Bitch pup weeing a lot

Pippa has today started weeing a lot more, as in, more often. Just when walking, she'll stop more regularly to wee except really quickly and with hardly any wee left. Is this scent marking, and does it mean she's coming into season? She's only 4 1/2 months but a toy breed.

Hi Jackie, I'm not sure about the 'coming in to season' bit but it does seem a little early for her first season even for a toy breed but I have just read on-line that toy breeds can come into season as early as 4 months! If she is, you will notice her vulva becoming swollen and her behaviour will change a little due to the surge of hormones.
My last little dog (Lhasa Apso bitch) did wee a lot when out walking as though she was 'marking' but I'm not sure if that is what she was actually doing.

Is there a chance that she has a UTI (urinary tract infection) because that could possibly also account for her 'strange' behaviour the other week as well?

I was always under the belief (until I had my Lhasa) that girl dogs would have a couple of long wees while out walking and that is was only boy dogs that did loads of wees. I think I must have got that wrong as my last dog proved it!

She's also tonight started humping her bed...

I would definitely say it's a hormonal thing in which case and humping is not unusual prior to a dog coming in season

Eek! That might also explain the sudden grumpy temperament for the last couple of weeks?

Sounds like it. Don't worry - the first season is usually the worst! Hormones all over the place. Give her evening primrose oil to balance her hormones and lift her mood.

In what form / how much should I give that?

I would urge you to get a urine sample & your puppy to the vet ASAP. All the symptoms including the grumpiness point to cystitis which is common in bitch puppies as they squat so close to the ground & thus germs on the ground can travel up thru the uretha & cause infection. As they grow older & bigger most but not all, dont squat so close to the ground & also build up a better resistance. Wee puppy must be very uncomfortable - squatting, doing a few drips or trying to frequently, are classic cystitis (urinary tract infection) symptoms.

In case you have never had it yourself it causes intense irritation (pain) & burning sensation when passing urine or attempting to pass it with the urge to go frequently.

Good news is a course of antibiotics will clear it up, the longer you leave it however, the worse it will get for the little pup

Agree totally and none of mine have ever urinated more frequently when in season and nor are they ever grumpy when in season either, and none of them hump.

How does one best collect a wee sample?