Guide To Australian Shepherd Training & Care


What Type Of Heartworm Medication Is Safe To Use For Aussies?

by Melissa
(Monmouth, IL)

My vet had mine on Heartguard, my pup started having seizures a day or so after the 1st of month dose, after some research. I found that Aussies should not take Heartguard. After more research found that Aussies and herding breeds have a sensitivity to Ivermectin, which is in Heartguard. Inquired as to what I should give him for protection besides Heartguard. Interceptor was mentioned but never was offered to start my Aussie on that medication. When I finally questioned about changing, was told it was on indefinite backorder.

So all this time, because I'm a relatively new dog owner. My Aussie has been on phenobarbital for seizures that could have been avoided! Needless to say, I'm a little upset that my pup has to go through this. So my question, what are other Aussie owners using for heartworm protection? I desperately want my Aussie off phenobarbital and seizure free. I will not give him another dose of Heartguard!!! Any suggestions? Thank for any help anyone can suggest.

Aussie lover

Comments for What Type Of Heartworm Medication Is Safe To Use For Aussies?

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Heartworm medication
by: Heidi M


I am so sorry to hear that. I have a 2 year old Aussie and she is not on any heartworm med yet because I have read the reports. I asked my vet and she said it is not a problem b/c it has a low dose. I refuse to take the chance. I was quite surprised that she actually said that. So I am sorry I can't offer you advice. I would love to learn of another option. Once again I hope your sweetie can recover. Did your vet say that the seizure will go away or that the meds caused him to have epilepsy?- Best Wishes

What type of heartworm
by: Heidi M


I was just doing some research and I came across this...

Acute ivermectin toxicity paralyzed Charly, who was first treated with lipid infusion and had to be placed on a ventilator to help him breathe. On May 26, UF veterinarians disconnected the ventilator and Charly went home with his owner June 1, recovered from the ordeal.


Hope it can help!

by: jcrply

Glad to hear you are doing research. I have been using Interceptor. Novartis is supposedly going to resume manufacturing it sometime in the future. I still have some Interceptor because I always cut the pills. The medication in Interceptor is Milbemycin Oxime. Do some research on that on your own. Include the FDA (Food and Drug Administration) website. The FDA recommends 0.05 mg Milbemycin Oxime per pound of dog weight. So a 40 pound dog needs 2 mg per month. The smallest Interceptor pill has 5.75 mg. (They sell that for an 11-25 pound dog!) They put in so much extra so it will also kill intestinal parasites. My vet recommends TRIFEXIS while we wait for Interceptor to become available again. Trifexis is also Milbemycin Oxime. The difference is that Trifexis also has Spinosad in it. The Spinosad is added to kill fleas. If I run out of Interceptor, I will use the Trifexis, but I will also cut those pills since they too have 5 times as much milbemycin oxime as is needed for just heartworm. Even cutting these pills in half gives the dog a lot more than he/she needs for just heartworm.

by: gayle--big run aussies

There is a new product on the market called Trifexis. You can also use Sentinel. These products are more expensive than Interceptor and also have a flea preventative in them that I, personally, object to, but they do not have ivermectin. The other option is to have your dog MDR1 tested for drug sensitivity to see if that is the problem. The testing is done through the University of Washington veterinary school. Good luck.

Heartworm Medication
by: Anonymous

My aussie and lab are both on Heartguard Plus with no problems other than diarehha the day of. I would like to hear what other aussie owners are using.

Heartworm preventative
by: Colin

My mini Aussie has been on Sentinel for a year and we just recently changed him to Trifexis. Neither preventative medication had any adverse effect on him. He's happy, healthy and heartworm free. (2 years)

Sentinel back in production
by: Jen J

I just got back from the vet (I have two Aussies). Interceptor is not coming back, but Sentinel just started back up (May 2013). Sentinel is Interceptor plus a flea prevention product. So far so good. They've also promised to keep the price stable, since they lost a lot of customers when production ceased, and they need to win them back.

Heartworm medication
by: Carol

Thank you all for your posts, we are taking our 15 week old Aussie to the Vet next week for her first check up since buying her last week.
I did read some articles regarding Aussies and heart worm medication and was wondering what I was going to do.
Your information has helped me.

