My chook is losing her toes!

[LastStrawCottage]

Hi guys, one of my chooks is losing her toes.
We caught her last week and smothered in vaseline as google search suggests mites. Caught her again tonight and the previous injury has healed (toe gone) but another toe is hanging off and bleeding. Have smothered her legs and feet again in vaseline.
Just to say we clean hen house every week and liberally dust in mite powder (Smite). The other chooks all seem fine. See have had scaly legs in the past but I thought we had cured them as the problem seems to have disappeared.
We are in mid winter here (NZ) and so wonder if the mites die off in winter??
Anything else I can do for this poor chook who is in pain? She is still eating but sits around in the chook yard most of the day as the leg is clearing painful.
I read that Ivermectin might be a good choice and plan to go out tomorrow to buy some and will get my (long suffering!) partner to pop 2 or 3 drops onto each chook whilst they roost tomorrow. Luckily we are not in laying season....how long should eggs be withdrawn if using Ivermectin?
Any advice would be greatly appreciated.
Thank you all heaps!

 

[Bertram]

Sounds like it might be frostbite. How cold is it getting at night? Are her toes turning black? Vasaline is good for frostbite but I would bring her inside to warm up.
I have never heard of Ivermectin for toes falling off, but if it is just Ivermectin with nothing else added you should be fine eating the eggs.