Tag Archives: pet cancer

Can Pets Get Cancer from Cigarette Smoke?



You must have been living on a desert island for the last few decades if you are not aware of the danger that smoking poses both to smokers and to the people who come in contact with second hand smoke. Less well known, however, is the effect that a smoke filled home can have on pet health.

First some definitions. Second hand smoke is smoke that is exhaled or otherwise escapes into the air and can then be inhaled by non-smokers, including pets. Third hand smoke is the residue from smoke that remains on skin, fur, clothing, furniture, etc. even after the air has cleared. Both second and third hand smoke can be referred to using the term “environmental tobacco smoke,” or ETS.

Now let’s take a look at the scientific studies that reveal a link between environmental tobacco smoke and serious diseases in cats and dogs.


A study published in 2002 demonstrated a greatly increased risk of malignant lymphoma (also called lymphoma or lymphosarcoma) in cats with exposure to ETS. The relative risk for malignant lymphoma in cats with any household ETS exposure was almost 2 ½ times higher than that seen in cats who lived in smoke-free households.

For cats with five or more years of ETS exposure, the relative risk climbed to 3.2. In other words, these poor cats were more than three times as likely to develop lymphoma as were cats who lived in a home where no one smoked.

This study and others also strongly suggest a link between oral cancers in cats and third hand smoke. It is thought that cats groom the toxins contained in tobacco smoke out of their fur, which damages tissues in their mouths. This eventually leads to oral cancer.


Dogs can become seriously ill after long term exposure to second and third hand smoke as well. Two studies, one published in 1992 and the other in 1998, determined that cancer of the respiratory tract was more common in dogs who were exposed to environmental tobacco smoke. Interestingly, the type of cancer the dogs got was influenced by the shape of their heads.

The risk of nasal cancer increased by 250% when dogs with long noses (picture a Collie) were exposed to tobacco smoke. On the other hand, dogs with short or medium noses tended to develop lung cancer under similar conditions.

When you think about it, these findings aren’t all that surprising. The extensive nasal passages of long-nosed dogs are good at filtering out the toxins contained in cigarette smoke, which protects the lungs to the detriment of the nose. These same toxins pass right through the relatively shorter noses of other dogs and then become lodged in and damage the lungs.

Many other studies underline the damage that tobacco smoke does to the lining of the respiratory tract and a possible link to non-cancerous diseases such as chronic bronchitis and asthma.


By now you might be thinking, “I’ll just smoke outside.” While direct research into the effect that outdoor smoking has on pet health hasn’t been performed, we can look at a 2004 study on infants and draw some conclusions. It found that smoking outside of the home helps but does not eliminate smoke exposure to babies. The infants of parents who smoked outdoors but not inside were still exposed to 5-7 times as much environmental tobacco smoke in comparison to the infants of nonsmokers. Similar results could be expected for pets.

And what about vaping? Again, no direct research into the health effects of second and third hand vaping solution on pet health has been done, but according to the American Lung Association:

In 2009, the FDA conducted lab tests and found detectable levels of toxic cancer-causing chemicals, including an ingredient used in antifreeze, in two leading brands of e-cigarettes and 18 various cartridges. A 2014 study found that e-cigarettes with a higher voltage level have higher amounts of formaldehyde, a carcinogen.

It’s hard to imagine that inhaling substances like these or licking them off their fur could be completely risk free for pets.


Looking at the science brings us to the inevitable conclusion that second and third hand smoke exposure is very dangerous for pets. If you must smoke, do so outside or switch to vaping, but know that you are still likely putting your pets’ health at some degree of risk… to say nothing of what you are doing to yourself.

Diana Ruth Davidson,  Westside Dog Nanny,             Certified Professional Pet Sitter,                            Certified by American Red Cross in Pet First Aid

We offer:  Pet Sitting,  In-Home Dog Boarding, Dog Walking, Overnights in Your Home, Doggie Day Care.

310 919 9372

Processed Food vs. Whole Food for Pet Cancer Patients — What’s Better? Part 1

When a pet is diagnosed with cancer, a series of life-changing events occur. The pet is potentially faced with a treatment protocol involving surgery, chemotherapy, radiation, or some combination of the three on a short or long-term basis. The owner is faced with the uncertainty of not knowing how long the beloved pet will live, in addition to the financial and time-management aspects of managing the pet cancer.

The process of getting a pet’s cancer treated involves many factors that come into play. As I work alongside veterinary oncologists providing chemotherapy or radiation to treat canine and feline cancers, I’ve observed that often the conversation about how to nutritionally support the body to best handle the prescribed treatment may not be part of the initial treatment conversation.

Diet For Dogs With Cancer

Yet, the “you are what you eat” perspective especially applies to cancer patients. The treatments used to manage the disease, or the cancer itself, can affect a pet’s appetite and ability to digest food and absorb nutrients. This is why owners must be proactive in ensuring that the meals entering their pets’ mouths contain ingredients that are highly bioavailable (easily absorbed) so that the nutrients can be readily utilized to fight cancer’s effects, reduce inflammation, resolve infection, and manage other ailments.

My own dog, Cardiff, exclusively eats a whole-food based diet and treats (The Honest Kitchen, Lucky Dog Cuisine, and human foods), and has since he was a puppy. So, even though I took all measures to prevent him from consuming foods and treats that are known to have toxins or are known to be carcinogenic, his body had other ideas and he still developed cancer.

Yet, I generally see that my patients who eat whole-food diets throughout their lives have fewer health problems. Additionally, my patients undergoing chemotherapy, including Cardiff, typically tolerate chemotherapy better than those eating processed pet foods.

Here in part 1 of 2, I will be sharing my perspective on this topic.

What Are the Differences Between Processed and Whole Foods?

