Most – if not all – rats who reach old age, will arrive there with some degree of kidney disease. Male rats are more readily affected due to a male-specific protein found in their kidneys. This shouldn’t cause us too much anxiety, as a rat can lose around 70% of kidney function without showing any signs of a problem. That said, we can still aim at supporting kidney health, by feeding kidney friendly rat food for the majority of our rats’ lives.
So what is kidney friendly rat food? Well, in principle it is a diet that:
- restricts calories,
- restricts protein
- uses egg or soya as the main protein source
- isn’t too high in phosphorus
- contains some flax (linseed).
Kidney friendly rat food shouldn’t be used until a rat has stopped all of it’s infant and adolescent growth (around 6 to 8 months). Protein, phosphorus and calorie requirements are higher during this phase of life, and need to be met. But there’s still likely some benefit in meeting most of the protein needs after the rapid growth phase (approximately 10 to 12 weeks) with egg or soya.
The three main factors that delay the onset of kidney degeneration in rats are calorie restriction, low to moderate protein and that protein being mainly egg or soya.
So the biggest dietary influences over the first 18 months of your rats’ life are probably your method of feeding and the amount you feed. By this I mean, feeding at volumes that are less than the amount a rat would eat given constant access to food – but enough to maintain slow growth, lean weight and good condition.
How much food is that? Well, it varies from rat to rat, based of genetics, nutritional background, size, gender, activity levels and such like. There’s a discussion here to guide you, but I would encourage you to learn how to tell whether your rat is under/over weight and be able to spot a drop off in condition for yourself. This will be helpful, not only in your day to day dietary management, but also in detecting illness, parasites etc.
A good place to meet and handle a wide range of rats is at a rat show, and these are held around the UK on a regular basis. They make a great rattie day out and you’ll be able to pick up some rat goodies too. Find out more on the Fancy Rats forum, you’ll have to create an account to see this area, but that’s worth doing as there is so much help and information there. The rat shows are listed under You and your rats, once you log in.
The best method of food delivery to keep your rats in great shape is scatter feeding.
Kidney friendly rat food
Up to the age of 16 to 18 months (when the aim is prevention) the main thing to consider – beyond the amount and style of feeding – is the protein level and source in your food. Protein should be around 10-14% of overall diet, with a gradual reduction over time and around 10-12% being the maintenance level from a year or so onward. Actual requirements are less, but not all protein that is eaten will be fully digested. Most easily digested and with the least toxic load on the kidneys is egg, while soya seems to have some kind of protective effect, especially in male rats. Rats fed a soya based diet in labs, have been shown to show significantly less kidney degeneration by age, than those fed other proteins.
From 16 to 18 months (when the aim becomes slowing progression) more thought needs to be given to reducing levels of phosphorus in the diet, and adding in some flax/linseed.
An adult maintenance kidney friendly rat food
There are a few choices available when deciding what to feed your rat as a kidney friendly alternative.
- Make up a mix from individual ingredients (possible recipe below).
- Buy in a complete straight grain mix (example: Rat Rations No. 8). This is an easy option, as there is nothing else to do except to add a multivitamin/calcium supplement.
- Use a base mix and add to it. Base foods could be Harrison’s Banana Rabbit Brunch (or a similar commercial brand), a suitable Rat Rations base mix such as No. 3, or a soya-based rat muesli like Mr Johnson’s supreme rat and mouse mix. This mix does have a fairly high protein content but this can be diluted with adding cereals, leaves and veg. Various recipes for adding to base mixes can be found in The Scuttling Gourmet book, or the Rat Diet: health, prevention and treatment ebook.
Recipe for a straight grain mix
- 4 scoops micronized barley flakes
- ½ scoop pearl barley
- 1 scoop flaked peas
- ½ scoop split peas or
- ½ scoop soaked and roasted chick peas
- 1 scoop micronized soya flakes
- 2 scoops flaked maize
- 2 scoops paddy rice
- ½ scoop brown rice
- 6 broken wholegrain rice cakes
- 1 scoop oat groats
- ½ scoop whole oats
- ½ scoop no added sugar muesli
- 2 scoops mixed millet
- 1½ scoops buckwheat
- 1 scoop white milo (dari)
- 1 scoop Shredded Wheat Bitesize or Puffed Wheat
- 1 scoop Weetabix Minis
- ½ scoop whole wheat mini pasta shapes
- 6 broken sesame seed Ryvita
- ¾ scoop hemp seeds
- ½ scoop linseed
- ¼ scoop pumpkin seeds
- ¼ scoop milk thistle seeds
- ½ scoop flaked carrots
- ¼ scoop red pepper
- ¼ scoop dried tomato
- ½ scoop dried mixed vegetables
- 1 packets rabbit herbs (various)
- ¼ scoop flaked kelp
- 1 scoop dried river shrimps
- A few chopped cranberries
- A few chopped Brazil nuts
- A little dried beetroot
- A little dried apple
Elderly rats (or those with active kidney problems) would have the mix without the shrimps, Ryvita, Weetabix, Shredded Wheat and oats, but with a little extra soya and an increase in any of the other grains or cereals, to replace the lost volume of grains.
This is not an exact science and you can leave things out or put a bit more of one thing and less of another into it. Only the soya is needed for it’s protective effect. If you don’t want to use soya, I would suggest some EMP mixed in instead, so that at least your mix uses a kidney friendly protein. Egg protein can, of course, also be given as fresh food.