Researchers at the Texas A&M College of Veterinary Medicine & Biomedical Sciences (CVM), in collaboration with the Institute for Infectious Animal Diseases (IIAD) at Texas A&M, have received funding for the third phase of research from the U.S. Department of Homeland Security (DHS) to secure the health of dogs working at the United States and Mexico border.
With this new wave of funding, Dr. Sarah Hamer, an associate professor in the CVM’s Department of Veterinary Integrative Biosciences (VIBS); Alyssa Meyers, one of Hamer’s doctoral students; and a team of researchers are taking an in-depth look at dogs working along the U.S.-Mexico border to further study the impending health implications of Chagas disease and the effect this disease has on the canines’ ability to work.
Chagas disease, caused by the protozoan parasite Trypanosoma cruzi, is transmitted through kissing bugs, or cone-nose bugs, and can cause acute or chronic heart disease or death in dogs and humans.
While Chagas disease has long been known in Central and South America, there is now increasing awareness for the disease in the southern United States where kissing bugs occur.
“Though Chagas is an emerging disease that we know is in Texas and know can infect dogs and people, we don’t know the full extent of the impact or spread of the disease,” said IIAD director Melissa Berquist, Ph.D. IIAD is a U.S. Department of Homeland Security (DHS) Science and Technology Center of Excellence and a unit of Texas A&M AgriLife.
“By gaining a better understanding of the geographic areas where dogs are becoming exposed and the prevalence of exposure, we are gaining critical information for health management and vector control programs in order to decrease transmission within the DHS human and canine workforce,” she said.
“The DHS maintains more than 3,000 working dogs across the country, including the security dogs at the airports, customs and border protection dogs, Coast Guard dogs, federal protective service dogs, and secret service dogs,” Meyers explained. “These are highly valuable dogs, often selected for their drive and pedigree, and, unfortunately, our initial research found that up to 18 percent of the working dogs along the Texas-Mexico border were positive for exposure to T. cruzi, the Chagas parasite.”
The team then expanded their study to look at government working dogs across the U.S., not just on the southern border. This expanded study found that approximately 7 percent of the dogs were exposed to the parasite that causes Chagas disease.
After this eye-opening discovery, Hamer decided to narrow the research on the long-lasting health implications of Chagas disease in these working dogs.
“It’s pretty cool work because we’re intercepting these border patrol dogs while they’re working,” Hamer said. “We just want a glimpse, to take a blood sample, monitor their heart, have them run on a treadmill, and we want to put on a Fit Bark—which is like a Fit Bit, but for dogs—all while they’re still working and doing their normal jobs.”
Because there is no vaccination to prevent Chagas disease in humans or animals, and treatment is limited, Meyers said the team also plans to use this grant to focus on what can be done to control the kissing bugs and prevent transmission.
“Vector control includes things like clearing brush where kissing bugs can dwell from around kennels and houses, minimizing the use of light at night because kissing bugs are drawn to light, and securing access to kennels, to prevent bugs from getting in,” Meyers said.
Although securing the kennels may seem like an easy fix, it can be a costly and challenging intervention for these facilities, which house dozens of dogs, according to Hamer.
Along with studying Chagas disease, Hamer’s team will be using the grant to study other vector-borne disease- including those spread by ticks and mosquitoes- that may impact these working dogs.
“Because these working dogs spend lots of time outside where they may be exposed to vectors, they may provide a sensitive indication of the different vector-borne infections across the landscape that are not only important for dog health, but also human health,” Hamer said. “Our studies will have an increased focus on what we can do to ensure these animals remain healthy. We’re excited that Texas A&M University is really helping secure the health of these important animals that are on the frontlines of security for our country.”
Contact Information: Jennifer Gauntt, Interim Director of Communications, Media & Public Relations, Texas A&M College of Veterinary Medicine & Biomedical Science; email@example.com; 979-862-4216
We’ve all seen and heard them—lurking in well-lit, open areas, swooping down from trees, lining up on power lines, and pecking at food left on the ground.
