Gazza
Going on the dogs ability of which by the standards it has acheived , which you also recognise and its age , plus also given the fact it's a Weimaraner
Nothing against the breed , just they were bred with hunting in mind and I can't imagine for one moment this instinct has been trained out of it unlike some of our other breeds of dog that hav been bred for a specific purpose in mind.
Plus I would say this dog has a bit more brain than you are really giving it credit ( not a dig, but some times you really can teach an old dog new tricks)
And given that all tracking is just scent association, to this dog a different scent is just that
If it was a 3 year old then I would feel it would not cope aswell or even cope at all with the change at all untill it had matured , as I feel this dog has matured
It has already taken and passed the BMH apptitude test
not that is anything special, but it is still a test of a certain standard related to deer,
so by passing this , it does show already it has distinguished the difference in scents and possibly might of tracked the blood instead of the person laying it, that is a good sign I would suggest
Also given the fact it has already been used to track blood does help if deer blood was used
Obviously in my eyes you are not really going to put a dog of this standard straight into the deep end with out doing a bit of extra training in the direction you are hoping to go,
I may be wrong , but as I don't actually know the dog or handler so I can't really say if they are or possibly they may feel the dog is more than capable which is fair enough, as if you don't try then you will never know
I still think it would cope with an easy find of which the handler could also visibly see and be able to watch how the dog is working,
Which is why I Also suggested visiting a deer park , so you can see what reactions the dog has and possibly gauge it's potential even at the age of 10 of possibly tracking deer to a high standard or even to a standard you feel is exceptable
Also as deer scent and blood is a lot greater than human scent and this will be a main factor to the dog, as I would possibly think it's noise now must be looking to start to degrade shortly if it has not already started,
and if it is adapting to the change from my experience of shooting deer and finding runners, it is always better to start to look for the deer with a dog at the point where the person who has shot it stopped looking , following the blood trail or last place it was seen dissapearing out of sight
that way the only scent on the ground is usually that of the deer and not the hunter..