We have a 30-gallon tank in our living room with red parrot fish and silver dollars. The same fish have been in it now for more than seven years. I was wondering how long these fish can live and what is their natural life span?

A: We really do not know the natural life span of many fish because it is hard for us to track them from birth to a death of old age in a natural setting. Many aquarium fish do live more than a decade, but that is not a natural environment. Thus it is hard to tell if their life span is longer or shorter than nature directed it should be.

I have a friend who has had a silver dollar fish in her tank for just over 20 years. This fish has outlived three glass tank changes in its life.

Q: My 3-year-old Yorkie thinks she is part otter -- she loves to play in water. The problem is, she plays in her water dish so much that she splashes all the water out in 10 minutes. Not only does this make a big mess, but then there is no water for my Chihuahua to drink. I give them as much as they want to drink when I am home and then take up the dish so the Yorkie cannot splash it out. They seem fine with this, but I hate the fact that if they are thirsty when we are not home, they have nothing to drink. What can I do about this situation?

A: Pet stores sell heavy-duty glass water bottles with stainless steel mounting brackets and spouts. They are pretty much indestructible. I have even used them for big parrots and monkeys.

The mounting brackets are designed to be screwed onto the outside of a cage. The bottle is mounted on the outside of the cage with the spout going into the cage so the animals can drink.

However, the bracket can be reversed so you can screw it to a wall and then clip the bottle right up against the wall at a convenient height for both dogs. Then all they have to do is lick the water out of the spout. The dogs will be comfortable with this, and there is a stainless-steel ball inside the spout that falls into place when the dog is not drinking from it to prevent the water from coming out. This should solve the issue for you, but remember that the water bottle must be taken completely apart every day and washed out to prevent bacteria from growing in it.