There are a host of other things you can do to lower general stress in your dogs’ environment.
If you’ve ever had a massage, you know how calming touch can be. Dogs aren’t that different from us; you can calm and soothe your dog with physical touch, both through canine massage and TTouch. Combine your calming touch sessions with aromatherapy, by using a therapeutic-quality lavender essential oil in an electric nebulizing diffuser in the room while you massage your dog. Then you can build your dog’s “ahhh” association with the lavender scent to help him be calm in more stressful environments, by putting a few drops of essential oil on a bandana that you tie around his neck or on the bedding in his crate.
For more details and advice on modifying dog aggression, purchase Whole Dog Journal’s ebook, The Aggressive Dog.
I share a fence, across the back of my lot, with a family who has three dogs. The dogs are out in the yard about 23 hours a day. They bark a lot, especially when people with dogs walk by their home. Their yard is littered with things the dogs have torn up, like an old mattress that started out on the back porch.
This evening, I let Otto into the backyard to go pee. I heard the usual volley of barking from the back fence as Otto strolled around my yard. I was actually turning to go back in my own house to get a glass of water when I heard an odd noise. I turned just in time to see an entire plank of the back (wooden) fence plunk to the ground in my yard, and the biggest of the three dogs, a black male pit-mix-type, charge into my yard toward Otto.
Well, I went berserk. In stocking feet (and a skirt, no less) I also charged into the yard, running down the back porch steps while yelling and grabbing things to throw at the dog. Initially, he glanced toward me but kept running toward Otto – who, by the way, alarmed by all my yelling and strange behavior, started running away from me. I don’t think he even saw the strange dog until it was right behind him, he was so afraid of my antics. I threw a trash can, a broom, and a pair of shoes, and was also able to turn on a hose and start spraying water toward the dog – just as the two smaller dogs also came through the fence. I kept yelling “GET OUT! NO! GET HOME!” and spraying all the dogs with water. Faced with this unexpected onslaught, the neighbor’s three dogs – thank God – turned and ran back through the fence. I ran behind them, spaying the hose to make them move far enough from the fallen fence plank that I felt confident in bending down to pick it up and jam it back up against the fence.
I then ran inside and grabbed a hammer and nails and ran back outside and nailed the plank back on. Only then did I look for Otto.
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I found Otto quivering in the house . . . and spots of blood on the kitchen floor. I don’t know what happened, it all happened so fast. But he had a nasty laceration on his back leg. Did he get bitten? Or run into something in the yard in his panic to escape from his suddenly insane owner? I have no idea. Just a vet bill, a dog with a shaved butt and a few stitches (staples, actually), and a list of materials for a new fence.
Maybe I overreacted, but I’ve heard enough of the dogs frustrated barking (and then redirecting their frustration onto each other in short but intense-sounding fights) that I wasn’t going to take the chance that Otto get attacked by all three – or that I get attacked while trying to save him. All I know is that I certainly won’t take that fence for granted anymore. Ugh.
Dependency on luring is a common dog training mistake. Luring is using a treat to show your dog what you want him to do. To lure a “down,” for example, hold the treat in front of your dog’s nose while he’s sitting, then lower it a tiny bit toward the floor. As his nose follows the tidbit, “mark” the behavior that you want with the click! of a clicker or a verbal marker, such as the word “Yes!”, and feed him the treat.
Continue gradually moving the treat toward the floor, clicking and treating along the way, until he’s lying down. If at any time he stands up, say “Oops!” and have him sit again, then resume luring the down, moving the treat toward the floor in smaller increments this time.
Luring to teach behaviors is just fine. Forgetting to “fade” (gradually remove) the lure is not. If you don’t fade the lure early in the training process, you and your dog can become dependent on the presence of treats to get the behavior to happen. While I almost always have treats in my pockets or close by, I don’t want to have to rely on treats to get my dog to offer behaviors when I ask for them.
For more details and advice on positive training, purchase Whole Dog Journal’s ebook, Positive Training Basics.
A crate, or, in other words, short-term close confinement, can be used to help dogs teach themselves two very important skills. The first is eliminating only when and where it is appropriate. The second skill is keeping out of trouble – behaving appropriately in the house. Without these two skills, a dog doesn’t have much of a chance in this world.
To get your dog to go into the crate, start with the crate door open, and toss some irresistibly yummy treats inside. If he is hesitant to go in after them, toss the treats close enough to the doorway that he can stand outside and just poke his nose in the crate to eat them. If you are training with a clicker or other reward marker, each time he eats a treat, Click! the clicker (or say “Yes!” if you are using a verbal marker).
On Friday night, I picked up my brother’s dog, Hannah, from his house (about an hour away). Keith, his wife, and their darling almost-two-year-old daughter went out of town for the weekend, and Hannah came to stay at our house.
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It struck me at some point during the weekend how much taking care of a relative’s dog is similar to taking care of a niece or nephew. You love the dog, because she’s “family” – after all, you said you would take her if anything ever happened to her! But you can’t help but notice differences in how she was “raised” – differences that you can’t quite help but feel slightly judgmental about. When Hannah jumps on the couch without “asking,” pants in my ear and whines and is generally just obnoxious (anxious) in the car, and sneaks the cat’s food every time I forget to put it back up onto the counter, I find myself thinking, “She’s a nice dog but sheesh! I sure love my Otto.”
