HWhen Janet Riordan returned home from a European vacation in January, she expected a storm of tail wagging and barking from her 7-year-old golden retriever, Reggie. The moment she saw him, she knew something was wrong.
 
"He came to me in my arms and appeared to be sobbing. I had never seen an animal behave like that," said Riordan, who lives in Mequon, a suburb of Milwaukee, Wis.
 
A veterinarian confirmed her fears: Reggie had an aggressive form of lymphoma, a cancer of the white blood cells.
 
Riordan knew the toll that lymphoma could take. Four years earlier her father died of it.
 
"It was devastating," Riordan said. "I never thought I would lose my dad and my dog to the same disease."
 
Pet owners share their homes, their exercise habits and sometimes even their food with their four-legged companions. And increasingly, they are sharing the same diseases: Dogs and cats suffer from obesity, diabetes, heart disease, cancer, thyroid disorders and asthma, just like humans.
 
Now researchers are examining the role that pollutants and other environmental factors may play in these dual diseases. Doctors and veterinarians have begun to work together to investigate common risk factors, such as pesticides, air pollutants, cigarette smoke and household chemicals.
 
Pets, like many young children, often have higher exposures to lawn and garden pesticides and to household chemicals that can accumulate in dust or on carpets."Because our pets share our environments, they are exposed to many of the same pollutants as us," said Melissa Paoloni, a veterinary oncologist at the National Cancer Institute in Maryland.
 
Pets, like many young children, often have higher exposures to lawn and garden pesticides and to household chemicals that can accumulate in dust or on carpets.
 
Scientific research is beginning to reveal some links between their environment and their health. Lawn care chemicals may increase the risk of canine lymphoma and bladder cancer. Cats exposed to flame retardants have a higher rate of thyroid disease, according to one study. And researchers are launching the Golden Retriever Lifetime Study, the largest project ever to tackle disease prevention and treatment in dogs.
 
"People are beginning to realize the untapped resource that companion animals present for research in human health," said Rodney Page, director of the Colorado State University's Animal Cancer Center.
 
Lawn pesticides may increase the risk of lymphoma in dogs and in people.
 
Studies in pets can never replace studies in humans, but they can present corroborating evidence. Linking pollutants to human health effects can prove controversial, "but if we can find the same links in dogs or cats, that can have a powerful effect," said John Reif, a Colorado State University veterinarian and epidemiologist. "It's one more piece of evidence that the link is a real one."
 
Riordan will never know what caused Reggie's lymphoma. Golden retrievers generally have a high rate of cancer, most likely for genetic reasons. But some research suggests that environmental chemicals may play a role in the development of lymphoma in dogs.
 
Researchers at the University of Massachusetts and the Tufts University Cummings School of Veterinary Medicine questioned the owners of more than 700 dogs about use of pesticides. Roughly one-third of the dogs had been diagnosed with canine malignant lymphoma, while the other two-thirds had either benign tumors or were undergoing non-cancer surgeries.
 
Dogs whose owners reported use of professionally applied lawn pesticides were 70 percent more likely to have lymphoma, according to the study published in the journal Environmental Research in January.
 
Dogs also were at higher risk of lymphoma if their owners used self-applied insect growth regulators on their yards, such as Nylar, Precor and Gentrol, which control cockroaches, fleas and other pests. However, dogs exposed to flea powders, sprays and on-spot treatments were no more likely to develop lymphoma than those whose owners did not use them,
 
In addition, Scottish terriers exposed to certain herbicides, including the common weed killer 2,4-D, were more than four times likely to develop bladder cancer than those whose yards were untreated, according to a 2004 study by Purdue University veterinarians.

In one study, dogs exposed to certain herbicides had a higher rate of bladder cancer.
 
Linking pollutants to human health effects can prove controversial, "but if we can find the same links in dogs or cats, that can have a powerful effect." -John Reif, Colorado State University  Results of other studies have been mixed, with some showing an increased lymphoma risk in pets exposed to lawn chemicals and others finding no link.
 
Malignant lymphoma in dogs closely resembles non-Hodgkin's lymphoma. More than 60,000 Americans a year are diagnosed with the disease, making it the sixth most common cancer in the United States.
 
"The close interaction and shared household environments of dogs and their human owners provides a unique opportunity for evaluating how herbicide and pesticide exposure may contribute to human non-Hodgkin's lymphoma," the study authors wrote.
 
