1.Dogs should have a litter before they are spayed.
This is not true. Spayed dogs are at lower risk of getting breast cancer and uterine infections.
2.All dogs like to be petted on their heads.
Some dogs like it, many don't.
3.Happy dogs wag their tails.
This may be true, but aggressive dogs often wag their tails too!
4.Dogs that are indoors don't need heart worm prevention.
This is not true.Indoor dogs are still at risk of heart worm.