Janete and Tony,
You can alter your prices at any time, and change the rates manually when booking with a specific client. Simply explain to them (or note it in your profile) that your rate for a intact male is higher than for a fixed one. Explain why, and that it's more work for you to keep them safe around other dogs and typically for cleaning up after them. Anyone who says any differently about intact males, doesn't understand dog behavior and tendencies. It is true that an intact male marks more frequently than fixed ones (not to mention their urine is much more potent), and are prone to attracting more aggressive behaviors from other dogs (typically male:male, female:female). Each occurrence is different for every dog, but the risks are higher with intact males over the age of 1 (in some cases even before then).
I take care of a 7 year old in tact Rottweiler, and every time he comes over, not only do I have to wash everything he's laid on and any jackets or sweaters I've worn while he's here (BECAUSE OF THE DROOL!), but I also have to go around the backyard and spray down all the bushes and trees. The reason for this? Because his urine is POTENT! It's so strong that it makes me sick every time I pass by it. He is a very healthy Rottie, drinks plenty of water, and is in fabulous shape, he's not fixed though, so his urine has a strong smell. He has marked 1 time in my house, the first time he every came over, but I made it VERY clear to him that it was NOT okay! He never did it again. He's potty trained, and knows he isn't suppose to go into the house, so because I made it clear that he wasn't going to get away with marking in the house, he understood, and hasn't done it since.
So I don't have issues with marking in the house anymore, though he does it VERY frequently everywhere else (outside, on a walk, at the park). My problem is the constant fear I'm in when walking him around town and on the trails. I understand that dogs tend to attract negative attention when they are not fixed, but he is like a MAGNET! I had to stop walking him down a specific street in my neighborhood, because two male dogs (that are normally very friendly when I walk any other dog down that street) that live on the corner house were trying to jump the fence to get to him, but they were unsuccessful. Knowing that they could not jump the fence, the next time we passed by this house, they were trying to tear through the fence to get to him! They were literally tearing the boards off of the fence trying to reach him, so I had no choice ... (more)
I agree with charging more for in neutered males. They tend to mark in the house and there's always the concern that a female at a neighbors home is in heat. Have to be extra careful with supervision. I keep them on a leash the first 12-24 hours to see how they interact.
I recently watched an intact male. He actually did great, he did mark once but that was it. I usually try to keep the dogs busy so they don't get bored or restless. I take them on longer walks so that they can empty their blatters, versus shorts walks, in which they still have urine to "mark" with.
marking isn’t the only downside to not being neutered, there are a few reasons with the main one being the male keep wanting to mate with the other dogs because of their hormones which causes aggravation in the pack and can cause them to fight. Not only that but they can sense dominance in the pack.
Really what you're saying is not the full range of possibilities. Intact dogs can be just as well behaved. It depends on the owner and upbringing and breed and individual and surroundings.