SAN DIEGO -- The number of heartworm cases in San Diego pets is on the rise and some vets are pointing the finger at rescued Hurricane Katrina dogs.

Some dogs that were rescued from the Gulf coast after Hurricane Katrina and brought to San Diego were apparently infected with heartworm.

Mosquitoes that bite dogs already infected with heartworm can spread it to other animals.

Until now, California has not been known for having much of a problem with heartworm.

Local vets are telling dog owners that heartworm is easy to prevent. A low-cost pill taken once a month by the pet will provide prevention.

The disease can be fatal if contracted.