Not only people are at risk for their job: even working dogs can face them.
A typical example shows that a surprisingly large number of dogs working for the US Department of Homeland Security are infected with the parasite Trypanosoma cruzi which causes Chagas' disease Disease that can occur in both humans and dogs.
The study analyzed blood samples from 1,660 federal working dogs helping with tasks such as border patrol, search and rescue and detection of drugs and explosives, and assistance in protecting federal buildings. The researchers found that 121 dogs or about 7 percent of the animals tested had antibodies to T. cruzi indicating a persistent infection. [7 Surprising Health Benefits of Dog Ownership]
Affectedly, many of the infected dogs showed signs of heart problems ̵
And although the insects that transmit the disease are called triatomine bug or kissing bedbugs, in parts of the United States – especially in the South – some of the infected dogs have been found in states outside the known range of bugs, including the northern states, found.
"We were surprised that so many dogs, including those working outside the field of kissing beetles, had been exposed to the parasite T cruzi and had heart abnormalities that were associated with the disease "Alyssa Meyers, Ph.D. candidate at Texas A & M University, said a statement.
Meyers presented the results today (October 31) at the annual meeting of the American Society for Tropical Medicine and Hygiene in New Orleans. The study has not yet been published in a peer-reviewed journal.
Disease moves north
Chagas disease was historically found only in Mexico, Central America and South America. But the disease has found its way north – although most cases of Chagas disease in the US are caused by Latin American-acquired infections, a small number of human infections have been found in southern and southwestern states such as Arizona, Arkansas, Louisiana, Mississippi, Tennessee acquired and Texas. In addition, kiss bugs were found in 27 states, and an increasing number carry the T. cruzi parasite, the researchers said.
The infection can cause fever and fatigue in both humans and dogs. But after that, the parasites can be "hidden" in the body for years, or even for a lifetime, according to the Centers for the Control and Prevention of Diseases. In some cases, this chronic infection can lead to heart problems, including an enlarged heart or abnormal heart rhythms.
Federal Dogs train in facilities in Texas and Virginia, two states where infected kissing bugs are known.  Dogs could be exposed to infected, kissing beetles when spending many hours outdoors, especially at night when beetles are most active, the researchers said. Dogs may also be exposed in kennels, where the large number of closely spaced animals can attract and thrive.
Previously, researchers had found evidence that dogs working with Mexico on the US border were at risk of infection T. cruzi . The new study also found an infection in dogs that work most of the time on the Canadian border, and in dogs patrolling Nebraska airports, an unexpected finding, Meyers said.
Finding Chagas disease in dogs in a particular area can be an early warning sign that the disease may also occur in humans soon. Currently, it is difficult to say what the new findings mean for human risk, in part because researchers are not sure how the dogs took the infection.
Dogs may also be at higher risk of infection than humans. partly because they "tend to eat insects that could become infected with the parasite, and dogs spend more time outdoors," Meyers said.
Heart health of dogs
Researchers have also outfitted some of the dogs with a portable electrocardiogram or ECG that monitors the dogs' hearts. Observers showed that more than two-thirds of infected dogs had early signs of heart disease related to Chagas disease.
However, there are no specific therapies for Chagas disease specific to dogs and even pre-existing treatments for humans may not be effective later during the infection.
Dogs are currently being monitored for the progression of their heart problems.
The researchers are also planning a study to find ways to reduce the burden of federal dogs during training with kiss-bugs or in the workplace.
Originally published on Live Science.