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It’s hard to remember to also give Hannah a ton of credit for paying no attention to my chickens or ancient cat, not climbing in my raised vegetable bins, not counter-surfing, not chewing anything in the house, and for getting along so nicely with Otto (whom, I can tell, she really is not very fond of). Here she is, dropped into a new household without her family for a long weekend, and she’s being a good sport and not crying herself to sleep at night. She’s actually a very nice dog, indeed. Even if her table manners aren’t up to my standards.
Have you ever cared for a relative’s dog? How did it go?
I doubt that WDJ readers need to be reminded to leave their dogs home, rather than allowing them to accompany them on driving errands or shopping trips, at this time of year. When it’s hot, leaving a dog in a car –even with all the windows fully down – can heat a dog to the point of heatstroke or even death within a shockingly short amount of time.
Dogs are much more susceptible to heat-related illness than adult humans; due to their smaller body mass, their internal temperatures rise much faster than ours do.
Fifteen minutes in a hot car is enough to cause a dog to suffer from heat stroke. This can be fatal, or cause permanent brain damage. Signs of developing heat stroke include:
excessive panting or difficulty breathing
drooling
mild weakness
seizures
bloody diarrhea or vomiting
stupor and collapse
And yet, I see dogs parked in cars all the time! Perhaps the owner parked in the shade, and left the windows down a bit. It doesn’t matter! It’s too hot for this!
My sister, a chef, was catering an event recently when she and other members of the serving staff heard a car horn blaring in the parking lot. She joked, “It’s probably that poor dog that someone brought and left in the car; it’s probably honking the horn to save its life.” Someone was sent to go investigate, and guess what? It WAS the little dog in the car, standing with his front feet on the steering wheel in an effort to reach the cooler air coming in the cracked open window on the driver’s door. An announcement was made, and the abashed owner summoned. My sister said the entire staff gave the person hard looks. I might have been tempted to flatten the guy’s tires or worse.
Dogs inside cars are not the only ones who suffer in the heat. Dogs who ride in the backs of trucks are at extreme risk of heat-related illness, too. Truck beds – whether they are lined or not – get hot enough to fry an egg in the sun, so why would you make your dog stand or sit on such a surface? Plus, the hot air quickly can quickly dehydrate a dog, whose main tool for regulating his body temperature is panting. Once the dog gets dehydrated, he can’t keep himself cool, and heat stroke can follow rapidly.
If you see any of these symptoms in a dog who has been exposed to excessive heat, get help from a veterinarian immediately.
A better solution? Leave your dogs home on hot days. As much as they may enjoy taking a ride with you in the car or truck, be a responsible pet owner and make them stay home.
And if you see a dog locked in a hot car (or tied in the back of a truck in the hot sun), call the local police department. In most communities, the police (or good Samaritans) may break a car window to free a dog if the dog’s life appears to be in danger.
A special, perfect food for every dog? That’s what the pet food industry would like you to believe; that’s the direction taken by most of the large pet food makers – foods for tall dogs, small dogs, fat dogs, old dogs . . . you get the picture. The tactic must work, because all the biggest companies do it, and they wouldn’t make so many foods if they weren’t selling well.
Dog owners should be aware, though, that there are actually only two types of products that provide legally defined “complete and balanced nutrition” for dogs. These are “adult maintenance” products formulated for adult dogs, and “growth and reproduction” (also known as “all life stages”) products formulated to meet the increased nutritional requirements of pregnant and nursing females and puppies.
As we explained in “Special Education” (in the May 2011 issue), only these two sets of “nutrient profiles” have been established as the basis for regulation of dog food in the U.S. There are no other dog food descriptions with legal mandates for certain nutrient levels.
We’ll say it another way: There are no legal nutritional guidelines or standards for foods that are identified by their makers as intended for senior dogs, weight loss, toy breeds, indoor dogs, Chihuahuas, or joint health. If they have a “complete and balanced” statement on the label, they meet the requirements for either adult dog maintenance or “growth and reproduction.”
Most of the giant pet food companies continually conduct research and tinker with their formulas, looking for anything that “performs” better in the dog. They want to be free to innovate and incorporate anything that gives their products a market advantage, including trendy food ingredients and higher (or lower) than average amounts of certain nutrients. No one in the industry wants another set of nutritional standards they’d have to meet for a certain type of food.
Devil Is In The Details
Now that you understand that there are absolutely no regulations or standards that ensure that a “senior” dog food has anything unique to offer senior dogs, or that a food for “indoor” dogs is in any way different from foods for outdoor dogs, you’re ready to look at these sorts of products with a justifiably cynical eye.
If you’re considering one of these specialized foods, try to determine what, exactly, are the features that are supposed to be unique to that product and so allegedly perfect for dogs like yours. In many cases, the differences in formulation between the “special” food and the plain old adult variety are negligible – but you won’t necessarily be able to ascertain that from the description of the product on the front of the bag, the company website, or the product’s literature.
As always, your best clues for a reasonable analysis of a dog food are found on its list of ingredients and guaranteed analysis (GA). By law, only the minimum amounts of protein and fat and the maximum amounts of fiber and moisture in the food are required to appear on the GA. However, when it comes to specialized foods (with attendant claims of special benefits) the makers should, in our opinion, include those nutrients on the GA.
