Most cats love tuna, and an occasional tuna treat is fine for them,
but too much tuna can cause some serious medical problems. We're
speaking here of tuna that is marketed for human consumption: most
tuna-flavored cat foods are not 100% tuna, and contain nutrients such
as added vitamins and taurine which are necessary for a cat's health.
I've gathered some information from online sources for you.
"Fairy tales and folklore tell us cats love to dine on milk and fish,
and that any cat worth her whiskers needs at least one catnip mouse to
chase when the live ones are not around. Although these century-old
stories always stir up warm images of contented cats, many of these
"truths" about feeding and nutrition are myths. And, some are
Fish is a good source of protein and other nutrients, but too much
fish in a cat's diet can be harmful. Tuna is high in polyunsaturated
fatty acids and requires substantial amounts of vitamin E to preserve
the fat. Cats fed a diet containing excessive amounts of tuna can
develop steatitis, also known as yellow fat disease."
Ragdoll Cats: Common Myths
"Tuna fish, and many other fish species, contain relatively large
amounts of unsaturated fats. Although health-minded people eat fish to
decrease their consumption of saturated fats, the excessive
unsaturated fat in a cat?s diet may be harmful.
Tuna and certain other fish possess very little vitamin E. Vitamin E
is an important antioxidant. When a cat?s diet consists mostly of tuna
fish that is not commercially formulated as cat food, the cat becomes
deficient in vitamin E. Dietary unsaturated fats from the fish are
oxidized by a biochemical called peroxidase into a substance called
ceroid. Since the affected cat has low vitamin E levels, this
oxidation process is not restrained. Ceroid, an abnormal, pigmented,
yellow-brown breakdown product of unsaturated fat oxidation, is formed
and deposited in fat cells. The result is yellow fat disease
Ceroid triggers an inflammatory response by the immune system as if it
were a foreign invader. The subcutaneous fat of cats affected with
yellow fat disease causes pain; these cats become hypersensitive and
will resist handling and petting. The muscles of affected cats will
atrophy and become weak; these cats do not want to move. As the
disease process progresses, the body fat degenerates and is replaced
by fibrotic tissue, leaving the skin hard and nodular. Affected cats
may also develop fevers unrelated to infection.
Yellow fat disease occurs most commonly in young, overweight male and
female cats with inappropriate diets. Treatment includes discontinuing
the inappropriate diet and administering therapeutic doses of vitamin
E. Corticosteroids may also be prescribed to relieve the inflammatory
Even if a tuna-fed cat receives prophylactic or supplemental doses of
vitamin E, there are other problems besides steatitis that make
feeding tuna unwise. Some believe that tuna contains specific
substances (allergens) that stimulate allergic-like disorders in cats.
Cats should be fed a balanced, commercially prepared diet to avoid
Connolly Animal Clinic: Why is tuna fish bad for cats?
"Several cat caretakers visiting ASPCA Pet Nutrition online have
inquired about feeding tuna to their animal companions. Mindy Bough,
veterinary technician for the ASPCA Pet Nutrition and Science Advisory
Service, dishes out the facts on this savory feline fave:
'An occasional tuna treat for your cat is generally harmless," says
Bough. 'However, if a large part of the cat's diet consists of
tuna--or if the cat is fed tuna exclusively--some problems are likely
Tuna does not contain significant amounts of vitamin E, for example,
so too much of the fish can lead to vitamin E deficiency, resulting in
yellow fat disease, or steatitis. Symptoms include loss of appetite,
fever and hypersensitivity to touch, due to inflammation and necrosis
of fat under the skin. Felines who are fed too much tuna can develop
other nutrient deficiencies, too, because most de-boned fish are
lacking in calcium, sodium, iron, copper and several other vitamins.
Mercury, frequently present in tuna, also presents a potential danger.
'At low levels, this may not be a concern,' explains Bough, 'but if
tuna is fed nearly exclusively, it could pose significant problems.'
The bottom line? 'I recommend premium commercial food for domestic
cats,' Bough says. 'These foods are formulated to meet all of a cat's
dietary needs. Then you can feed an occasional tuna treat for your
ASCPA: WE'RE TALKING TUNA: HOW MUCH IS TOO MUCH FOR YOUR CAT?
