Today I've felt a lump in my girl's mammary gland near her groin.  It's about the size of a golf ball, she hasn't got one on the other side.  I'm worried sick and going to phone the vet in the morning.  It seems to have just appeared and she's not bothered by me touching it.  She is 18 months old and was spayed in April. Can anyone please help put my mind at rest? 

There are so many things it could be. Most are quite treatable. Just get her to the vet and then you will know for sure.
Fingers toes and paws crossed for you.
Aileen

Are you sure this is not an Inguinal Hernia, if it's in the groin area???

Only about 30% of mammary tunmours are malignant, but either way if it's a tumour it needs to be removed as that is the best option for cure.

I have only ever encountered pea size lumps, in my first bitch, who had both removed and lived to 13 1/2 and died when her kidneys packed up.

Could be an inguinal hernia, but always best with a lump to get a vet check. There are loads of non sinister things it could be, try not to panic. :-)

My doggie had one but it was pea sized and in mammary gland she also had it removed weeks after recovering from emergency spaying, we nearly lost her then found this other lump just inches from where the incision had stopped, vet was really miffed they had missed it but she then lived on to the grand old age of 15. Try not to worry too much we are all thinking of you :)

well we've been to the vet who had to go and get another vet as it's very unusual apparently.  She has been given a week of antibiotics and has to go back next week. Then if it hasn't got any better they will take a sample etc.  So, still not sure exactly what it is, the only thing we do know is it's not a hernia.
Thanks for your replies to my original post-we will see what happens!  We are off to the coast for the week later today in a dog friendly cottage, so we are all going to chill and enjoy the beaches. And find different ways of disguising antibiotic tablets!

>And find different ways of disguising antibiotic tablets!

Soft cheese or pate works well here, easy to get the tablet inside a big lump of it and then pop into mouths!