Scaly mites, or regular canary scales

[Luvbirdlover]

I have 3 canaries that live together in an aviary. Two (red-orange birds in photos) of them are maybe a year old, or young and I’m not sure if they have symptoms of scaly mites or just regular feet. One (yellow bird in photos) has quite bad scales, he is 4-5 years old. I have read that scales like this are regular in older canaries but the scales look a lot like scaly mites too.. Their feet have been like this for a long time and haven’t gotten better or worse.
I went to the vets a couple months ago and they didn’t think it was nessecary to see the birds only my description. They gave me ivermectin solution to drop on their skin which I did, I treated all birds in the aviary. It confuses me that they said only once, but I only applied it once as they said to. There was no visible difference. I have heard you have to apply the treatment twice to get both the newly hatched and adult mites.
They have a variety of rope, bamboo, different textures angles and sizes of natural wood to perch on. They always have fresh water changed twice daily which they regularly bath in. I clean their aviary twice a day. They get a lot of flying time both inside and outside the aviary. They get artificial and natural light and have a natural sun rise and sun set. They are indoors. They are fed in the morning with Roudybush crumbles and a variety of fresh fruit and vegetables, and at night with a finch seed mix and sometimes more veg.

 

[HeatherG]

Those feet don’t look bad to me. I think your birds just have old bird feet.

 

[Terry57]

It does look like it could be scaly mites to me. I always repeated the treatment when my finches had that issue, it's been a long time but I believe I treated 3 times over a 10 day period.. That always did the trick.
That's odd that your vet didn't want to actually see your birds.