We're scratching our heads, too!

I recently adopted a Alsatian x Collie, three years old.
She's a very good girl although very nervous of strangers, the only problem we have is that on occasions she will shake her head violently and scratch her ears.
We have used ear drops for mites etc and this helps, we do for the amount of days instructed, then we have a clear spell, then it starts over again.
There are no visible signs of mites. Sometimes she will also rub down the side of her nose. We have put her on hypoallergenic dog food and treats to see if that makes a difference.
Any help appreciated.
Many thanks
Denise Nicol

The commonest reasons for a dog scratching at her ears are indeed ear mites and food hypersensitivity. Has a veterinary surgeon actually looked down your dog’s ears with an auroscope? Ear mites themselves are white, and move around when the warmth from the auroscope’s light falls on them – quite spectacular! You would not necessarily see them with the naked eye by simply looking into the outer ear.
The presence of ear mites can predispose to an infection, classically characterised by the presence of brown wax but, again, this may be deep down in the horizontal part of the outer ear canal. Your veterinary surgeon will be able to prescribe ear drops which not only kill the ear mites but also have action against a secondary infection and alleviate the itchiness.
The fact that it settles with the ear drops you are using and then re-starts could indicate the hatching out of ear mite eggs once treatment with the drops has stopped. If I see ear mites in a dog’s ears, I generally recommend a specific ear drop for a week, a week’s break and then another week’s treatment. There is also a spot-on which is effective against ear mites, applied to the back of the neck as usual.
If ear mites are effectively ruled out but the itchy ears continue then a food trial is indeed worth trying, given your dog’s young age. The theory behind hypoallergenic food is to be feeding a protein which your dog is unlikely to have eaten before, or in which the protein present will not trigger a reaction. Do ensure that your dog is only eating truly hypoallergenic food, including treats. I must admit, I tend to advise using the hypoallergenic diet as a source of treats as well so that just the one food type is being fed. It does mean ensuring she does not eat or scavenge whilst away from home, visiting family and friends and out on walks. Can be difficult!
If your dog continues rubbing at her ears, then I would seek help from a veterinary surgeon. There is nothing quite like painful ears …
Alison Logan, Vet