Drug Resistant Canine Intestinal Parasites

[Pipedream Farm]

We took our pups in for their rabies vaccination and had a very interesting conversation with our Vet on dewormers and their use in dogs. He wondered if we are selecting for drug resistance in canine intestinal parasites in the same way we are selecting for drug resistance in livestock intestinal parasites. For example, how many of us are using the same deworming drug every month when we treat for heartworm? Could this not lead to killing off canine intestinal parasites that are sensitive to our drug of choice leaving only those that are resistant? He wondered if dog owners and Vets shouldn't follow a similar deworming strategy in dogs as is being advocated in livestock.

 

Just a little something for you to ponder.

 

Mark

[Rebecca, Irena Farm]

I use something else, every three to four months, for intestinal worms (because my dogs are exposed to coccidea and giardia and the stuff we use is good for that).

 

I wonder whether the very different rate of digestion, between small ruminants (ie, sheep/goat) and dogs, has something to do with historic success with anthelmetics in dogs.

 

On the other hand, I'm a little nervous about heartworms themselves and to a lesser extent (because they are not lifethreatening), fleas. Frontline used to be "good" for three months against fleas. Now it's necessary to use it every two to three weeks and it absolutely has to be combined with the IGR.

 

Does the longer life cycle of the heartworm shield us from adaptation to some extent?

 

Ted weighs 18 pounds! What a hoss! He has definitely "discovered" the sheep so the days of wine and roses are over for him - it's under mama's eye all the time.

[Pipedream Farm]

Nell and BJ were both around 22 lbs yesterday.

 

Mark

[juliepoudrier]

Hi Mark,

I've often wondered the same thing. Interesting that your vet has voiced that concern as well.

 

J.

[Keegan's Mom]

Becca - what is IGR?

 

This is interesting to think about, Mark.

[juliepoudrier]

IGR = insect growth regulator. Many people are uncomfortable using IGR-containing products because they fear that the IGRs will enter the environment and affect nonmammalian life there. (In the case of fleas, the IGRs mimic certain hormones needed for the maturation of the flea larva into an adult flea; they disrupt the normal growth cycle so that the larva doesn't mature and dies in larval form.) So the fear is that if such chemicals enter the environment in high enough concentrations, they could disrupt the life cycles of beneficial insects or even "higher" forms like amphibians. I'm not taking a stand one way or the other with this post--just explaining why people don't like IGRs. (They are used in far more than just flea-control products.)

 

J.

[Keegan's Mom]

Where are IGR's found...in what kind of products?

 

Thanks for the explanation, Julie.

 

Becca - I'll be sending a check soon so for look for it in the mail early next week.

[Rebecca, Irena Farm]

I have a dog who ends up at the vet when he is bitten by fleas, therefore when the fleas appear, so sorry about the environment and all that. I tried all the organic stuff and it isn't 100% effective. 100% is necessary for Ben. Maybe when Ben passes on we can let it slide.

 

This is why I'm in a panic about flea control. Last summer was awful. Ben ended up at the doctor twice. He's too old for prednisone but nothing else will stop the huge reactions (his internal organs start shutting down). I finally spent $300 on various products and carefully applied them over the course of two months, timed to the flea life cycle (not to mention cleaning, vacuuming, washing, etc).

 

I've never had fleas in 13 years of owning dogs, until last year, and never had to use anything other than regular Frontline, applied every two to three months, until last year. I just don't understand it and that makes me very nervous.

[juliepoudrier]

Well, some of us have been sounding the alarm for some time now about the possibility that fleas are developing resistance to the current crop of flea-control products.

 

Rachel,

Remember the Ectokyl spray I told you about that I use here? Its full name is Ectokyl IGR. Frontline Plus contains IGRs, but regular Frontline does not. (Other insect-control products for, say, agricultural use, also contain IGRs.)

 

J.

[Keegan's Mom]

We use Frontline Plus. I tried to Ectokyl spray at our vet but they only carried the shampoo. So since we were moving, I didn't worry about it to much.

 

Yes, the fleas have been really bad this year and my vet said we weren't the only ones complaining so it was bad for everyone!!!!

[Lenajo]

Funny, I said I had resistance to Frontline here 2 years ago on a BC internet list and I was told if I applied it right, I wouldn't have a problem. When I persisted that I was, I was told there was no way resistance could happen.

 

Guess it did...

[juliepoudrier]

Lenajo,

Over the past several years I've been told repeatedly I must not be applying it right, etc. To that I always answered that I've been using it since it came out and applying it the same way all along. And it did work in the beginning. Therefore it's not likely to be my application technique that's the problem!

 

But what bothers me most is that the companies are making money hand over fist for products that aren't working as they once did. And the solution seems to be applying the stuff *more often* even though it's still not working well. Who the heck is benefitting from that????

 

Given how things were this year, I cringe at the thought of how bad it will be if the current crop of products quits working completely. Not long ago I tried to get Program again, thinking that since it hadn't been used as much it might still be effective. But trying to find it is like panning for gold.... (Back when Program was the first new product to come out and I started using it I remember being overjoyed at being flea free. I haven't had that situation for a few years now.)

 

To bring this back on topic, I had been asking about the possibility of intestinal worm resistance to the monthly HW preventives, and no one could give me an answer. I ended up switching my dogs to ivermectin for HW prevention and then using another product to take care of intestinal worms a couple times a year. I feel better knowing that I am trying to minimize the possibility of resistance developing.

 

J.

[Rhborder]

Ok, I'm glad to hear I'm not crazy and that frontline doesn't work for you all either. I used Frontline plus consistently about three years ago and was very unimpressed, so I tried Frontline Spray, and up untill now, it has done its job. So now what??? Also does the Ivermectin work fine on your dogs, I was told not to use it because of their sensitivity?

[nancy]

Maybe it's that Fergie is mostly an indoor dog - with at least 4 walks (minimum of 1 mile each) a day and out in the yard when we are. But Frontline has worked so great for 11 years that we wonder why our daughter and her family (who live in a state park - he's a ranger - amid gazillions of fleas and ticks) can't put dabs between their shoulder blades every month.

 

I will ask our vet about possible resistence to heartworm meds. He (well, the whole practice) is certainly one of the best I've ever known.

[Alicia]

I've yet to have a problem with Frontline. Kole has a flea allergy, though thank God not as bad as Ben's! He gets frontline every-everyother month during flea/tick season and It always has worked for the 2yrs of his life.

Interesting, maybe different areas have different resistence strength? or the ones around Kole just havent been exposed enough yet, he has lived in a few diffent areas..

[Pipedream Farm]

nancy,

 

I wasn't really taking about resistance of heartworms to meds (although that could be of concern too); I was really taking about intestinal worms becoming resistant to the dewormed that are part of the monthly heartworm meds (i.e. heartgard plus has ivermectin for heartworm and pyrantel pamoate for intestinal parasites).

 

Mark

[Eileen Stein]

>

 

You might want to read this.

[Rhborder]

Thanks Eileen!

[jrid]

Julie, if you go to the Pets Megastore website, you can order a product called "Profen" that is equivalent to Program. Although, the website carries Program, they are not allowed to sell it to people in the U.S. I have ordered heartworm medications from them in the past and received exceptional service.

[Rhborder]

UHHHH, the vet I work for still sells program, I've never thought to try it before, but perhaps I should

[Bill Fosher]

We have yet to have flea problems, but I did find that Frontline pretty much lost its efficacy on ticks in western Massachusetts. I switched to Advantix (NB, not Advantage) and that was the end of the problems.