For example, “joint health” foods generally contain glycosaminoglycan (GAG) supplements, such as glucosamine and/or chondroitin). If we were paying a premium for a product that contained a GAG supplement in a supposedly therapeutic or beneficial dose, we’d want to see the type of supplement used, and in what amount, guaranteed by its inclusion on the GA. (The GA is subject to testing and enforcement by state feed control officials.) And we’d be fairly suspect of a “joint health” product that did not have its “joint health” ingredients quantified on the GA. (We’ll discuss GAGs more in just a minute.)
The next thing we’d do is compare the ingredients list and GA of the “special” food with a regular, adult version of the food from the same company. If there are only minor differences between the ingredients of the two foods (say, the fifth and sixth ingredients are reversed), or only a small difference in the amount of fat or protein, you’re probably paying for marketing, not a genuinely novel food for your special dog.
Some pet food makers are fiddling with the physical form of the food to customize it for certain dogs. “Large bites” and “small bites” have been around for ages, but today some companies are going farther. For example, Royal Canin has a food intended for Golden Retrievers, with a kibble shape the company describes as “specifically designed to prevent gulping, help your dog to feel fuller more quickly, and reduce the amount of calories consumed.” Hmmm . . . if they say so . . .
GAGs for Joint Health
“Joint health” or “mobility” foods are now among the most popular types of “special” dog foods on the market. The ingredients that usually support that claim, as mentioned a moment ago, are glycosaminoglycan (GAG) supplements, although manufacturers will sometimes list other ingredients as contributing to joint health.
Glucosamine is usually derived from the shells of shellfish; the chondroitin used in dog food is usually sourced from poultry cartilage.
GAG supplements are often described as the building blocks of cartilage and joint fluid, and When given independently of the diet, the typical recommended therapeutic dose is about 500 mg glucosamine and 400 mg chondroitin per 25 pounds of the dog’s body weight per day. Dogs often require a therapeutic dose daily for as long as six to eight weeks before any improvement in mobility or a decrease in osteoarthritic pain is seen. If no improvement is seen after 12 weeks of a therapeutic dose of the supplement has been given to the dog daily, it probably will not help the dog to continue its use. We’ve heard
When GAG supplements first began appearing in dog foods, the amounts used were very low – too low, in our opinion, to provide any real benefit to the dog (though maybe their presence on the label made the owner feel better). Today, they are present in widely varying amounts in canine “joint care” products (and some senior foods).
To illustrate this point, in the table above, we’ve listed the amounts of glucosamine and chondroitin in eight joint health or senior dog foods. Notice how the amount of the supplements included in the foods doesn’t necessarily correspond with the implied level of commitment to the special purpose of the food? Innova and Wellness both offer regular old senior foods with fairly high amounts of the GAG supplements – and with very low-key descriptions of their GAG content. Contrast these with Iams’ Veterinary Formula Joint/Canine food; in our opinion, the serious name and serious description of the GAGs’ purpose in the product don’t match the amounts included. In fact, Iams’ “veterinary” product contains not much more of the supplements than one of its adult foods.
We included the Purina ONE SmartBlend food just so that you could wonder along with us: How on earth does one translate parts per million into a standard dosage of milligrams per kilogram?
The levels of glucosamine and chondroitin seem to be a major factor in how Royal Canin individualizes its many products.
Probiotics & Prebiotics
Probiotic organisms are living beings that support the resident microflora of your dog’s gut. Many of the ones used to supplement canine (and human) diets are beneficial species of bacteria, including Lactobacillus acidophilus, Bifidobacterium bifidum, and Lactobacillus bulgaricus. Probiotics are credited with enhancing digestion and absorption of nutrients, supporting detoxification and elimination processes, and helping to boost the dog’s immune system.
For greatest benefit, probiotics need to be delivered to the dog:
–in high amounts
–in live, active form
–in a variety of species (not just one).
Prebiotics are non-digestible food ingredients that selectively stimulate the growth of the beneficial bacterial species in the colon, such as Bifidobacteria and Lactobacilli.
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It’s become fairly common to see some sort of prebiotic in top-quality “natural/holistic” foods. Most common are fructooligosaccharides (FOS) – plant sugars that occur in a wide variety of fruits, vegetables, and cereals. They are produced commercially by partial hydrolysis of chicory inulin (an oligosaccharide found in chicory root), or from sucrose (sugar) using an enzymatic process. Only very small amounts of prebiotics are needed for a beneficial affect on the dog’s digestion. (Doses that are too high can cause gassiness.)
The amount or dosage of probiotics used is usually expressed in millions or billions of “colony forming units” or “CFUs.” For example, the label of the Innova Adult Large Bites food says it contains 90,000,000 CFU/lb “total microorganisms.” (The species of the beneficial bacteria used are not divulged.)
Prebiotics are stable substances; living, active probiotics are not. Heat kills them, rendering them inactive (that’s why they appear only in dry dog foods, not canned; the high heat of the canning process would kill them and render them useless). Most dog food companies that include beneficial bacteria in their products say that the probiotics are added to the food after it has cooked and cooled; and some say that live cultures were used in the food. However, none that we are aware of claim that the bacteria is still alive and active by the time it’s consumed by the dog.
Innova, for example, claims, “Innova products include live, active bacteria called probiotics . . .” We have no doubt the bacteria were alive when included in the food; probiotics are generally applied in the final step of food production. After the kibble has been cooked, cooled, and coated with a fat source, it’s dusted with the probiotic powder. But we doubt that the bacteria can survive the oxidative activity of the food as it ages and the temperatures that dry food is often subjected to.
Again, if we really wanted our dog to enjoy the benefits of a probiotic supplement, we’d look for a good supplement and administer it separately from our dog’s regular diet.
