We welcomed a new puppy aged 3 months into our family two days ago and he is settling in beautifully--a little charmer with bags of confidence. We have two older boys (24 months and 18 months) who weren't immediately thrilled with him, though they have both been quite friendly (just drawing the line at sleeping together though and pointedly seeking private quarters). The new lad has taken to paper training right away, no doubt due to the care and attention of his breeder. However, although our two older lads have been clean in the house for well over a year, in the last day we've had one boy cocking his leg on the furniture and the other deciding to save himself a trip out in fairly mouldy weather by having a quiet poo on the paper this evening. I guess this is fairly normal behaviour under the circumstances, but is there something I can do to help everyone remember their manners? I know I have 'brought it on myself' by having three dogs aged two and under and am prepared for any extra work.

get rid of the paper.

all that does is extend your toilet training, as you have to train them twice.

first to go on the paper, and the second time to go outside.

by using paper, you can inadvertently teach your dog that going to toilet indoors is ok, as appears to be happening with your older boy.

you may have been lucky before, but i know of many pup owners who went the paper route, and then discovered their dog would still go toilet in the same spot where the paper used to be, as they had taught them to do so.

cut out the middle stage and simply take the pup out at least once each every hour (you might need to do so overnight at first as well) and after each meal, each nap, and each excitement

this way, you arent re-teaching you other dogs to go to toilet indoors.

i wolud crate train the pup overnight as well.

re the leg cocker, my guess is the male is marking his territory due to new pup.
you need to have him on an indoor line, and as soon as you see he is about cock his leg, interrupt him verbally and take him outside

i think it's a good thing that that tall the dogs seek out their own private space.

It is hard work,but worth it :)  I have 2 youngsters in the house,a 5 month and 11 week old girl and boy.Not ideal but an unfortunate set of circumstances lead to this.(wouldn't change it for the world though)The older puppies toilet training was going well - no issues.But as soon as the baby came into our home and used newspaper the older girl thought - this is fine i will do the same.So out with the paper - as far as the garden area reserved for toileting.Put the paper out there with alittle soiled paper.After a little sniffing she will happily go out side.I take her out frequently - after meals/sleep/playtime etc but it has only taken days to acheive this.Though they both now prefer to do their toileting beside my car door!!!!not idea at 5am when I have to drive to work and the O.H  has taken them out during the night and not picked up after them.Good luck.

Agreed, never use newspaper or training pads in the house, teach pup from day 1 to go outside.  After pup has slept, after pup has eaten, after a long play session and approx every 45 mins-1hr.  Lavish praise for weeing and pooping outside, ignore any accidental weeing and pooping inside (i know easier said than done).  No fuss if mistakes happen is the golden rule, just mop it up and mark it down to experience and walk pup out.  Don't carry pup but encourage him to walk outside, otherwise he will never learn, he'll just get used to waiting for you to carry him outside and if you don't, well he'll just wee/poo in house. All newspaper and training pads do is teach a dog they can wee indoors.  Good luck with the training. 

i totally agree with the other replies and would get rid of the paper straight away.
this is new for your other dogs so i would expect that they will do a few things that isn't the nor for them ie scent marking and the odd toilet in the house.
as said before take the pup out constantly during the day and having two other dogs to learn off the toileting should be easy for your new boy as he will copy your others.
if your concerned at mess in the house then keep the dogs in the same room as you for a while so you can catch them quickly if they decide to mess. i'm sure your other dogs will soon settle down when their used to the new arrival but you must keep on top of things.
i don't use crates and don't like them much but that is personal choice. best to keep the pup confined to a smaller space though when lfet or at night and they seem to feel more secure and it's easier to clean up after them. also cleaning properly so there's no smell left other wise they will just repeat messing in the same place.
make sure you give all your dogs time away from each other, so the pup doesn't get too much for them.it will take a little time for you pup to learn not to jump on them and give them space.
i found making sure the older dogs are well exercised helped as there was no built up frustration around the new arrival and everyone stays a lot calmer.
you will also need to spend time and walk them at different times so they get enough attention off you but also because you need to build up a relationship with the pup.
you want the pup to listen to you for commands so it's good to have one to one time else when their out walking he will look to them for how to react,not always a bad thing but it helps if he sees you as in charge not them.
good luck with your new boy, you really have got your hands full. i've got three dogs but the age gaps are a lot bigger so things have been a little less hard for me,although it's still a lot of hard work sometimes.      

regression of older immature dogs is very common when a new pup comes along, another reason why so many of us advise a decent age gap of two to three years between dogs.

I myself have my smallest age gap ever of 19 months and found the older youngster going backward, though she herself went on to have a litter 6 months later which helped her grow up as she was occupied with motherhood, but once the pups went I had two hooligans.

Thank you everybody for excellent advice--the paper has been banished. the puppy has the use of the backyard and allotment until he has completed his vaccinations, and the two older lads get time off puppy...more work, but I earned it!

Are your older boys still entire or have they been castrated? Have they stopped cocking their leg now pup has been there a little while, good luck hope things settle down soon.

they are all entire and will remain so...and while they have never cocked their legs again, it's the new pup that's discovered this behaviour now! No doubt we will get through this in time :-)