Pesticides may increase the risk of the disease in people, too. Last year, Danish researchers found that people with high levels of DDT and other organochlorine pesticides were more likely to develop non-Hodgkin's lymphoma years later.
 
"Clearly dogs are not humans, but physiologically speaking, they are very similar," said Lisa Barber, a veterinary oncologist at Tufts University and study author.
 
"The most heartbreaking thing is their short lifespan. It's also what makes them useful models for human disease," she said. Because dogs live accelerated lives compared with humans, researchers can gather information on a lifetime of exposure much more quickly than in people.
 
Using animals as sentinels for human health is not a new concept. More than 100 years ago, miners took caged canaries into coal mines to warn them of toxic gases.
 
Because dogs live accelerated lives compared with humans, researchers can gather information on a lifetime of exposure much more quickly than in people.In the 1950s, thousands of people in Japan died or suffered serious effects from eating mercury-poisoned fish from Minamata Bay. Locals had first noticed strange neurological symptoms in cats, which they described as dancing in the streets before collapsing and dying.
 
Pets also played an important role in drawing a link between asbestos and mesothelioma. In the 1980s, researchers found high levels of asbestos fibers in the lungs of pet dogs diagnosed with the lung disease. The finding helped increase understanding of the threats that asbestos posed to people, said Reif from Colorado State.
 
More recently, researchers have found that ozone, the main ingredient of smog, may contribute to asthma in cats, and household tobacco smoke may be a risk factor for nose, throat and lung cancers in dogs.
 
A rise in hyperthyroidism in cats also has been linked to brominated flame retardants, which are used in upholstery and electronics and contaminate dust and canned cat foods. Cats with overactive thyroids - which can lead to weight loss, increased appetite, hyperactivity and death - had higher blood levels of the chemicals, according to one small study led by Environmental Protection Agency scientists.

Brominated fire retardants, used in upholstery and electronics, have been linked to an increase in hyperthyroidism in cats.
 
Because of their meticulous grooming habits, cats may ingest a lot of dust. The link to hyperthyroidism in felines "should be alarming to parents of crawling toddlers who explore their environments by putting everything in their mouths," said Donna Mensching, veterinary medical director of the Washington Poison Center in Seattle.
 
Toddlers with high exposure to the flame retardants have lower IQs, according to one study. The chemicals also have been linked to altered thyroid hormones in pregnant women, which might harm a baby's brain development.
 
Looking at the way environmental pollutants might interact with genetics in animal breeds susceptible to certain diseases may benefit human health as well.
 
"We know something about their breed history and susceptibility to certain diseases, which may make it easier to tease out gene-environment interactions," said Dr. Robert A. Hiatt, an epidemiologist at the University of San Francisco and a former family physician.
 
The functions of certain genes are very similar in dogs and humans, according to Hiatt. "What we learn from pets may also be applicable to humans," he said.
 
Because of their meticulous grooming habits, cats may ingest a lot of dust. The link to hyperthyroidism in felines "should be alarming to parents of crawling toddlers who explore their environments by putting everything in their mouths." -Donna Mensching, Washington Poison Center  
 
One of many questions the Golden Retriever Lifetime Study aims to address is how environmental chemicals may interact with genes in a breed that is susceptible to health problems. An estimated 60 percent of golden retrievers die from cancer, according to the Morris Animal Foundation, a nonprofit group that is funding the study. As a breed, they may be genetically susceptible, regardless of what chemicals they may have been exposed to.
 
The nationwide study will enroll 3,000 young golden retrievers and follow them through their entire lives. Page, one of the lead investigators, likens it to the Nurse's Health Study, one of the longest running women's health studies in the country.
 
"The opportunity will be quite seminal and transformative in terms of exposure science, because it will offer a new set of data with which to evaluate similarities with human exposure data," Page said.
 
This research also may help experts develop treatments for diseases.

People and their pets are exposed to some of the same household and garden chemicals.
 
"We can cure anything in a mouse, but so many times new drugs fail miserably when taken straight from lab animals to human trials," said Heather Wilson-Robles, a veterinary oncologist at Texas A&M University.
 
Dogs and cats develop diseases spontaneously for many of the same reasons people do, which means experts can predict from pets how a new drug may act in humans. "Mouse models are really important in the development of new treatments, but we are skipping a step when we take a drug from lab animals to humans without first looking to our veterinary patients," Wilson-Robles said.
 