Herbs, Berries, and Fruits, Oh My
It’s gotten very popular in recent years for dog food makers to include a long list of whole, healthy foods on their products’ lists of ingredients. Please understand that while it makes a food sound delicious, the actual amount of the ingredients that appear 10th or 15th or 25th on a list of ingredients that ends up in your dog’s tummy is very low; we’d characterize it as so low as to be negligible.
The real purpose of many of these ingredients on a pet food label is to whet your appetite. Pet food industry publications sometimes describe this as “humanization” of the pet food. If you want your dog to experience the benefits of carrots, apples, blueberries, garlic powder, green tea extract, spinach, cottage cheese, and other terrific foods that generally appear low on lists of ingredients, feed them whole and fresh as a healthy adjunct to your dog’s commerical diet.
We’ll discuss veterinary “prescription diets” in an upcoming issue.
The lawsuit filed by Kari Blaho-Owens, PhD, against Merial, her former employer, contains a number of serious allegations regarding Heartgard’s decreased efficacy and Merial’s knowledge of the problem.
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Merial denies the allegations, and has released the following statement regarding the lawsuit:
“Merial is aware of the lawsuit filed against the company by former employee, Kari Blaho-Owens. As a matter of company policy, we do not comment on the details of pending litigation or on employee-related issues. However, Merial believes we have acted appropriately and responsibly in all matters related to the allegations. Merial will vigorously defend the case and will assert strong defenses to the claims made. An earlier complaint filed by this former employee has already been dismissed by the United States Department of Labor.
“Merial stands by the effectiveness of our products. We are confident that the Heartgard® (ivermectin) brands are highly effective when used in accordance with their FDA-approved labels. Moreover, Merial strictly adheres to all regulations relating to the reporting of adverse events involving any Merial product.”
We may never know whether all the details alleged in the suit are true. It might take years in court – or it might be settled out of court. But the suit makes for fascinating reading. Here are some of the key points in the suit (to read the entire complaint, see tinyurl.com/44c6c44):
– In November 2004, the FDA’s Center for Veterinary Medicine sent Merial a letter, stating “there were numerous reports of ineffectiveness for heartworm prevention despite ‘Heartgard Plus’ being used according to the label directions.” In August 2005, FDA requested that Merial stop claiming 100% effectiveness for Heartgard Plus in preventing heartworm infestation.
– In 2005, Merial conducted an internal investigation regarding the increase in the number of reported cases of the lack of efficacy of Heartgard.
– When she reviewed the results of the 2005 investigation, Dr. Blaho-Owens asserts that “Merial had been aware of serious lack of efficacy adverse events reported regarding ‘Heartgard Plus’ since as early as 2002.”
– Merial claimed that its investigation showed that the increase in lack of effectiveness claims was the direct result of increases in sales, lack of owner compliance, and other factors – not a failure of the active ingredients in Heartgard products. Dr. Blaho-Owens claims she found numerous problems with the review, including “using ‘cherry-picked’ data, so as the persons evaluating the data would be led to support the conclusion sought by Merial.”
– In 2007, Dr. Blaho-Owens conducted further investigation in an effort to determine why “global monthly reports and the quarterly pharmacovigilance meetings demonstrated an obvious trend toward the increase in lack of effectiveness reports.” She was unable to find any reasonable explanation other than loss of efficacy of the Heartgard products.
– In 2008, Dr. Blaho-Owens’ supervisor “instructed her to stop her investigation.” One of the reasons given was that Merial had conducted a laboratory study showing “that heartworms had developed resistance to the ‘Heartgard Plus’ active ingredients, ivermectin and/or pyrantel; and that Merial was actively working to reformulate ‘Heartgard Plus’ to make it more effective by adding additional drugs to the combination product.”
– In September 2009, Dr. Blaho-Owens was notified that Merial was named in a class-action lawsuit regarding ‘Heartgard.’
– Dr. Blaho-Owens claims that on September 11, 2009, she was instructed to destroy a document that was likely relevant to the pending class-action lawsuit. Dr. Blaho-Owens also claims she was instructed to stop generating any new analysis of data regarding Heartgard despite her ongoing concerns relating to the lack of efficacy of Heartgard.
– Dr. Blaho-Owens says she reported her concerns to Merial’s legal counsel. Shortly thereafter, Dr. Blaho-Owens says she learned that the Heartgard class-action suit concerned Merial’s refusal to change its labeling as per FDA order.
– In conclusion, Dr. Blaho-Owens’ suit alleges that “Merial fraudulently promoted and sold ‘Heartgard’ as 100% effective despite its knowledge since at least 2002, that ‘Heartgard’ products were substantially less than 100% effective, in violation of FDA regulations.” The suit says, “Merial knew about the LOE (lack of efficacy) problem since at least 2002.”
There is now ample evidence that at least one strain of heartworms has developed resistance to some of the market’s best-known preventives. In addition, there is evidence to suggest that one of the most popular heartworm preventives, Heartgard, has an efficacy rate of less than 100 percent.
The U.S. Food and Drug Administration’s Center for Veterinary Medicine has sent at least one warning letter to Merial, the maker of Heartgard, asking the company to stop claiming 100 percent effectiveness for heartworm prevention. Given these developments, what should responsible dog owners do differently to better protect their dogs?
Photo by Isha Buis
The answer depends a bit on where you live and what you’ve already been doing to prevent heartworm infection.
