Ivermectin Sensitivity & Desexing

[Dame Aussie]

We have just sent off for a DNA test so we can test our Aussie to see if she has sensitivity to Ivermectin.

In the meantime we have been trying to decide when to have her desexed. I was just wondering if any of the drugs she could possibly be sensitive to would be used during the operation. In the anaesthetic, pain relief etc?

Does anybody know?

Preferably we’d like to have the DNA test done first but it’s taking it’s time arriving.

Thanks all

[alanglen]

Ivermectin, nor any of it's family drugs would be used in a desexing procedure, it's quite specifically for parasite control so you are quite safe!!! Best of luck for the test anyway!

[Bonnie N Her Aussie2]

We have just sent off for a DNA test so we can test our Aussie to see if she has sensitivity to Ivermectin.

In the meantime we have been trying to decide when to have her desexed. I was just wondering if any of the drugs she could possibly be sensitive to would be used during the operation. In the anaesthetic, pain relief etc?

Does anybody know?

Preferably we’d like to have the DNA test done first but it’s taking it’s time arriving.

Thanks all

Hey Aussie, Ivermectin has nothing to do with desexing procedures, or atleast I am 90% sure.

How old is your little girl now? There's a fair bit of debate about when a good age to desex is..

My Aussie bitch is nine months old, has no sensitivity to Ivermectin, but her sister was never tested and was desexed last week.

Her desexing was fine, she was a little groggy for a while, but otherwise just fine.

[wylie]

Here is a website with the list of MDR1 drugs that can cause sensitivities if used

Problem Drugs for dogs with MDR1 sensitivity

There are definitely drugs that should not be used ever with Aussies and your breeder should have given you a list or a website with those.

If anyone does not have have it i am happy to send some of the information i have collected over the years.

ASHGI website also has lots of information on it re MDR1 sensitivity and the drugs that are contraindicated.

Edited December 3, 2008 by wylie

[Guest Tess32]

Yep Ivermectin is not the only drug that effects dogs with the MDR1 gene..

[Bonnie N Her Aussie2]

Here is a website with the list of MDR1 drugs that can cause sensitivities if used

Problem Drugs for dogs with MDR1 sensitivity

There are definitely drugs that should not be used ever with Aussies and your breeder should have given you a list or a website with those.

If anyone does not have have it i am happy to send some of the information i have collected over the years.

ASHGI website also has lots of information on it re MDR1 sensitivity and the drugs that are contraindicated.

good list.

[leopuppy04]

some stuff I've collected over the years:

****

If your Aussie has 2 mutant copies of the mdr1 gene, he/she could have neurtoxicity with some drugs. If he/she has 1 mutant copy and 1 normal copy, problems can occur.

These are the problem drugs:

http://www.vetmed. wsu.edu/depts- VCPL/drugs. aspx

******

http://www.vetmed.wsu.edu/depts-VCPL/

******

The 'Not For Collies' Drug List

Be aware of anything with "ectin" on the end.

Abamectin Antiparasitic Agent

Acepromazine Tranqualizers

Butorphanol Tartrate (Torbutrol, Torbugesic) Pain Control

Cyclosporin Immunosuppressive agent

Cyclosporin A Immunosuppressive agent

Deramaxx

dexamethasone, Steroids

Digoxin Heart drug

Domperidon Gastrointestinal Agents

domperidone

doramectin

Doxorubicin Chemo drug

Erythromycin Antibiotic

etoposide

Grepafloxacin Antibiotics

Heartgaurd

Hydrocortisone Steriods

Immodium Loperamide

Ivermectin Antiparasitic Agent

Kaopectate (some formulas)

Loperamide (e.g. Immodium AD) Gastrointestinal Agents

Macrocyclic Lactones Anti-helminthic pharameuticals that are

P-glycoprotein substrates include

the family of compounds

Milbemycin Oxime Antiparasitic Agent

mitoxantrone

morphine

Moxidectin Antiparasitic Agent

Ondansetron

ondansetron

Oxorubicin Anticancer agents

paclitaxel

PeptoBismol (some formulas)

Pro Heart6

Quinidine

Revolution

rifampicin

Rimadyl

Selamectin Antiparasitic Agent

Substrates for P-glycoprotien

Tacrolimus Immunosuppressants

Vinblastine Chemo drug

Vinca Alkaloids Anticancer agents

Vincristine Chemo drug

Advocate and Milbemax

******

[leopuppy04]

Article:

The Mystery of Ivermectin Toxicosis

For many years, veterinarians knew a certain pharmaceutical used to eliminate internal parasites in animals was very toxic to a subpopulation of collies. What they didn’t know was why.

