Canaries molt (change plumage) once a year - usually during the summer. A molt should take no longer than 6 to 8 weeks.
Fruit and vegetables are essential parts of the diet, and should comprise about ¼ of the diet. Wash all items well to remove chemical residues and cut them into manageable sized pieces. You may need to offer a wide variety to encourage a bird to eat them if he has not had them before. Even if your bird refuses something one day, try it again later. Spinach and dark-leaved vegetables are much more nutritious than light-leaved ones, like lettuce. Avocado is reportedly toxic to canaries.
Scrambled, hard boiled, and crushed eggs are good. ANd so are boiled crushed up egg shells, very good source for calcium, but make sure you cook it first!
Besides a pelleted or a seed mix diet, each day offer chopped dark green and yellow vegetables, and a small amount of fresh fruits. Millet seed sprays are relished by canaries. Protein supplements can include mature legumes, chopped hard cooked egg, or tofu. Remove fresh fruits and vegetables within 4 hours of offering to prevent spoilage. If the bird gets too much liquid from the fresh fruits and vegetables, the droppings could become runny and discolored. Stop the fresh fruits and vegetables for a day if this occurs to determine if this is the reason.
As soon as he is used to his new home, he should start singing. The males have very beautiful singing voices, most people who have any breed of canary say that the singing makes their day! My American canaries love to sing, I wish females did, though.
The canaries could have a heart attack. I suggest to keep the dog away from the canary and its cage, and make sure you don't startle it too fast. I've had a few finches and canaries died that way, my nieces and nephews didn't know how to be careful, and they had a heart attack.