mite spray affects mice badly

Question
QUESTION: Hi Natasha,
My vet prescribed mite spray for my 2 mice, which I sprayed them with a little over a week ago. They seemed off balance with some neurological issues, twitching etc for a few days so my vet said to wait a bit longer to give the second dose and also reduce the dosage. My question is, do you think spraying them each just once on their hind quarters will be effective? I'm so afraid to give them too much like last time or not enough...Please advise.
Thanks so much!

ANSWER: Dear Tracy,

First I always have to remind you that I am not a vet and have no medical training. I have experience, and access to advice from others who know more than I do.

Mite sprays work in radically different ways, and I don't know which one your vet gave you. I have had mice react to pyrethrins badly but it was skin pain and temporary. However, I had a cat almost die after a flea dip (no idea what chemical), so I'm not that surprised that there can be a worse reaction. It scares me, though.

If the spray works by killing the mites directly, like pyrethrins, the second spraying is to kill the mites which were in eggs at the first spraying, so if you wait much longer than ten days these mites will have laid eggs and the problem will happen again. In this case, spraying on the hind quarters will likely not solve the problem, because mites like the areas near the neck.

On the other hand, if the spray works by entering the bloodstream and killing whatever bites the mouse, like the product Revolution, it might not be an issue. Revolution usually only has to be used once. The vert might have given you ivermectin, which I have personally never used but it is common. This is often applied several times.

If it were me I would gently ask the vet if I could try Revolution, since it is just one simple drop rubbed into the back of the neck. I have no idea if mice ever have reactions to it, but it does seem less dangerous. In any case, ask your vet, and trust them more than you trust me.

best of luck and health to your little girls.

squeaks,

Natasha

---------- FOLLOW-UP ----------

QUESTION: It is ivermectin 1:10 (mixed with water). I sprayed them last night. About 2.5 sprays each. They don't seem to have the side effects to the extent that they did the first time, but I hope the dose was enough to be effective. It's sad because the one mouse has bloody ears from scratching :( I just want the mites gone! I started freezing their bedding, so hopefully that will prevent any reoccurrences. I still have to treat them a few more times; maybe I will check on the Revolution oil. They are such sweet little mice.

Answer
Dear Tracy,

Thanks for the update. Let me know what happens with the 10:1. I assume you started with 5:1? And let me know if the situation improves.

If the 5:1 doesn't hurt them, I would repeat it in another 10 days to  make sure. Otherwise not.

Of course the Revolution is better.

Good health to the mice.

squeaks,

Natasha