From: young@clpd.kodak.com (Rich Young)
Newsgroups: rec.food.veg
Subject: Re: Vegetarian Cats
Date: 20 Dec 92 17:41:54 GMT
Reply-To: young@clpd.kodak.com
Organization: Clinical Diagnostics Division, Eastman Kodak Company
Originator: young@sasquatch


   Since "ted" has seen fit to re-post his July treatise regarding vegetarian
   cat food (albeit with a few thinly-veiled sarcasms added in an effort to
   discredit these comments, which he knew would be forthcoming), I feel that
   it is only fair to re-post a few comments regarding his data.  Most of the
   comments are simply small differences or actual agreements, but there are
   a few (about methionine and raw eggs, for example) which do disagree.

   This is presented as a balance to the original posting, not as a personal
   attack.  It is worth noting that the majority of the sources "ted" quotes
   advocate vegetarianism for cats; the source used for these comments does
   not advocate any particular diet, except a healthy one, for cats.


-Rich Young (These are not Kodak's opinions.)

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Ted Wayn Altar wrote:

[...]

>Methionine (as well as ammonium chloride) in amounts
>safe for mature cats have proved toxic for kittens, but this is
>usually the limiting amino acid of plant proteins and therefore
>is not a practical worry.

   From THE CORNELL BOOK OF CATS: Faculty and Staff, Cornell Feline Health
   Center, College of Veterinary Medicine, Cornell University, Mordecai Segal,
   ed.; Villard Books, 1991, pp. 72-73.  [quoted without permission]

	"The essential amino acids required by cats include arginine,
	histidine, isoleucine, leucine, lysine, methionine, phenylalanine,
	taurine, threonine, tryptophan, and valine."

	"METHIONINE - The cat's requirement for methionine is much higher
	than that of other mammals, and it is often the limiting amino acid
	-- that is, THE ONE MOST LIKELY TO BE LACKING IN PRACTICAL CAT DIETS."
	(emphasis added)

	"ARGININE - Cats are unable to synthesize arginine from its
	precursor amino acid, ornithine. [...] While arginine is a critical
	amino acid in feline diets, it is of little concern, since arginine
	is present in most proteins used in practical cat diets.  IT WOULD BE
	A CONCERN IF A CAT WERE EATING A LOW-PROTEIN, HOMEMADE DIET COMPOSED
	MAINLY OF CEREAL PROTEINS."  (emphasis added)

	"LEUCINE - Kittens require more of this amino acid than species such
	as the dog or pig.  The reason for this is not known."

[...]

>First, unlike dogs, cats need is PREFORMED VITAMIN A since
>they cannot utilize the readily available plant pro-vitamin A
>carotenoids such as beta-carotene.  Cats (and apparently
>foxes) lack enough of the metabolic enzyme needed to cleave
>the carotene molecule in the conversion process.  Hence,
>synthesized vitamin A acetate or palmitate tablets will
>suffice or dairy products.

   Generally true, except that many cats are lactase deficient and react
   poorly to all but tiny quantities of dairy products...especially mature
   cats.  [ibid., p. 73]

>Second, cats also need an exogenous source of the amino
>acid, TAURINE (2-aminoethanesulfonic acid), since unlike
>most animals they don't synthesize it from the sulfur amino
>acids methionine and cystine (hence taurine is not an
>"essential" amino acid for us since we can readily
>synthesize it).  Without taurine cats will suffer from
>Central Retinal Degeneration (CRD).  Taurine is also
>important for regulating the heartbeat by controlling the
>amount of calcium entering the tissue.  A deficiency makes
>for a degenerative heart disease called Cilated
>Cardiomyopathy (DCM).  The heart muscle becomes enlarged
>hindering the hearts ability to pump efficiently.  If caught
>in time both this blindness and heart disease can be
>reversed.  Some cat foods in 1975 were implicated as not
>providing enough taurine (up to 50% is destroyed by the heat
>of cooking).
> 
>There is no known source of taurine found in plants but it
>can be obtained in abundance from "lower" animals like clams
>or chemically synthesized.

