Thyroid enlargement has been seen in Great Lakes fish and in rodents fed on these fish. President George Bush was also found to have an enlarged thyroid. It is not clear what if any similarities exist among the thyroid conditions in the salmon, rodent, cat, and former President, but further research is needed. The majority of cancers are caused by environmental factors. Since most animal cancers progress at a more rapid rate than the same cancers in humans, they can be studied more rapidly and the results extrapolated to humans.
Cancer is one of the leading causes of death in dogs and cats today.
Compared to humans, dogs develop tumors twice as frequently. Insecticides Associated With Bladder Cancer in Dogs A statistically significant association between exposure to topical flea and tick dips, and the occurrence of bladder cancer in dogs has been found. The risk of bladder cancer was increased further in dogs living in proximity to areas sprayed regularly with insecticides for mosquitoes. This herbicide was a component of Agent Orange, and is the active ingredient in many products on the market. DDT and Breast Cancer Breast cancer is a disease of increasing concern.