Now a pharmacologist at the WSU College of Veterinary Medicine has discovered a mutant gene for a key transport protein in the susceptible collies. The gene codes for P-glycoprotein, a large protein complex that acts to pump medications out of the brain and back to the bloodstream where they can be metabolised safely. In the collies that lacked the complete gene for P-glycoprotein, they do not produce the complete protein and cannot pump out the medications. The drugs then build within the brain to toxic levels. P-glycoprotein also helps transport other drugs out of the brain and other tissues in humans and animals, including popular over-the-counter medications.

Discovery of the mutant P-glycoprotein gene may be a key step in screening individuals for certain drug susceptibilities or even pharmaceutical re-design of popular medications to make them.

In the veterinary news…

Washington State University scientist, Dr. Katrina Mealey has solved the mystery of ivermectin toxicosis in collies. Using blood samples donated by collies from a variety of lines, she has determined the gene responsible for a collie’s adverse reaction to ivermectin administration

In the mid 1980 's ivermectin was presented to the small animal veterinary community. It's beneficial use in cattle and horses were already apparent. Ivermectin was introduced to small animal veterinarians as the most broad-spectrum anti-parasitic agent available.

It could eradicate most intestinal parasites (not tapeworms or coccidia), scabies, ear mites, some lice, circulating microfilariae from heartworm infection, and act as a preventative against adult heartworm

Ivermectin showed up in a variety of forms:

1) a once a month heartworm preventative

2) a solution taker orally or by subcutaneous injection to eliminate intestinal worms, scabies and ear mites

3) an adjunct therapy for treatment of demodectic mange

4) a topical ear drops specific for ear mites

5) a microfilaricide oral solution

The Mystery of Ivermectin Toxicosis cont...

The problem in collies and some other breeds of dogs was that sometimes the ivermectin not only killed the parasites, it also killed the dog! For years, the pharmaceutical companies tried to convince the collie owners and breeders that ivermectin was a safe drug for collies. They even put a picture of a sable collie or one of the ivermectin products.

Some of our collies did well and had no adverse reaction to ivermectin administration. A lot of our collies became ill, some even died Death was usually a result of the increased levels of ivermectin in the brain.

Here are two of my own ivermectin sensitive nightmares…

When we sell a puppy, it goes to its new owner with a warning label. The puppy also takes a note directly to the new veterinarian on its first visit to the veterinarian's office. The warning label and the note explain some of the sensitivities of collies to certain drugs. Ivermectin is at the top of that list. The note says

DO NOT USE IVERMECTIN UNDER ANY CIRCUMSTANCES

Puppy #1 received one labeled dose of heartworm preventative containing ivermectin The puppy spiked a fever, started to convulse and died within 24 hours.

Puppy #2 had some hair loss on its foot. The area was scraped and was negative for demodectic mange. Still thinking it might be demodex; 1cc of liquid ivermectin was applied to the foot. That night the puppy became ill, started to convulse, and died.

Now Dr. Mealey has determined the mechanism and consequently the gene responsible for adverse reactions to ivermectin in collies. P-glycoprotein (P-gp) is the neurotransmitter (vehicle) responsible for keeping ivermectin out of the brain. Dr. Mealey has found that if the protein P-gp is present then ivermectin cannot enter the brain, hence no reaction. The absence of P-gp allows ivermectin to cross into the brain and allow adverse reactions.

Dr Mealy has also determined the habitability of ivermectin sensitivity. There are three populations of these dogs. One is homozygous for the production of P-gp. These dogs are not sensitive. The second population is heterozygous for the production of P-gp. These dogs are rot sensitive to ivermectin but can produce puppies that are sensitive when bred to another heterozygote or an ivermectin sensitive dog, and third, the homozygous ivenmectin sensitive affected dogs that do rot produce P-gp.

The Mystery of Ivermectin Toxicosis cont...

Dr. Mealey has determined ivermectin sensitivity to be widespread in the collie population. Thirty-five percent are affected and show sensitivity, whereas 42%

are carriers. That leaves 23% to be ivermectin non-sensitive non-carriers.

A test is in development to screen for the presence or absence of the gene responsible for the production of P-gp. Testing individual collies will allow us to predict the sensitivity of that particular collie to ivermectin.

