I would use a behaviourist as these are both problems that can easily escalate and result in legal situations. If you use an APBC certified behaviourist, they have had the most rigorous practical and academic training. They have a website with a list of members and where they are.
My dog loves chasing birds! She would run after them all day if she could. We taught her the leave it command using toys etc at first and treating when she dropped it or left it. When walking on lead, I would watch her near birds and as soon as she looked like she was ready to run after them, I told her leave it. ( technically she couldn't anyway as she was on lead) this really helped her.
I am at the end of my tether with my dogs, and need to get some professional help. At home they are lovely - quiet, well mannered, go to bed when told, don't climb on furniture or counter-surf or raid bins etc. But out on walks they are an unpredictable nightmare.
If we see a cat or a squirrel they go nuts and nearly pull me over - have to use Haltis on both of them. 99% per cent of the time they walk nicely beside me and don't pull, but the reaction to small chaseable creatures is so extreme that I daren't let my kids or my mother walk them. So I feel very trapped by them and starting to get resentful.
And one of them has a tendency to run off on walks and only come back when she damn well likes. Which was fine up till recently, I only let her off if I had plenty of time to wait for her to finish sniffing every nice smell in the woods. But since a short stay at a dog minders in November, she has also become rather snappy towards other dogs. If she sees another dog approaching she does that horrid head down staring stance, sometimes squatting right down, and as the dog gets near she rushes at them. If the other dog is happy and not intimidated, then all is good and she'll play happily with them. If the other dog doesn't like being rushed at though, and growls or snaps back, then she growls more and all the hackles come up and the other one then rushes in to join the bunfight. I now don't let her off the lead at all because I can't trust her not to start a scrap. And yet mostly dogs are less aggressive off the lead, aren't they?
So basically, do I need a dog behaviourist to deal with the chasing/agression, or do I need a trainer to work with both dogs so that they return to me instantly when called. Is that ever likely? How can you stop a dog from chasing things?
Would love any advice and/or recommendations. I'm in the Reading/Caversham/Henley area.