Catching cancer early in dogs and cats

These new blood tests can determine your companion’s risk of developing cancer, and even detect it in its earliest stages.

Cancer can be very insidious. Often, there are few symptoms until it has become advanced. Detecting it in dogs and cats can be even trickier, because they can’t tell you about any subtle symptoms they may be experiencing. So wouldn’t it be great if there was some way to increase our chances of finding cancer before it spread, not to mention the conditions that increase the risk of its development in the first place?

As it turns out, there is a way. A series of simple, new, inexpensive blood tests bundled into a diagnostic panel now allows doctors to detect cancer and other serious problems before they develop in your dog or cat. Created by VDI Laboratories, the tests look for two biochemical markers of inflammation and cancer – TK (thymidine kinase) and CRP (C-reactive protein; cats are tested for haptoglobin rather than CRP) – and are combined with a vitamin D test to give your vet an easy way to analyze your dog or cat’s cancer risk.

1. TK levels offer a crucial clue

If increased levels of TK are found in an animal’s blood, there is a high likelihood of cancer somewhere in the body, or of cancer developing within the next four to six months, unless steps are taken to lower the levels. However, TK levels may also increase with undiagnosed infections since this enzyme is shed by rapidly dividing cells such as bacteria, rickettsia and viruses as well as cancer (making it useful as a general health profile to screen for infectious diseases as well as cancer).

In the healthy animal, an increased TK level indicates the possibility of cancer, just as an increased PSA level in men indicates the possibility of prostate cancer or other prostatic issues (precancerous or infectious conditions). Animals with increased levels of TK may not have active cancer, but may have precancerous conditions that will respond to holistic treatment. Further testing is necessary to monitor TK levels and look for cancer.

In my practice, animals with increased TK levels are supplemented with specific herbal remedies (Healthy Qi, CA Support, etc.) to support their immune systems. The blood is retested one month later. If TK levels are back to normal, no further testing is needed for four months. If TK levels continue to increase, then we must search further for the reason why it’s increasing. A persistent elevation of TK levels predicts the likelihood of cancer developing over the next six months.

2. CRP levels related to inflammation

Chronic inflammation damages cells. If long-term inflammation leads to the production of free radicals and other destructive agents, tissues and organs in the presence of these agents can lead over time to cellular alterations resulting in disease and cancer.

There is a long-standing and studied relationship between cancer and inflammation. There is evidence that inflammation plays an essential role at each stage of cancer (initiation and proliferation), and both tumor and inflammatory cells are able to directly or indirectly either inhibit or stimulate tumor growth. The effectiveness of tumor development has been demonstrated to correlate directly with the degree of inflammatory reactions. And it seems there are interactions between the cytokine chemicals produced by white blood cells in response to inflammatory reactions and tumor growth, and even indications that inflammatory cytokines favor tumor promotion.

Furthermore, with the assistance of inflammation, tumor cells infiltrate neighboring tissues, enter the bloodstream, migrate, and establish remote colonies (i.e., metastases).

Since chronic inflammation leads to many diseases, including cancer, it’s important to know if inflammation is present and to treat it accordingly so that serious diseases do not appear. In dogs and people, testing levels of C-reactive protein (CRP), the second part of this important blood profile, is done to check for harmful levels of inflammation. In cats, testing for a different inflammatory protein, haptoglobin (Hpt), is more useful.

Diagnosing and treating inflammation in the early stages is essential to trying to prevent cancer. In animals with elevated CRP or Hpt levels, specific nutritional supplements (antioxidants, fatty acids, etc.) are administered to reduce harmful inflammatory proteins. Diseases know to be associated with inflammation, such as dental disease, arthritis, and allergies, are diagnosed and treated appropriately to reduce inflammation in the body. The blood is retested in one month and CRP/Hpt levels should have returned to normal. If they haven’t, further investigation is undertaken.

3. Vitamin D3 helps protect against cancer

The final step in this blood profile is to check your dog or cat’s level of vitamin D3. Vitamin D3 is not simply thought of as a vitamin to protect bones anymore. Instead, it has far-reaching effects on every cell in the body, regulating metabolism and gene expression. As such, proper levels of vitamin D3 can have cancer-protective (and cancerkilling) effects; reduce the risk of infectious diseases such as the flu and canine and feline respiratory infections; and promote good health and proper regulation of other body systems.

Unlike people, animals typically do not make vitamin D from exposure to sunlight and therefore require it in their diets or via supplementation. While pet food is formulated with enough vitamin D3 to prevent deficiency disease (rickets), the levels are too low for maximum health. Testing shows most dogs have blood levels considered insufficient for optimal health, and would benefit from supplementation. Low levels of vitamin D have been linked to inflammation, cancer, heart disease, kidney disease, inflammatory bowel disease, and various infectious conditions.

Exactly how much vitamin D3 an individual requires depends on the animal’s size and health, the presence/absence of disease, and most importantly his blood level of vitamin D3. Once the vitamin D3 test results are available, supplementation is given with the goal of shooting for a blood level of 100 mg/ml (in studies, animals with cancers tended to have vitamin D3 blood levels lower than 100.) Additional testing is done to confirm if the prescribed amount of vitamin D3, typically given once daily with food, is enough to reach the recommended blood level.

While these new cancer tests are very helpful for determining the status of your animal’s health before he becomes ill, they are also helpful for monitoring dogs and cats that already have cancer. For those already diagnosed with the disease, monitoring their TK, CRP/ Hpt, and vitamin D levels helps veterinarians make decisions about changing treatment and to predict when/if the cancer may return and when the animal may come out of remission. Fine-tuning an animal’s therapy prior to a failure of remission may keep him cancer-free longer. Cancer is a scary disease, but these ground-breaking new tests promise to be a valuable weapon in the fight against it.

Pros and cons

This testing is very cost effective. In our office, we charge under $200 for the entire three-test profile, making it very inexpensive considering the wealth of information we receive from it. Additionally, this profile is the easiest and least expensive way to screen dogs and cats for cancer and other serious inflammatory diseases.

There are really no disadvantages to having this testing done. It does have limitations, however. It’s very accurate at determining vitamin D levels and levels of inflammation, but in order to detect cancer (or rare infections that might cause elevated TK levels), there needs to be enough of this enzyme released into the blood by the dividing cancer cells. No test can detect just a few cancer cells, so if only tiny amounts of cancer are present, the TK test will miss them. However, once enough cancer is present and producing the TK enzyme, the test is in most cases sensitive enough to allow early detection, before the cancer produces clinically significant disease.

AUTHOR PROFILE

Veterinarian Dr. Shawn Messonnier wrote The Natural Health Bible for Dogs and Cats, The Natural Vet’s Guide to Preventing and Treating Cancer in Dogs, and 8 Weeks to a Healthy Dog. He’s the pet care expert for Martha Stewart Living’s “Dr. Shawn – The Natural Vet” on Sirius Satellite Radio, and creator of Dr. Shawn’s Pet Organics. His practice, Paws & Claws Animal Hospital (petcarenaturally.com), is in Plano, Texas.