When a patient is infected with heartworm, it can cause devastating and irreversible damage in dogs. Because of this, compliance is critical in the battle against heartworm and heartworm resistance in veterinary practice. So, how can we improve compliance?

Heartworm Surveillance: Staying Ahead of Resistance with New Research

 at the 2025 WVC Annual Conference in Las Vegas, Nevada, Chris Adolph, DVM, MS, DACVM (Parasitology), shared the latest research on heartworm resistance surveillance to educate attendees on new data and help improve compliance.

“We're going to talk a little program study in the next few minutes, and I'm going to give you some new updates on what's really going on out there. Heartworm is maybe different than the last time you thought about it, and it makes a difference in which prevention you use, for sure,” Adolph kicked off his lecture with.

According to the American Heartworm Society (AHS), most cases of heartworm medication failure can be attributed to compliance issues. Even missing or delaying just one preventive dose can leave an animal vulnerable to infection.

Once a patient is infected with heartworm, the damage is often severe and irreversible. When diagnosing heartworm, veterinary teams typically determine that if a pet is unprotected, it is susceptible to infection. However, when a patient is taking medication as prescribed and still tests positive for heartworm, it signals an evolution in the parasite’s resistance over the past 40 years.

Adolph presented prevalence maps from the American Heartworm Society comparing data from 2001 to 2022, demonstrating the rise of heartworm resistance in the United States. He addressed skeptics—whom he referred to as “heartworm resistance deniers”—pointing out clear patterns emerging across the country.

Adolph also explained that the transportation of dogs across the country for adoption has contributed to the spread of resistant heartworms. Pet owners may unknowingly introduce heartworm-infected animals to regions where resistance was previously uncommon.

“How many of y'all live somewhere other than here, but you see dogs that their book started their life down there. Maybe you guys see these dogs. We're moving them all over the country. When you adopt a dog, guys adopt its parasites, okay, its package deal, right? And if they are resistant heartworms, they get in your ecosystem. And that's the ball game. Okay? Now they live there, right?” Adolph explained.

Between 2013 and 2016, results from a AHS survey on the incidence of adult heartworm infections in adult canine patients in the US showed a 21.7% increase. A study followed the release of the survey results to determine if heartworm testing results available from the Companion Animal Parasite Council aligned with the findings, and whether change in heartworm preventive dispensing accounts for the increase.2

Between 2013 and 2016, results from an AHS survey on the incidence of adult heartworm infections in US canine patients showed a 21.7% increase. A follow-up study examined whether heartworm testing results from the Companion Animal Parasite Council (CAPC) aligned with these findings and whether changes in preventive medication dispensing contributed to the rise.

Researchers analyzed 7-9 million heartworm antigen tests reported annually to CAPC and compared them with the AHS 2016 survey. A state-by-state analysis focused on the southeastern US, where heartworm prevalence is particularly high. National heartworm preventive dispensing data were obtained from Vetstreet LLC and analyzed. The study included oral, topical, and injectable heartworm preventives, with injectable moxidectin counted as six doses.

The results showed a 15.28% increase in positive antigen tests from 2013 to 2016, aligning with the AHS survey. In the southeastern US, the increase was 17.9%, compared to 11.4% in the rest of the country. Nine of the 12 states studied had an increased positive test frequency greater than 10%. Additionally, the findings revealed that two-thirds of canine patients in the US received no heartworm prevention each year.

“I see a lot of low hanging fruit here. I see a tremendous opportunity to have that conversation, and when they say, No, I don't really want to do this and [can I explain for a little bit] why this is super important, and just don't take that person. No, I don't really want any harm or okay, I'm on my 25th patient today. I don't have any gas in the tank for this, but they deserve the best, even if you're on the 25th appointment of the day,” said Adolph.

Taking the time for education and trying to get that third of a third giving their pets preventatives, it can help continue the battle against heartworm resistance and improve the lives of pets across the US.

Adolph C. Heartworm Surveillance: Staying Ahead of Resistance with New Research. Presented at: WVC; Las Vegas, NV. March 2-5, 2025.

