External Parasite Trends from Virbac’s Veterinarian

Shelters United hosts this live conversation discussing key trends and challenges facing parasite prevention and control with Dr. David Whetstone from Virbac.

Why Broad-Spectrum Parasite Control is So Important
Understanding and Using the CAP-C Parasite Prevalence Map
Facts and Data Around How Many Heartworm Doses are Dispensed
Choosing A Parasiticide


Watch via video or continue reading below.

This was part of a previously recorded webinar, Saving Money on Parasiticides: A Crash Course for Animal Nonprofits. To watch an instant replay, click here.

Previous recorded webinar - Saving Money on Parasiticides

Parasiticides And You

So why didn’t I name today’s presentation, Heartworm Prevention, And You? Why did I name it Parisiticides And You? Well, for several reasons. And the one is that there are many common parasites that affect our dogs and cats, and they’re both internal and external. It’s not all just about heartworms, heartworms, certainly important, but there are many other important parasites that we need to pay attention to. And that really impacts when we’re choosing parasiticides, who decides and how we’re going to control and prevent and treat those. It really does impact that.

Another reason that we want to pay attention to all parasites is that they cause disease. And just by the nature, the definition of a parasite is that they cause disease. They have a negative impact on dogs and cats and not only their health, but their well-being as well. And then we also know that parasites are zoonotic, not all of them, but some of the parasites that affect our dogs and cats are zoonotic, meaning they pose a real and significant health risk to humans. And that’s important when we think about the shelter environment, where we have dogs and cats coming into the shelter and who may not have had any parasite asides given to them, applied to them in the past. And so their parasite burdens (the shelter) – we’ll take a look at some numbers to show you that. So definitely from a health human health risk, the workers inside of a shelter certainly are at increased risk. And many parasites have a significant impact on the human-animal bond. Think about fleas or tapeworms and the impact. Although they may not pose a significant health risk in many cases, especially to the dogs, they certainly can have a significant impact on the human-animal bond.

Think Broad-Spectrum Parasite Control, Not Heartworm Protection

One of the things I want to challenge you in your language and look, when we talk about parasiticide control or parasite control, we often talk about heartworm preventatives. And I know that’s the common language, not only in the shelter environment but in veterinary medicine and inside of veterinary clinics. Heartworm prevention is often the term we use. But I would challenge you to start thinking about and speaking about broad-spectrum parasite control or another term you can use as a comprehensive parasite control what that does for you. One within your organization imparts value and the importance of all of the parasites that were controlling, and that we’re not just becoming singularly focused on heartworms, but also imparts value to your customer, to your adopters about what you have applied to the dog and what you’re recommending that they continue to use even after adoption.

Valuable Resources Available to You

I wanted to give you some resources that many of you are probably familiar with, at least some of these resources, maybe all of them, but I want to make sure that you all are aware of the resources available to you. Certainly, the Association of Shelter Veterinarians has a very robust website with many resources, including guidelines for parasite control. The next resource that we’ll drill down a little bit deeper into this one, particularly today, is the Companion Animal Parasite Council, which includes some prevalence maps around all of the parasites and disease risks across the country, and also some guidelines about parasite control. The American Heartworms Society, specifically around heartworm disease prevention and treatment. The Centers for Disease Control. Because many of the parasites are zoonotic and pose a human risk, the CDC offers some really great resources when it comes to preventing parasites to decrease the risk posed to humans. Universities across the country now, veterinary colleges. Now, I have to state up here, and that’s because I’m a Kansas State grad. But many of the veterinary colleges now have really strong, robust shelter medicine programs. So within your region, I think reaching out to those universities and seeking out their help can very be very valuable as well. And then lastly, I would hope you would certainly see now that Virbac has partnered with Shelters United, I would hope that you would see Virbac as a valuable resource as well today.

Again, my hope is that you’ll leave here today saying that was helpful, that was educational. I learned something today that I can apply in my own shelter. And going forward, we have many resources across the country. I’m one of 10 technical service veterinarians. So within your region and I’m happy to help you any time. I’ll share my cell number and email with you later, but don’t ever hesitate to reach out to the field technical veterinary staff here at Virbac to help guide you around your parasite control.

Why is Broad-Spectrum Parasite Control So Important?