Great-tailed grackles are notorious for congregating in our most frequented parking lots and city parks, but have you ever considered the diseases these pesky birds may carry?
Dr. Sarah Hamer, director of the Schubot Exotic Bird Health Center and an associate professor at the Texas A&M College of Veterinary Medicine & Biomedical Sciences, has focused her studies on just that.
“This species has expanded in geographic range and thrives in urban environments, where it breeds and communally roosts,” Hamer said. “With such a large number of birds in close proximity, we have been interested in the disease-causing organisms that might be transmitted among the birds and potentially to people and other animals.”
To test for these pathogens, Hamer and her team, including students enrolled in a field research course, trapped birds in parking lots around town and collected blood and fecal samples from them.
Although our pets typically do not hang out in parking lots where grackles roost, there is a chance for fecal exposure when walking your dog on well-lit sidewalks, around city parks, or in other areas where grackles hang out. To avoid exposure and contamination, it is imperative that owners keep their pets away from any disease-carrying bird and its feces.
“We tested the feces of the grackles for Salmonella, a bacterium that lives in the gut of animals and can be excreted,” she said. “Fecal contamination can lead to transmission of the Salmonella to other animals or humans. We found that a small percentage of the birds, 2 of 114 birds, or 1.8 percent, were shedding Salmonella in the feces.”
We also examined the blood of the grackle under microscopes using molecular and immunology methods for parasites. According to Hamer, the grackles they have studied were found to be infected with tiny microscopic roundworms, protozoan parasites related to malaria, and West Nile virus. Some of these parasites are zoonotic, meaning they can spread to humans, whereas others only infect birds.
“Avoiding avian feces, or any wildlife feces, is good practice in general,” Hamer said. “If shopping carts are in parking lots with grackle roosts, washing the handles with a hand sanitizing wipe would also be wise.”
Like many other wild animals, they can be infected with pathogens that are detrimental to our health and the health of our furry friends; however, avoiding direct contact with the birds and their feces can minimize risk.
Whether your dog stays outside for hours at a time or is primarily an inside dog, all dogs are at risk for Chagas disease, a potentially fatal disease that affects the heart and other organ systems.
Chagas disease is caused by the protozoan parasite Trypanosoma cruzi, which is spread to dogs through insects in the Reduviidae family, also commonly known as cone-nose or kissing bugs.
“Kissing bugs are blood-sucking insects that often hang out in or around places where sources of blood are readily available, such as dog kennels, woodrat nests, and, unfortunately, sometimes in human dwellings,” said Dr. Sarah Hamer, an associate professor at the Texas A&M College of Veterinary Medicine & Biomedical Sciences. “The parasite is transmitted to dogs when they are exposed to the feces of the bug or when they eat the bugs. About 60 percent of kissing bugs across Texas are infected with the parasite.
“Many dogs can be infected with the Chagas parasite and show no signs of disease, while others may develop life-threatening heart complications,” Hamer added.
Chagas symptoms can appear within weeks of infection (acute) or months to years later (chronic). Typically, dogs that are younger than 2 years old are more likely to develop acute disease, with possible symptoms of diarrhea, lethargy, seizures, swollen lymph nodes, fluid retention, and heart failure. Symptoms that occur during chronic disease are those of congestive heart failure, including lethargy, fainting, increased heart rate or abnormal heart rhythm, and fluid buildup in the abdomen or lungs.
Although there is no vaccine or veterinary treatment for Chagas disease, pets can be protected through insect control.
By reducing the amount of outdoor lighting at night, kissing bugs may be less attracted to an area. If you keep your dog in a kennel outside at night, consider installing a protective screen on the kennel. In addition, try to keep your backyard free of wood piles and other brushy areas, because these areas can serve as a breeding ground for infected insects. Hamer added that licensed pest control operators can help recommend a pest control plan to combat the bugs.
