I first became interested in rat diet after reading Debbie Ducommum's Rat Health Care booklet. In it she states "I believe that the short life span of many rats is due in large part to poor diet" and that "the average lifespan of rats can be lengthened, perhaps to 5 years" with "improved care and nutrition and selective breeding over successive generations".

Whilst I think that this view is rather extreme, the idea had captured my attention, and I am sure that good nutrition can only help to increase overall health and longevity, or perhaps more accurately, reduce disease processes within the body as it ages.

So what constitutes a good rat diet?
All mammalian diet is made up of certain constituents, which are needed by different species in varying amounts. Roughly broken down these are protein, fat, carbohydrate, fibre, vitamins and mineral.

Protein
Protein is required for the health, growth and repair of body cells and structures (for example muscle, bone, nerves and blood). Adult rats, other than those who are pregnant or lactating, require a diet with approximately 12%-15% protein. Rtas seem fairly tolerant of slightly higher lveles of protein, however, extra protein is broken down and detoxified in the liver, and then excreted by the kidneys. Over time this can cause nephritis and kidney failure (which male rats seem particularly susceptible to). However, too little protein (probably less than around 8%) or a completely vegetarian diet may lead to a deficiency in the essential amino acids, which are so necessary for the health and repair of body tissues.

Rats are omnivores and require some animal protein to provide them with essential amino acids that are not available in other sources. A completely vegetarian diet may support a non-growing rat, but (unlike humans) has been shown to be insufficient to support the needs of pregnancy and lactation. Growing, pregnant and lactating rats need extra protein to cope with the demands made upon their bodies, around 20-22% is appropriate.

Fat
Fat is a useful high-energy source and also contains nutritional factors essential for health. However, a healthy rat diet is low in fat, around 4-6%. It has been demonstrated that the incidence of mammary tumours in rats increases substantially with diets high in total and saturated fat. High levels of fat in the diet may also lead to itchiness, skin lesions, hair loss and obesity, which increases the risk of strokes, diabetes and other illnesses.

Carbohydrate
These are the high energy but low fat foods such as pasta, rice and cereal. These should make up the bulk of a rat's diet (approximately 75-80%). They supply the body with energy for everyday activity, growth and reproduction. If fed in excess they will be turned in the body to fat.

Fibre
Rats do not require high fibre diets to remain healthy. Their needs for indigestible fibre are well supplied in the whole grain element of their diet. However, when feeding pasta, rice, cereal and bread it is best to choose unrefined 'brown' or whole grain varieties, as these are rich in vitamins and minerals that are generally removed by processing.

Vitamins
Rats do not seem to suffer greatly from vitamin deficiencies, though potentially they can. Almost all lab blocks, generic mixes and human cereals have vitamins added to them. Feeding a small amount of fresh fruit and vegetables everyday can also serve to boost vitamins in the diet. Rats, unlike humans, are able to make and store their own vitamin C, so do not rely on a regular daily intake.

Minerals
These are trace elements that are essential to health. They are added to lab blocks, EMP (egg based hand rearing food for birds) and generic mixes to varying degrees. One or two are worthy of special mention. Magnesium has been found to have a protective effect against the formation of calcium crystals in the rats kidneys (female rats are susceptible) which lead to blockages, pain and kidney disease. Copper deficiency can lead to many problems and can be diagnosed by loss of hair from around the eyes. Young rats have a higher requirement for copper (up to about 4-6 months). Requirements for rats seem to be around 15mg/kg of food. Calcium, Vitamin D and Phosphorus are essential, especially during times of growth, pregnancy and lactation, for the laying down of bone and production of milk. One of the best sources of these minerals in the diet is curly kale. If unavailable this can be substituted with other green leafy veg (such as spring greens, pak choi, broccoli).

Foods with special properties
Some foods have some antibiotic properties such as bananas, plums, prunes, garlic, courgettes and raspberries, while others have some anti-viral properties such as cranberries, strawberries, plums and prunes.

Fish oils, dates, ginger and garlic may help rats with arthritis. Broccoli and red grapes are thought to have protective effects against cancer, while regular soya in the rats diet has been shown to reduce the rate of mammary tumours significantly.

Chocolate is a mild broncodilator (dilates the airways when breathing is difficult) and can be used in small quantities for rats with respiratory illness, in an emergency.

