It depends on the purpose of the show (cute, tricks, obedience) each will have its own rules. The American Kennel Club prohibits spayed or neutered dogs from conformation competitions. It states:
To be eligible to compete, a dog must:
Spayed or neutered dogs are not eligible to compete in conformation classes at a dog show, because the purpose of a dog show is to evaluate breeding stock.
For aesthetic reasons neutered male dogs may be implanted with silicone testicles (e.g. Neutricles).
Neutered dogs can participate in AKC shows in such performance events as Obedience, Agility, and Rally (sort of a cross between Obedience and Agility). They can not show in Conformation. There are also events for particular types of dogs--herding and tracking, for example--in which they can participate. Some cities have non-AKC, just-for-fun shows with categories like "furriest," "most kisses per minute," and so forth, and they do not care whether your dogs is neutered or not.
A spayed female cannot be shown in the conformation classes in a AKC dog show but can be shown in any of the agility or obedience classes.
it depends on the show
I don't know if there are any dog show that allow spayed and neutered dogs.
A dog can be neutered at any age after 6 months.
The risk of a dog developing certain types of cancer is reduced if the dog is neutered.
The sterile dog can not cause/have puppies, either because it has been spayed/neutered, or because of genetic issues.
no
a neutered dog
A neutered dog can achieve an erection. It has nothing to do with sexual urges. General excitement, such as a new person in their home can cause this.
Conformation shows are designed as a way for responsible breeders to showcase their dogs and display their breeding stock. The goal is to show other breeders their dogs in hopes that they will find a good potential pairing they can breed to produce quality puppies. Bringing a spayed or neutered dog to such an event would be considered pointless, since they cannot breed.
Yes. A neuter dog's penis is still intact, and that is what causes the tying, although neutered dogs generally don't have the drive to do so.
He will eventually, my dog is six and he was neutered. Give it a couple of weeks.
yes
Yes, a neutered male dog will not have as strong a scent and there won't be as much testosterone in the marking urine.