Again, going back to the importance of intestinal parasites and thinking about broadspectrum parasite control, comprehensive parasite control, and why is that so important? Well, one of the reasons is besides the impact that hookworms, roundworms, whipworm tapeworms have on our dogs and cats, again, they pose a significant health risk to people. And this happens in the United States. We’re not talking about a third-world country. We’re not talking about someplace outside of the United States. These significant health issues happen right here in the United States. And again, shelter those working in the shelter environment certainly would be at an increased risk because of the population that’s coming into that shelter. And so it’s important that we talk about this and that we all understand the importance of preventing this.

This is the Centers for Disease Control pamphlet PDF file that’s available to help educate the public about the necessity and importance of regular parasite control. And again, just we’re not going to get down into the details of the transmission of some of these intestinal parasites, but again, just to remind you how simple this can be when we look at hookworms, our dogs and cats that have adult hookworm infections are passing those eggs into the environment. If we don’t practice good sanitary control, which often isn’t done in the home, in the yards, certainly something we need to pay close attention to in the shelter environment is the removal of feces. That can just be a really strong preventative program in and of itself. But we know that those eggs and go on to develop into larvae that then when humans are exposed to those larvae when they have skin exposure to those larvae largely around the hands and the feet, those larvae will penetrate through the skin and now can become infected in the person and really, again, caused some very significant health issues in people.

So let’s talk about the prevalence of intestinal parasites across the country, so I’ll just show you three different resources, a couple of studies that demonstrate how common these are. Sometimes I think we take this for granted. You think about some of the parasites that are common in dogs, hookworms. We cannot see hookworms in dogs. You and I can’t see them. We can’t diagnose them without looking under the microscope. Whipworms the same way and roundworms. Yes, we can see those. But those are largely puppyhood issues. Largely tapeworms. Yes, we can see that. So again, it’s not always readily apparent to any of us how common these are just by visually inspecting our dogs.

The Surprising Stats of a Dog Park Study

 This was a study done by Dr. Little at Oklahoma State sponsored by Elanco, looking at dog parks across the country and just simply surveying these dogs in two ways.

One, looking at their stool samples to see what parasites they did have and to find out from the owners if they were on any parasite control. So understand that a dog park represents owned dogs, but they don’t necessarily all have the same health care or veterinary care. They’re not all necessarily going to the veterinary clinic. They’re all not necessarily on regular, monthly, broad-spectrum preventative. So this really gives us a good cross-section of our dog population. You can see that this study was done across the United States. So regardless of where you’re attending from, you could find a dog park in this study near you that would really represent the kind of parasites that are an issue in your region. I’ll just point out, because we’re going to drill down a little bit further using a couple of other resources, I’ll just point out that in the southeast region of this particular study, Oklahoma City and Tulsa were two metropolitan areas where dog parks were surveyed. So we’re just going to use that as an example.

You can see that over 20 percent, almost twenty-one percent of the dogs across the country had at least one parasite. So that’s a significant number and again, many of these dogs, are all owned dogs and many of these dogs are visiting the veterinary clinic regularly. You can also see because sometimes people say, well, maybe they survey dog parks that were in not a higher socio-economic part of town. Know, these dog parks represented all socio-economic areas of these metropolitan areas. And eighty-five percent of the parks had at least one dog that was positive for a parasite. So it’s a problem across the country, across all metros, and over 20 percent of dogs.

And then in the bottom three graphs, you can see how it divides out between hookworms, whipworm and the majority is really largely a problem across the country. Whipworm tends to be more the southeast, as do hookworms. But again, it doesn’t matter what region you’re in, none of them are immune to these parasites.

Another Look at Parasite Prevalence

Then, we’ll look at a study now that was done by Dr. Adolphine team, basically trying to determine how good our diagnostics were, meaning when we do fecal exams, how well can we figure out what the dog has for parasites?

Now, these are dogs in two shelters in northeast Oklahoma. So, again, similar to that Oklahoma City, Tulsa Dog Park study that we just looked at. And these are dogs in shelters. And they had already been identified for humane euthanasia for other reasons. And so they weren’t euthanized for the purposes of this study. They had already been identified for humane euthanasia and then were allowed to survey the intestinal parasite load. What did they find? Here are the results.

