Low Calcium Diets
If your bun requires a low calcium diet it’s important to remember that it is still an essential nutrient for them and that a rabbit’s body is designed to flush excess calcium from its body via its urine, which it does very efficiently. There is no hard and fast ‘science’ behind law calcium diets (you can read more about this in the links below) however often a low calcium diet is recommended. If this is the case, then of course it is up to you and your vet to decide which approach you will take.
Personally, I approach low calcium diets from another angle because I feel it is important not to focus soley on calcium intake. Rather, it is more better to understand the relationship calcium has with oxalates. Oxalates bind with calcium and this can result in bladder sludge and or stones.
Other factors that can come into play are the age of your rabbits, how active it is, obesity, renal status etc. So as well as making sure you are not feeding high oxalate foods, make sure that your rabbit is a healthy weight, any age related conditions are diagnosed and treated - eg pain relief for arthritis, that your rabbit is mobile and active etc.
Some foods are high in both calcium and oxalates and these should definitely be avoided or restricted for a rabbit that has bladder issues etc.
- Parsley
- Carrot Tops
- Spinach
- NZ Spinach
Others that have problemmatic levels of oxalates are -
- Chicory / Endive
- Miner’s Lettuce
- Radish Tops
- Silverbeet
- Watercress
- Beetroot Leaves
- Sorrel
More information re Veg etc can be found here - Veg & Fruit - Proceed with Caution
The following can help with urinary tract health and are mildly diuretic, so help to flush the bladder -
Dandelion (but not masses as highish in Calcium)
Yarrow
Birch
Goldenrod
Hawthorn
Cranesbill Geranium incl Herb Robert
Stinging Nettles
Chickweed
Fennel
Sow Thistle/Puha (Good for hydration and general tonic but not masses as highish in Calcium)
Cleavers - kidney tonic
Willowherb - kidney tonic
Chickweed
Oxbow Urinary Support
The lowest calcium pellets available in NZ are -Selective: Grain Free, 4+ & Adult: 0.6%
Oxbow Adult: 0.35-0.75%
Burgess: 0.8%
FibreSafe Complete Rabbit Pellets: 0.6%
"Calcium is essential for rabbits to maintain healthy bones and teeth, but the special way rabbits process it means that some rabbits encounter urinary tract problems if their diet is too high in calcium. If your rabbit suffers from stones or bladder sludge you may need to adjust their diet to reduce their calcium intake to help control the problem."
Low Calcium Diet for Rabbits - The Rabbit House
"Rabbits’ urine can change dramatically depending on what they have eaten. If they have eaten red cabbage, beetroot leaves or other foods with strong colouring, their wee may be stained red. This is called beeturea, and it’s normal."
Rabbit Bladder Problems - RWAF
"Urolithiasis (stones or sludge) within the urinary tract of rabbits, has been a ‘hot topic’ in the veterinary profession and amongst owners for several years. Many theories have been put forward and researched as to why rabbits seem to readily develop these deposits…but sadly there is still no hard facts as to exactly what causes these problems and how best to treat and prevent them from happening."
Urolithiasis (urinary sludge and stones) - RWAF
"Incorrect dietary intake of calcium is often suggested as an underlying cause of disease in rabbits. Too little calcium in the diet calcium is linked with dental disease and feeding high amounts of calcium could contribute to sludgy urine and other urinary tract problems. Feeding a balanced diet that does not have too much or too little calcium is beneficial but it can be hard to know what to feed. "
Calcium and Rabbit Food - Frances Harcourt-Brown
"The Recommended Daily Allowance (RDA) of calcium is approximately 500mg for fully grown rabbit that is not pregnant or lactating. The amount of some common food items that a rabbit would have to eat in one day to meet the RDA are illustrated below. The dish they are in is the same. It can be seen that it would be impossible for a rabbit to meet it's RDA by eating flaked maize. It might be difficult with spinach, broccoli and other 'high calcium' foods but it would be easy to exceed the the RDA by eating a lot of nuggets.It can also bee seen that a very small amount of a mineral block would provide enough calcium and it would be easy to ingest excessive amounts if a rabbit decided to eat a lot of it."
Amount of a food item that contains RDA of calcium - Frances Harcourt-Brown
"Although no direct scientific link between dietary calcium and an excess amount of calcium excreted in the urine has been proven, many veterinarians are advising clients whose rabbits have urinary/bladder problems to decrease the amount of calcium in their rabbit's diet."
Lowering Blood Calcium - House Rabbit Society
Further Reading including dealing with urine scald can be found here - Pee / Urine.