Be careful of ant poison containing abamectin!
by: Francesca

Hi Melissa, I am so sorry to hear about your aussie's seizure. Since your dog has this sensitivity, please be aware of other things that contain a compound called abamectin which is related to ivermectin. Some ant poisons contain this ingredient, and my aussie stepped in it, licked his paw and went into seizures. The Washington state lab (mentioned by my breeder Gayle of Big Run Aussies in this post hi Gayle! ) can be reached at for the test kit. Wishing you the best.

by: Colin

I've used Trifexis for 2 years now with my 2 year old Mini Aussie. Absolutely no problems what so ever. It smells really bad. A little cheese and he woofs it right up. :) Sorry you had a bad experience. :( I do pray all is well now. <3

A veterinarian's opinion
by: Anon

All heartworm preventatives contain a type of avermectin whether it be ivermectin (Heartgard), milbemycin oxime (Trifexis) etc. ONE of the drugs MDR1 dogs can be sensitive to is an avermectin. Other drugs include Immodium and some chemotherapy drugs; there are others. At the doses used in veterinary prescribed heartworm prevention products, even MDR1 positive dogs can receive them as heartworm prevention safely. Is it impossible for a dog to have a seizure from properly prescribed heartworm prevention? No. That being said, it is unlikely. If you are concerned, have your dog tested for the gene through Washington State then have a conversation with your VETERINARIAN or even multiple veterinarians if you want a second, third opinion. There is so much dangerous and inaccurate information floating around the web I beg you to talk with someone who has the education behind their opinions (ie. a veterinarian.) If you don't trust your veterinarian, find a new one! For the woman with the seizing dog: My opinion is that you should see a boarded internist or neurologist - that is the ultimate level of care you could get for your dog.

Re: FDA Page
by: CaliAussieGal

The FDA page says (referring to Interceptor) "The tablets supply the recommended minimum dose level of 0.5 mg milbemycin oxime per kilogram (0.23 mg/lb.) of body weight."
So, dogs need .5mg, NOT .05mg per KILOGRAM, not POUND. This changes the numbers a lot.
I just wanted to get the correct information out there so no one thinks they are treating their dog when they aren't actually!

No heart worm poison given
by: Sharon

I have a 9 year old Aussie boy and an 11 year old mixed girl, and neither have been on any heartworm poison for the past 8 years. I object to giving my dogs pesticides or any other harmful chemicals. Call it heartworm "medicine" all you like, but it is nothing but poison. My dogs are fed good, healthy, natural food and are cared for as naturally as possible. My vet can't believe my girl is 11 years old because of her outstanding health and appearance, and she understands and respects my choice not to poison them. They are tested every year and have always tested heart worm negative. I can't understand why a dog's good health should be compromised by poisoning them unnecessarily, so will not do that to them.

Interceptor can be purchased in Australia
by: Anonymous

You can buy interceptor with tapeworm preventative at . It is sold in Australia and Canada but not in the US.

I am with you. I would opt to not give my asussie anything rather than have her on a medicine that made her that sick. I hope yours is better soon :)

by: Anonymous

I have had 3 friends who have used Trifexis and all of their dogs have had seizures. Aussies have a chemical imbalance in their brains and the Trifexis is very harmful to them.

by: Em

We have been using Trifexis for our aussiedoodle. I'm thinking about trying Sentinal. He's only 9 months old. We would consider going all natural, but that's how we lost our lab to heartworms in the past. We won't do that again. She lived a long life, but she had heartworms in the end. We do live on a farm, so our animals are exposed to more (they aren't apartment animals).

by: Kat

When Interceptor was no longer available my vet recommended this product. I hesitated but live in an area with a lot of mosquito. I gave two monthly doses in the fall and began again in June of the following year. After four more doses my dog became completely deaf. I feel so terrible that I wasn't more careful. His life is changed completely, so I am going back to a medication like Interceptor.

Vets should be more cautious and ask to monitor for symptoms.

Trifexis can cause dog deaths
by: Anonymous

Here's a link to a story on dog deaths caused by Trifexis.

Btw, we're on Sentinel, but my dog still got heart worms. No great solutions out there.

by: Anonymous

Be careful with the Trifexis - If you go to their website the advise to use caution in using it in epileptic dogs!

5 month old mini aussie - revolution
by: Julia

Has anyone used Revolution topical medication? I would love to know if anyone has had problems with this medication.

by: Sandi

We have been using vet recommended Revolution since the production of interceptor stopped. All good on both of my Aussies for a long time. I would caution not using any med for this disease. I know someone who's 2 yr old shep has it and it is tragic to watch the dog go through this illness. be careful.

Advantage Multi for dogs
by: Indianapolis,in.

We adopted an Aussie, she is now a year and a half old. The rescue highly recommended Advantage multi for dogs. She just had her second checkup and shots and was clean. I apply this every month but noticed that she boggs down, goes to bed and sleeps alot and is'nt her self for about 12 to 16 hours after application. Anyone have this same issue using this product?

by: George

I had a similar issue with Chief. He was a pup at the time but had bloody stool w/ mucus and eventually just mucus.

The first time I thought it was something he ate... then it happened again.

Hopefully I will find something soon...

My Aussies
by: sherry

I am using Sentinel Spectrum but I feel the dosage is too high for my one Aussie as they give the same dosage for a dog for 51 lbs to 100 makes no sense, so that is why I would like to hear from other Aussie parents. I sent an email to Novartis asking why the same dosage, as my Vet feels it is safe & I feel it is overdosing.

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