Heartworm Disease, Cloudy Eyes, and Upcoming Events
Heartworm Disease and Prevention
A question I often get in my practice is my recommendation for the use of monthly heartworm prevention. I think it’s time to explain fully about how heartworms are transmitted and their effects, the current state of treatment, and why we vets recommend what we do. I will give you a hint—it’s not about making money.
Heartworms are transmitted as a stage 1 microfilaria (that means tiny worm) inside a mosquito that has taken a blood meal from an infected animal, then bitten a non-infected animal where some of the microfilariae escape the mosquito into their new host. This baby heartworm goes through a series of molts while swimming in the bloodstream until it becomes an adult which settles in for a long stay inside the right ventricle of the heart. That’s the side that pumps blood into the lungs for oxygenation, and the worms live there because they get several inches long and are too big to pass through the tiny blood vessels in the lungs. This takes SIX MONTHS from the time of infection. Remember this number.
The standard recommendation for prevention is to administer a tiny dose of preventive drug once monthly to your pet. This drug is capable of killing the first three (out of five) stages of the heartworm larvae, but not later stages or adults. If you miss a dose, but give it correctly for the next three months, you should stop any early infection in its tracks. Most heartworm prevention also controls two or more intestinal parasites, which is why most vets recommend year-round use since these other parasites are contracted from contact with contaminated soil and can be picked up any time of year.
The most common test for heartworms is called an antigen test and is checking for a specific protein given off by the female when she is reproducing. For this reason, it will not show positive for an infection until at least six months after the pet has been infected since the worms must reach the adult stage first. It will not detect a single-sex infection since the worms will not be reproducing, nor will it detect the immature worms in the bloodstream. The original test, performed rarely now, is a blood test that actually looks for these immature worms, and requires large numbers of them to be accurate so will also most likely not detect an immature infection. It is possible that a pet can test negative (immature infection), be started on prevention (which only kills infections 3 months old or younger) and test positive 2-3 months later if they were infected 4-5 months before the test was done.
Treatment for a heartworm infection requires anti-clotting drugs to prevent lung blood clots, an arsenic-containing drug to kill the adult worms in the heart, and a follow-up drug to kill any immature worms in the bloodstream. Restricted activity for up to six weeks is a requirement. Other medications such as antibiotics or heart drugs may also be indicated. This treatment is expensive, painful (the injections are given in the back muscles) and hard on the patient. Occasionally, dogs die from blood clots ending up in the lungs or other complications. But if you don’t treat, there is continuous damage to the heart and lungs that will most likely end in heart failure and death. In contrast, the monthly prevention costs less than $10, is a very tiny dose of medication, and is usually taken as a chewable treat.
Some people on the internet are advocating only seasonal heartworm prevention, not testing before starting after being off prevention, or administering prevention at a schedule other than the monthly dosage recommended by the manufacturer. I have yet to see any studies indicating that the increased intervals between prevention have truly been tested under laboratory conditions, meaning dogs on that schedule were purposefully infected with heartworms to determine if the new schedule was truly protective. Until such studies are done, I am not comfortable advocating a 45 day or other schedule as I feel the risk of infection if it doesn’t work is too costly to the pet. For the same reason, I can’t recommend “natural” alternatives as again, no studies have proven their effectiveness. All reports of “my dog didn’t get heartworms” with natural control methods are anecdotal, and I question whether many of these dogs have even been tested for heartworms, were even exposed to a positive mosquito, or live in areas of the country like ours where they are common. The risk of not testing before using prevention is that if your pet is infected but you believe the prevention is protecting them and don’t do a test, the worms could live inside the heart causing damage until signs of heart failure develop. Early detection and treatment can prevent many of these later problems. Also, if you use year-round prevention and your pet somehow gets infected, most manufacturers will pay for treatment IF you have a documented negative test prior to starting their prevention, and yearly thereafter.
In the Kansas City area, 30% of unprotected dogs will develop heartworm disease. I feel this is a very high incidence, and the incidence of illness after oral monthly heartworm preventive drugs (NOT combined with flea prevention) is vanishingly low. Risk vs. Benefit. And now that you have read this, I hope you will schedule your pet’s heartworm test (yes, we can test and use prevention in cats as well, though their incidence of heartworm is much lower) and get your prevention soon. Mosquitoes will be hatching out soon if they haven’t already! And yes, they can get to your inside pet as well—who hasn’t chased a mosquito around their living room?
PetVison Pro eye drops: I recently received information about a new product with all-natural ingredients such as amino acids and antioxidants that is reported to help clear the lens of the clouding associated with aging and possibly even early cataracts. It is applied to the eyes daily for about 30 days, then you can wait up to six months (or when you see clouding ) to use it again. It sounds like a great product….except that it would cost you as the client about $120 for a month’s supply. In our fledgling practice, it doesn’t make sense for us to purchase such expensive inventory that could potentially expire before we sell it. SO, I wanted to make my clients aware of its existence, as it sounds very promising for treatment of a common problem that many pet owners have concerns about. If you are interested in this product and will commit to buying it, we are happy to order it for you. You would just have to wait a few days for it to come in before picking it up. There is an over-the-counter product that is similar (without the “Pro”) available online. Reports indicate it is not as effective as it is not as strong a product. Feel free to research this yourself, and let us know if you are interested in having us order this product for you to try. We have not yet had personal experience with it so are mostly basing our promotion of this product on the numerous positive reviews we have seen.
Thunderstorm Fears: Just a reminder that we carry an all-natural herbal formula called Nutri-Calm that can help reduce noise-induced anxiety, as well as pets that are anxious about travel, fireworks, boarding, moving, or new pet introductions. Just give us a call if you’d like to come by and pick some up!
April 11: 3 p.m. Free Seminar at the clinic about Holistic Therapies for Pets, detailing many of the holistic therapies we offer here at Whole Health Pet Center and how they can benefit your pet
April 17: Canine Massage. Call 816-331-1868 to schedule an appointment for your dog to receive a relaxing and beneficial massage by a licensed canine massage therapist.
May 23: 3-5 p.m. Dog Training 101 by Mike Deathe, owner of K.I.S.S. Dog Training. Mike is a positive reinforcement trainer well-respected in the local dog-training community. His talk will be focused on helping dog owners understand the psychology of dog training and how to be more effective at training their dog at home. A question/answer period will follow his lecture, and there will be opportunity to sign up for classes with Mike at our clinic which we will offer if at least 6 people sign up.