My girl had a Histiocycoma removed a few weeks ago, all healed and entered for Boston in January. 
I was speaking to someone recently who said I would now need permission to show from the KC.
This didn't sound right to me but she said it's altering her appearance, whereas I though the lump was altering her appearance I was putting it right!!
What are your thoughts? Thanks :)

It always used to be that you had to get written permission from the KC to show, after a spay surgery.  I did with those I continued to show after being spayed.  Phone them, when open (they may have shut already for the Christmas season - but you could check on their website?) to confirm what is the current situation.

Actually neutered (castrated) dogs can be shown although having no 'nuts' present is a tad more obvious than an entire male and if faced with two equally good examples of the breed, I'd lay odds most judges would put the entire dog up ahead of the neutered dog.   Breed Standards have never been altered to allow for this change btw.  Assuming it's still possible to show castrated males!

ps   I have always been able to tell if a bitch of my main breed has been spayed, especially if done as a puppy.  Their lady bit (vulva) is not as pronounced as those of an entire bitch.

You will not need to get permission to show as you have not altered the dog's 'makeup'.

15. Do owners know they are supposed
to ask for permission from the
Kennel Club to  show their dog after it has had surgery?
a. The owners of registered dogs are required to request permission to
show after any surgical procedure. In fact the majority of applications
for permission to show are received from the dogs’ owners, therefore
it can be assumed that most dog show exhibitors are
aware of this requirement.
Source - the BVA website.  Advice to vets.

Note 'after any surgical procedure'

I will take a look on the KC website.
http://www.thekennelclub.org.uk/forms/neutered-dog/
Note the date of the update!!!

Yes, after spaying I always get permission to show.

From the way you are wording it, this would even be after say stiches(from maybe a barbed wire incident)!!

> From the way you are wording it

Not my words Lexy!   Taken from the BVA information about this, to vets.
http://www.bva.co.uk/uploadedFiles/Content/Workplace_guidance/Ethical_guidance/faqs-reporting-surgical-procedures-on-kc-dogs.pdf

But you are right, it would infer that even a minor procedure has to be reported - which I can't believe to be honest.   Routine Dentals (not corrective surgery for a bad bite)?   Fatty cysts removed?   Hum.   But neutering a dog is a bit more significant.

It definitely does require permission as per the pdf linked to. A letter from the vet. They now accept it over e-mail (again as per the pdf). One of my veteran bitches had a mammary tumour removed recently, the vet wrote a letter stating what had been done (obviously stating dog's reg'd name etc), I scanned and e-mailed the letter and received the permission to show letter within a few days.
Edited to say, just noticed it was not the correct pdf linked to. This is the one to read: http://www.thekennelclub.org.uk/media/494542/sh126_exhibitors_faqs_1.pdf

"If your dog has had an operation you are required to write to the Kennel Club to seek permission to continue to show your dog." Operation being the important part -not just stitches.

I had this done on a 9 year old some years ago and asked for permission.

Basically any op needs to be reported.

> Routine Dentals

The two of mine who needed teeth out as veterans always got permission to show, also loss of the tip of a tail.

> Edited to say, just noticed it was not the correct pdf linked to. This is the one to read: http://www.thekennelclub.org.uk/media/494542/sh126_exhibitors_faqs_1.pdf

http://www.thekennelclub.org.uk/forms/neutered-dog/

This link give you the form to fill in re neutered dogs, but not for anything else.