While touring in Costa Rica for two months, it was very apparent that there was a major difference between Costa Rican dogs and American dogs. It is rare for a Costa Rican dog to bark at bicyclists or passing pedestrians. The only dog that even attacked me dog was one belonging to an American. The dog owner's excuse was "He [the dog] hates bikes".
The stupidity of the dog owner regarding dogs irked me as much as the dog. The fact is, dogs do not hate bikes. Unless directed otherwise by their owners, dogs enjoy running after, barking at, and nipping at deer, cattle, bicyclists and fast-walking pedestrians. Dogs must be trained by dog owners not to pursue these activities. Costa Rica is proof that this can be, and is being, accomplished.
A recent article in Smithsonian Magazine [Jan. 1991] explained why dogs bark and/or chase (unless taught otherwise). All juvenile canine (wolves, foxes, coyotes and dogs) have the following characteristics: barking, playfulness, chasing for playing purposes, friendliness to other species (including humans), and different colored coats with patterns (a camouflage against predators). Except for dogs, these canine, as adults, do not bark (they howl or growl), but never as often as barking dogs. These adult canine do not chase except when hunting for food, are unfriendly to other species, and have a uniform coat color.
In dogs, the juvenile characteristics have extended into adulthood because some of the genes that control timing of adult characteristics have been transformed through selective breeding. This was demonstrated by a breeding program for foxes in Russia. Foxes most "friendly" toward humans were bred with other "friendly" foxes to tame the species and make it easier to raise foxes for their fur. After 20 generations, the foxes exhibited characteristics of dogs, including a color pattern in their fur coats.
Dog owners need to understand dogs, and train them to behave properly toward humans. The culture in Costa Rica is such that this is being done: it is socially unacceptable to have irreverent dogs. Just as it is now considered rude to blow smoke into someone's face, a dog owner in the USA also needs to be considered rude for not training his/her animal. Dogs cannot be faulted for lack of respect toward humans. The dog owner's respect for other human beings is or should be brought into question by not training his/her dog properly.
Also see: list of bicycle articles.