Commercially-available kibble and many canned pet diets undergo significant processing to achieve the final product and are thereby considered processed foods. Processed foods contain fractionated ingredients (a process that separates the components of whole foods into smaller parts), like meat and grain “meals and by-products,” which either don’t exist in nature or are radically changed from what nature created.

Conversely, whole foods appear identical or very similar to their natural form. Whole foods contain vitamins, minerals, carbohydrates, and proteins that all work best when consumed together. By breaking nutrients apart, the synergistic qualities of whole foods can be lost. Co-factors essential for digestion may be lacking and can lead to poor absorption of nutrients and digestive tract upset (inappetence, vomit, diarrhea, flatulence, etc.).

Synthetic vitamins may not be efficiently absorbed as compared to natural vitamins existing in whole foods due to improper binding with receptors inside the digestive tract (see visual examples in Good Food/Bad Food: A Little Book of Common Sense Nutrition). Additionally, the body may identify synthetic vitamins as foreign and eliminate them in a process that creates free radicals that are harmful to internal organs.

Natural, whole-food vitamins are generally better absorbed as a result of improved binding with digestive tract receptors, and are not eliminated in a manner that creates additional stress on the body like their synthetic counterparts.

Is Kibble Considered Whole Food?

No, kibble is not considered to be whole food. Even from a visual perspective, which is what drives many owners to feed particular types of food or treats to their pets, kibble doesn’t lend a natural appearance.

Kibble is produced through a moisture-depleting cooking process called extrusion, which requires the body’s gastric acid and pancreatic enzymes, or an external water source, to facilitate digestion. Extrusion also denatures proteins and deactivates enzymes that are essential to the digestive process.

After being high-heat cooked, kibble is sprayed with rendered fat to improve its taste and is also often artificially colored (caramel coloring, etc.).

Kibble is often associated with gastric dilatation volvulus (GDV or “bloat”) in dogs, and vomiting in cats.

Many types of kibble, and some canned foods and treats, have caramel color added to make them appear more like real meat. When it comes down to it, dogs and cats don’t care about the color of their food. The aroma and flavor, yes; the color is added to satisfy humans.

According to information I received while on a media tour at a major pet food brand that produces many types of kibble, studies showed that pet owners responded better to kibble that included caramel color to make it look meatier.

But caramel color has come under fire as a toxic food additive, as it contains 4-methylimidazole (4-MIE), a known animal carcinogen. Studies have found that long-term exposure to 4-methylimidazole (4-MIE) caused lung cancer in mice, so it’s been added to California’s list of Chemicals Known to the State to Cause Cancer or Reproductive Toxicity.

So, by choosing to feed a their pets a diet with ingredients that have been radically modified from nature’s version and added color to replicate real meat, owners may be unknowingly predisposing their beloved canine and feline companions to develop cancer. Considering most pets eat the same 4-MIE-containing foods for morning and evening meals on a daily basis, we’re continually showering their internal organs with a carcinogenic substance that could otherwise be avoided if whole food options were fed instead.

If you haven’t already done so, it’s time to move away from kibble to fresh, moist, whole foods.

Are Canned Foods Considered to Be Whole Foods?

Canned or moist food has water as the primary ingredient and often appears closer to a whole-food format. Some even have real pieces of meat, vegetables, fruit, and whole grains. Such options are better choices for pet owners seeking to feed a whole-food diet than canned foods that appear smooth and “pate-like” without discernible chunks of whole-food ingredients.

Yet, some canned foods appear to have chunks simulating meat but which are actually conglomerations of meat and/or meat and grain “meals and by-products” that appear different from real meat when examined in cross section (after cutting in into the piece). So, make sure to use a discerning eye when comparing canned food options to make sure your pet consistently eats canned diets that are whole-food based.

Unfortunately, many canned or moist foods are congealed or have a glistened appearance; this is due to stabilizing agents like guar gum, xanthan gum, or carrageenan.

Guar gum has its origins in ground guar beans and is a polysaccharide (complex carbohydrate). Let’s Take Back Your Health-Starting Now reports that guar gum actually has some health benefits, as rodent studies showed “reduced body weight and lower blood glucose, even with guar gum making up 15% of the diet.”

Yet, 15 percent of the diet is “over 100 times the FDA Acceptable Daily Intake” for humans and is something I don’t recommend you provide for your pets. Guar gum is linked to digestive tract upset, including soft stools and gas-related bloating.

Xanthan gum is also a polysaccharide—the product of fermentation by Xanthomonas campestris bacterium. Fortunately, xanthan gum hasn’t been correlated with cancer. However, xanthan gum is reputed to be indigestible and, as with Guar gum, animals with digestive tract sensitivities can experience vomiting or diarrhea after eating xanthan gum-infused diets.

Carrageenan is derived from red algae and is another polysaccharide. TheInternational Agency for Research on Cancer (IRAC) has reported “sufficient evidence for the carcinogenicity of degraded carrageenan in animals to regard it as posing a carcinogenic risk to humans.” Like Guar and Xanthan Gum it is also correlated with digestive tract upset.

If you were making home-prepared pet food, you would not add guar gum, xanthan gum, nor carageenan to make the food smooth and shiny. You’d just use basic, whole-food ingredients, perhaps slightly warm the food to release aroma, and then feed it to your pet.

Feeding fresh, moist, human-grade meals during times of illness and wellness is my recommendation.

Make sure to check back for Part 2 of this article where I delve further into whole food feeding for cancer patients.

Diana Ruth Davidson, Chief Pet Officer and Managing Nanny, Westside Dog Nanny

We offer pet services such as:  Pet Sitting,  In-Home Dog Boarding, Dog Walking, Overnights in your home, Doggie Day Care.

310 919 9372