Feeding sick rats
Sick rats often don't eat well, and lose weight rapidly. Their energy requirements can in fact be raised as a result of high body temperature, increased heart rate, extra effort used to breath or perhaps the extra effort of supporting a large tumour. It is important for sick rats to receive a diet that is rich in calories but low in volume. This is the time to drop the usual cereal based dry rat mix or lab blocks in favour of cereal products that are easier to eat. Human (low sugar cereals) with soya milk or Lactol, cooked grains (pasta, rice, noodles, potato) or wholemeal bread soaked in warm soya milk can be offered instead. Nature Diet dog food (moist), cooked egg, chicken, live full fat yoghurt, banana, avocado and coconut milk are all useful in tempting sick rats to eat. Soya based human baby milk is very useful as it is high in fat and easy for the sick rat to digest. This can be used to make up powdered baby food, cereals or EMP. There is also a soft dietary supplement called Nutrical, which seems very palatable to rats and a small pea-sized blob of which will provide the sick rat with calories and a wide range of nutrients including vitamins and minerals.

Feeding healthy rats
Many diets fulfil the criteria for a healthy rat diet, and what follows is simply the mix that I have found works for me, and my rats. After feeding various generic rat mixes and getting tired of throwing the uneaten half of them into the bin, then trying lab blocks (at which point I could hear the sounds of rattie laughter, and a line of little faces at the cage door asking where the 'real' food was!) I eventually stumbled across the Suebee diet. Suebee is an American rat keeper who has designed her own rat diet. Over the years that I have been feeding it, I have gradually modified it for easy use in the UK (some of the components that she recommends are unavailable here), and have now settled on a sustainable diet - that the rats never seem to tire of. While suitable for feeding to a small or moderate number of rats (I have a floating population of around 35, plus babies), I accept that this diet would prove expensive for those with much bigger numbers. I have found this diet to be excellent in keeping the rats in great condition, they don't get overweight and seem to be fairly resistant to infection.

I make up a big batch in a large plastic crate and then store in a swing bin. One batch lasts my crew around 2 weeks.

Ingredients
Approx 45-50% by volume Alpha herbal Deluxe Rabbit food or substitute
Approx 10% by volume dry (uncooked) pasta spirals
Approx 5-10% by volume Alpha Lite Dog Kibble or substitute
Approx 35-40% by volume mixed human breakfast cereals from list.

Substitutes for Alpha Herbal:
Harrison's Banana Rabbit Brunch, Thumper's Rabbit, Alpha Rat, Xtra Vital Rat, Burgess Supa Rat, PAH Rat Muesli etc. If using a rat food you don't really need to add the extra dog kibble. Some of the rabbit food can be substituted with PAH Rat Nuggets, Rat ('Lab') Blocks or Nutro Choice Lite Dog Kibble.

Substitutes for the Alpha Lite Dog Kibble:
Nutro Choice Lite, PAH Rat Nuggets, Rat Blocks, Autarky Nature Lite, Burns Dog Kibble.

Cereals list:
Cornflakes, puffed rice, puffed wheat, bran flakes, Weetabix, Shredded Wheat Bitesize, multigrain flakes (Finesse, Special-K), jumbo oats etc. Look for really low sugar varieties (these are usually either the cheapest or the organic ranges).

Occasional additions for variety:
Dried fruit especially banana chips, dried vegetables, cream crackers (broken), dog biscuits (broken).

This mix makes up approximately 80% of my rats diet and most days I feed a small amount of fresh food (cooked pasta, rice, cous-cous, noodles, fruit, vegetables, nature diet dog food [12% protein and 7% fat] or EMP). Once or twice a week I add a teaspoon of SA37 (vitamin and mineral mix) or Dr Squiggles Essentials Plus to their fresh food.

To increase their protein and calorie intake pregnant, lactating and growing rats here get less of the cereal mix (about 50% of diet) and I add a higher protein dog kibble (Burns puppy, or Alpha puppy) and a few sunflower seeds. The other 50% of their diet is fresh foods as above plus EMP, scrambled egg, chicken, fish, wholegrain bread soaked in human baby soya milk or Lactol, and moist Nature diet puppy food. These rats also have human baby soya milk or Lactol in a gravity bottle alongside their water.