Dog Summer Bummer Diseases


Dr. Sheldon Rubin delivered sobering news to the owner of a schnauzer during a recent visit to his Chicago practice. The dog tested positive for heartworm and faced a long, expensive treatment involving painful shots, says Dr. Rubin, DVM, who is president of the American Heartworm Society.

The heartworm parasite in this case was most likely an unwelcome souvenir from last summer, believes Dr. Rubin, who is also a spokesperson for the American Veterinary Medical Association. A year ago, the affected dog’s owner had decided preventive medicine wasn’t necessary for a city pooch, but he learned the hard way that dogs are at risk no matter where they live.

In this case, heartworm is just one dog disease that is spread by vectors like mosquitoes, fleas and ticks. Vectors spread parasites and organisms by biting an infected animal then transporting the disease when they bite healthy animals. Although your dog can contract a vector-borne illness year-round, summer is a prime time for these diseases.

Summer Trouble
It makes sense that the risk expands exponentially in the summer. Time spent outside frolicking with your pal, whether in the backyard, at the beach or camping, means more potential exposure to diseases such as heartworm and Lyme disease. The same warm summer temperatures that lure us outdoors are the same ones that jump-start mosquito, flea and tick populations. “It only takes one mosquito bite,’’ Dr. Rubin says of mosquitoes carrying the heartworm parasite. “It’s not like it takes a bunch of mosquito bites to infect your animal.”

Dr. Stephen Steep believes yet another factor plays a role in spreading vector-borne diseases among dogs during the summer. We hit the road more at this time, and many of us bring our dogs along for the ride, says Dr. Steep, DVM, an Oxford, Mich., veterinarian and past president of the Michigan Veterinary Medical Association. Unfortunately bug pests can hitch a ride during such trips. “We’ve dramatically increased our exposure,” he says. “If you go to a dog park, a dog there might have visited another part of the country and brought back a parasite.”

He and other veterinarians suggest that all dog owners, whether or not they are planning a summer trip, should educate themselves about these vector-borne diseases. Here’s a look at three of summer’s most common dog disease bummers:

Heartworm disease

  • Vector: Mosquito Heartworm is now present in all 50 states, says Dr. Rubin.

  • Symptoms Look for loss of breath, lack of stamina or coughing in your dog. By the time your pal shows symptoms, however, the disease is usually advanced. Heartworms infest the chamber of the right side of the heart and the arteries in the lungs. Chances are you’ve seen graphic depictions of the disease at your veterinarian’s office.

  • Prevention Heartworm is easily prevented through topical medication or a monthly pill, says Dr. Rubin. While some pet owners dispense the medication just during the height of mosquito season, Dr. Rubin recommends a year-round program. You’ll see an added bonus, he says. “Almost all of the heartworm medications prevent intestinal parasites.”

Lyme disease

  • Vector: Deer tick Even if you’re a conscientious dog owner who conducts tick checks on your dog, it’s not enough, says Dr. Steep. Deer ticks, the size of poppy seeds, are difficult to detect.

  • Symptoms Lyme disease is also difficult to recognize, and its symptoms resemble other diseases, says Dr. Steep. Look for muscle weakness, joint pain and limping in one front leg. Your dog will likely run a temperature. Lyme disease is treated with antibiotics.

  • Prevention A vaccine is available to protect against Lyme disease. Consider asking about it during your dog’s next visit to the veterinarian, since some dogs are at greater risk than others because of lifestyle or geographic location.


  • Vector: Tick The tick carries an organism that can infect the white blood cells of your dog.

  • Symptoms Erlichia, as for other parasitic ailments, can resemble different diseases. Look for spots of bleeding on your dog’s gums, lethargy or a loss of appetite. Erlichia develops in stages. The prognosis is good if the disease is diagnosed before the chronic stage. Because it is hard to recognize in its earliest phases, veterinarians will sometimes treat for erlichia with antibiotics before they make a firm diagnosis.

  • Prevention Tick control is the key. Don’t settle for a flea and tick collar, advises Dr. Steep. Collars often provide protection, but only for the region near your dog’s neck. Use prevention such as Frontline, Advantage or Revolution, which work systemically and provide whole-body protection.

Fortunately, West Nile virus and encephalitis, two other troubling vector-borne diseases, do not often affect dogs, says Dr. Rubin. For those diseases that do pose summertime threats, just a little work on your part can help prevent the debilitating and sometimes life-threatening health problems that could impact your tail-thumping pal. Your efforts carry an even greater reward, since many of these ailments, such as Lyme disease, can affect humans as well.

Think prevention, says Dr. Steep. Talk to your veterinarian, and educate yourself about which diseases are prevalent in your part of your country. Your veterinarian is also likely to know which medicines and products will work best in your area. Year-round prevention efforts are advised, says Dr. Rubin.

“Don’t put this off. Know that the potential exists,’’ says Dr. Steep. “Ask your veterinarian. It’s on our radar, and we’re thinking about it all the time.”

by Kim Boatman