Resistant Strains of Heartworm
Reports of dogs developing heartworm disease despite being given preventives year-round were dismissed for years as being due to “owner non-compliance,” but the outcry finally became too loud to ignore.
In August 2010, representatives of the American Heartworm Society (AHS), the Companion Animal Parasite Council (CAPC), and experts in the field of nematode resistance met in Atlanta for a “heartworm roundtable.” A joint statement released afterward announced, “This meeting was convened to discuss the implications of reports of lack of efficacy of macrocyclic lactones [preventive medications] against Dirofilaria immitis, the canine heartworm. Participants concluded that while we do not have a comprehensive picture of the scope or severity of the problem, we agree that there is a problem. There is evidence in some heartworm populations for genetic variations that are associated with decreased in vitro susceptibility to the macrocyclic lactones.”
Translation: investigators have verified that one strain of heartworms shows resistance to heartworm preventives in the lab.
Further, the statement offered a hint that the resistant strain is not yet present everywhere heartworms are found. “Most credible reports of lack of efficacy (LOE) that are not attributable to compliance failure are geographically limited at this time.” The statement did not identify the region, but investigations have centered on the Mississippi Delta.
Useful information has since emerged from a small study conducted by researchers at Auburn University’s College of Veterinary Medicine in Alabama. Four commercial heartworm preventive medications (Heartgard Plus, Interceptor, Revolution, and Advantage Multi) were tested on the resistant strain of heartworm. Forty dogs were infected with heartworm larvae. Thirty days later, the dogs were treated with one of the four preventives.
Four months after treatment, an average of 2.3 adult heartworms were found in seven of eight dogs in each of the first three groups; only Advantage Multi was found to be 100 percent effective. There was no significant difference in efficacy against the resistant strain between Heartgard Plus, Interceptor, and Revolution. Based on the number of adult worms found in the untreated control group, the efficacy rate for the other three products was determined to average 95.5 percent.
Say what? How can the efficacy rate be more than 95 percent, when 7 of 8 treated dogs (87.5 percent) were heartworm-positive? One might guess that “95 percent effective” means that 95 percent of dogs remained heartworm-free, but it actually means the treated dogs had 95 percent fewer adult worms than untreated dogs – a whole different can of worms!
What’s the Best Heartworm Preventive for Dogs?
Does this mean we should all switch to Advantage Multi, the only heartworm preventive found in this study to be effective against the resistant strain of heartworms? Well, the answer is not that simple.
The active ingredient in Advantage Multi is moxidectin (Advantage Multi also contains imidacloprid, the flea-killing ingredient in Advantage and K9 Advantix).
Moxidectin is the same ingredient used in ProHeart 6, an injectable heartworm preventive that reportedly caused problems for many dogs when it was first introduced. Due to the large number of adverse events reported, including many deaths, it was withdrawn from the market in 2004; it was reintroduced in 2008 with new warnings on the label.
Unlike ProHeart 6, a sustained-release injectable product used every six months, Advantage Multi is applied topically once a month. There’s a strong probability that the worst dangers of ProHeart 6 were related to the injectable, sustained-release method of application rather than to the drug itself. If there is an adverse reaction to moxidectin, it’s unlikely to be as intense or as long-lasting from a topical application as from an injected form, which continues to be released into the body for six months.
While every product has some adverse side effects, I have not heard any horror stories associated with Advantage Multi since it was introduced in the U.S. in 2007. Note that moxidectin remains in the system much longer than ivermectin (Heartgard), selamectin (Revolution), or milbemycin (Interceptor), so adverse effects can occur up to three weeks after application.
Dr. Byron Blagburn, one of the vets who participated in the Auburn University study, has hypothesized that moxidectin’s persistence in the body might account for its increased effectiveness against the resistant strain of heartworms.
NW SPCA
What about the other preventives? The study above found no significant differences in effectiveness between Heartgard, Interceptor, and Revolution against the resistant strain of heartworms; their efficacy rate ranged from 95.4 to 95.6 percent.
These findings correspond with anecdotal evidence observed by practitioners in the area where the resistant strain has been reported. Dr. Everett Mobley of Kennett Veterinary Clinic in Kennett, Missouri, is one of the veterinarians who drew attention to increasing failures of heartworm preventives that led to this discovery. He found reports of failure coming from the Mississippi River valley, starting about 100 miles south of St. Louis, and getting worse as one goes south.
“I saw roughly equal rates of lack of efficacy whether the dog was on Revolution, Heartgard, Interceptor, or Sentinel (the four preventives I was using at that time),” comments Dr. Mobley. He emphasizes that “I’m a simple general practitioner, detailing only my own clinical experiences and the impressions of those I have spoken with personally. I am by no means a specialist in parasitology or in pharmacology. My opinions are based on my experience with my cases.”
While he has not yet seen any failures with clients using Advantage Multi, he feels that the study referenced above is inconclusive due to its small size. Dr. Mobley says he has also seen a decrease in the number of heartworm-positive dogs taking other medications from 2009 to the present. He says, “while the big switchers to Advantage Multi feel that they see no product failures at all, our non-switchers have also seen a reduced failure rate in the last two years.”
This could be due to cooler and drier weather, at least in 2009. The American Heartworm Society’s (AHS) triennial survey for 2010 showed that “the pattern of heartworm incidence overall was similar to that of previous years.” While heartworm was found in all 50 states, the incidence map does show a decrease from the previous survey done in 2007, when the fallout from Hurricanes Katrina and Rita had far-reaching effects on mosquito vectors and heartworm transmission. The wet winter we’ve just had may well have a similar effect.
