Bearing down on grizzlies By Dr. David Suzuki

Years ago, I was surprised to learn that a grizzly bear is protected in the United States, but if it walks across the border into British Columbia, it can be killed for sport. So we did a program on them for the CBC’s The Nature of Things. I was amazed to see pictures from the 1800s of immense piles of skulls from grizzlies that were slaughtered to make room for early settlers on the prairies.

Grizzlies were not just mountain animals; they flourished on bison all the way across Canada to Manitoba and south to Texas and California — where the only place you’ll find one now is on the state flag! Grizzlies need space. Tagged animals have been known to travel over hundreds of kilometres in a season. But the cumulative impacts of habitat loss and fragmentation from logging, mining, road-building, urbanization and other land-use pressures have forced them into isolated patches of territory.bear canstockphoto21007677

The U.S. Endangered Species Act lists the grizzly as “threatened”, meaning it is in danger of becoming extinct. Grizzly bears in Canada are ranked as “special concern” by Canada’s scientific committee on species at risk, the Committee on the Status of Endangered Wildlife in Canada, or COSEWIC, but remain legally unprotected. In the absence of legal protection, they continue to be hunted unsustainably in B.C.

The B.C. government argues that the grizzly hunt is sustainable, but the methods by which it estimates bear numbers are imprecise. Many leading bear biologists say the B.C. government’s numbers — about 17,000 grizzlies — are high and that the number may be as low as 6,000. When scientists and researchers are unable to determine accurate population numbers, they often rely on the precautionary principle to ensure sustainable management. This is the idea that when potential risks exist, it’s better to be safe than sorry. In other words, if we suspect that grizzly populations are imperiled, we should stop killing them, even if we aren’t yet 100 per cent certain about the existing population size or rate of decline.

Some might ask why we should protect the grizzly. After all, it’s a large, dangerous animal that has been known to kill humans and livestock. But the dangers are exaggerated: grizzlies tend to be more afraid of than threatening to people, and their impact on livestock is minimal. More importantly, grizzlies are essential components of the ecosystems where they live. They help to disperse seeds and nutrients throughout the forest, and because they eat both plants and animals, they have a significant “top-down” influence on the food web. When salmon are spawning, grizzlies carry the fish into the forests to eat them, leaving much of the carcass behind. Those salmon remains feed many other birds, mammals, invertebrates and microorganisms, and the nutrients in the rotting carcasses fertilize the surrounding trees. It’s a marvelous story of interconnections and interdependence.

The B.C. government has made some progress in grizzly conservation by setting aside some of its habitat, including the Great Bear Rainforest, as protected areas. But even there, trophy hunting is allowed, and many of the parks and protected areas are likely too small and isolated to maintain the grizzlies’ long-term survival. For this reason, the way we manage the rest of its territory is critical. As a start, the B.C. government must suspend the controversial grizzly hunt, as Alberta has done, and must continue to protect large areas of grizzly habitat from resource development, roads and other human pressures. British Columbia is unique in that grizzlies still inhabit much of the province, even though they have been eliminated from almost all of their historical territory across the planet.

All life on Earth ultimately provides our most fundamental biological needs — fresh air, clean water, productive soil and food for the energy in our bodies. Without nature, we cannot survive, yet we continue to tear at the web of life that sustains us. We are at a critical moment in human history. Humans are shaping the biophysical properties of the biosphere on an unprecedented scale, leading scientists to call this period in geological history the “anthropocene epoch.” We are now the most numerous mammal on Earth, with an immense appetite for resources and the technological prowess to explore virtually every part of the planet in search of them. But we are also driving the rest of nature to extinction as we destroy habitat and pollute air, water and soil.

Charismatic megafauna like grizzly bears require space and resources that clash with our demands. In recognizing their right to survive and flourish, we acknowledge their importance in keeping the planet habitable for us. In developing relationships based on love and respect for other species, rather than such selfish and fleeting pleasure from killing, we may learn how to live in a truly sustainable way.

Dr. David Suzuki is a scientist, broadcaster, author and co-founder of the David Suzuki Foundation.

You can learn more about grizzly bears and the David Suzuki Foundation’s campaign to protect them by visiting

How much Taurine Should I add to a Raw Meat Diet?

By Margaret Gates

Question: How much taurine should there be in the raw frozen diets? The brand I have says each patty contains 0.06%. Another brand I have says their chicken variety has 0.064% and the rabbit only 0.04%. Both companies claim to be providing complete and balanced diets in their raw formulas. It’s so hard to know. I would really rather avoid adding supplements if I can help it.
There is no “precise” feline requirement for taurine, as many factors influence requirement levels. These include protein source, dietary fiber levels, food processing, sulfur-containing amino acid content and the metabolic needs of the individual cat.¹ Recommended ranges for an average cat fall between 35 and 250 mg a day.² The AAFCO lists .2% as the minimum for canned/wet foods (dry matter percentage), so here are some calculations: ³
The first brand you mentioned lists the taurine content of .06% on an “as fed” basis, not on a dry matter basis, so we have to convert. The moisture content is 70%, so dry matter is 30%. So, .06 divided by 30 = .002 or .2%, exactly the required minimum.
To measure in ounces, we convert again: 1 oz = 28.35 grams, 28.35 x .2% = .0567gr or 56.7 mg. So there is about 56.7 mg of taurine per ounce of food. Multiply that by how many ounces you feed a day to get your total. An average cat would probably eat about four ounces of food a day, so the daily taurine intake would be over 200 mg.

