Aggressive when off lead

[arthurx1234]

My 6 year old male (neutered) has over the past few weeks become very aggressive when he is off the lead, he rarely bothers with other dogs and does not go to greet other dogs however when dogs come to him and they both start sniffing each other after about 5 secs he attacks them, it used to be quite a high pitched bark ( i assume he feels threatened) but now its more low pitched.
His last attack was on a 10 month old lab bitch (bitches he is usually OK with) he had gone for her 3 times before i could grab him, he had the lab on her back and she was squealing---no harm done thank god.
I felt so bad afterwards i went back to the couple to apologise properly, this attack shook me, so much so i considered having him destroyed
So today i will be buying a muzzle and putting it on him when i intend letting him off lead, and looking for some local socialisation classes and see if this will improve things
If anyone has any other advise i would be grateful.

just a bit more background he was attacked twice in the same week about 2 years ago when he was on his lead, this made him more aggressive when he was on his lead but his temperament off the lead remained the same till now

thanks
arthur

[Maria]

I'd suggest a check over with the vet if you haven't already done it. If you get a clean bill of health then maybe find a good behaviourist to help you.

Boysie started to get grumpy with other dogs (though he didn't attack them), and he turned out to be hypothyroid.

Good luck

[PennyB]

Boysie started to get grumpy with other dogs (though he didn't attack them), and he turned out to be hypothyroid.

Plus I know of a spaniel that was low normal for hypothyroid and vet decided to treat him with very good results

[minimoo]

please dont think of having him destroyed, dogs dont think like us and we dont always understand reasons behind their actions, there is often a very good reason why a dog will change temperement, and f one vet isnt very helpful find another who is, you will also get very good advice and help on this site

[Rufus MacD]

Try reading Control Unleashed by Leslie McDevitt. She talks a lot of sense and there are lots of reward based exercises you and your dog can work on to deal with this kind of behaviour. Don't be put off by the fact that the book appears to be for agility classes, it has very good programmes for dealing with aggression. TT touch massage could help as well. Very calming and confidence building for your dog. there are books available a nd often workshops to take yr dog along to be taught properly. Could be worth trying. Don't despair, i have a dog aggressive dog too. (a Welsh Springer) I know how awful it is.