Jim Thompson

With spring at its fragrant peak and summer right around the corner, it's easy to get caught up in the pleasures of the season and lose sight of a sobering fact: This is when ticks, mosquitoes, and other critters capable of endangering your retriever's health begin to prowl. So it's the perfect time to make sure your dog is up to date on vaccinations and other preventive medications.

The foundational weapons in the preventive arsenal are vaccines-medications that confer immunity to specific diseases. Vaccination for rabies is required in most states, and there are three other vaccines-distemper, hepatitis (adenovirus), and parvovirus-that are considered "core" vaccines that every dog should receive. These vaccines are typically combined in a single injection along with the vaccine for parainfluenza. Beyond this core group are a number of noncore or "add-on" vaccines. Whether or not these are appropriate for your dog will depend on a variety of geographic and lifestyle factors as well as the clinical experience of your veterinarian.

"It's a matter of weighing the risks," says Dr. Ben Character, who practices in the Tuscaloosa, Alabama, area. "For example, if you're hunting in water where there's any kind of rodent population, including beavers, I'd strongly advise that you have your dog vaccinated for leptospirosis. Bordetella (kennel cough) is another vaccination that I'd recommend for most retriever owners, especially if your dog will be in a kennel or any environment that puts him in contact with a lot of other dogs."

Lyme disease is probably the best known of several tick-borne diseases that can affect dogs and lead to potentially severe complications (others include ehrlichiosis, anaplasmosis, and Rocky Mountain spotted fever). The use of the vaccine for Lyme disease is strongly influenced by geographic location and the clinical experience of the prescribing veterinarian. Noting that this vaccine protects only against Lyme disease, and also that it is not 100 percent effective, Character maintains that the best defense is keeping ticks from embedding in the first place.

"Back in the day you had to lsquo;dip' your dog every two weeks to keep the ticks off him," he recalls. "Now we have oral medications that work great and last three months. The topical treatments also work well, but I prefer the orals because I know the dog has ingested the active ingredient. With the topicals, there's always some question of whether it was applied correctly or if it might have gotten washed off before it was fully absorbed into the skin." You should still check your dog for ticks, Character stresses, and remove any that you find. The chances of a tick transmitting Lyme disease diminish greatly if the tick is removed within 24 hours of attaching to its host.

The same medications that keep ticks at bay also kill fleas. While typically more of a nuisance in adult dogs than anything else (although fleas are the primary vector for tapeworms), you don't want them to become established in your house or vehicle, as they can be very difficult to eradicate.

Warm spring weather also activates mosquitoes. In Character's words, "Anywhere or anytime that you have mosquitoes, heartworm is a concern." Once heartworms are established, the damage they do is irreparable. Fortunately, there are several effective preventive medications available, including monthly "chewables" and annual and semi-annual injections. These products also prevent infections of roundworm, hookworm, and whipworm, although in Character's experience they're somewhat less effective on this last-mentioned parasite.

Whipworm is also the intestinal parasite that poses the greatest danger to otherwise healthy dogs. "When I see a dog that's skinny, won't gain weight, and is in poor overall condition," Character says, "whipworm is one of the first things I want to rule out."

An annual fecal test for intestinal parasites and a blood test for the presence of heartworms should be integral elements of your dog's health-care regimen. "It's important to know," Character says, "that the prevention is working. And if there is a problem, the sooner you discover it, the better the chances are that it will respond to treatment. This is why there's no substitute for an annual checkup with your veterinarian. Our dogs' lifespans are so short, and we have so much invested in them-not just monetarily but emotionally, too-that it just makes sense to catch any health issues as early as you can."