Dog Whisperer’s Dog, Daddy, has died.

Dog Whisperer Cesar Millan’s favorite pit bull, Daddy, has died. The 16 year old pit bull was well known to Millan’s audience as the role model for calm submissive behavior, and had become instrumental in helping to repair the image of pit bulls as violent, savage, uncontrollable beasts. Daddy first came to live with the Millans at 4 months old when he became too challenging for his original owner, rapper Redman. Up until the time he retired at age 14 years, Daddy was Cesar’s right-hand man (or should that be pawed dog?), helping him to rehabilitate many “unbalanced” dogs. His last official task was to train his replacement, the pit bull Junior, who Cesar received about two years ago. In his retirement, Daddy was diagnosed with cancer (type unspecified) and “successfully” received chemotherapy.

If you would like to honor Daddy’s memory and the contribution he made to improve the lives of other animals, you can make a donation to Daddy’s Emergency Animal Rescue Fund, which will provide assistance for dogs who are victims of abuse or violence, man-made disasters (hoarder and puppy mill rescues), and large-scale natural disasters (hurricanes, fires, and other natural catastrophes).

Daddy’s death and recent battle with cancer brings up an interesting topic- that of Comparative Oncology- comparing naturally occurring cancers in animals and people, and exploring their similarities and differences. A 2006 Scientific American article, “Cancer Clues from Pet Dogs“, by David J. Waters and Kathleeen Wildasin, discusses how treating cancer in dogs may have beneficial consequences for both dogs and humans.

Consider this- more than one third of American households have dogs, and nearly four million of these dogs will be diagnosed with cancer each year. Comparative Oncologists would ask, “Why not transform the cancer toll in pet dogs from something that is only a sorrow today into a national resource, both for helping other pets and for aiding people?” (Waters and Wildasin).

Pet dogs can reveal a lot about human cancers for several reasons:

• They are frequently afflicted with the same cancers that affect people. Examples include:
  • lymphoma in dogs and medium and high grade B-cell non-Hodgkin’s lymphoma in people
  • osteosarcoma (bone cancer) in large breed dogs and the osteosarcoma seen in adolescents
  • bladder, breast, prostate, mouth cancers and skin melanomas.
• Metastases (cancer cells that have traveled to other sites in the body) often spread to the same sites in dog and man
• Compared to humans, dogs have a “compressed” life expectancy, which allows researchers to determine whether therapies are beneficial in dogs sooner than they would be in people.
• Trials for experimental cancer treatments for humans are stacked against success. In order to ensure potential benefits outweigh risk, new drugs are often tested on the sickest patients first. Cancer patients in earlier stages, who might show greater benefits, are not tested unless results are seen in those sicker patients.

Because of these factors, treating cancer in dogs can help:

• Study mechanisms of how cancer spreads (metastasizes)
• By being a faster way to determine which therapies should go to human trials, and what range of doses may be most effective.
• Work out the means of treatment therapy- such as optimizing the route of drug delivery.

A great example of this last concept is seen with osteosarcoma in teenagers. Twenty-five years ago, the diagnosis of osteosarcoma in a teenager meant amputation of the limb involved, chemotherapy which was ineffective, and high mortality rates. Now, because of techniques partially perfected by work on pet dogs at Colorado State University, limb-saving procedures and significantly improved rates of survival for osteosarcoma patients have been achieved.

Dogs may also help themselves and humans in the prevention of cancer. They can act as sentinels for potential cancer-producing hazards by highlighting geographic “hot spots” where animals and humans have increased cancer rates. They can also be used to test cancer protective substances. A good example of this was seen in trials of selenium in dogs. The supplement showed promise in decreasing prostate cancer rates, but only at moderate doses. This helped researchers streamline the process of dosing the preventative supplement.

Now, before I get a bunch of emails stating that I am advocating widespread “experimentation ” on our pets, I want clarify that this is not the case. As an avid dog lover, who lost a dog to bladder cancer four years ago, I wish I had known about potential research studies for dogs when our pet was undergoing chemotherapy. Even if it hadn’t helped our dog, it may have helped another dog, or possibly even a person with bladder cancer. In addition, the cost of chemotherapy is not cheap, and for many families (most of whom do not have health insurance on their pet), it is prohibitive. A clinical cancer trial may be the only opportunity they have to treat their pet, rather that letting the disease run its course, or putting their pet down. It could be a win-win situation for all involved.

In 2003, the National Cancer Institute developed a Comparative Oncology Program which designs clinical trials for dogs. A link to their site is here.