To better protect humans and animals from Chagas, Hamer and a team of researchers have been coordinating a special project since 2013.
“We run a ‘Kissing Bug Citizen Science’ program to engage the public in Chagas research and provide resources for people to better protect themselves and their pets,” Hamer said. “Our program accepts kissing bugs encountered by the public across the southern United States. Submitters provide important data, including the location, time, and behavior of the bug when it was encountered. Each bug provides a wealth of information for our research—we’ve received over 4,000 kissing bugs since the start of our program.”
Hamer added that her research helps to characterize the natural cycle of Chagas transmission and determine risk factors for human and animal exposure.
For more information on Hamer’s project, please click here.
A kissing bug app is also available on iTunes and Google Play. Through the website and apps, Hamer said the public can submit photos of bugs if they are unsure if they are kissing bugs.
With no vaccine or treatment available, prevention is key in protecting your pet from Chagas. Fortunately, Hamer and her team are working to learn more about Chagas and how to better protect you and your pets.
Pet Talk is a service of the Texas A&M College of Veterinary Medicine & Biomedical Sciences. Stories can be viewed on the web at vetmed.tamu.edu/pet-talk. Suggestions for future topics may be directed to firstname.lastname@example.org.
As the new director of Texas A&M’s Schubot Exotic Bird Health Center, Dr. Sarah Hamer brings an array of professional experience and, most importantly, a passion for studying and preserving native and exotic bird species.
As a graduate student at the University of Illinois, Dr. Sarah Hamer spent countless hours inspecting trees and bushes and scanning yards and sidewalks in search of the American crow, transforming residential neighborhoods and community parks into vital sites for her research.
Hamer was tracking and observing this particular species in order to understand their movement, behavior, and nesting habits, hoping to find out why the birds seemed to adapt to urbanization better than other native bird species.
“We sewed radio-transmitters onto the birds’ tail feathers to track their movement and see what habitats they were using,” said Hamer, now an associate professor in the Texas A&M College of Veterinary Medicine & Biomedical Sciences’ (CVM) Department of Veterinary Integrative Biosciences (VIBS). “By understanding how these birds moved and utilized resources, we could identify critical factors that allow these birds to thrive in the urban environment.”
Hamer and her colleagues began to notice that a large number of American Crows were getting sick and dying.
“Because we were tracking their movement, we were able to locate and test the birds quickly after their death,” she said. “Nearly all of the dead birds tested positive for the West Nile virus. The virus impacted a lot of different types of birds, but disproportionately impacted American Crows.
“We also sampled and tested mosquitoes from the key habitats where the crows were roosting at night and found the virus within the mosquitoes, as well,” Hamer said.
As they conducted this sampling, people living in those neighborhoods also were getting sick from the virus, and what began as a young student’s ecology project quickly morphed into research on the relationship between human and animal health.
“That experience as a master’s student really set me on a career path of studying these emerging pathogens that impact animal health, but also impact human health,” Hamer said. “I became very interested in studying wildlife populations and disease vectors, such as mosquitoes and ticks, and how the pathogens they transmit are passed to humans.”
As she was pursuing her doctorate in disease ecology at Michigan State University, she began to realize that much of her work involved communicating with health practitioners, which sent her down yet another route.
“I realized about midway through my Ph.D. that I was communicating with a lot of medical doctors and veterinarians,” Hamer said. “I decided then that if I had a medical background, it might open up more doors for my research, so that’s when I started in vet school.”
After completing her Doctor of Veterinary Medicine degree at Michigan State University, in conjunction with the completion of her Ph.D., Hamer came to Texas A&M University to start a faculty position and lead a research program that focused on the ecology and epidemiology of a variety of human, animal, and vector-borne diseases.
Her work has ranged from Chagas disease in humans, dogs, and wildlife, to conservation medicine for the endangered Whooping Crane, to studies of ticks and tick-borne diseases across the country.
