Ivermectin

I just came across this thread and wanted to put something out here about Ivermectin.  My sister-in-law's lab was given this for treatment of demodex mange.  I had (lives w/my ex-hubby) a German Shepherd (yes, a herding dog) at 6 mos old that was given this too about 8 years ago for demodex. I trust my vet...he stressed the importance of the minimal amount that would could give him.  We could only inject a very tiny amount (I don't remember how much anymore) into a little scoop of ice cream.  The vet said how if we weren't very careful adminsistering this we could cause neurological damage.  The treatment worked for us with no side effects.  Well imagine how shocked I was when my sister-in-law came back from the vet and told me about the large dose they injected into her dog!  Well, after that he started to act weird...shook his head sometimes...then began having seizures.  I never mentioned my concern about the injection her dog got because I didn't want to start some "vet war" but I've always had my suspicions that it related to that injection of ivermectin.  Last year...her 4 year old lab died from these strange seizures that he started having almost continuously.  They never gave her a diagnosis/cause even though many test were done along the way to this sad ending.

Using ivermectin for demodex is commonplace and I have huge huge huge issues with it.  Demodex mites never touch the blood supply in the dog (they eat skin oil---*not* blood and never 'bite' the dog) -- and ivermectin only lasts 24 hours in the dog's body.  This is one reason for the enormous doses -- they are trying to get enough of it in the body to 'push' it into the skin to kill the mites.

What actually happens is the ivermectin has a side effect that manipulates the immune system.  It's a 'pseudo' immune boost if you pardon the quotes.  It simply chemically turns on the immune system, but it's not a lasting change and if used at all regularly the dog often will crash when the ivermectin is removed finally.

But this is one of the many reasons why I have a major problem with posting the doses of ivermectin.  It's too easy to abuse it and ANY dog can develop a problem with it -- not just herders.  Partly it's a breed thing, but partly it's just a 'reaction' thing.

The way ivermectin works (the way it *kills* parasites) is it crosses the semi-permeable brain membrane in the parasite and disrupts it's nervous system to such a degree that the parasite dies.

YES FOLKS *nervous system* -- this is what happens in dogs that have a 'bad reaction' to it (herders and other breeds) -- the drug does to the dog what it does to the parasites. What the above-poster has described is exactly what can happen when a dog has a bad reaction (typically herders but sometimes others).

It's not frequently a problem in small doses -- which is why HeartGuard has consistently made its dose smaller and smaller, but then there's a point where it won't even kill microfilaria reliably.  But like any medicine you have to be aware of what it is, what it does, what a bad reaction is and how it accomplishes what it does in the body.  *sigh*  And most people don't want to bother with that.

 Thi should help those who want to use the pour on. Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

ivermectin in dogs is not a simple answer - are you talking about controlling heartworm? Controlling ascaridal worms? Mites and lice? Mange?

The general dosage we use for heartworm control is to use the INJECTABLE (1%) given orally at one-tenth ml per 100 lb. One-TENTH. Some people will use one ml per 100 lb but that's waaaaaaay too high and will cause side effects in vulnerable dogs.

If you are using POUR-ON (.5%) for mites or mange, the dosage is one-tenth ml per kg, poured on the topline. So a 25-lb dog would get about one ml. This dosage should never be given to a sensitive breed and it, again, is way overkill for heartworm. It's for treating mites and generalized mange. This dose will also work pretty well on worms (intestinal) but it's kind of like hitting a nail with a bomb. You can control worms with much gentler medications and it's a good idea to do that if you can. Ivermectin is not a gentle medication and I'd always rather use a gut-only medication (pyrantel or fenbendazole) than something that's absorbed throughout the body.

Obviously, it's important not to mix up the two, since they are not the same strength.

If I can be preachy, it's not a good idea to overdose on ivermectin even if it doesn't kill the dog (or even hurt the dog in the short term). Ivermectin is linked with the later formation of autoimmune disease, and treating a dog with Cushings or polyarthritis makes treating worms look like a cakewalk. I would reserve the big doses of ivermectin ONLY for mites and bad mange, where the dog actually needs that strong a treatment and will be hurt more by the mange than by the ivermectin. I don't even treat the tiny puppy mange spots; they'll go away on their own just as fast as if you treat them.