how to administer Ivermectin:
https://thesquirrelboard.com/forums/...Wild-Squirrels
When you say to leave it for a "younger squirrel" to eat, do you mean to leave it for babies to eat? - unclear. If you intend for babies to eat, then it is not a good idea. The Ivermectin dose ppl use to treat mange in the wild is calculated for adult squirrels. Because it is very easy to overdose, even minimal changes in the dose are crucial - likewise, the fairly significant changes in the squirrel size (as in adults vs. babies) may also prove detrimental b/c the dose will be too big for a small baby.
This dose is intended for fully grown adult squirrels only.
Mothers often have scruffy look when they are raising babies (even remember reading that they would even pull their own fur to line the nest for the babies). So, this may not even be mange.
Also, when you say patches of fur missing - does it look like it was pulled in different places? - because it sounds more like mothers pulling their fur for nests, and/or molt.
The most common pattern for mange - starts around eyes, and/or can start on the scruff and spread around arms - it will look kind of like a vest (i.e., if a squirrel wore a vest). And the fur loss is usually uniform, i.e., not patchy as if pulled, but spreading gradually over large areas.
From that "vest" it spreads further around and down the body.
Of course, there may be other less common patterns of mange spreading, but still - it may be a good idea to get a better look at her fur loss before giving ivermectin.
Another thing to note - if those missing patches of fur remain more or less consistent (not getting gradually visibly worse) - that may be an indication that it is not mange. Mange is usually progressive, whereas "baby-feeding-related" fur loss and/or molt aren't.
If possible (if it is, indeed, mange), wait for a week or so (for however long it is possible without letting her mange go too far) before giving ivermectin - for the babies to get bigger and stronger, so that if they end up ingesting some through her milk, it won't do them harm.
Personally, I have no info on how safe it is for nursing mothers, just trying to use common sense. If anyone has had experience with giving Ivermectin to nursing mothers, i'm sure they will share.
You could also post pics of her with fur missing, and experienced people here may be able to estimate whether it is mange or molt.