Protecting your dog from parasites is one of the most important things you can do to help ensure long-term health for your pet. And heartworm disease is one of the most deadly threats your dog can face. Heartworm disease is a serious problem. The American Heartworm Society estimates that over one million dogs currently have this potentially fatal disease. And more cases are being diagnosed each year, many in parts of the country that are not normally known as hotbeds of heartworm. So let’s take a closer look at the heartworm lifecycle. Heartworms are spread to dogs through the bite of an infected mosquito. Immature or juvenile heartworms, called larvae, enter the dog’s body at the site of the mosquito bite. They then pass through the dog’s tissue, enter the bloodstream and make their way to the heart. Once in the vessels near the heart, the larvae gradually develop into adult heartworms. The adult worms will cause the dog serious health problems. In severe infections, the worms can disrupt heart function and blood flow, and can even damage the dog’s lungs, liver and kidneys. If left untreated, heartworm disease can be fatal. As adult heartworms reproduce, they send more newborn heartworms into the bloodstream. At that point, if the infected dog is bitten by a mosquito, the disease may then be spread to other dogs. The time between the initial mosquito bite and a positive test result for heartworm disease is often more than six months. So unless you are continuously administering a monthly heartworm preventative, your dog could test negative, yet still develop heartworm disease. Heartworm disease often doesn’t present with many symptoms. So it can be very difficult for pet owners to spot. When symptoms do appear in your dog, they can include coughing, fatigue and exercise intolerance. Unfortunately, by the time these symptoms appear, it’s usually a sign that significant damage has occurred. So what can you do to protect your dog? You can take steps to reduce your dog’s exposure to mosquitoes by eliminating standing water where mosquitoes breed. Cleaning gutters, emptying bird baths and outdoor pet bowls will all help a little. But it’s hard to eliminate mosquitoes. They can survive extreme temperatures and reappear when you least expect it. Fortunately, it’s easy to prevent heartworm disease. Simply have your veterinarian test your dog annually, and give heartworm prevention each month, all year round. Preventatives don’t kill adult heartworms. They kill the juvenile heartworms before they can grow and reproduce. That’s why it’s important that your veterinarian tests your dog for heartworms before starting a monthly preventative routine. A positive test result may be an indication that your dog requires more aggressive treatment. And serious health issues can occur in dogs with a pre-existing heartworm infection if they begin a heartworm preventative routine. So follow your veterinarian’s advice and have your dog tested for heartworms regularly. To avoid the deadly effects of heart worm disease, your best bet is to start a monthly heartworm routine as soon as you can – and stick to it. Ask about Trifexis, the combination product that kills fleas and prevents infestations, prevents heartworm disease, and treats and controls hookworm, roundworm and whipworm infections. See the full product label for complete safety information. Serious adverse reactions have been reported following concomitant extra-label use of ivermectin with spinosad alone, one of the components of Trifexis. Treatment with fewer than three monthly doses after the last exposure to mosquitoes may not provide complete heartworm prevention. Prior to administration of Trifexis, dogs should be tested for existing heartworm infection. Use with caution in dogs with pre-existing epilepsy. The most common adverse reactions reported are vomiting, depression, itching and decreased appetite. To ensure heartworm prevention, observe your dog for one hour after administration. If vomiting occurs within an hour of administration, redose.