It makes sense for pet owners who live in the Mississippi valley to use Advantage Multi, as long as their dogs have no problems with it. For the rest of us, presumably not yet threatened by the resistant strain of heartworm, other products may be acceptable.
Heartworm Medication: Your Options
Interceptor, another heartworm preventive, may have one advantage over other products: its dosage of active ingredient (milbemycin oxime) is five times the minimum amount that has been determined to prevent heartworms; the higher dose is used to control intestinal parasites as well.
Because the level of medication is higher than was needed in the initial approvals for 100 percent efficacy, it’s possible that Interceptor may continue to be more effective against non-resistant strains of heartworms. Sentinel, which combines Interceptor with Program (lufenuron, a product that prevents fleas from reproducing), is another option with the same dosage of milbemycin oxime.
Revolution, a topical heartworm preventive whose active ingredient, selamectin, is also effective against fleas, ear mites, sarcoptic mange, and one type of tick, offers another alternative. You might use Revolution if you want to take advantage of any of these other properties, or if you prefer a topical treatment but do not want to use Advantage Multi.
Heartgard
Heartgard, like Interceptor and Revolution, demonstrated an efficacy rate of only about 95 percent in the Auburn University study on the preventive-resistant strain of heartworms. But there is evidence – some of it in active legal dispute – to suggest that Heartgard may exhibit only about 95 percent efficacy against all heartworms, not just the drug-resistant type.
In a letter sent in 2006 by the Food & Drug Administration (FDA) to Merial, the maker of Heartgard, the FDA warns, “In a letter dated August 24, 2005, we requested that you stop claiming 100% effectiveness for heartworm prevention. As you know, this request was based on the post-approval adverse drug event (ADE) reports we have received for lack of effectiveness for heartworm prevention. In a letter dated September 30, 2005, you agreed to immediately discontinue promotion and advertising 100% effectiveness for your heartworm prevention products.”
The allegation that Heartgard has only a 95 percent efficacy rate was leveled at Merial recently from another source – a “whistleblower” lawsuit filed by a former Merial employee.
Kari Blaho-Owens, PhD, global head of pharmacovigilance for Merial from 2006 to July 2010, alleged in documents filed in late May of this year that she “discovered that Merial had been aware of serious lack of efficacy adverse events reported regarding ‘Heartgard Plus’ since as early as 2002.” She believes that Merial terminated her employment because she refused to stop her investigation of the loss of efficacy of Heartgard and its related products. Dr. Blaho-Owens also asserts that she found a statistical analysis done by another Merial employee showing that Heartgard Plus was 95 percent effective. (That analysis would apply to all heartworms, not just the resistant strain.)
Even if the allegations of a 95 percent efficacy rate were true, there are a couple of good reasons to continue to use Merial’s Heartgard, in our opinion. The first is the fact that Heartgard’s active ingredient (ivermectin) has some effect against adult heartworms – ones that developed while the dog was unprotected by any preventive or ones that developed despite the use of preventive.
One study we reviewed showed that Heartgard had nearly 100 percent efficacy in killing young adult heartworms when administered continuously for 31 months, and more than 50 percent efficacy after 18 months. Other recent studies on the use of a combination of pulsed doxycycline and weekly ivermectin resulted in a reduction of over 78 percent of adult worms after 36 weeks (see “Links for More Information,” below).
According to studies we’ve reviewed, selamectin (Revolution) has a lesser effect on adult heartworms, while neither milbemycin (Interceptor) nor moxidectin (Advantage Multi) have been found to have a significant effect against them. If your dog is infected with heartworms, it makes sense to use Heartgard prior to and during treatment with Immiticide, as it weakens the adult worms. It also makes sense to continue to use Heartgard for one year following treatment, to kill any heartworms that might mature from older larvae that neither Immiticide nor heartworm preventives can kill.
Iverhart and Tri-Heart Plus are generic equivalents to Heartgard that are manufactured by different companies. Efficacy and safety should be identical to Heartgard. Just be sure to purchase these products from reliable sites, preferably those that carry the Veterinary-Verified Internet Pharmacy Practice Sites seal of approval (Vet-VIPPS) and offer guarantees against product failures.
Heartworm Preventives: Use More, or More Often?
If you want to continue to use Heartgard for heartworm prevention, it also may be reasonable to use a higher dosage. The studies done for the initial approval of Heartgard showed that lower doses were less effective at eliminating heartworms than the dosage that was ultimately chosen for the label recommendation, which was the lowest dose found to be 100 percent effective. Increasing that dosage may well increase Heartgard’s effectiveness in preventing heartworm infection from non-resistant strains.
Is an increased dose safe? For most dogs, the answer is yes. Ivermectin is used to treat dogs with demodectic mange (demodex) using a dosage that is 50 times the amount used to prevent heartworms, and this dosage is given daily for weeks or even months. Compared to this, doubling the dosage of Heartgard should be safe. Keep in mind that dogs at the low end of the weight range for each Heartgard product are already getting twice the dosage compared to dogs at the high end of the range; smaller dogs weighing 12 pounds or less get even more.
