The vet can determine age by teeth ect.. and breed is never 100% that's why it will say for example German Shepard mix , the German Shepard will be obvious but the mix would be unknown.
I agree with Karen, and I will add my thoughts. The Humane Society can estimate age, but they can be wrong. For a dog under six months old, it's easy to tell. Around a year old, they can be off by two months. If the dog is older than a year, they can be off by a year in their estimates. After a dog reaches two years old, it takes a well trained vet to estimate age, and they can be off by 6 months to a year. Breed estimates are even harder. One breed HS doesn't like to name is a pit bull because of bad press and reputation. Usually the HS will say a dog is a Lab mix because Labs look something like Pit Bull Terriers.
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