First of all there is no such thing as a bad dog, just bad dog owners. Second, dogs by their very nature will chase. It is one of their instincts. Third, dogs do not show or are intent on being angry or show any animosity toward most people, especially if you do nothing to provoke it. (riding past a dogs house on the public street is not provoking it)

Now even though the dog may percieve you as a threat it is not out of anger toward you. But it will do what it thinks it needs to do to defend its territory.

And there are a lot of dogs that just want to run along with you just for fun.

What you need to do when rover gives chase is determine what the dog's intentions are. You may have only a few seconds at the most to do this.

If the dog is snarling, growling, or barking in a menacing or defensive manner it is obvious what it wants to do to you.

If it is barking in a happy or excited tone it probably wants nothing more then to be your new friend. Most if us that have dogs or have been around them can tell the differance between these kinds of barks.

The dog's body language is also a factor. Is the fur on the nap of its neck up? If it has a long enoungh tail, what is its position, straight out behind it, up in the air, down?

You also need to be aware of where the dog is running when it gives chase. Is it making a beeline for you? Or is it running along side of you? Does it start running at you before you even ride by its home?

And there is one more factor as well. What is the owner doing, if they are aware that the dog is chasing you? Is the owner trying to call the dog back? Is the owner encouraging the dog to continue the chase? Did the owner send to dog out after you in the first place?

All of these factors are things you need to be aware of when encountering a dog while riding. Then you decide what if any action you need to take.

I do recommend having and using if needed a can of pepper spray. I've tried water, yelling and waving a frame pump, none worked for me, but pepper spray has. In fact the dogs that live along my favorite bike routes now know that if they chase they will be sprayed. So they stay on their property. I have only ever sprayed the dogs that I know are a physical threat to me.

There are also dogs I have never sprayed and never will. These dogs just want to run with me while I ride and I'm sure thye'd love it if I stopped and gave them some attention. In fact more often then not I have to turn around so the dog will follow me back to its home.

I'm always afraid of any dog that chases me getting hit by a car, no matter if it is a threat to me or not. That is the last thing I want to see happen.

Most of the owners also know enough now to keep their dogs under better control, especially the dogs I have had to use pepper spray on.

Using the pepper spray is always the last thing I do though. I attempt to out run the dog and wait and see if the owner will call the dog back. If the owner makes no such move and I can not out run rover and the dog is a threat I then use the spray.

But there is one time I had to use law enforcement and have a owner arrested for using his dog as a weapon. I was riding on a route I had never taken before so I knew nothing about it. About halfway through I here the loud "get him boy" from someones front yard. I turn and look and big dog is giving chase. I try to out run him. That didn't work the dog was gaining ground on me. While I was trying to spray it with the pepper spray I lost control and crashed. And I still hear the owner encouraging the dog to attack me. The dog catches up with me as I am picking myself up off the ground. The dog stops in front of me and just looks at me wagging its tail. So I let him sniff me, (I knew at this point the dog was not going to bit me). He was a very friendly dog. All this time the owner never leaves his yard and is still trying to get the dog to attack. Other people heard and saw this so there were witnesses. I was really pissed at the owner for this. I felt he had tried to use his dog as a weapon, thus resulting in my crash. So I called the police. I explain the the officer what happened and the witnesses back me up on it, of course the owner deny's it. Well he is arrested and charged with assault with a deadly weapon. The dog is taken to the pound to be quarantined and checked over. Guess the is procedure even though the dog never bit me. The owner never got the dog back but I did make sure it was not destroyed. I found it a good home and it was adopted. (The dog was also found to be in bad health and abused by its owner so that added to his charges).

Like I said you may only have a few seconds at best to determine what the dogs intentions are, and then to make a decision on what to do yourself.

Good luck.