Higher dosages are not safe for dogs with the MDR1 mutation that makes them more susceptible to ivermectin and other drugs. There is an inexpensive genetic test available to find out if your dog has this gene. Most affected dogs are from herding breeds, primarily Australian Shepherds (including Minis) and Collies, but it’s also common in Long-Haired Whippets and Silken Windhounds. Mixed-breed dogs can also be affected. See www.vetmed.wsu.edu/depts-vcpl for more information.
Note that dogs with the MDR1 gene are also affected by selamectin, milbemycin, and moxidectin, the active ingredients in Revolution, Interceptor, and Advantage Multi, respectively, though heartworm-preventive dosages are considered safe.
One problem with increasing the dose of Heartgard is that most people use Heartgard Plus, which also includes pyrantel pamoate, used to kill roundworms, hookworms, and tapeworms. In fact, it’s become difficult to find plain Heartgard. Just as with ivermectin, dosage of pyrantel pamoate is twice as high for dogs at the low end of the product’s weight range compared to those at the high end. This is not a problem, as the recommended dosage range for pyrantel pamoate is 5 to 10 mg per kg, exactly the amounts used in Heartgard Plus. Increasing dosage further, however, can lead to increased side effects, primarily vomiting.
If your dog is at the high end of the weight range for the Heartgard product you’ve been using, it should be safe to move to the next level product. For example, if your dog weighs 45 pounds and you’ve been giving Heartgard Green for dogs weighing 26 to 50 pounds, it may be better to switch to Heartgard Brown, for dogs weighing 51 to 100 pounds. If your dog is at the low end of the weight range (say, 30 pounds), you’re already giving a higher amount of ivermectin and so Heartgard may already be more effective.
Another option might be to give heartworm preventives twice a month rather than monthly, particularly if you live in an area with a high incidence of heartworm disease. There is a window of opportunity in which heartworm larvae are susceptible to the treatments used against them. Once the larvae reach a certain age, preventives will no longer affect them. By giving the preventives twice as often, more larvae may be killed. You could use the same product each time, or use two different products when using this approach.
Keep in mind that none of these changes are likely to work for the resistant strain of heartworms. Dr. Mobley, whose practice is in the Mississippi valley, says that he has seen or heard of heartworm infections occurring despite using higher doses of ivermectin, in one case an extremely high dose. “I have tried changing preventives, giving two different preventives per month (every two weeks), increasing doses, and still had some failures.” After seeing the increase in heartworm preventive failures in 2006, he began giving his own dog Heartgard on the first of the month and Revolution on the 15th, and she became infected with heartworms anyway.
Final Thoughts on Heartworm and Heartworm Treatments
It’s important that people continue to give their dogs heartworm preventives, even if they are not 100 percent effective. A small number of heartworms cause far less damage than a heavier infection would. All of the preventives destroy most heartworm larvae before they can mature into adults and thus continue to offer significant protection.
Dr. Mobley points out that “Merial (and the other manufacturers) have been super great to honor their guarantee and pay for the treatment of these dogs. While they initially felt veterinarians were overreacting, they took steps to hold meetings and get feedback on the situation.” He also says, “These dogs do not have heartworm disease, per se. They test positive, meaning that they do have some small number of heartworms, but they are not sick. Thus, I (and others) feel that most of the heartworm exposure has been handled by the preventives, even when we have these ‘lack of efficacy’ cases.”
While Whole Dog Journal has made recommendations in the past that it can be safe and effective to give a dog heartworm preventives less frequently than every 30 days (e.g., every 40 days) or to use slightly lower dosages than the label recommendations, this newer evidence about the decreasing effectiveness of heartworm preventives made us rethink our position. We strongly advise against giving heartworm preventives less often than monthly, or giving lower than recommended dosages. While this may have worked in the past, based on the original efficacy studies, it seems clear that it’s not working now.
It’s best to give heartworm preventives year-round as well, not only for better protection against infection, but also to ensure that the manufacturer will pay for treatment should your dog become infected with heartworms. We also recommend annual testing for dogs, especially for those who live in heartworm-endemic areas, even if you give preventives all year round.
You can reduce the risk of heartworm infection by keeping dogs indoors, particularly during peak mosquito times at dawn, dusk, and early evening, and at night; installing screens on windows and doors; reducing outside lights and using yellow bulbs where possible; and eliminating mosquito breeding sites, such as by draining any standing water, changing the water in birdbaths and wading pools at least once a week, and stocking ponds with mosquito fish. None of these measures, including keeping dogs indoors at all times, is 100 percent effective or replaces the need for heartworm preventive medications.
HEARTWORM RESISTANCE TO MEDICATION: OVERVIEW
1. Make sure your dog is tested for heartworm annually.
2. Give your dog preventives year-round for better protection – and to ensure that you meet the terms of the preventive’s guarantee.
3. If you live in the Mississippi River Valley, consider switching to Advantage Multi for better protection from the resistant strain of heartworm.
4. If your dog’s risk is high, talk to your vet about possibly giving your dog a higher dose of Heartgard or using preventives twice a month.
Food treats are an easy and effective reward for a dog when training. But food rewards are only one way to build strong behavior. There may be times when you do not want to or cannot use food, and there may be times when the best reinforcement is something other than a hot dog! Here are five great ways to reward your dog when you don’t want to reach for the treat pouch.
Ways to Train a Dog Without Treats:
1. Play with your dog!
Anyone who has trained for an active sport like agility or flyball knows the value of using toys, games, and play in training. But toys, games, and play don’t apply only to the sports-minded. Playing with your dog can be a powerful relationship-building tool, as well as a potent reward. Tugging and retrieving may be the most obvious play rewards, but playing games with your dog is limited only by your (and your dog’s) imagination.