You can see that in these shelter dogs, again, these aren’t necessarily own dogs. They might have been surrendered dogs, but they also may not have been dogs that were necessarily being cared for. You can see that the parasite load is quite significant, almost 50 percent for hookworms, 40 percent for whipworms. You can see toxic roundworms are quite low. Again, puppies would not represent the largest part of the population coming into the shelter. So that’s not surprising, but also tapeworms are extremely common as well. So, again, just helps demonstrate how common the intestinal parasite loads are, even though we may not be able to see them in and when our diagnostic tests can even be negative.

Understanding and Using the CAP-C Parasite Prevalence Map

One of the resources that I’ve already mentioned is CAP-C, the Companion Animal Parasite Capsule Council, and they have a really powerful website, not only again, from just being getting education about particular parasites and the diseases that they cause, but also prevention guidelines. They can also help you just determine what parasites are common in my area, heartworms. We can look at heartworms, we can look at the intestinal parasites. We can also look at vector-borne diseases like Erlik Yosses as an example that is transmitted by ticks.

I would highly encourage you to use these maps. And if you need help analyzing this data again, I think this is where the Field Technical Service Veterinarians at Virbac can help you drill down into this data and really make some educated decisions about the spectrum of activity you need in your parasite control for your particular shelter.

This map is just an example, again, we’re looking at you can look at the top ribbon menu, we’re looking at hookworms and dogs, and you can also see that I chose the year 2021. These maps go all the way back to 2012 when CAP-C started collecting this data. So you can actually look at trends as well, which I think is extremely helpful in a couple of areas. One is heartworm disease is heartworm. The disease’s prevalence is changing. We’ll look at that more specifically in a moment. And also I think looking at tick-borne disease, these maps can be extremely helpful. I think we get lured into believing that because of some of our newer compounds, that tick-borne disease would be reduced. But when you look at these prevalence maps, it’s clear that that’s not happening. So tick-borne disease is still a very significant issue and it’s actually spreading as well. Both are like Yosses and apply osmosis more to come on that.

Parasite Prevalence in Oklahoma, For Example

Then we can drill down further and look at a particular state. So if you happen to reside in Oklahoma now, you can look at Oklahoma, and now it’s divided by counties. The gray counties mean there’s no data reported. What’s an important thing to remember is that what CAP-C is showing you is just the dogs tested and the test results that are reported. So some veterinarians may test but not report results and some veterinarians don’t test and don’t report results. So the gray counties are where there are no results being reported. What that means, then, is these numbers would be an underestimate. Again, these numbers are going to be less than what I just showed you on the shelter study, but also the dog-park study. And that’s because it’s the dogs going into veterinary clinics, getting tested, and then get reported again. It’s going to show you trends and it’s going to show you what parasites are present in your region.

So, again, we’re looking at the state of Oklahoma now. We can drill down further and look at the county of Tulsa, which is where the metro area, the city of Tulsa. You can see that the county of Tulsa is white, and so that’s how specific you can really drill down.

One note I would just tell you is that when you’re looking at these maps, what if you have a county that’s gray? What if your shelter resides in a county that’s gray? You have no results. Look at the counties around it. And even in the case of this Tulsa County, if I was analyzing this data for a shelter in Tulsa, I would also look at the surrounding counties as well to see if the data stays consistent, see if anything changes. And that may help guide us as well.

All right, so really powerful resource on a no, we’re going to share that website with you so that you can use that again, I think Virbac can really help you analyze that data as well to help guide your decision-making process. All right.

Facts and Data Around How Many Heartworm Doses are Dispensed

Let’s switch gears a little bit and talk about heartworms in heartworm disease in 2018. The AVMA did a survey and published their pet ownership and demographic sourcebook. And it’s estimated that in 2018 there were 77 million dogs across the United States.

So if you think about, and we would certainly recommend and when you talk to when you look at the resources like CAP-C and when you look at resources like the American Heartworms Society, talking about heartworm prevention in the case of the American society, but also just again, going back to comprehensive or broad-spectrum parasite control. All of those experts recommend monthly prevention all year round, so if we did that for 77 million dogs, there would be 924 million doses of heartworm or broadspectrum parasite control given annually.

