Canine alopecia is a condition that affects the hair. It is basically the complete or partial lack of hair in an area of the dogs body where there would usually be hair.
It can be caused by excessive scratching, chewing or rubbing against objects. A common example of rubbing against an object can be when your dog might rub its back against the underside of a bed frame or table, and repeat this several times.
It can also be a result of hair diseases that cause the hair to fall out or the complete lack of hair growth in an area that had previously suffered hair loss.
If your dog is suffering from hair loss and is constantly scratching or is generally depressed about its situation then you should contact your veterinarian immediately as he could be suffering from alopecia in dogs.
You will be asked a number of questions from how long your dog has had the condition, to, whether or not you used any medication.
Do not leave any information out as it could be very helpful to the vet and could benefit your dog immensely.
Remember if your yorkie seems to be very ill, in a lot of pain or there is an emergency situation please do not use an online vet service, take him in to see a vet straight away!