When do puppies have their first season?

She will come in some time after 6 months. I'd suggest that in her case, getting her spayed before her first season would be a good idea much as some vets do suggest allowing one season first. This is more normal in the bigger breeds to avoid bone growth issues however, but you do need to speak to your vet about the timing of this. If you do wait and allow one season, on his advice, you absolutely must be able to account for every single minute of where she is, throughout her entire season - 21 days. No letting her outside in the garden on her own. Preferably taking her off for exercise in your car to somewhere quiet (if you have to exercise off your property at all), keeping her on her lead all the time. She will, when she's ready to mate, be as keen to escape and find a mate, as any stray male will be to find her.

If she were mine, I'd not wait but get her spayed by the time she's over 5 months.

That used to be true many years ago, but now they say (the vets here in France anyway) that they prefer to spay before the first season, so that is what I tell my new owners of female puppies. Unless of course your vet in the UK has told you otherwise - what did your breeder advise?

As for a cockerpoo I would hazard a guess (because it's a mixed breed) you take an average of 6 months. It's hard to tell with any breed of dog when they will come into season. My last litter of pups 1 came into season at 6 months the rest were 7 to 8 months.........unless your talking about a giant breed (which your not) they are nearly always approaching 1 year +.

They can come into season for the first time at around 6 months . Who has told you to let her have a first seaon before spaying her. I would talk to your vet about this. Usually most are spayed before their first season but if the dog is very hyper some vets will advice letting them have a season as it can help mature them a bit.

She is a mix of small breeds so it's fine to spay her before her first season. I'd have it done at about 6 months.

Your mixed breed dog can have a season anytime after 6 months