I believe my dogs prey drive for birds exceeds all else. I do not believe it would be an issue but you never know. His ears perk up and he basically points at them staring them down but he doesn't chase deer...to date. I just don't pay it any credence if he is posturing at some deer and tell him to come along...he drops his ears and follows. He has always chased squirrels and tries to catch them...always has. If he is "on" a bird I'm not too sure anything could get him off of it save my telling him to do so and even then I don't think he would oblige all that willingly. I've seen groundhogs in the field but have taken notice to them before pup has...I just changed our direction before he took notice to avoid any issue as pup was young and I just can't cover ground that fast if a fight ensued. I'm sure pup has been faced with critters at some point out of sight in the field however I don't know of it. He finds turtles all the time..he hates turtles and I am confident we will never suffer a turtle attack thanks to him. He has found snakes...and I did my best to snake break him which seemed VERY effective however it was only a black snake...hopefully this will transcend to CopperHeads and all other snakes if he encounters one, and hopefully his memory serves him well.
I will say this so far as the whole squirrel thing goes. There was a period during the extreme heat when pup didn't see a field for awhile...during this time we did a little "squirrel management". Took him out to a training field and at the onset he was hugging my shoes...took me a minute to figure out what was going on and told him it was ok...hunt 'em up...he bolted and began his normal search. Since then we've done a little squirrel stuff and I've also been taking him out to the training areas. In typical form he heels to the field and does his best as he has a difficult time containing himself but he does rather well really. Whoa'd at the fields edge and then given the ok, he promptly goes from zero to top speed in about a nano-second and starts looking for birds as usual showing no sign of confusion after that first time. I don't think there's any reason to stop when we "manage" the population however I don't think I'll start taking him squirrel hunting per my brothers request who is the squirrel eater...I won't eat one
And Neil...I'm with you..the squirrels have never bothered me a bit and I also enjoy having them around. The population has exploded the last few years and I've tried everything to secure things etc. I looked into the habit/nature of squirrels and what i learned is that if an area is over-run w/ them they will stay there so long as there is food even if additional good habitat is near, and it is in my case. Once the food source has depleted they will move on leaving a typical population behind. We have had bumper crops of acorns the last several years and there is no sign of letting up nor is there any sign of the population moving on but worse than that they are multiplying fast...I've not wanted to kill them for the sake of killing them and I'm just not into tossing a critter into the woods to rot either so I got my brother on board to take them..he will eat anything

That's how my attitude evolved after nearly burning my shop down. They got into my bird cage and killed five pigeons along with four babies, now my attitude has changed yet again...until further notice...squirrels beware...the buzzards need to eat too.