   Essentially correct.  [ibid., p. 73]

>Finally, cats need a preformed source of ARACHIDONATE ACID
>which most animals synthesize from linoleic acid.  Cats
>simply can't easily convert linoleic to arachinodonic (the
>omega6 series of fatty acids), nor can they convert easily
>linoleic to its longer-chain metabolites (the w3 series of
>fatty acids).  Deficiencies manifest themselves primarily
>as reproductive failure in female cats.  Susceptibility to
>infection could also be caused by a lack of arachidonic acid
>due to its role as a precursor of prostaglandins and in turn
>their function in the immune system (hence, slow wound
>healing, skin lesions, and a fatty liver would be possible
>indications of a deficiency).  A dry lusterless coat and
>scaly skin are possible symptoms as well, ....

   No argument here.  [ibid., p. 74]

>.... and this may account for the effectiveness of raw eggs in
>improving the hair coat (including the hair of humans with their egg
>shampoos?). [...]

	"Biotin is synthesized in the intestine.  Avidin, a constituent
	protein of raw egg white, can interact with biotin to render
	it unavailable to the body.  Indeed, eggs are a good source of
	protein, fat, and vitamins.  HOWEVER, EGGS SHOULD BE COOKED
	BEFORE BEING FED TO CATS."  [ibid., p.77]  (emphasis added)

   [NOTE: this applies to humans as well.  And then, too, there's the
	salmonella risk from raw eggs.]

>Some other less crucial nutritional concerns with a plant
>diet for cats include a direct source of niacin (other
>animals normally convert tryptophan into niacin (vitamin B).

   Actually, it's not "vitamin B", but rather part of what is known as the
   "B-complex" and is sometimes referred to as "vitamin B3", although I have
   at least one source which refers to pantothenic acid as "vitamin B3".
   Otherwise true, however.  [ibid., p. 77]

>Nutritional yeast (not to be confused with brewers yeast)
>is an abundant source of niacin that one should feed to cats
>in any case (most cats really like it).

	"Good sources of niacin include brewer's yeast..."  [ibid., p. 77]

   [Of course, this says nothing about whether cats like it more or less
	than nutritional yeast...it's simply an adequate source.]

   Commercial cat foods which carry a "statement of nutritional
   adequacy" (in the U.S., anyway) eliminate the need for niacin
   supplementation.  National Research Council standards insure
   only that the food contains a minimum amount of a given nutrient,
   not that the nutrient is actually available for absorption.  The
   "statement of nutritional adequacy" should clearly state that
   the food is complete and balanced, and that this has been verified
   with actual in vivo testing.  [ibid., p. 82]

>Also, supplements of B12, zinc, an ideal calcium to phosphorous ratio
>of 1.2-1.4 to 1, a plant form of calciferol (so-called "vitamin" D)
>should also be considered.

	"Signs of a [vitamin B12] deficiency, WHICH HAS ONLY BEEN SEEN IN
	CATS EATING DIETS CONTAINING ALL VEGETABLE PROTEIN, can include
	inappetence, weight loss, and anemia.  In kittens, vitamin B12
	deficiency may be manifested by retarded growth."  [ibid., p. 77]
	(emphasis added)

	"Excessive amounts of calcium in the diet can bind zinc in an
	insoluble complex, preventing its absorption and thus making it
	inaccessible for the body to use.  HOWEVER, A NATURALLY OCCURRING
	ZINC DEFICIENCY IS RARE IN CATS."  [ibid., p. 75] (emphasis added)

	"For cats, a calcium-to-phosphorus ratio of 1:1 up to 2:1 is
	satisfactory for the absorption and utilization of both."
	[ibid., p. 74]

[...]

>Now, if anyone is seriously considering a vegetarian regime
>for their cats I would of course recommend extreme caution
>and due care.  One should buy the commercial products and I
>would also recommend that they read very carefully Barbara
>Lynn Pedens book, DOGS AND CATS GO VEGETARIAN, 1988.  Some
>useful scientific papers are referenced in the book.  Also
>useful is James Peden's recent book, "vegetarian Cats & Dogs,
>1992.  And of course, one should have one's cat regularly checked
>by their veterinarian.

   Good advice.

	"Formulating and compounding a cat food is a difficult, inconvenient,
	and time-consuming process.  Feeding a homemade diet cannot assure the
	presence or availability of all the nutrients in the right quantities
	needed by the cat.  Commercial, nutritionally balanced products
	are usually advised unless a veterinarian has recommended a 
	homemade ration and provided a specific recipe that can be accurately
	compounded at home."  [ibid., p. 82]
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Newsgroups: rec.food.veg