“unfortunately, there is no speCifiC approveD treatment for Chagas Disease in Dogs in the uniteD states, although experimental treatments are in Development.”
photos are available on our website, http:// kissingbug.tamu.edu, where you can also find instructions on how to submit a photo for species confirmation and directions for sending kissing bugs in to help our research project. If you find kissing bugs on your property, it may be a good idea to talk with your vet about testing your dogs for exposure to Chagas disease. wHat are tHe signs of disease? In dogs, infection with the Chagas parasite can cause severe heart disease and death, however, many infected dogs will never develop disease. Cha- gas disease has three stages, known as acute, indeterminate, and chron- ic. The acute stage, which occurs in the first few weeks after infection, is often associated with no signs at all or with nonspecific signs such as fever, lethargy, enlarged lymph nodes, and decreased appetite. Uncommonly, dogs may develop severe heart disease dur- ing this stage leading to heart failure or even sudden death with no prior signs. Signs of acute heart failure include leth- argy, subcutaneous edema (fluid under the skin), ascites (fluid in the abdomen), and difficulty breathing due to pulmo- nary edema (fluid in the lungs). Dogs less than one year of age are the most likely age group to develop heart dis- ease during this stage. The indeterminate stage is a period where the animal is infected with the parasite but shows no clinical signs. Many dogs will remain in this indeter- minate stage and never show signs of heart disease, and it is currently impos- sible to predict which infected dogs will eventually develop disease. The chronic stage is characterized by progressive cardiac dysfunction including severe dilation of the heart chambers (dilated cardiomyopathy), conduction abnormalities leading to arrhythmias (abnormal heart beats), and overall weakening of the heart walls. These all result from the pres- ence of the parasite within the heart muscle cells and resulting inflamma- tion (myocarditis). Signs that may be
kissing bugs can be active during the day as well. Additional measures that can be taken to reduce bug exposure include fully screening open areas of kennels to exclude bugs; reducing cracks, crevices, and other dark areas where bugs can hide within the ken- nel and/or around dog resting areas; clearing vegetation in the immediate vicinity; and treating perimeters with safe pesticides. Additionally, breed- ing females in or exposed to at-risk areas should be tested, and positive females should not be bred to prevent congenital transmission. references 1. Barr SC. Canine Chagas’ Disease (American Trypanosomiasis) in North America. Vet. Clin. North Am. Small Anim. Pract. 2009;39(6):1055–1064.
noticed during this stage are similar to those seen in the acute stage (fluid buildup, lethargy) but tend to develop
more gradually. diagnosis and treatment
Dogs can be tested for Chagas dis- ease through the Texas Veterinary Medical Diagnostic Laboratory (http:// tvmdl.tamu.edu). A blood sample is screened for antibodies to the Chagas parasite, and a positive result indicates that the dog has been exposed to the parasite. This test is not able to pre- dict, however, if and when the dog will develop clinical signs of the disease. If the dog does develop heart disease, additional tests such as an echocardio- gram (cardiac ultrasound) can provide further information. Unfortunately, there is no specific approved treatment for Chagas disease in dogs in the United States, although experimental treatments are in develop- ment. In the chronic stage of disease, the heart disease is treated symptomati- cally, based on signs the patient is cur- rently showing. Drugs can be given to improve cardiac contractility, reduce fluid buildup, and manage arrhythmias. In some cases, pacemakers have been placed in dogs with severe arrhythmias. These measures can extend the life of the dog, but as there is no cure avail- able in the chronic stage, affected indi- viduals may eventually succumb to heart failure. How can it Be prevented? There is currently no vaccine avail- able for either dogs or humans, though several research groups are currently working on vaccine development. The most important thing that can be done to prevent disease transmission is limit- ing contact with kissing bugs. Kissing bug nymphs utilize nesting sites such as brush and wood piles, so debris should be cleared from the areas surrounding residences and dog kennels. Dogs ideally should be housed inside at night, though, this does not completely eliminate the risk, as
2. Bern C, Kjos S, Yabsley MJ,
Montgomery SP. Trypanosoma cruzi and Chagas’ Disease in the United States. Clin. Microbiol. Rev. 2011;24(4): 655–681.
3. Curtis-Robles R, Wozniak EJ,
Auckland LD, Hamer GL, Hamer SA. Combining Public Health Education and Disease Ecology Research: Using Citizen Science to Assess Chagas Disease Entomologi- cal Risk in Texas. PLoS Neglected Tropical Diseases. 2015;9(12): e0004235.
4. Tenney TD, Curtis-Robles R,
Snowden KF, Hamer SA. Shelter Dogs as Sentinels for Trypanosoma cruzi Transmission across Texas. Emerg Infect Dis. 2014;20(8): 1323–1326. 5. Texas Department of State Health Services. Chagas Disease Data, https://www.dshs.state.tx.us/ idcu/disease/chagas/data, updated June 29, 2015.
6. Centers for Disease Control and Prevention. Parasites—
American Trypanosomiasis (Also Known as Chagas Disease), http:// www.cdc.gov/parasites/chagas/ gen_info/vectors, updated Febru- ary 19, 2016.
Contact a.m. lopker, m.D., amlopkermd@icloud.com for permissions/reprints. all rights reserved.
5 01 / 05$) 5 0:4 . ": t
Powered by FlippingBook