Thought I would give you the story of one of my daughters dogs, Tadge,
she is a Boarder Collie age 13 yrs, loves her Agility, in 2002 she came second at the Finals at Olympia, by 300th of a second, she qualified the following year but did not make the final 8,
The end of June this year it was found she had a growth near her bladder, they could not operate and the vet said it was only a matter of time, he said anything from 3 days to 3 weeks before she would not be able to pee and then a decision would have to be made, well that was over 4 months ago, and she is still with us, still doing her agility,
we know when the time comes it will be hard, she does have trouble sometimes now, but if you could see her going over the jumps and also playing with her toys, you would think she is just a 'old' dog enjoying herself.