Drake J, Wiseman S. Increasing incidence of Dirofilaria immitis in dogs in USA with focus on the southeast region 2013-2016. Parasit Vectors. 2018;11(1):39. Published 2018 Jan 17. doi:10.1186/s13071-018-2631-0

Articles

Understanding recent heartworm research will help professionals stay ahead of resistance 

Updates on the current state of heartworm resistance 

Interview with Dr. Ernie Ward about his Fetch Charlotte 2025 presentations

Ernie Ward Fetch Charlotte 2025 interview

At Fetch Charlotte 2025, Ernie Ward, DVM, CVFT, will share his wisdom and advice on getting ahead in vet med with the session 

The 5 lessons every veterinary professional needs for success.

 In this video preview, Ward breaks down 1 of those lessons: that consistent, long-term focus and intentional actions are key to effective leadership. 

: Yeah, I'm Dr Ernie Ward. I'm a veterinarian now, going on 33 or so years, if you're counting those kind of things, and I'm super excited to be at fetch once again, talking about management issues. And this year we've got a jam-packed sort of slate of really hot topics, including how to get your team to take ownerships. You know, some of the top lessons that I've learned over those 33 years is how to be a good, effective, caring and compassionate leader. And then we're also going to talk about some new technologies are going to help us with endocrinological testing in clinic that actually meet a lot of our clients demands, while also offering the best patient outcomes.

Yeah, I think I'm really excited about one of my talks, the 5 lessons that every veterinary professional needs for success, and these apply throughout time. But the one that I think most of us forget about is that there's a formula for success. And it really goes like this, success is equal to consistency times, duration times, focus. Now it kind of makes sense on the outset, but if we can just apply consistency in all of our actions, these are intentional things, whether it's training ourselves or how we act in the world, right? And then if we can do this over a long period of time, even though small changes begin to add up. But the secret element here, the variable too often we forget about, is the amount of focus. And that's that intentionality that's actually saying I've got a strategy, a plan, because success can be defined in many, many different ways, and for us, however we're going to apply that, we're going to do the same things, and even if it's small, over a long period of time, we're going to have a lot of focus, and then we're going to just continue to build on those skills and whatever success we have. So it's 1 of those things where there's four other lessons that we're going to talk about. But if I had to sum it up and say, gosh, you know, guys, success is consistency, times duration, times focus, rocket ship.

Videos

Catch an exclusive sneak peek from Ernie Ward, DVM, CVFT, as he shares 1 of his secrets to success ahead of Fetch Charlotte 2025.

The formula for success in veterinary practice

Domenico Santoro, DVM, MS, DRSC, PhD, discusses culturing and PCR in this interview 

The challenges of diagnosing fungal infections

According to Domenico Santoro, DVM, MS, DrSc, PhD, DACVD, DECVD, DACVM, associate professor at the University of Florida College of Veterinary Medicine, and service chief of dermatology in the Department of Small Animal Clinical Sciences, the main challenge when diagnosing fungal infections is actually making an accurate diagnosis. In this interview, Santoro emphasizes the importance of culturing to identify the causative agents of the infection. He also talks about the polymerase chain reaction (PCR) technique and when this technique may offer a more effective diagnostic approach than a culture.

Below is the interview transcript, which has been lightly edited for clarity

Domenico Santoro, DVM, MS, DrSc, PhD, DACVD, DECVD, DACVM:

 The most common challenge that we see in diagnosing fungal infections is actually making an accurate diagnosis. And the reason is because sometimes it's not easy to identify these organisms as a causative agent of the disease that we see. Sometimes even with 

—so for yeast dermatitis—sometimes we have [a] hard time identify[ing] [it] due to... a secondary issue....

With dermatophytes, it’s even a bit more complicated just because...the diagnosis is based on multiple types of techniques and specifically done by the identification of the fungi after culture. And if we do not do a culture, at times it can be kind of tricky, ...again, to figure out if [it] is a causative agent or not.

Other techniques may involve a [polymerase chain reaction] (PCR) for example, but the PCR may not necessarily identify that the dermatophyte is a causative agent. At times it is not able to differentiate live organisms from dead organisms. So even monitoring the therapy, it can be complicated through PCR, so that's why the culture is the best way.

There are also other more uncommon fungal infections, or fungal-like infections, like pythiosis, for example, which a PCR of the tissue can be a more sensitive diagnostic. So it really matters what type of fungal infection we are targeting and...suspecting in our patients.