Do you think that is the number that we give? And the answer is no, we don’t. So what if we gave a third? What if we just gave a third of those doses? How many would that be? Well, that would be 308 million heartworm doses. Is that the amount that we are able to give in the United States that people are giving to their dogs? And the answer to that is no. So what is that number? How many doses annually do our people giving to their pet dogs?

And the answer is it’s even just a little over a third of that 308, it’s 137 million doses – and that number is decreasing. It’s actually down from 2017 by 3.5%. So that’s presenting some additional challenges and obviously leaving dogs at risk.

Trends in Heartworm Infection

So what are the trends in heartworm infection? We now know that heartworm is a disease is in all 50 states, there were states before areas of the country, especially when we kind of get to the Rocky Mountains and West, where folks for a long time have said we don’t have heartworms and you can’t say that anymore. Heartworm disease exists in all 50 states.

And just in 2018 annually, over a million dogs were infected with heartworm disease or diagnosed with heartworm disease. I think another thing again, going back to broadspectrum parasite control, think about that, we don’t just give heartworm prevention. When we give a heartworm preventative, we’re giving broad-spectrum some broader than others parasite control. So when we know that doses are going down and the incidence of heart disease is going up, we also know that dogs are not getting the intestinal parasite control as well. So they’re not being [treated for] whipworm or hookworms. Roundworms are not being controlled also.

All right, so what about shelters? So this is from a combined survey, a cooperative survey between the American Heart Room Society and the Association of Shelter Veterinarians, and they wanted to know or simply asked the question to the shelters. What percentage of dogs admitted to the shelter, to your shelter last year were heartworm positive? So what were the results?

In 63% of the shelter’s 5%, or less of the dogs were heartworm positive. Twenty-one percent, 5%-10% percent of the dogs are positive. Eleven to twenty-five percent of the dogs are positive at 9% of the shelters. And over 25%, over a fourth of the dogs’, heartworm positive at 7% of the shelter. So certainly a significant problem with dogs coming into the shelters. Even that 5% certainly presents a challenge to any shelter.

The Challenges in Compliance

What are the challenges in compliance and these are results of the same survey or this? In a survey done by Dr. Pryor, why many dog owners are using heartworm preventatives, only 25% of US dogs receive heartworm prevention regularly. Right? So some of them are getting it part of the time, but they’re not getting it regularly. They’re certainly not getting it 12 months out of the year.

Twenty-seven percent of dog owners believed they were giving heartworm preventative when in fact they were just administering a flea and tick, protect flea and tick protection. And that’s been complicated by some of the new oral flea products, flea, and tick products, because, again, owners often think that they’re giving a Heartworm preventative. This was demonstrated in Dr. Little’s study, the dog park study that we looked at just a few minutes ago.

One of the questions I asked them after collecting the stool sample was what were they giving? Well, they asked him where are they giving heartworm prevention? That was a yes or no question. And then they asked them what product they were using. And many times as an example. Now, this isn’t this is this isn’t the answer they gave all the time. But in many of the cases where they said, yes, they were giving a heartworm preventative, then what were they giving?

One of the products that were often reference was Frontline Plus, as an example. We know Frontline Plus does not do anything for intestinal or heartworm disease prevention. So there’s a lot of confusion with owners as well. And these are some of the challenges that we face.

And so these three barriers were identified, these are the three biggest barriers to heartworm compliance, certainly perception of risk. Again, in many areas of the country, people still believe that the risk is low, even though heart disease is spreading. That word is not getting out. And it’s not easy for people to see heartworm disease. Right. In fact, they don’t know it until their dog is sick from heartworm disease. They can’t see the heartworm. They can’t see that happening in the dog.

And then there’s concern about the side effects of the heartworm preventatives, ease of use. It does require a prescription. And so that certainly can be a barrier for many people. And then cost by far is the biggest barrier to noncompliance. And so if we can help reduce that cost, we ought to see compliance increase as well.

A Brief Mention of Internal Parasiticides – Stay tuned for more!

So we’ve talked a lot about the internal parasites, heartworms, and intestinal parasites, and really in the interest of time, we knew we couldn’t cover it all. So I don’t want to forget about the external parasites. And I think I’ll let the folks from Shelters United make any announcements that might be forthcoming, but more to come on that, but certainly not to diminish the importance of external parasites, the most important ones being ticks, fleas, and even ear mites, especially in cats.

