From: altar@beaufort.sfu.ca (Ted Wayn Altar)
Subject: Vegetarian Cats
Organization: Simon Fraser University, Burnaby, B.C., Canada
Date: Sun, 20 Dec 1992 01:05:23 GMT


     The following is just for information.  I am not suggesting
that anyone do anything different for their cat, but I thought
people might be interested in fact that it is possible for even
true carnivores like the domestic cat to be adequately nourished
on a vegetarian diet.


PROTEIN NEEDS

While not widely known, it is true that the specialized
nutritional needs of domestic cats can be met by a vegetarian
diet, but care must be exercised.

First of all, cats don't specifically need animal protein per se,
just protein that has the right balance of amino acids.  Indeed,
the first 4 ingredients in Ralston Purina Cat Chow are ground
yellow corn, soybean meal, ground wheat, and corn gluten.  Only
then is the slaughterhouse *awful* (pun intended) like poultry
by-produces added.  This most common brand of cat food is almost
vegetarians already!

This is not to glibly suggest that any plant protein will do
since the right amino balance is a concern.  For instance, there
should not be an excess of glutamic acid (many plant proteins
have generally twice as much as animal products), especially for
kittens.  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.  While too much methionine reduces
urine pH to dangerous levels (< 5.9) inducing metabolic acidosis
(this can result in decreased growth or even death), too little
may contribute to an alkaline urine.  Hence, a vegetarian cat mix
would aim for a conservative intake of about 1,000 mg/d for a 10-
lb cat, which is under the estimated upper limit of 1,800 mg
(this will help keep maintain urine to be slightly acid which
helps with struvite dissolution).



NECESSARY NUTRIENTS VIA SUPPLEMENTS:

What is really crucial for the diet of cats is not the proteins
in general, but in particular three other substances which cats
cannot, unlike many other animals including dogs, synthesize very
well from the usual precursors readily found in plant foods. 
Here is where real care must be exercised.

First, unlike dogs, cats need is PREFORMED VITAMIN A since they
cannot utilize 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.

Second, cats also need an exogenous source of the amino acid,
TAURINE (2-aminoethanesulfonic acid), since unlike most animals
they don't synthesized 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.

For many years now, it has been more economical to obtain
synthesized taurine.  Many commercial meat-based pet foods use
the same synthesized taurine supplements as do the vegetarian pet
foods.  For those interested in how synthesized taurine is
chemically produced, see the note at the bottom of this message.


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
manifests 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, and this may
account for the effectiveness or raw eggs in improving the hair
coat (including the hair of humans with their egg shampoos?).
The good news is that cats can synthesize their own arachidonate
from gamma-linolenic acid (GLA).  This is a fatty acid on the
conversion pathway from linoleat that occurs just before it
becomes arachidonate acid.  Evening primrose oil or black current
seeds are potential sources of GLA.  A kelp source (ascophyllum
nodosum) which is lower in iodine than most kelps (too much
iodine can cause hyperthyroidism) has even been widely used for
many years in animal feeds and it provides both the w3 fatty acid
series and the w6 series .

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). Nutritional
yeast (not to be confused with brewers yeast, which cats don't
like as much and which is a by-product rather than something
directly grown for its own sake) is an abundant
source of niacin that one should feed to cats in any case (most
cats really like it).  An 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).  In FELINE MEDICINE & SURGERY
edit by Catcott [there's a name to trust :) ] (2nd ed.), Amer.
Veterinary Pub.

     "The classic ratio of calcium to phosphorus in the diet (.9
     to 1.1 calcium to 1 part phosphorus) has been found most
     satisfactory in promoting sound growth of bone in growing
     kittens.  A ratio of 3 parts Ca to 1 part P results in a
     form of rickets; a ration of .5 part Ca to 1 part P results
     in osteoporosis. . . .Clinically, calcium deficiency is
     probably the most frequently encountered form of
     malnutrition in cats.  It is often due to the owner's habit
     of feeding young kittens meat or fish from which all bones
     have been removed . . ."


CONCLUSION:

Now, one does not need to be a biochemist to feed a cat. There
are now on the market vegetarian cat foods or supplements to add
to a vegetarian regime (like Vegecat) where all of the above
consideration are automatically provided for.  These products
have been checked by veterinarians and animal nutritionists 
meet the requisites for a balanced ration according to the 
Committee on Animal Nutrition of the National Research Council 
(latest report being "Nutrient Requirements of Cats", 1986).

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.

In the event some minor quibbles over the fine points of cat
nutrition ensue (and some people here do seem to have a penchant
to get distracted with quibbling :-( , please keep in mind that
such fine points on cat nutrition was not the purpose of my
posting.  Nor was the purpose to provide a comprehensive guide on
cat nutrition.  The purpose was to correct for an egregious point
of misinformation that cats MUST eat animal protein, i.e., they
must eat meat.  In point of fact, the nutritional needs of cats
can be adequately met without resorting to using the
slaughterhouse offal from the meat industry.

To reiterate, the main point of this posting was to indicated
that:


     1  The nutritional needs of cats can adequately be met by a
     plant based diet (along with a synthesized taurine).

     2. Cat nutrition is indeed a complex affair and responsible
     owners should not attempt to experiment on their own but use
     commercially prepared cat foods, whether it vegetarian or
     not.


                                          ted

P.S.  The above information was based upon the Peden's books and
upon Patricia Scott's chapter, "nutrition and disease", in  E. J.
Catcott's veterinarian text, FELINE MEDICINE & SURGERY,  2nd
edition..

Note:
     "Synthesized taurine starts with the Haber-Bosch process.
     Using iron as a catalyst along with high pressure and
     moderately high temperature, ammonia (NH3) is synthesized
     from air.  Ammonia's hydrogen atom is replaced with a
     hydroxyethyl radical by adding ethylene oxide.  This
     mixture, separated by fractional distillation, results in
     ethanolamine.  Further chemical reactions result in
     ethyleneimine that is converted into crude taurine.  In
     solution, it passes through activated carbon several times
     for purification and is then dried.  Taurine can also be
     synthesized by sodium sulfite sulfonation of ethylene
     chloride followed by ammonolysis with anhydrous ammonia or
     with aqueous ammonia and ammonium carbonate."  (from James
     Peden, 1992, p. 96)




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