Domenico Santoro, DVM, MS, DrSc, PhD, DACVD, DECVD, DACVM, discusses culturing and PCR in this interview 

Sandra Koch, DVM, MS, DACVD, offers a comprehensive overview of available therapies for feline patients with this allergic skin condition

Treatment options for cats with feline atopic skin syndrome

Treating feline atopic skin syndrome (FASS) can be challenging, as treatment options for cats with this condition are limited, according to Sandra Koch, DVM, MS, DACVD, professor at the University of Minnesota College of Veterinary Medicine and director of the school’s Veterinary Medical Center Dermatology Service.

In this interview discussing her lecture on FASS at the 2025 Western Veterinary Conference, Koch goes into detail about treatment options available for FASS. As Koch explained, although there is a wide range of treatment options for dogs with allergies, research on the pathogenesis of this condition in cats is lagging. 

The majority of patients with FASS will need systemic medication, Koch explained. In severe cases, Koch recommends beginning with a higher dose of steroids, as it will increase the chances of the treatment being effective. Moreover, it is important for veterinarians to ensure that they are using prednisolone and not prednisone, as prednisone is not metabolized well in cats.

Another treatment option available for cats is cyclosporine. However, as Koch explained, veterinarians should keep in mind that this medication is slow-acting. In patients with severe pruritus, this medication may not be ideal as an initial treatment. Instead, veterinarians can begin with steroids and transition to cyclosporine or combine both.

Below is a partial interview transcript that has been lightly edited for clarity.

I think [managing FASS is] a combination of strategies and creativity, because unfortunately, cats with FASS don't have as many treatment options available to them as there are for dogs with allergies. Research is moving very slowly in the understanding of the pathogenesis of this condition in cats compared [with] dogs. And if we don't understand the disease very well, it becomes more of a challenge to treat.... For example, in dogs, you have many labeled medications, from Apoquel [oclacitinib]...Atopica [cyclosporine]...many other generics. You [also] have Cytopoint [lokivetmab]—you have a multitude of options. [With] cats, we are limited to steroids [and] cyclosporine, which have been shown to have good efficacy. There's evidence based on good studies.

For everything else, there's no good evidence yet that [the treatment] works.... We’re very limited in options.

Sandra Koch, DVM, MS, DACVD, offers a comprehensive overview of available therapies for feline patients with this allergic skin condition.

Our host Adam Christman, DVM, MBA, welcomes Tyler Primavera, DVM, to the show to discuss his recently published children's book

The Vet Blast Podcast presented by dvm360: Lessons from Eli: A veterinarian's perspective on pet love and loss

On this week's episode of The Vet Blast Podcast presented by dvm360, our host Adam Christman, DVM, MBA, and special guest Tyler Primavera, DVM, discuss his new book 

. The book was inspired by his own dog as a way to talk about all the good and bad days of owning a pet with children, giving them a place to learn about caregiving, grief, and the human-animal bond. 

Throughout the episode, Primavera and Christman discuss grief in the veterinary space, the importance of addressing grief with children, and what his journey to become a children's book author looked like. 

You know, at our fetch conferences this year, our theme is storytellers, because we're all storytellers in what we do and what we say, whether we're in the exam room or not. This is one chapter I would say in your life journey that you're talking about of doing something that's really remarkable, and part of your legacy is telling the story, and now everyone gets to share the love of Eli in this book that you've done. So which is, that's got to make you feel amazing, right? What a nice tribute.

: Yeah and the funny thing is, you know, when writing this book, I couldn't really decide what age group this was for. And a lot of kids, they'll read it and they say, I love this one silly part, and completely miss the point of the book or they just see it from a different perspective, and their point of the book is not what I intended.

: One of your points of the book, which is something that can be very challenging for children specifically to understand, is grief. And you know, what are some of the tips out there to help clients handle grief?

I think everyone handles it differently. You know, it, it may take different forms of connection with your inner circle, your family, your friends, also taking care of your physical body, I think is an important part of that. But really there's all the stages of grief, and I think being patient is a big part of it. Like being patient with yourself, I think you and I, Adam, are both type A people. We want things done yesterday, and we can be very hard on ourselves, but just giving us that, that grace to say, hey, it might take me longer than I would like to get over this, and I'm not okay right now, but that's okay because it's not forever.

