My 9 yr old patt bitch had one pup the other month and killed it, second time in pup, last time I will bred a dog at that age, my Lurcher bitch was same age when she had her first litter, cost me almost 2 grand for a c-section and keeping pups alive only to die at 3 weeks old, ended up with 2 pups from 12 and my bitch being spade, your dog your choice, but if it was me I'd be cautious. Both my bitches were fit and healthy before hand.my lurcher bitch never had a season till she was gone 8,thats how hard she's been run since I've had her, she was at her peak so to speak same as the terrier bit