[quote LadyWhistledownsQuill]Your dog sounds bored and undertrained. How did you expect puppy ownership to work? Like toddlers, they don't turn into nice, well mannered beings with no effort.
He chews all DS's toys, all of my underwear to shreds (he gets it out of the washing basket)
Put the toys and underwear out of his reach - preventing the behaviour is highly effective.
Has he got chew toys of his own? Dogs, particularly young ones, need to chew - and it's a naturally calming activity.
he terrorises the cat, (we have to now feed the cat on the kitchen table as he eats her food)
It's totally unrealistic to think that a dog will leave the cat's food alone. They're natural scavengers who cannot possibly be expected to tell the difference between their own food and something else's.
Putting the cat's food in a high location the cat can reach but the dog can't is entirely par for the course.
Is there anything else the dog is doing to terrorise the cat, or is it just eating cat's dinner? If there's any chasing behaviour, you need to give the cat lots of high escape points, and use baby gates the cat can walk through but the dog can't to give the cat some peace and quiet.
goes into the bins and rips everything up that's in then
Again, you need to manage access. Either keep the dog away from the bin, get a bin with a dog lock (SimplyHuman often include this feature) or put weights in the bottom of the bin to stop the dog tipping it over (if the dog needs to tip it to get in - this is the method I used with my small dog; he's now forgotten that bin raiding is a "thing").
he annoys DS and steals food from his plate
So, begging at the table with some theft too? Manage access during mealtimes, but you also need to teach some commands such as "leave it", and a settle. Invest in a Kong, fill it with food (wet food, smear of peanut butter, etc. etc.), and give it to your dog during dinnertime so he has something else to do.
he constantly jumps up on the back of the sofa to look out of the window and bark..
Close the curtains, or use window film, so he can't see out.
when DP is away I can't even go and stay with my parents for support as he hassles their elderly dog..
Find a dog home boarder. They have to be council licenced nowadays so there should be a list for your local area.
What training have you actually done with the dog?
How much exercise is the dog getting? Have you trained recall so he can go off lead? As the saying goes, a tired dog is a good dog...
You really need some sessions with a dog trainer - one that exclusively uses positive reinforcement methods. Avoid any that use the words alpha dog / dominance / pack leadership / balanced as it's a good sign of someone who is 20 years out of date and scientifically illiterate. APDT is a gold standard qualification for dog trainers (NB literally anyone can call themselves a dog trainer, so this is important) and they have a directory at apdt.co.uk/find-a-trainer/[/quote]
Agree with everything written here.
Would also add, the cocker in him needs mental exercise and sleep - lack of both is when they get naughty and destructive. Too much physical exercise will just make him wired, fitter and needing more.
Mental exercise should also be easier for you to do now, late pregnancy and with a newborn than lots of walking. Join some canine enrichment facebook groups, and Google games for dogs.
Good luck:-)