Podcasts

On this episode of The Vet Blast Podcast presented by dvm360, Adam Christman, DVM, MBA, and Tyler Primavera, DVM, explore the world of grief through Primavera's recently published children's book

 Lessons from Eli: A veterinarian's perspective on pet love and loss

As the demand for animal care grows, more veterinary centers, as well as animal supply stores are opening. These veterinary facilities, equipped with newer technologies and suites, help improve access to care for pets, livestock, and other animals. Animal supply stores, meanwhile, help meet the everyday needs of animal owners.

Below are 3 animal care business that have recently opened:

Ribbon Chewing Ceremony. (Photo courtesy of Lovet Pet Health Care)

Formerly known as AZPetVet, Lovet Pet Health Care—a network of animal hospitals in the Phoenix, Arizona area—has opened the doors to a new hospital in Queen Creek, Arizona. The new location marks the network’s 23rd hospital in the greater Phoenix area.

Lovet offers a series of services, including urgent; primary care; surgery; and advanced services like acupuncture, cold laser, endoscopies, cardiology consultations, care for reptiles and other exotics, and more.

 The network also offers same-day appointments and welcomes walk-ins. To mark its new opening, Lovet held a community event with a Ribbon Chewing Ceremony, where a rescue dog from #LovePup, a local 501(c)3 rescue focused on shelter prevention, chewed through an edible ribbon.

Virginia Veterinary Centers (Short Pump, Virginia)

Virginia Veterinary Centers (VVC) recently announced the opening of a new 32,00 sq ft emergency and specialty veterinary hospital in Short Pump, Virginia. The new center is providing 24/7 emergency care and a variety of specialty services like ophthalmology, radiation oncology, neurology, and more. Moreover, the hospital contains a critical care unit (ICU) with high-ﬂow oxygen and ventilators, dedicated isolation suites for respiratory and gastrointestinal infectious diseases, radiation therapy, 7 surgery suites, 31 exam rooms, and a full in-house lab.

"We are thrilled to open the doors to our new state-of-the-art hospital, designed with both innovation and care in mind. With the latest medical equipment and a team of world-class specialists, we are poised to oﬀer exceptional care to pets in our community,” Andrea Bulifant, VVC director of operations said in an organizational release.

 “This facility reﬂects our commitment to the health and well-being of animals, providing cutting-edge diagnostics and treatment options that were previously unavailable to metro Richmond area. Pet owners can now feel conﬁdent knowing that their beloved companions will receive the highest level of care in a compassionate and advanced environment."

Feeds’n Needs Hammonds Plains interior. (Photo courtesy of Feeds'n Needs)

In Nova, Scotia, Canada, Feeds’n Needs Hammonds Plains—an animal feed and supply retail store—has opened. With 15 stores in Canada, Feeds’n Needs is the retail division of Shur-Gain/Trouw Nutrition. The store offers dog, cat, small animal, birds, farm, and lawn and garden supplies under one roof.

"We are excited to open our doors in Hammonds Plains and become a part of this vibrant community," Brittni Crowell, Hammonds Plains store manager, said in a company release.

 "Our store offers an extensive selection of pet supplies, livestock feed, wild bird food & supplies, and gardening products, all under one roof. We look forward to welcoming our customers and providing them with the best shopping experience."

Lovet Pet Health Care marked the grand opening of its newest hospital in Queen Creek with an adorable ‘Ribbon Chewing Ceremony’ led by local rescue dog from #LovePup. News release. Lovet Pet Health Care. February 26, 2025.

Urgent and primary care. Lovet Pet Health Care. Accessed March 12, 2025. 

Virginia Veterinary Centers (VVC) Short Pump is now open. News release. Ethos Veterinary Health. March 5, 2025.

Feeds’n Needs opens new location in Hammonds Plains. News release. Feeds’n Needs. February 21, 2025. Accessed March 12, 2025. https://prnmedia.prnewswire.com/news-releases/feeds-n-needs-opens-new-location-in-hammonds-plains-815160160.html

Take a look at these newly opened, coming soon, or expanding animal care establishments