I have 4 adult male dogs and a very large kitchen with a doggy flap. My dogs can hold their pee which has been proved when we go away and sleep in the caravan but when I go to work, go to bed or even just nip out I come back to puddles of pee. They can get to the garden all day and night but they still insist on peeing inside and destroying my kitchen. It is becoming exhausting and making me resent my beloved pooches. What can I do or use to stop this happening? I refuse to crate them as I have the doggy flap. I would appreciate any help what so ever
Two possibilities: either they get anxious when they are left in the kitchen for some reason, and react by peeing, or they just don't understand that peeing in the kitchen is something they are not supposed to do. If you have four of them all loose together, it's going to make it hard because if just one gets confused and starts marking, then it will encourage the other three to do the same.
Personally, I would use (large, comfortable, well padded) individual crates for each dog short term while you are re-training this behaviour. That way you can at least work out which dog is doing it, and where you need to focus your attention on retraining. You can then eliminate the crates as you establish which dog(s) need more help, so you don't have to have your kitchen stuffed with huge boxes forever. It may well be that one or two of them are not part of the problem at all, so if you can borrow crates even for just a couple of weeks, that might be long enough to give you a clearer idea of where the problem lies.
Scrub the whole area with a cleaning agent designed to eliminate dog odours. Simple Solution is widely recommended, although there are a number of products that will do the job. You will need to check that no urine has seeped into the floor or under kitchen units: their noses are very sensitive and if they can still smell it, then they will be stimulated to urinate in that area again.
I would also suggest that you video their behaviour while you are not there, so you can see if any individual is just peeing in an absent minded kind of way, or if they are pacing, howling, barking or appear otherwise stressed. Sometimes, you'll find that dogs can hear sounds, pick up scents, see animals passing or pick up vibrations in one room that they can't detect elsewhere, and that makes them more anxious in that location and more likely to urinate inappropriately.