Lowering Blood Calcium

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.

Calcium is an important mineral for bone growth and maintenance, nerve and muscle function, and blood clotting. However the minimum daily requirement for calcium of a medium sized rabbit is about 510 milligrams. This amount of calcium is contained in less than two ounces of commercial pellets or 1 cup of turnip greens. The percentage of calcium in alfalfa and clover hay is 2-5 X the amount needed for an adult nonbreeding rabbit. Grass hays have a much lower amount of calcium, less than half the amount found in alfalfa and clover hay. Commercial pellets provides more than enough calcium for the average house rabbit and could cause a persistently elevated (“high normal”) level of calcium in the blood. If the amount of calcium excreted in the urine becomes too high, problems may develop.1

Calcium metabolism appears to be less complex in rabbits than in many mammals. For rabbits choosing a lower calcium diet can be as simple as knowing the amount of calcium contained in each food item to determine if it should be restricted or eliminated.

Alfalfa hay is extremely high in calcium and should be replaced with lower calcium hays such as timothy or oat hay. Fruits are low in calcium but high in sugar and should make up a very small part of the diet. Root vegetables such as carrots and radishes are low in calcium. Most greens are comparatively high in calcium but they are also a very important component of a healthy rabbit diet and should not be eliminated. Broccoli flowers and stem, cilantro, dark leaf lettuce, watercress, Brussels sprouts, celery leaves, cabbage, and endive are good choices when trying to reduce dietary calcium. Turnip greens, broccoli leaves, mustard greens, kale, and collards greens should be restricted or eliminated depending on the severity of the problem.*


1. Summary of Calcium in Rabbits, John E. Harkness (Rabbit Health News, 1994: Vol.11, p.7)


Calcium Content of Raw Vegetables per 1 cup serving, unless otherwise noted

6 mg Peppers, sweet
10 mg Alfalfa sprouts
15 mg Pumpkin leaves
16 mg Coriander (cilantro)
18 mg Chard, Swiss
19 mg Radish seed sprouts
20 mg Lettuce, Romaine (per 100g serving)
20 mg Squash, zucchini
21 mg Jerusalem artichoke
24 mg Pumpkin
26 mg Endive
26 mg Squash, summer
28 mg Asparagus
28 mg Cauliflower
28 mg Purslane
28 mg Radishes
30 mg Carrots
30 mg Egglant
32 mg Arugula
32 mg Cabbage
32 mg New Zealand spinach
34 mg Kohlrabi
38 mg Lettuce, looseleaf
39 mg Turnips
40 mg Cress, garden
40 mg Watercress
42 mg Broccoli
44 mg Celery
46 mg Beet greens
56 mg Spinach
58 mg Mustard greens
59 mg Dock
62 mg Peas, edible pod
65 mg Rutabagas
68 mg Celeriac
74 mg Chinese cabbage
78 mg Parsley
82 mg Borage
82 mg Okra
94 mg Kale
103 mg Dandelion greens
105 mg Turnip greens
137 mg Kale, Scotch
180 mg Chicory greens
218 mg Collards
309 mg Lambsquarter
315 mg Mustard spinach


Sources United States Department of Agriculture, Human Nutrition Information Service, Agriculture Handbook Number 8-11, “Composition of Foods: Vegetables and Vegetable Products.” Revised August 1984. These are values representative for vegetables collected from across the country; precise values will vary somewhat between regions.

Compiled by Kathleen Wilsbach, PhD