2. Use “life rewards.”
These are things that your dog enjoys in his daily life, such as going for a walk, running in the backyard, or splashing in a sprinkler – and they can be harnessed by using the Premack Principle.
This principle says a “low-probability behavior” (one that the dog or other subject is less likely to perform, such as waiting calmly at the door) can be reinforced by a “higher probability behavior” (one that the dog prefers, such as getting to race happily around the yard). For example, to strengthen your dog’s sit, ask him to sit before giving him access to any of the things he really enjoys – running with his pals, swimming in the pond, or cuddling next to you on the couch. This type of reward is easy to integrate into your daily life, and can be especially helpful for dogs who need assistance with self-control.
3. Offer warm words to your dog.
Praise, “happy talk,” or a simple “Good dog!” may be the most common type of reward there is! Some dogs naturally find praise rewarding, but even dogs who don’t seem to can become praise seekers if you frequently pair your praise with other great things. For example, if you teach your dog to “down” with a click, followed by a treat or tug, you can add in “Good dog!” as you deliver the treat or play the game of tug. Soon, your dog will learn to associate that happy praise with the treat or tug, and “Good dog!” will become its own reward.
4. Touch him where he likes it.
Touch can be a wonderful reward for some dogs, but it is also a tricky reward to use. Before using petting, rubs, or massage as a reward, first consider two things: What types of touch does my dog enjoy? And, when does he enjoy being touched? For example, your dog might enjoy a chest scratch, but may shy away from a head pat. Long, slow strokes may feel good and be rewarding when he is settled next to you, but irritating if he is waiting for a run in the backyard. Pay attention to what your dog does when you touch him; if he ducks away or does not engage with you, it probably is not rewarding. If he engages, comes toward you, or asks for more, then it probably is rewarding.
5. Create space.
You can use space as a reward by increasing distance or by removing social pressure. In the right situation, space can be very powerful reinforcement. For example, a dog can be rewarded for an appropriate behavior (such as looking away) in the face of an anxiety-producing trigger (such as a scary person) when you increase distance by moving the dog away from the trigger. (This tactic, described as “Behavioral Adjustment Training” or BAT, is more fully discussed in Pat Miller’s article, “Dog-on-Dog Household Aggression,” in April 2010.)
In your day-to-day interactions with your dog, you can also use space in smaller or subtler ways by removing social pressure. If you are teaching your dog to stay out of the kitchen by using gentle body blocks, for example, you can reward your dog’s acceptance of the kitchen door boundary by simply backing up a little bit – or removing the social pressure of the body block.
These are just some of the many ways you can reward your dog when you don’t want to use food or treats. Remember, when you are thinking about rewards, you can consider anything your dog finds valuable
Mardi Richmond is a writer and dog enthusiast in Santa Cruz, California.
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A few years ago, I asked Whole Dog Journal’s readers about the use of the words “owner” versus “guardian.” The response was polarized; either term makes some people see red. Perhaps that’s why the phrase “pet parent” has become so popular – it seems to avoid the third-rail effect of the other options, and conveys both caring and responsibility. But I have to admit; when one of my friends talks about her “canine son,” I tense up a little. I can’t even tell you why; it’s weird.
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This isn’t the only term having to do with our canine companions that twists my tail. I can’t stand the word “command” – as in, “Give your dog the command to sit.” I’m not royalty, and slavery was abolished in this country long ago, so what’s with the commanding? When training, I believe in giving the dog a cue that alerts him to the opportunity to perform a behavior and earn a reward. When hanging out with my dog – you know, socially – I usually “ask” him for certain behaviors; I might even insist that he sit or down when I give him the cue to do so . . . but command? The concept is not representative of my relationship with anyone I know.
Whole Dog Journal’s Training Editor Pat Miller was the first to ask me to omit the use of “it” when discussing any sentient being – as in, “I wanted to pet the dog, but it bit me.” I’m glad she sensitized me to this issue. It’s difficult to distance yourself from (or elevate yourself above) another living creature when you’re forced to consider (at a minimum) his or her gender. You’d never say, “A kid got hit by a car; it suffered serious injuries;” or “A tourist got its shoes muddy at the beach.” Using he, she, his, and her when talking about any species of animal, human or nonhuman, preserves the respect for the individual.
This principle can be extended a bit farther. In WDJ, we also use the word “who” when talking about individuals. So we’d say, “The dog who earned a treat is happy,” rather than “The dog that earned a treat is happy.”
These are small things, but consideration for all sentient beings is not.
More congratulations for Pat Miller are in order. She was recently welcomed to the Board of Directors for the Certification Council for Professional Dog Trainers (CCPDT).
The certification program administered by the CCPDT was the first national certification for dog trainers in the U.S. Candidates who pass the CCPDT’s written examination earn the title Certified Professional Dog Trainer-Knowledge Assessed and may use the designation, “CPDT-KA,” after their names. All certified trainers must earn continuing education credits to maintain their designations. They must also adhere to a strict code of ethics in their dog training practices.
A dog trainer as professional, educated, and ethical as Pat Miller will be a terrific asset to the CCPDT Board and its mission.
A couple of days ago, I received a text from a dog-training client, wondering about a video she had just watched—and which she linked in the text. “Is meat meal bad for dogs?” she asked. She followed that message with, “I get that she’s selling her own pet food, but is it (meat meal) that bad?”
