Bechorot 15 - If a Consecrated Animal Became Blemished
If an animal was consecrated, but afterwards developed a blemish and was redeemed, it never completely goes back to its previous state: it is exempt from the laws of firstborn, and one does not have to give gifts from it to a kohen , that is, foreleg, jaws, and abomasum. Why is this? The Torah said about a redeemed sacrifice, "You can eat it, like a deer or an ibex." The extra word "deer" teaches us that it is not subject to the laws of firstborn, just as a deer is not subject to them, and the extra word "ibex" - that the kohen's gifts need not be given - just as they need not be given from an ibex.
The redeemed animal cannot be shorn or put to work, and its milk is prohibited. Why? The Torah said, "you may slaughter it" - but not shear it or work with it, "for its meat" - but not drink its milk. Finally, "and you will eat" teaches that you may not give it to your dogs. In general, an animal that's once been a consecrated may not be redeemed with the purpose of feeding it to the dogs.
Art: Winslow Homer - Dogs In A Boat