Now, it seems that all we should have to do to eliminate the ivermectin problem is avoid ivermectin. TRUE! But, go one step further. P-gp is responsible for keeping other drugs out of the brain. Those collies that have lymphoma or leukemia, or those that have autoimmune blood disorders would benefit by the use of vinblastin and/or cyclosporin. In the absence of P-gp, the drugs cross the blood brain barrier and can cause death. Loperamide (immodium), an anti-diarrhea drug will also cross the blood brain barrier in the absence of P-gp. Death by immodium has been anecdotally reported in collies. Now, we know why.

This is only the beginning of the list of drugs that are affected by P-gp. Soon we will be able to test our collies for the ability to handle P-gp affected drugs before using them. We will no longer have to find out if reactions occur after administration of often necessary, but potentially dangerous drugs. Often, these reactions result in death.

If you would like to learn more about this incredible discovery, visit Dr. Mealey's web site at ttp://www.vetmed.wsu.edulannouncements/ivermectin/ownerinfo.html

Reprinted with permission from Dr Katrina Mealy.

Footnote:

Do not let your Dog become a statistic at the Vets, bring this important information to his/her attention immediately.

Ivermectin affects Shelties as well as Collies and several other breeds, copy this article and show it to your vet, and place a copy of it in your puppy folders. Draw to the attention of your new puppy people the detrimental affects of this drug which is found in many Medications and Heartworm preventions. Tell your new puppy buyers to be very aware about which Heartworm treatment they use on their new pup. If in doubt get them to ask the vet which Heartworm treatment does not have Ivermectin in it, their new pups life may very well depend on this advise.

[Banshee]

As well as the Washington State University web site which gives you that actual name of the drugs researched, have a look at

www.Busteralert.com

This site gives you a list of these drugs with North American Brands and trade names. Between both of these sites you will get a pretty comprehensive list of what you can use and can't use, and can use but in reduced doses.

[Dame Aussie]

We have just sent off for a DNA test so we can test our Aussie to see if she has sensitivity to Ivermectin.

In the meantime we have been trying to decide when to have her desexed. I was just wondering if any of the drugs she could possibly be sensitive to would be used during the operation. In the anaesthetic, pain relief etc?

Does anybody know?

Preferably we’d like to have the DNA test done first but it’s taking it’s time arriving.

Thanks all

Hey Aussie, Ivermectin has nothing to do with desexing procedures, or atleast I am 90% sure.

How old is your little girl now? There's a fair bit of debate about when a good age to desex is..

My Aussie bitch is nine months old, has no sensitivity to Ivermectin, but her sister was never tested and was desexed last week.

Her desexing was fine, she was a little groggy for a while, but otherwise just fine.

Hey Bonnie, She's just turned 6 months....I've been debating over when to do it but am thinking in the next few weeks...

[Dame Aussie]

Thanks everyone, really helpful as always . I'm hoping the test will be fine but it pays to be cautious

[InspectorRex]

I would be waiting for the Results of the DNA test prior to the desexing because if your dog is Affected or Carrier for the mutant MDR1 gene there are commonly used drugs that MUST NOT be given to the dog; eg most vets use ACP for sedative and morphine for pain relief. If the dog is Affected or Carrier it MUST NOT have these drugs

Because I have had our Collies DNA Tested and they both are AFFECTED if they have to go to the Vet I take a copy of the DO NOT GIVE DRUGS to me to the Vet so at least they know what I mean.

It can mean the difference between life and death if a Affected or Carrier is given a drug that they MUST NOT be given.

[Banshee]

I would be waiting for the Results of the DNA test prior to the desexing because if your dog is Affected or Carrier for the mutant MDR1 gene there are commonly used drugs that MUST NOT be given to the dog; eg most vets use ACP for sedative and morphine for pain relief. If the dog is Affected or Carrier it MUST NOT have these drugs

Because I have had our Collies DNA Tested and they both are AFFECTED if they have to go to the Vet I take a copy of the DO NOT GIVE DRUGS to me to the Vet so at least they know what I mean.

It can mean the difference between life and death if a Affected or Carrier is given a drug that they MUST NOT be given.

Rex I think you might need to have a look at the research that has been done by a highly respected and promenant university in USA.

"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). " ACP

Yes you will need the results of the test to be able to give the correct dosage to a drug sensitive dog, but you are still able to use this drug.

As for Morphine, this is only suspected as MDR1 sensitive, and personally I wouldn't use it until research has confirmed the facts.

Please Aussie3, just research the drugs before you use them. Some are safe to use when necessary, but under strict safety guidelines, some are definate no nos.