In Reggie's case, Riordan and her vet looked first to human studies to form a treatment plan. He received chemotherapy and experimental high-dose vitamin C injections, a treatment that Riordan had uncovered while researching options for her father. "We thought if it worked in humans, it might work for dogs," she said.
 
In February, less than two months after being diagnosed with canine lymphoma, Reggie died.
 
Riordan wasn't aware of the link between lawn-care products and lymphoma in dogs, but, she said, "we were always really careful about chemicals. We don't use pesticides in our yard or a lot of chemicals in the house."
 
While Riordan hopes researchers may one day be able to prevent dogs like Reggie from getting cancer, she knows tragedy comes with pet ownership. "We love them so much that even if they don't die of cancer, they will ultimately break our hearts," she said.

This article was originally published by Environmental Health News, and is reprinted with permission. Lindsey Konkel is a researcher at Environmental Health News, and a frequent contributor of its original content. A health and environment journalist, she also has written articles for Reuters Health and OnEarth magazine. She is a 2009 graduate of New York University's Science, Health and Environmental Reporting Program.

Environmental Health News is a foundation-funded news service which publishes its own enterprise journalism and provides daily access to worldwide environmental news. 

Photo: normanack/Flickr Creative Commons 

With the media whipping fears about the current flu epidemic into a frenzy, we're all looking for ways to stay healthy. I offer the following tips to help you navigate the flu season with your health, and your sanity, intact.

Vaccinate or Not?

Flu viruses change from season to season, and while a flu vaccine may be necessary and even effective for some people, keep in mind that this season's flu vaccine is based on last year's virus and may not offer complete protection. The decision on whether to get vaccinated should be an individual decision and take your health history as well as your risk of exposure into consideration. While your physician should always be your ultimate source for health information, keep in mind that not all physicians take a holistic view when it comes to preventive health care. Do your homework, and get educated.

Common Sense

Common sense precautions against the flu have not changed over the years. Frequent hand washing is still the best precautionary measure against the flu as well as colds. But don't waste your money on antimicrobial and antibacterial soaps - they don't work against viruses and provide no added value over soap and water. In fact, they may contribute to the spread of resistant bacteria. Don't touch your face unless you've just washed your hands - that's a direct route for viruses to get into your respiratory tract. Listen to what you mother taught you: cover your mouth when coughing and sneezing, and throw the used tissues away - don't leave them for someone else to deal with.

Boost your Immune System

• Take a good multi-vitamin. Do your research and make sure the brand you take has good bio-availability. Most grocery store brands do not meet this requirement.
• Take extra vitamin C. I regularly take 1000mg a day, and I double or triple this when I've been exposed to someone who is sick.
• Sip warm fluids. Sipping hot tea can make your mouth unfriendly to microbes and reduces your risk of getting sick even after you've been exposed. Gargling with warm salt water can have the same effect.
  Use a Neti Pot (nasal saline rinse) regularly to flush your sinuses before microbes have a chance to get a hold in your system.
• Avoid inflammation promoters such as sugar, alcohol and tobacco.
• Optimize your vitamin D levels. Generally, the more optimal your vitamin D levels, the less your chances of getting the flu or a cold. Ideally, you should have your vitamin D levels tested, but if you live in the Northern hemisphere and don't want to pursue testing, experts feel that it's safe to take at least 1000-2000 IU's of vitamin D during the winter months.
• Support your intestinal flora with probiotics. It may seem odd that your intestinal tract's health has anything to do with flu and cold prevention, but most inflammation begins in the gut, which in turn, affects your immune system.
• Get enough sleep. This is one of the best ways to keep your immune system rested and healthy.
• Exercise regularly. Better yet, exercise outside.
• Listen to your body. We all get early warning signs when we're about to catch a cold or come down with the flu. For some, it may be a tickle in the throat, for others, a mild stomach ache, nausea, or simple that "just ain't right" feeling. Gargle with warm salt water, use your Neti pot, increase your vitamin C and D supplementation, and get some rest. Sometimes something as simple as slowing down can boost our immune system enough to ward off a cold or the flu in the early stages.
• Maintain a positive attitude. If you constantly worry about getting sick, chances are, you will get sick. Picture yourself healthy with a strong immune system, and don't stay glued to the news reports of flu outbreaks and pandemics.

I hope these common sense precautions put your mind at ease and help protect you and your family members from flu and cold viruses.

(c) Ingrid King, 2013. All Rights Reserved.