Fleas don’t pose a huge risk to dogs, pose a significant risk to cats, more significant risk when it comes to disease state. And we also know that there’s some zoonotic disease cat scratch fever as an example that fleas play a role in as well. So significant issues there. And then ticks certainly pose a huge disease risk not only for our dogs but also for people as well. And this is just a map from the parasite Farkash, showing the forecast for Yosses. You can see that no state is immune from our doses and it’s certainly increasing in prevalence. So more to come on external parasites. I just didn’t want you to think I was totally forgetting about that.

Choosing A Parasiticide

Cost is a Factor to Compliance

So how do you choose a parasiticide? When we think about broad-spectrum parasiticides, and again, more to come on helping you with the external parasites, the ticks, the fleas, but thinking about the heartworm and broad-spectrum intestinal parasite control, how would we choose a parasiticide?

Well, I think certainly for any shelter, price or cost is going to be number one. It has to fit into the budget. And I’m sure any shelter is certainly a challenge from a budgetary standpoint. So cost is going to be a significant decision-maker, a significant piece of information when it comes to making that decision.

Followed by Value – Level of Protection for Cost

But I think also you should consider the value and there’s a difference between value and cost. Right? So cost or prices is the money. That’s the amount we write the check for or the amount we debit the account for to pay for a particular product. But value is about what does that bring to you? What does that bring to the dog? What about its spectrum of activity? Is it broad-spectrum? Is it comprehensive enough? So if we have two products that are equally priced and one is a broader-spectrum product than the other that broader-spectrum brings you greater value.

And is it regionally appropriate? Are we covering the parasites again? Going back to CAP-C maps, let’s determine what would be regionally appropriate for your shelter. And is this parasiticide bringing to you what you need for your dogs and cats?

And then lastly, when it comes to values, support of the manufacturer, you know, just examples of how manufacturers can support you. I hope today is one example of how Virbac can support you from an educational standpoint. Again, I’ve I’ve offered to you and I hope you’ll take advantage of our ability to help you with understanding what parasites are prevalent in your region as an example and even doing problem-solving inside your shelter, if that can be helpful as well.

When it comes to guaranteeing the products, Virbac products are 100% guaranteed. There’s a heartworm guarantee with Virbac products that some other manufacturers may have that as well. But again, we do and we stand behind that as well.

I think certainly the Every Pet Project would be another example of how Virbac supports you as well and just brings greater value to to Shelters United and its members.

Consider Cost + Value for Your Shelter, But Also Your Adopters

And then lastly, as far as choosing a parasiticide, I believe, cost and value to the adopter. So I know inside your shelter, we’re not just talking about a concrete block building or a steel building. That’s not the shelter, the shelters, the people, the people inside that. And it’s from the board of directors to the manager, to all of the people working inside that shelter. There are people, too. And I know most people working in shelters don’t work there because of the money or the wages or the salary. They’re part of that mission as well. And that’s part of their personal mission, to be involved in animal welfare and make a difference. And so I know they care about those dogs and those cats well beyond their stay in the shelter. They care about you all care about them once they leave your shelter. And you want to know that your adopter has a product that provides value at a cost that they can afford. And I think that should play an important role in your decision-making process as well.

So how can Virbac partner with you and help? Again, we believe it’s our responsibility to help that, to ensure that more dogs are protected from heart disease and also, you know, control intestinal parasites, prevent intestinal parasites, protect that human-animal bond, protect the health, not only those of you who work inside the shelters but also your adopters as well.

And I think lastly, I’m going to just share my email address and my cell number again, don’t hesitate to reach out to me. I can also get you in contact with your Field Technical Service Veterinarian who might be closer to you than I am if an actual site visit might be helpful. But again, don’t hesitate to reach out to me.

Call Dr. David Whetstone: (620) 288-9408

Email Dr. David Whetstone: [email protected]




This was part of a previously recorded webinar, Saving Money on Parasiticides: A Crash Course for Animal Nonprofits. To watch an instant replay, click here.

Previous recorded webinar - Saving Money on Parasiticides

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