It was her passion for wildlife, paired with her success in mentoring students and leadership in interdisciplinary federally funded research, that led to Hamer’s appointment as the Richard Schubot Endowed Chair and director of the Schubot Exotic Bird Health Center at Texas A&M.
In the role, which includes a joint appointment with the CVM’s Department of Veterinary Pathobiology (VTPB), Hamer oversees the expenditures of the Schubot endowment to enhance avian health research, teaching, and clinical practice, including work conducted at the unique and world-famous aviary for exotic and native birds.
“I’m fortunate that my research and my hobby have converged,” Hamer said. “I’ve loved raising birds for most of my life and being a bird watcher. Being out in nature—studying wild populations and trying to keep them healthy—has helped fuel a lot of the research questions that I’m asking.”
Her leadership position gives her a chance to assist researchers and current students in reaching their academic goals, while also expanding on the current scholarship in which the center is engaged.
“It is awesome to be surrounded by so many people who are united by their passion for bird health. I value this opportunity to help solve important bird health problems and to provide meaningful training experiences for students,” Hamer said. “I also have a vision to expand the scope of the types of bird work the Schubot group tackles.”
Part of that expansion involves finding opportunities for internal and external partnerships.
“I’m looking to grow collaborations with a number of partners that also share this mission of improving avian health,” Hamer said.
Partnerships, Hamer said, are going to be essential as the team at Schubot moves forward.
“Many pressing issues with respect to avian health are complex, requiring expertise from different disciplines,” she said. “We will combine the strengths within the Schubot Center and partner with others to expand our capabilities and solve these complex problems.”
Hamer said the Schubot Center’s strong foundation has provided her with a great opportunity to lead researchers and establish the center as a powerhouse in avian health research.
She said the resources and facilities at Texas A&M will help tremendously.
“We have a lot of resources and capability as one of the top vet schools at this big, tier one research institution,” she said. “Combine that with what we have in the wild lands just outside of our campus and it puts us in a good position.”
Education and research will be one-and-the-same in the center under Hamer’s leadership.
Because her education helped her discover her passion for studying zoonotic diseases, Hamer hopes to empower students with similar opportunities to launch into their own career paths focused on improving health.
Combining her teaching and research, for example, Hamer co-designed a new, high-impact course, “Methods in Vectorborne Disease Ecology,” with funds awarded to her as a Montague Teaching Scholar. In the course, small teams of undergraduate and graduate students worked together to conduct original research throughout the semester. Several projects centered on wild bird health.
“Our students completed a study that was published last year looking at zoonotic pathogens associated with the Great-Tailed Grackles, the large, black, noisy birds that hang out by the hundreds in the urban grocery store parking lots around town,” Hamer said. “We worked through the federal, state, and local permits necessary to allow our students to capture and band the birds and also collect blood and fecal samples that the students then analyzed back on campus.
“Our students found that some of those birds were shedding Salmonella, a food-borne pathogen,” she said. “When those birds hang out on your grocery carts that your food is in, this can be an issue. This is an example of how wild birds maintain pathogens that might have an impact on human health.”
Hamer said the Schubot Center’s world-class aviary provides countless opportunities like these for student research studies.
“There is no shortage of students who want to be involved in avian health research—undergraduates, graduate students, and veterinary students,” Hamer said. “These students will continue to be the fuel behind all our research output.
“Education is a key component in my vision for the center. In order to succeed as a research powerhouse, we must serve as a training ground for students of various capabilities,” she said.
Hamer’s leadership at the Schubot Center, she said, is just another way for her to pursue a passion that started as a hobby and led her down a unique educational path—and, hopefully, will lead others to do the same.
“I view my position at the Schubot Center as a way that I can merge some of my own background and perspective with an awesome team of enthusiastic clinicians, faculty, and students so that our research and training can have even more of an impact than we would have been able to individually,” Hamer said.