DEAR DR. FOX: In at least one past column, you strongly discouraged using Frontline on dogs and Advantage on cats because of the risk of cancer. I also vaguely recall that these products came out or became popular in the late 1980s.
We started using these medications at our veterinarian's recommendation beginning in the '80s. Since then, both of our dogs were diagnosed with terminal cancer at ages 12 and 13, as were two of our three cats at age 10. The last one was recently diagnosed. We have another cat, 11, who doesn't get this treatment because she never goes outside; therefore, she is the only one not to contract cancer. The other two cats have gone outside on a 20-foot rope attached to our garage, and we check them regularly. The dogs went out on a rope to do their business and were walked on a leash.
None of our previous dogs and cats ever had these products -- and they never had cancer. Our dogs lived to 14, 16 and 17. One cat lived to 19; the other two died at young ages when we were young and naive about letting them loose outside.
Could you cite a study that documented this phenomenon? -- D.A.R., Reston, Virginia
DEAR D.A.R.: Cancers that are not caused by viruses or specifically identified carcinogens such as asbestos have complex causes. Some of those causes include genetic and epigenetic susceptibility, coupled with environmental triggers including radiation, consumption of DNA-damaging food and water contaminants, and exposure to various chemicals. Furthermore, some chemicals, like dioxins, are more toxic in minute doses over a long time period. While in the body, chemicals can break down into metabolic byproducts that can be damaging, and they can combine with other chemicals to be more harmful than when tested alone.
Since it can be extremely difficult and costly to confirm that one synthetic petrochemical or other compound is safe, it is common sense and good preventive medicine to invoke the precautionary principle, which calls for greater vigilance and never using any such products of the Age of Chemistry without accepting the potential risks, which generally outweigh the benefits.
Read more on this subject -- which your experiences certainly support -- on my website, DrFoxVet.net. You can also read about the related risks to humans and companion animals from exposure to the chemicals released unwittingly into the environment that end up inside other life forms.
DEAR DR. FOX: I never hesitate to email you when I disagree with your views regarding trap-neuter-release, so I felt it only appropriate that I do the same when I agree with you on an animal-related issue. Your column supporting the reintroduction of cougars and wolves in areas where they once thrived was "spot on" -- as the Brits say.
Obviously, as you note, such efforts need to be carefully controlled, but they are definitely doable. The cougars are making their way back east of their own accord anyway. There are definitely wilderness places where wolves and cougars could be re-established in limited numbers. There are plenty of deer (and coyotes) available to sustain the wolves and cougars, and the deer population would not be endangered by the reintroduction of such predators.
In urban and suburban areas, wolves and cougars could not coexist with humans, but in large, sparsely populated rural and forested areas, such reintroduction could work. We already coexist with a growing black bear population. I applaud your position on this issue. -- T.R.S., Olney, Maryland
DEAR T.R.S.: There does seem to be a groundswell of public support for "rewilding" of deer as well as wolf and American lion prey-rich habitats. This would benefit from encouraging natural recolonization and would help establish viable populations of these large predators.
I am currently reading Dan Flores' remarkable book "Coyote America: A Natural and Supernatural History," which I highly recommend for all readers who are concerned about the future of wildlife and their environments in North America. Readers will be engaged immediately by the historical, cultural and ecological insights Flores provides with scintillating wit and wisdom. He raises a significant point that effective municipal control of free-roaming dogs across the United States has reduced competition over food resources for the opportunistic, relatively omnivorous and highly adaptive coyote. The coyote has also benefited from America's decades-long extermination of wolves and lions. While some 500,000 of these incredible desert song dogs are killed annually -- including around 80,000 at taxpayers' expense by USDA Wildlife Services for the livestock industry -- they outwit their human adversaries at every turn and are in every state and ever more suburbs and urban environments. Their resilience calls for greater respect and understanding, as advocated by Flores and projectcoyote.org.
The coyote challenges us to find peaceful ways of coexistence for the good of all and to appreciate the presence of a native carnivore who provides significant ecological benefits to healthy ecosystems -- including our own backyards and communities.
(Send all mail to email@example.com or to Dr. Michael Fox in care of Universal Uclick, 1130 Walnut St., Kansas City, MO 64106. The volume of mail received prohibits personal replies, but questions and comments of general interest will be discussed in future columns.
Visit Dr. Fox's website at DrFoxVet.net.)