Heartworm is transmitted by mosquitoes, not ticks. But as a serious and potentially fatal threat to dogs, it's worth a mention here. Despite widespread awareness of the disease, it's estimated that as many as half of all dog owners are not using heartworm preventatives. In early stages, heartworm has no visible signs, which is why preventive measures are so important. As the infection takes hold, more signs will emerge.

Most common signs of heartworm:

  • Persistent cough
  • Exercise intolerance
  • Difficulty breathing/abnormal lung sounds
  • Abnormal heart sounds
  • Swelling of the abdomen

Note: The above signs indicate advanced infection, which often results in death.

U.S. Regions Where Heartworm May Affect Your Dog

Heartworm is found in all 50 states, with the highest number of reported cases in the South, Midwest and California.

For more information about heartworm, visit the Web site of the American Heartworm Society at www.heartwormsociety.org.