happygardening I think you must be arguing for the sake of it now. Can you only see things in black and white? No, nothing is guaranteed, but there is such a thing as risk assessment.
I will repeat myself yet again. There are of course some unavoidable situations where rehoming a dog becomes necessary. But I can assure you that the majority are either unnecessary or predictable. A lot of the time it comes down to attitude. Some people are prepared to do anything to keep their dog - get up at the crack of dawn to walk it, do without luxuries to afford a sitter, take jobs that are well below their earning potential etc. Then there are others that can't be bothered and bail at the first sign of difficulty. They see dogs as disposable commodities. There is often a way around the problem, but they don't even want to try. I think maybe you just don't understand the situation - perhaps you are assuming everyone that rehomes a dog is in some kind of dire situation, but that's just not the case.
My comment about careers is valid. As I have progressed in mine, my security has increased. I don't mean in my current job, but in terms of my general employability should I be made redundant etc. I would be able to pick and choose a job that would accommodate my dog, in a way I may not have been able to in my twenties. Furthermore, I have very deliberately chosen to go into a field where, even if I didn't do a lot of work flexibly from home now, I know I would be able to take my dog to work with me should the need arise. This, even though it means I earn considerably less than if I had taken a different route. I realise the above steps may sound extreme to some, but it illustrates my point that a bit of contingency planning can often negate some of the more common reasons for rehoming.
Having to 'choose between a child and a dog' is thankfully rarely a necessary dilemma (genuine behavioural concerns aside). The OP in this thread isn't choosing between her dog and her child. She's choosing between her dog and a slightly easier life for the immediate future. The child, presumably, will be well cared for regardless. And may well benefit from the presence of the dogs as she grows.
I am not responsible for gumtree dogs, thanks for that lovely assumption. The main motivation for listing on gumtree tends to be financial, when an owner is trying to recoup some of the costs of their expensive puppy-farmed pedigree. I rarely deal with owners at that point anyway, but I know those that do try to be polite and professional at all times (whatever they might be thinking underneath).
As I say, my agenda is not for all dogs to be kept on regardless of circumstances. I would just like to see people giving their suitability as a dog owner careful consideration before they buy - thinking not just about the immediate future, but looking at the whole anticipated lifespan of the dog. For example, a 25 year old woman has a pretty decent chance of having a baby within the next 15 years, even if she is currently single and motherhood isn't on the radar. Perhaps she will start a relationship with someone who doesn't like dogs. Would she drop the dog for the new man? I would think it rather shortsighted of her to not at least give some consideration to these posibilities before buying a puppy. If someone feels they cannot commit to that kind of timeframe, perhaps they could consider rehoming an older dog. Or just, you know, give dog ownership a miss. It is a privilege, not a right, afterall.