gene. Lucky for her we lived in a place where heart worm was exceedingly rare though many vets recommended it anyway. Makes me wonder if the vets there were just selling drugs, not necessary for the dog in its current environment.[/QUOTE]
I know many a veterinary dermatologists and heartworm dosages of ivermectin are just fine. ANY DERMATOLOGICAL dose even on the low end is contraindicated 100%. If you live in the lower 48 your animal needs to be put on heartworm prevention.
Our one dog (wheaten terrier) would have a similar but lesser reaction (only vomiting) after receiving Heartgard. After it happened a couple times vet suggested that she was allergic to something in the treat form. So we switched her to the Sentinel pill (which also does fleas) and haven’t had a problem since. Hopefully it’s that simple for you!
This dog did turn out to have quite a few food allergies and we ended up having her tested so we could find the right dog food for her to stop issues with itching and/or vomiting that happened as we tried different dog foods as well.
I’d consider using Revolution for your dog
Try Revolution or Interceptor 
I’ve used Sentinel successfully for years. My dogs will even take it without the pill pocket, but I always feed after a meal.
DH says she is doing much better today. We are slowly re-feeding after not feeding her last night. She woke up once overnight, around 3 am, puking. I took her outside and she pooped. That was her last “episode.”
I haven’t had a chance to visit by phone with the breeder yet today, we are both at work.
If pup seems okay from now on, we have a few weeks before we need to make a decision on brands. My plan is to ask the breeder what she suggests and then call the vet and say, “The breeder suggested such and such, what do you think?”
I have a dog that gets sick no matter what heart worm pill we give. We have tried every brand. After trying the different brands we went back to Heartguard. The vet suggested cutting the Heartguard in half and feeding half in the morning and half in the evening and that did not help at all. This time the vet gave me an anti-nausea pill to give an hour before. That did the trick. He said give the entire pill the next time too and then the third month try only half a pill. He thinks we may be able to stop giving the anti-nausea entirely after 4-5 months. He indicated this was not uncommon and many dogs react well to this program. The anti-nausea started with a “C” and came in a four pack but I am blanking on the name. I can check when I get home if you want.
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