"TUNA FOR CATS? NO!
Tuna can be fatal to cats and is not something to be fed to them...
The human variety of tuna fish contains an enzyme that destroys
vitamin B1 (thiamine). Cats who regularly eat tuna can develop a
vitamin B1 deficiency, which results in neurological symptoms like
dilated eyes, loss of equilibrium, seizures and death if this vitamin
is not replaced. The scientific name of this disease is
Clearwater veterinarian Richard Brancato said that though most
domestic cats do enjoy fish, feeding them a diet of only tuna can
cause serious disorders.
Although it is high in protein, tuna lacks sufficient amounts of
certain amino acids, mainly taurine, to maintain feline health. There
is insufficient calcium to balance the phosphorus; the ratio in canned
tuna is 1-to-14.8. This results in bone disease.
Many essential vitamins such as A and most B vitamins are also
lacking, Brancato said. A common disease in cats fed a mainstay of
canned tuna is steatitis, or yellow fat disease, an inflammation of
the fat tissue in the body due to a deficiency of vitamin E.
St. Petersburg Times, published May 14, 2000"
Healthy Pet Corner: Natural Pet News
"Tuna is low in calcium and too high in phosphorous. It may cause
vitamin E deficiency or yellow-fat disease. Plus it may increase
susceptibility to 'rubber jaw,' a form of osteoporosis. Several
problems are associated with feeding cats tuna. The first one is that
it's highly addictive--cats love tuna oil! Additionally, 'people' tuna
lacks many of the essential amino acids and vitamins, especially
taurine and vitamin A, B and E, necessary for feline health. Be aware
that the high amount of mercury in some canned tuna is detrimental to
your cat's health. Tuna should not be a staple of any cat's diet.
Reserve it for an extra special treat."
Minew-KajunKat: More Facts About Feeding
Also bad for cats are tasty treats such as ham, bacon, and lunchmeats.
Extra salt, spices, and preservatives that cause few problems in
humans can wreak havoc with a cat's delicate digestion. Here you'll
find an article on everyday human foods that are bad for pets:
Humane Society of the Harrisburg Area: Top Ten List of Things You
Should Never Give Animals
Here is some advice regarding raw meats:
"Any raw meat fed to cats needs to be:
1. as fresh as possible (cats naturally kill and eat prey on the spot
--their systems do NOT tolerate spoiled meat like a dog's might be
able to. Proper storage and use within 2-3 days will also reduce the
chance of your kitty getting parasites from the meat)
2. as natural as possible (reducing the chance of chemical additives
and antibiotics compromising your kitty's health)
3. only available to the cat for a short time (don't leave it out to
spoil -- give no more than 25 minutes according to some people!)
4. part of a well-balanced diet (most cat foods are formulated to be
complete, additions to diet in the form of treats can change throw the
kitty's diet out of balance, which can compromise a cat's health. Be
sensible -- you just need to be careful not to give your kitty too
much of anything not part of the his or her staple diet.)
5. not pork (while every meat may potentially carry parasites, etc.,
pork is one of the worst offenders. Additionally, pork fat molecules
are apparently larger than those of other animals, making it hard for
a cat's tiny system to properly process them.)
6. preferably cut or ground from a single quality piece of meat/animal
(many ground meats bought at typical stores contain the meat of many
animals in them -- that means if there is a single animal that had
some sort of parasite that may be passed to the consumer of its meat,
the whole batch of ground meat of which it becomes a part becomes
contaminated. Some grocers will grind the meat for you on the spot
from a cut of meat you select -- this reduces the chances that you get
7. If you are concerned about parasites, some vets suggest using an
extremely diluted bleach/water solution on the surface of the meat.
(We tried it once of twice per our vet's instructions, but found that
the bleach worried us more than whatever might have been in the
The Cat Site: Ok to feed raw lamb?
I hope this is helpful. If anything is unclear or incomplete, please
request clarification; I'll be glad to offer further assistance before
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