would you try to rewire your house or replace your plumbing?? even if you would, those are fixed inanimate objects that you can follow directions ...
The pup needs training, he is not "stubborn" - he merely is following his instincts....you need hands on experience to get control.....and seriously, some dogs just have so much prey they cannot help themselves...that is where training comes in, the dog learns to be obedient even when in drive.
I got a dog back that was too interested in the family cats -which were terrified of him....(among many other reasons!!!) My Bengal kitten thinks she is one of the dogs and marched up to him and nuzzled him...he never chased her...he was so happy and amazed that the cat was friendly...
At the very least, the dog should always have a long tab (leash with no handle to tangle in his feet) so you can get hold of him and say 'leave it' - of course, without training, the leave it command means nothing
Csabre Sch1, Hexe Sch2, SG Bengal, Lynx, Komet, Kira HGH & Kougar v Wolfstraum ~ Ziberia IPO1 ~ ATB Basha, Kougar & Kyra, Fenja, Sch3s, Cito, Sch2, Danger RH & Alice Sch1s ~Kelsey