Mdr1 'safe' Drugs

[Lucy's mama]

I have an Aussie Shepherd pup going on 10 weeks old. Most people say it is usually o.k to use drugs on the mdr1 sensitive list in the low doses that are in heartworm medications.

I'm not keen on taking the risk and have decided to get him genetically tested for mdr1. Untill that is done I want to use only safe drugs butt can't seem to find a list of 'safe to use' drugs.

His breeder started him on intestinal worm treatments so I will e-mail her today to see what she used on him, but what about things like heartworm, fleas and ticks? The name of a brand or drug I CAN use would be very helpfull at this stage.

[Vickie]

Sentinel has no ivermectin

[Lucy's mama]

But it has another drug on the MDR1 list. Will check what it is.

ETA: Drug list of what NOT to use

Drugs that have been documented to cause problems in dogs with the MDR1 mutation include:

Acepromazine (tranquilizer and pre-anesthetic agent). In dogs with the MDR1 mutation, acepromazine tends to cause more profound and prolonged sedation. We recommend reducing the dose by 25% in dogs heterozygous for the MDR1 mutation (mutant/normal) and by 30-50% in dogs homozygous for the MDR1 mutation (mutant/mutant).

Butorphanol (analgesic and pre-anesthetic agent). Similar to acepromazine, butorphanol tends to cause more profound and prolonged sedation in dogs with the MDR1 mutation.We recommend reducing the dose by 25% in dogs heterozygous for the MDR1 mutation (mutant/normal) and by 30-50% in dogs homozygous for the MDR1 mutation (mutant/mutant).

Erythromycin. Erythromycin may cause neurological signs in dogs with the MDR1 mutation. A mutant/mutant collie exhibited signs of neurological toxicity after receiving erythromycin. After withdrawal of the drug, the dogs neurological signs resolved. There were no other potential causes of neurological toxicity identified in the dog.

Ivermectin (antiparasitic agent). While the dose of ivermectin used to prevent heartworm infection is SAFE in dogs with the mutation (6 micrograms per kilogram), higher doses, such as those used for treating mange (300-600 micrograms per kilogram) will cause neurological toxicity in dogs that are homozygous for the MDR1 mutation (mutant/mutant) and can cause toxicity in dogs that are heterozygous for the mutation (mutant/normal).

Loperamide (ImodiumTM; antidiarrheal agent). At doses used to treat diarrhea, this drug will cause neurological toxicity in dogs with the MDR1 mutation. This drug should be avoided in all dogs with the MDR1 mutation.

Selamectin, milbemycin, and moxidectin (antaparasitic agents). Similar to ivermectin, these drugs are safe in dogs with the mutation if used for heartworm prevention at the manufacturer's recommended dose. Higher doses (generally 10-20 times higher than the heartworm prevention dose) have been documented to cause neurological toxicity in dogs with the MDR1 mutation. Vincristine, Vinblastine, Doxorubicin (chemotherapy agents).

So reading that it IS actually safe. Now why couldn't I find that before I posted? And why so many cautions if it is safe?

Edited November 26, 2009 by Lucy's mama

[Natsu chan]

Lucy's mama I have a collie who is a carrier, my old girl was probably affected. I wouldn't use spot ons and really it's not necessary most of the time. We have used collars and sprays but for fleas I find we rarely have much of a problem, but then I don't live in a tick area.

The daily heart worm tablets are safe for affected dogs since they don't contain any of the mectin family of drugs. Most of the collie breeders I've spoken to won't take the chance with the monthly heart wormers, even the ones who don't own affected dogs.

[mutt lover]

Have been reading all posts re yearly injections and h worm injection vs tablets etc. My old dog lady has been having yearly injections for last 9 years but last year noticed the reaction to injections was more severe but vet will tell you is very rare, she was quite off for 2 days after having injection had slight temperature and was generaly very listless, has also now got wart type things on various parts of her body which I've since found out is a build up of toxins from yearly injections which was in a dog magazine.

So this brings me to the question is it really safe injecting these toxins into our dogs and what is the alternative as I want to research more before I go down that track when I get another dog, I thought I was doing right thing getting injections every year and heart worm one vet admitted to me last year that some dogs can have a reaction but it is usually very mild.

