Pets share a common environment with people making their exposure risk to environmental contaminants similar to that of their owners whereas exposure of food animals to toxins and pathogens can affect public health through food supply. Early detection of environmental risk factors in animals can lead to early intervention and reduce their harmful impacts for both animals and humans.
Toxicology and Analytical Chemistry
Companion animals, livestock and wildlife share homes, farms and the outdoor environment with people. Our companion animals live in immediate proximity to, and are often part of, our families. We are all exposed to the same air, water and sometimes even the same food. So, when one of us is exposed to a toxic chemical, the other is frequently exposed as well. There are many cases in which companion animals, livestock or wildlife have had greater exposure, or were more sensitive to those chemicals and warned us of an imminent danger. For centuries, canaries have warned us of toxic gases in mines. In the 1960s, eagles and falcons warned us of the dangers of DDT. In the 1980s, in older houses with lead-based paint, people with lead poisoning drew attention to lead exposure in their dogs and cats and vice versa. In this millennium, dogs alerted us to melamine in wheat gluten that was being used for dog food, livestock feed, and human food.
The Toxicology section helps this interdependent system by conducting chemical analyses and by providing clients with the results & interpretations of those analyses. Detection and awareness of toxins in our animals and our common environment helps guide treatment of the sick and the protection of the world we live in.
Dr. Stephen B. Hooser
PROFESSOR OF TOXICOLOGY; HEAD, TOXICOLOGY SECTION, ADDL; DIPLOMATE, AND PAST PRESIDENT, AMERICAN BOARD OF VETERINARY TOXICOLOGY
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Dr. Christina Wilson
CLINICAL ASSOCIATE PROFESSOR OF TOXICOLOGY; HEAD CHEMIST, ADDL
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- Indiana Animal Disease Diagnostic Laboratory Website
- American Board of Veterinary Toxicology Website
Environmental Triggers of Respiratory Diseases
Horses, like people, commonly suffer from asthma. In fact, it is the second most common cause of disease in young Thoroughbred racehorses. Exposure to dust in the stall, particularly from hay, is likely an important contributor to the onset of equine asthma. These horses can be treated with anti-inflammatory drugs; however, treatment may not be effective and carries the risk of drug residue resulting in a positive drug test at competition time. Dr. Couetil’s research team is working to identify factors that contribute to the development of equine asthma, such as exposure to mold or viral infections, and develop better methods of treating the disease either with pharmaceuticals or changes in management practices. The team focuses on using horse as a preclinical model to study human respiratory illnesses.
People associated with equine industry like riders, trainers and stable workers are constantly exposed to the same environment as the horses and are at an increased risk of developing respiratory diseases. Therefore the efforts toward improvement of equine environmental health will subsequently benefit human health.
Dr. Laurent L. Couëtil
PROFESSOR, LARGE ANIMAL INTERNAL MEDICINE; SECTION HEAD, LARGE ANIMAL INTERNAL MEDICINE; DIRECTOR, EQUINE RESEARCH PROGRAMS; DIRECTOR, DONALD J. MCCROSKY EQUINE SPORTS MEDICINE CENTER
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- Dr. Laurent L. Couëtil's Equine Respiratory Disease Research Program
- Donald J. McCrosky Equine Sports Medicine Center
Cancer risk from environmental pollutants
Cancers have long latency periods in humans. In other words, it can take many years to several decades to manifest clinical symptoms of the disease after exposure to causative agent/s. This makes it difficult to identify the environmental risk factors for cancer. Since the average life expectancy in dogs is only around a tenth of that in humans, the cancer development processes in dogs are compressed into a much shorter period of time. This shorter latency period for cancer in dogs, coupled with restricted daily movements or travel compared to humans, make them ideal models to study and identify the environmental factors that affect the occurrence and spread of this disease in both pets and humans. Dr. Knapp’s research team at Purdue Veterinary Medicine focuses on finding causes and treatments for urinary bladder cancer in both pets and people. She teamed up with Dr. Larry Glickman, and their team studied exposure levels and adverse health effects of various household lawn and garden chemicals on pets. One of their studies identified lawn herbicide residues in the urine of dogs who had been exposed to lawns i) treated with herbicides or ii) contaminated by drift of herbicides from the neighborhood. The team also carried out a study on the role of herbicides and insecticides in increasing urinary bladder cancer risk among Scottish Terriers. Dogs in this breed are at a much higher risk of developing certain kinds of cancer than mixed breed dogs. Results showed that exposure of dogs to lawns treated with i) herbicides and ii) a combination of herbicides and insecticides was strongly associated with increased risk of bladder cancer. As pets share the same environment and encounter many of the same agents as people, particularly children, they can be sensitive indicators of environmental health and can provide early warning system to gauge public health.
Knapp DW, Peer WA, Conteh A, Diggs AR, Cooper BR, Glickman NW, Bonney PL, Stewart JC, Glickman LT, Murphy AS. Detection of herbicides in the urine of pet dogs following home lawn chemical application. Sci Total Environ. 2013 Jul 1;456-457:34-41.
Glickman LT, Raghavan M, Knapp DW, Bonney PL, Dawson MH. Herbicide exposure and the risk of transitional cell carcinoma of the urinary bladder in Scottish Terrier dogs. J Am Vet Med Assoc 2004;1290-1297.
Raghavan M, Knapp DW, Dawson MH, Bonney PL, Glickman LT. Topical spot-on flea and tick products and the risk of transitional cell carcinoma of the urinary bladder in Scottish Terrier dogs. J Am Vet Med Assoc 2004;225:389-94.
Dr. Deborah Knapp
DOLORES L. MCCALL PROFESSOR OF COMPARATIVE ONCOLOGY; DIRECTOR, PURDUE COMPARATIVE ONCOLOGY PROGRAM; CO-SECTION HEAD, ONCOLOGY
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