Cancer

A beloved family pet like this boxer has about the same chance of dying from cancer as a human does.

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As I mourned the loss of yet another close friend, I raged inwardly against the beast we know as cancer, the cause of his death. Starting almost 40 years ago when I lost my mother to cancer, this disease has been an ever-present boogeyman in my life and the lives of loved ones. I hate it with the passion of a TV evangelist.

What is cancer? Cancer comes in many forms, but always starts as changes in DNA. A gene or strand of DNA is injured, changing signals in how the cell divides. Cell division runs out of control, requiring no signals to multiply like a normal cell does. Cancer is also a trickster, sometimes fooling the immune system into protecting it, ignoring signals for apoptosis or “programmed cell death” that normally tell cells to stop dividing or to die, and persuading blood vessels to grow and supply it with nutrients. As the cancer grows, it forms a tumor and may break into chunks and spread around the body (metastasis).

Humans, however, are not the only species to deal with cancer in its many forms. Animals, wild and domestic, are also susceptible. One study, published in the journal, Nature, documented death by cancer in ten percent of 110,148 individuals across 144 of 191 mammal species investigated living in zoos.

Research shows that cancer reaches back millions of years as well. Even dinosaurs dealt with cancer. Specimens of hadrosaurs, or duck-billed dinosaurs, and centrosaurus—horned, plant-eating dinosaurs, and the 240-million-year-old stem-turtle all had it. Metastatic cancer and osteomas have also been detected in mosasaurs (great aquatic lizards) as well.

One thing that I have been grateful for is that cancer is not contagious. If I get it, it is mine and my wife is safe. That is not true throughout the animal kingdom. One form, called contagious neoplasia, is similar to human leukemia and in some animals can be passed from one to another. Species at risk are usually clams, mussels and other bivalve mollusks. It is interesting that these species seldom have contact with each other, but do share water that they filter.

Tasmanian devils, predatory marsupials of Australia, can pass a facial cancer from animal to animal when they bite each other, something that they apparently do routinely. This cancer had been 100 percent fatal and threatens the species with extinction. The devils are fighting back though with an immunity that is developing far quicker than most evolution normally occurs.

Dogs also can share a venereal cancer called canine transmissible venereal tumor (CTVT). This one is unique in that it behaves like a parasite. The tumor cells are the infectious agents, and the tumors they create are not genetically related to the host dog. This seems to be especially prevalent in packs of feral dogs.

In the 1970’s, researcher Sir Richard Peto postulated that given that larger animals have more cells and more cell divisions, they should be at higher risk of cancer than smaller animals. Thus, a mouse should have less likelihood of developing cancer than a whale. Called Peto’s Paradox, Peto determined that this is actually not the case. Later studies, for instance the one reported in Nature, demonstrate that, “cancer mortality risk is largely independent of both body mass and adult life expectancy across species.”

Some animals are less susceptible to cancer than others. An example is the elephant which is about four times less likely to develop cancer than a human. The reason scientists have been able to propose is related to a tiny protein dubbed, p53 or “the guardian of the genome”. “It stops damaged cells from copying themselves so they can be repaired, and, if they can’t, it causes them to die, meaning DNA damage can’t build up into cancer.” And as it turns out, elephants have 20 copies of tp53 the gene that manufactures slightly different varieties of p53, while humans have only one copy.

Our favorite pets, dogs and cats, are also susceptible to cancer. Some breeds of dogs, golden retrievers, boxers and rottweilers, to name a few, seem particularly vulnerable, especially in later life which seems to contradict the conclusion of the study in Nature.

Cancer is the devil itself and almost all living animals are susceptible to it. It just seems so strange that it starts with a mess-up in the division of a single cell, something that can be initiated by environmental factors, dietary habits or simply genetics. I get that no one gets out of this life alive, but I hope I don’t have any more family and friends who have to battle this disease. 

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Help Idaho Wildlife

When we traveled across the state in October 2017, most of the vehicles we saw using the wildlife management areas did not have wildlife plates. Buying wildlife plates is a great way for non-hunters and hunters alike to support wildlife-based recreation like birding.

C'mon folks, let's help Idaho's wildlife by proudly buying and displaying a wildlife license plate on each of our vehicles! 

See below for information on Idaho plates. Most states have wildlife plates so if you live outside Idaho, check with your state's wildlife department or vehicle licensing division for availability of state wildlife plates where you live. 

And tell them that you heard about it from Nature-track.com!

Wildlife License Plates

Idaho Wildlife license plates provide essential funding that benefits the great diversity of native plants and wildlife that are not hunted, fished or trapped—over 10,000 species or 98% of Idaho’s species diversity. Game species that share the same habitats (such as elk, deer, antelope, sage-grouse, salmon, trout) also benefit from these specialty plates.

No state tax dollars are provided for wildlife diversity, conservation education and recreation programs. Neither are any revenues from the sale of hunting or fishing licenses spent on nongame species. Instead, these species depend on direct donations, federal grants, fundraising initiatives—and the Idaho Wildlife license plates.

Both my vehicles have Bluebird Plates. I prefer the bluebird because the nongame program gets 70 percent of the money from bluebird plates, but only 60 percent of the money from elk and trout plates - 10 percent of the money from elk plates supports wildlife disease monitoring and testing programs (to benefit the livestock industry) and 10 percent from cutthroat plates supports non-motorized boat access.

Incidentally, in 2014, the Idaho Legislature denied the Department of Fish and Game the ability to add new plates or even to change the name of the elk and cutthroat plates (very specific) to wildlife and fish plates, a move that would have allowed for changing images occasionally and generating more revenue. It would seem that they believe that we Idahoans don't want a well funded wildlife program.

I think it is time we let the Legislature know that Idahoan support wildlife funding and that we would like to see these generic plates come to fruition.