Age concern

My Golden Retriever is now 10 and is a lot slower than she once was. Is it worth me switching her to a senior diet? What I want to know is what differences there are between adult food and senior food, and if the dog’s body changes to the point where a change in diet if necessary.

If you could provide me with some information I would be very grateful.

Mrs P. Austin, by email

Growing old gracefully

I have a Border Collie bitch who is nearly 10 years old, and I have recently noticed that her tail has lost some of its bushiness, especially around the base. Is this normal as a dog ages?
She is fed a raw chicken wing every morning and a scoop of Burns every evening, sometimes with added meat and veg. Should I supplement her diet in any way to help her cope with the ageing process?
She is spayed and weighs 15kg so is quite a small collie. She has so far shown no signs of athritis and is happy and active.
Mrs V Garrad, by email