It is a sad fact of life that as the fox gets older it doesn't go off to some happy little leafy glade in the forest that is a hospice for the elderly where it is cared for by unselfish and dedicated members of the pack.
The truth is a little more stark. As a fox deteriorates, due to age or health, it ceases to be able to hunt for itself and eventually becomes weak and vulnerable, prey to predators in the form of younger and healthier animals to the point that, if it can hide, it will starve to death but if unable to hide it will be attacked, chased and eventually ripped to death by these predators, the natural balance of nature.
The foxes that the hounds find are usually in the not so fit category and hounds are well aware of the damage a cornered prey can cause, they will not mess with it but leap in for a very quick kill, usually by throwing the animal into the air and breaking it's neck, only after it is dead will they rip it to pieces.
Countrywide we would all be a lot better off if the know-it-all townies would leave the countryside to look after itself.