Respiratory diseases such as tuberculosis and asthma were common in the 1930s, and some doctors treated them using a specific raw food diet. Dr. Francis Pottenger Jr. was one doctor working to heal those patients, and he worked on creating and implementing an extract from the adrenal cortex to treat allergies and exhaustion.
An Accidental Discovery
Dr. Pottenger used laboratory cats to try to determine correct dosages. The cats had their adrenal glands removed and were given adrenal cortex extracts to gauge the correct amount that would keep them alive. He was feeding the cats a diet that was considered ideal at the time: cooked meat scraps, cod liver oil and milk. Many cats did not survive the operation or were in poor health afterward. Meanwhile, cats kept coming in, and soon Dr. Pottenger had more cats than food to feed them.
He ordered meat scraps from a local plant and began feeding some of the cats this raw meat instead of the cooked meats given to the others. The group of cats eating the raw meat showed better health and a higher postoperative survival rate than the other cats. This notable difference prompted him to conduct a series of experiments.
The Famous Pottenger Cat Study
The study consisted of 900 cats divided into five groups. The first two groups were given raw meat, raw (unpasteurized) milk and cod liver oil. The remaining three groups were given cooked meat, cod liver oil and one of the following milk types: pasteurized, evaporated or condensed milk. All groups were fed their diets and observed over multiple generations.
The first two groups fed the raw meat diet experienced excellent health, reproduction, normal size and temperament, and were not easily affected by infection or diseases. They were studied through four generations, and the results were favorable.
The other three groups fed cooked meat and processed milk had strikingly different outcomes:
- The first generations had healthy offspring but were prone to disease and illness later in life.
- The second generation started to show health concerns in the middle of their lives.
- The third generation showed illness in the beginning of life, with some dying at birth or barely living to 6 months old and having problems reproducing.
- The fourth generation did not exist.
The remaining cats from the third generation were placed on the raw meat and raw milk diet. Their offspring were considered to be in normal health after four generations on the raw diet.
The results could be summed up this way:
- Raw meat and milk = healthy generations.
- Cooked meat and processed milk = degenerative results that increased with each generation until reproduction was impossible.
A Legend Builds Up Around the Study
You might be tempted to draw the conclusion that a raw food diet, rather than cooked, is better (not only for cats but for people as well). But not so fast. This study took place 70 to 80 years ago — and had some fundamental flaws.
Among the shortcomings of the study:
- There were no good scientific controls. For example, there was scant information on the health histories of the subject cats.
- Not until several decades after the study was the role of taurine fully understood. Lack of taurine can lead to the very results noted in the experiments by Pottenger. But these days, commercial cat food contains taurine as well as other supplements.
- The results of the study have not been replicated by other studies.
Dr. Pottenger himself had speculated that some sort of protein was being eliminated through the cooking process. He didn’t know the culprit was taurine, because it was not known to be an essential element for cats at the time. But today this amino acid is added to cat food after the cooking process to ensure healthy development.
The big lesson for cat owners: If you’re contemplating making your own diet for your cat, think twice, and be careful. Even raw diets can be low in taurine. The right nutritional mix is a delicate balance indeed.
- Beyond Vegetarianism: Science on raw vs. cooked foods
- WebMD: Biologically Appropriate Raw Food (Dogs)
- WebMD: Homemade/Raw (Cats)