[ozjen]

But it has another drug on the MDR1 list. Will check what it is.

ETA: Drug list of what NOT to use

Selamectin, milbemycin, and moxidectin (antaparasitic agents). Similar to ivermectin, these drugs are safe in dogs with the mutation if used for heartworm prevention at the manufacturer's recommended dose. Higher doses (generally 10-20 times higher than the heartworm prevention dose) have been documented to cause neurological toxicity in dogs with the MDR1 mutation. Vincristine, Vinblastine, Doxorubicin (chemotherapy agents).

So reading that it IS actually safe. Now why couldn't I find that before I posted? And why so many cautions if it is safe?

Only safe at the recommended dose, sometimes when they are used for other treatments where the dose is higher they would not be safe for a dog with MDR1 mutation.

Welcome to owning an Aussie, they are great dogs. Do you know the parents MDR1 status? this may save you having to DNA test for MDR1.

[ozjen]

Have been reading all posts re yearly injections and h worm injection vs tablets etc. My old dog lady has been having yearly injections for last 9 years but last year noticed the reaction to injections was more severe but vet will tell you is very rare, she was quite off for 2 days after having injection had slight temperature and was generaly very listless, has also now got wart type things on various parts of her body which I've since found out is a build up of toxins from yearly injections which was in a dog magazine.

So this brings me to the question is it really safe injecting these toxins into our dogs and what is the alternative as I want to research more before I go down that track when I get another dog, I thought I was doing right thing getting injections every year and heart worm one vet admitted to me last year that some dogs can have a reaction but it is usually very mild.

I believe that one of the biggest problem with the yearly injections is that if you have a dog that reacts badly to it, there is no getting it out of their system its there for 12 months if the dog survives. With the daily treatment if the dog reacts it has a chance of being treated while it is active in their system until it has run its course within the 24 hours.

With the annual injections for parvo,distemper ect I do think we over inoculate and while vets here are just starting to do it 3 yearly it has been happening in America for many years.

This is only my opinion though and some of the vets or vet nurses on this forum could probabaly advise you bettter.

[Lucy's mama]

No, the parents were not MDR1 tested. The vet reccomended a six monthly injection but I think I will use daily tablets untill I get the test done. His breeder uses frontline plus on hers wih no ill effects so if necesary I will use that.

I probably shoudn't be so worried, but he is just so precious and I'm looking forward to doing so much with him and having a lovely companion.

[luvsdogs]

I have had a border collie since 1993, on my 2nd one now. I always gave April, the 1st one heartguard when it 1st came out. Back then there was no mention that ivermectin could cause problems in collies. It wasn't until about 2003 that I learned at a pet expo that it could be a problem when I went to buy heart-worm tablets from one of the exhibitors & she asked my what breed of dog I had, when I told her she said it was not recommended for collies so I started to use Proheart tablets instead which I used until her death.

When I got Tilba I was given a sample pack of Heartguard plus from the breeder & at the time my vet said she didn't think it would be a problem if she didn't have a reaction from the 1st dose she had had b4 I got her. So I used it for the next few months. When I went to get some Prohart tablets I had read on another forum that it wasn't recommended either for collies as it's ingredient is related to ivermectin which I didn't know when I used to give it to April. They recommended to use either Interceptor or Sentinel for collies (may have been the bc sub forum?) . So I used Interceptor over the winter months & have given her one Sentinel tab this month because it also treats fleas. So I will soon see how this goes.

On another forum a couple of years ago, there was a big thread about the use of Prohart 6 injection & how dangerous it was. I had to google it to know what it was. In the US they were using 6 mthly injections for heart-worm prevention. Fort Dodge eventually recalled Proheart6 & recently it's been allowed back with restrictions. The google search also had a link to the dol thread on Proheart injections.

http://www.dolforums.com.au/index.php?showtopic=6475

There are 8 pages to wade through & some of the links no longer work but worth the read.

http://www.upi.com/Science_News/2008/06/05...80311212687545/

And all this for a 6 mth injection where here in Aus we have the 12 mth injection which would be twice as strong.