It is taurine (or the cat’s dependence upon it) that makes felines ‘obligate carnivores’. This means it doesn’t matter what the cat’s ethical stance on eating other animals, they must eat meat or become unwell. This is because the cat has evolved in a way which means their body can’t make its own taurine. So, just like oxygen or water, a cat must have taurine or they die . . . albeit slowly over several months and years.
Taurine’s Tasks in the Body
To understand the importance of taurine let’s find out more about this essential amino acid.
Taurine is one of the building blocks of protein, and it has a significant role in several important functions to do with the heart, eyes, and blood. It is one of several nutrients which the cat must eat in her diet because she can’t make them from constituent building blocks. These other nutrients include:
- Arachidonic acid
- Vitamin A
This dependence came about because cats evolved to eat mice and rats that are rich in such ‘ingredients’. In that economical way of cats, their body decided not to waste energy making taurine for itself when it was supplied in every meal, but the flip side is a dependence on meat.
Taurine helps to regulate the movement of electrolytes across cell walls, and in its absence cells become damaged and die. This slow decay of heart muscle and retinal cells takes years before it causes clinical disease, but by the time it does the changes are irreversible.
The Dangers of Deficiency
Plants and cereals are low in taurine, hence why cats can’t be vegetarian. The typical taurine deficient cat is fed dog food, with most of the protein derived from plant or cereal sources.
Raw Food Diet and Deficiency
Interestingly, it should be noted that cats on a raw food meat diet* can also become taurine deficient. Sounds counter intuitive doesn’t it, so how can this be?
The explanation is that frozen raw food is defrosted; the thiamine leaches out into the defrosted juices. If this liquid is thrown away, then the thiamine-rich part goes straight down the drain and the resulting meat is thiamine depleted. Moral of the story? Use the defrost juices to moisten ground up meat or incorporate it in as gravy.
*This is why the raw food diet we recommend includes a supplement mix that includes taurine.
So what of the dangers of thiamine deficiency?
The heart is a muscle which contracts in response to shifts of electrolytes across the cell walls. Thiamine deficient cats have a reduced ability to move potassium and calcium, which ultimately leads to flabby muscle cells that lack tone – the equivalent of a coach potato rather than a marathon runner in training.
Over time, this lack of tone means the heart dilates and loses its elastic recoil. This is similar to a party balloon that’s been inflated and let down several times, becoming saggy and baggy as a result. A stretched heart is poor at pushing blood round the body, so the cat steps over into heart failure. The symptoms include:
- Lack of energy and sleeping more
- Rapid shallow breathing
- Decreased appetite
- Fluid build-up in the chest and/or belly
Once clinical signs develop the physical changes in the heart are irreversible (just as no one can make that stretched balloon tight again). However, treatment with medications to shift retained fluid and support the heart can help.
Eyes and Blindness
Blindness as a result of taurine deficiency was first diagnosed in the 1970s, in a group of cats fed on dog food. The lack of taurine damages the delicate cells of the retina, leading to blindness. The signs include:
- Dilated pupils that don’t respond to light
- Bumping into objects
Treating Taurine Deficiency
Fortunately we now recognise the importance of taurine and it is a legal requirement that government approved cat foods contains satisfactory levels of taurine. Thus, feeding a good quality cat food should be all you need to do to stop your cat developing deficiency disease. If you are feeding a raw food diet, make sure you follow a recipe that includes taurine supplementation.
For those cats that are deficient, their blood levels can be boosted by giving a supplement (250-500mg of taurine twice a day) for four months, in addition to eating a balanced diet.
The damage to heart or eyes is not reversible. However, cats do quickly adapt to blindness, whilst medications to support heart function can help improve the cat’s quality of life. However, this is a classic case of prevention being better than cure and feeding an appropriate diet from kittenhood is by far the best option for the long term good health of your feline friend.
Is your cat getting an appropriate amount of taurine in its diet? Have you ever known a cat who has been diagnosed by a vet as taurine deficient?
Top image: Philip James via Flickr