Both grinding and freezing reduce available taurine, but by how much is not clear. That is why I add supplemental taurine when making homemade or supplementing pre-ground meat/bone/organ mixes. Taurine is not toxic in cats and is water-soluble, so any extra the cat can’t use just gets flushed out in their urine.⁴ I would rather add some extra taurine to the food and have a cat with expensive pee than risk a taurine deficiency which could lead to serious heart problems or death.
  1. Claudia A. Kirk, Jacques Debraekeleer and P. Jane Armstrong, “Normal Cats,” Small Animal Clinical Nutrition, 4th ed. Walsworth Publishing Company, 2000, 301-302.
  James G. Morris, “Idiosyncratic Nutrient Requirements of Cats Appear to be Diet-induced Evolutionary Adaptations,” Nutrition Research Reviews 15, 2002, 153-168.
  2. I. H. Burger, K. C. Barnett, “The Taurine Requirement of the Adult Cat,” Journal of Small Animal Practice 23, no. 9, April 10, 2008, 533-537.
  3. AAFCO Nutrient Requirements for Cats Table 47, The Merck Veterinary Manual, 2008.
  4. U.S. National Research Council Ad Hoc Committee on Dog and Cat Nutrition, Nutrient Requirements of Dogs and Cats, 2006, 137.

Margaret Gates is the founder of the Feline Nutrition Foundation. If you would like to learn more about feline diet and health, please visit We have a wealth of information on how to feed your cat a healthy, bio-appropriate diet. We especially welcome raw diet beginners!

No Bull, Taurine is a Must for Kitty

By Marta Kasper

I am sure that you have all heard about the importance of taurine in a cat’s diet. Taurine is a naturally occurring amino acid mostly found in muscle meat and organs like heart, kidney and liver and in seafood. In muscles, taurine gets more concentrated the harder the muscle works. Dark meat has more than light meat because it comes from parts of the body that work harder, legs as opposed to breast. Heart is another great example. Although it is termed an organ, it is really the hardest working muscle in the body and it has one of the highest concentrations of taurine. Shellfish such as mussels and clams also have a lot of taurine. They are constantly filtering and they follow the same “hard-working” scenario, concentrating taurine to a high degree in their tissues. Small amounts of taurine are found in dairy products. Plant products contain either low or undetectable amounts taurine. Despite meat being a good source of taurine, there is a significant amount of variability within meat samples according to a published study.¹ Taurine content of meat was not only affected by diet, breed and environment, but also by the freshness of the meat.

Cats, unlike some other carnivores and unlike herbivores or omnivores, are not able to synthesize all the taurine they need from other amino acids like methionine and cysteine. In addition, many animal species can use glycine or taurine to conjugate bile acids into bile salts, but cats can only conjugate bile acids with taurine. This low rate of taurine synthesis combined with the loss of taurine in bile contributes to an increased dietary requirement of taurine for cats. With insufficient amounts of this essential amino acid in their diet, cats can develop central retinal degeneration, reproductive failure and impaired fetal development or heart cardiomyopathy. Clinical signs of taurine deficiency will not be apparent right away, it might take couple of months or years in some cases, but once a cat starts exhibiting clinical signs, usually significant damage has already been done.
One very important property of taurine is its high solubility in water. The final amount of taurine in the food will depend on the food preparation and storage techniques. To minimize the loss, one should always try to retain all of the liquids coming from the meat. For example, if the meat is cooked, it should be done in a small amount of water so that it can all be incorporated back into the food. Cooking meat at temperatures used for normal food preparation by itself does not change the amino acid in any way. It just leeches the taurine out from the meat into the water. I have been asked many times if taurine loses its potency during food storage in the freezer. The answer is yes and no. Freezing does not affect taurine potency, but, during the thawing process a lot of liquid is released. Since taurine is highly water soluble, that liquid will be taking a lot of the meat’s taurine with it. For example, if you buy raw ground meat/bone/organ packages, the liquid that comes out as it thaws – which is not blood despite its red color – is full of dissolved taurine. If this broth is discarded, the meat ends up with a lower taurine content than before freezing.
The Association of American Feed Control Officials, or AAFCO, recommends the minimum allowance of taurine for wet food to be 0.2% on a dry matter basis. The chance is that this amount might be covered by the natural taurine in meat alone, but due to a significant amount of variability of taurine concentrations in meat, high taurine solubility in water, danger of delay in exhibiting clinical signs of taurine deficiency and the fact that taurine supplementation is relatively safe with no reports of any issues associated with taurine overdose, it might be beneficial to always have a small amount of taurine excess in your cat’s diet. So what would be a reasonable amount to add? It is approximately 250 mg of taurine per 1lb of meat. I intentionally use “mg” because all taurine supplements are sold as “mg per capsule.” Since the smallest amount available is 500 mg per capsule, you can either add one of these capsules to two pounds of meat or 1/2 capsule per one pound of meat.
A lot of you might not like the fact that supplemental taurine is always synthetic. While I would also prefer a natural product over synthetic, in this case unfortunately, there is currently no other choice. It is important to keep in mind, however, that chemically there is no difference between synthetic or natural taurine because both structures are exactly the same. Taurine, unlike many other amino acids, does not polarize light so there is no left or right rotation which can differentiate natural or synthetic types. Some companies use this exact reasoning to justify their claim for a natural taurine, but I can assure you that it is only a marketing strategy. Taurine can be extracted from natural sources – there is a company in New Zealand that extracts it from ox bile – but this method is commercially unappealing and significantly more expensive. Nevertheless, I am hopeful that one day, a truly natural taurine will be available to consumers.

1. AR Spitze, DL Wong, QR Rogers and AJ Fascett, “Taurine Concentrations in Animal Feed Ingredients; Cooking Influences Taurine Content,” Journal of Animal Physiology and Animal Nutrition 87, 2003, 251-262.

Marta Kaspar is a Feline Nutrition Foundation Advisory Board member. You can find more of her articles at