I have had multiple dogs in my lifetime. I have NEVER seen anything but good come from having a dog fixed. Specifically, I'm thinking of my last three dogs, an Old English sheepdog who was unaltered at 5 years of age when I got him. I immediately had him fixed. He was the best guard dog I ever had! Also, my labrador, who I had fixed at 4 months of age. He is a fantastic guard dog! I have no doubt that he would kill anyone who tried to harm me. I also have a Britney Spaniel who was a wussy, lovey dog when I got him, had him fixed, he's still a wussy, lovey dovey dog. It has more to do with the personality of the dog than anything else.
if you mean a dog being spayed or neutered, No they do not get mean, only people make dogs and cats mean!!
On the contrary, it generally makes male dogs less aggressive. He might be ticked off for a while, but then he'll forget.
A male dog will hump anything, not just female dogs that are able to breed. But a female dog that has been fixed still has some of the smells that attract a male dog.
Especially if she has been fixed, and there are no male dogs in the household, the female may consider the male owner her mate.
Male cats and dogs are usually fixed, or neutered, in order to prevent unneeded pregnancies to deal with overpopulation and avoid extra animals who could be abandoned, or sent to overcrowded shelters.
Dogs sniff each other whether they are fixed or not. It's how they get to know the other dog better. Don't worry, it's casual like waving to a friend.
There is no easy way to stop dogs from sniffing each other as this is the way dogs find out information about things. A male dog does not go into heat. Only female dogs do.
Dogs do not view sex as humans view sex. A dog will, at times, hump anything. A lot of times, a male dog will actually hump other male dogs and that is due to a fight for dominance. So yes, a male dog will hump a fixed female.
No. However male dogs can still show interest in them even if they are spayed.
If you mean, Can dogs be male or female? Then the answer is yes. They can be both.
Yes, they cut the dogs balls off... not his penis.
If by 'fixed' you mean spayed then no. Once a dog has had a castration they no longer have their period.