Posted By Karla on 04/12/2010 04:42 AM

 I’m not sure about the Phosphorus – is that a guinea pig thing, or should rabbit owners be aware of this as well?

 

To answer my own question: yes, it is something rabbit owners should be well aware of!

“Although the main mineral of concern when keeping rabbits, guinea pigs and chinchillas is calcium and its relationship with phosphorous, magnesium, manganese, selenium and zinc, it is also important to ensure a supply of these minor minerals and trace animals which may not be present in commercial diets.”http://www.galensgarden.co.uk/herbivores/nutrition/minerals.php

So, now is a good idea to try out the excel sheet and see what veggies are good or bad to feed – if one is concerned with the calcium-phosphoros level.

A rabbit fed on a good, balanced diet should not be calcium deficient and does not need a calcium or mineral supplement. The average sized pet rabbit (approx. 2.5kg) needs typically around 510mg of calcium per day. Any more and they may be predisposed to developing calculi (stones) or sludge‚ in their urinary tract system.

The calcium mg content per 100g of food is shown alongside in brackets:
Good Calcium Providers:
• • Kale (130)
• • Spinach (170)
• • Parsley (200)
• • Watercress (170)
• • Mint (210)
• • Spring Greens (210)

Moderate Calcium Providers:
• Cabbage (49)
• Broccoli (56)
• Celery (41)
• Lettuce: round/flat (53)
• Parsnip (41)
• Swede (53)
• Turnip (48)
• Oranges (47)

Poor Calcium Providers:
• Brussel Sprouts (26)
• Carrots (25)
• Cauliflower (21)
• Cucumber (18)
• Lettuce: Iceberg (19)
• Peppers: Red/Green (8)
• Tomatoes (7)
• Apple (4)
• Apricot (15)
• Banana (6)
• Grapes (13)
• Kiwi Fruit (25)
• Nectarines (7)
• Peaches (7)
• Pears (11)
• Pineapple (18)
• Strawberries (16)

So, if you have a bunny with calcium deficiency, you should feed veggies with a high level of calcium. And for those with bunnies that already have a high level of calcium in their blood, they should look for veggies with a low level, of course.

And of couse, the phosphorus intake must never exceed that of calcium (gotta read up on that. I will share it with you).

Yes, please do. And ask her about the calcium-phosphorus balance, please I didn’t know that stones were such a big issue, but now you are saying it, most of the info I found was actually on guinea pigs.

It’s worth to give it a go about the diet. I can see that all the veggies I feed are listed as moderate providers, so perhaps I will try to serve something completely different to Jack. The thing is that celery, brocolli and cabbage are in fact high in silicate, so they have an abrasive effect on the teeth and should be feed mostly every day to bunnies, so that is why I have kept to these veggies. I guess it is a matter of prioritizing in that case.

That is interesting!! And just when I thought I had it all figured out and everything was great. I will see if I can contact this specific vet and learn more.

On page 342, she does suggest that one should reduce the calcium in the food. And on 344 she says that bladder stones is usually attributed to a high level of calcium in the food.

Unfortunately, I don’t have access to all pages on hypercalciuria. But on one of the pages she does mention the phosphorus level in regard to urinary excretion of calcium (339).

So until I get a hold of this book, I will definitely use the excel sheet which I linked to earlier in this thread. Sarita, have you heard from your friend?

It is VERY confusing. Well, perhaps, we need the whole book to read and get the bigger picture. And perhaps the reason why it is online is that it is an older edition?

But so far, a few things does point to the diet…I guess, if the rabbit is genetically disposed to it, the diet can trigger the disease. And rabbits without this disposition can eat food with a high calcium level perhaps without any problems…I guess…

Posted By Petzy on 04/12/2010 11:01 AM
It is a fact that rabbits excrete calcium proportionately to their intake, or at least they are supposed to. However, I had searched for information on mineral composition of drinking water in relation to the formation of urinary sludge and stones in rabbits since this is a factor in the formation of urinary stones in some livestock species. A rabbit vet online didn’t believe there to be a correlation between calcium content of the water and the formation of sludge in rabbits. I since met a pet owner online who has had several animal species affected by urinary stones, including rabbits and a bird species that is very unlikely to develop these. Once she herself developed stones also, her vet agreed that the only common source in her household was the water. I mean to say, Karla, that it might be worth putting Jack on distilled water at least as long as you can’t be sure what’s in your water.

I did actually start filtering his water about two weeks ago because our tap water is very high in calcium. So the fact that you also mention this is quite interesting. Thank you for that info.

If anyone is interested, the reason that it is important to know the phosphate level in veggies (IF your rabbit is prone to sludge or bladder stones) is that a phosphate-deficient diet actually increases the urinary calcium levels.

Also, as mentioned there is a downside to feeding a low-calcium diet (this is what Dana Krempel was referring to):

“Despite their efficient calcium absorption, rabbits can suffer from calcium deficiency if they are fed a low-calcium diet. In other species, hyperparathyroidism affects mineral deposition in the mandible more than other bones, and this is also true in rabbits. Nutritional secondary hyperparathyroidism is manifested by loss of alveolar bone that allows root elongation and loosening of the teeth. The structure of the continually growing teeth is affected.10 Less enamel is produced (Fig 4), and the teeth become progressively weak until the crowns break off altogether. The bones of the skull become demineralized, and other areas of the skeleton, notably the spine, may also be affected. “

“More recent laboratory investigations suggest that a dietary calcium level of 0.6-1.0% is optimal for rabbits. This is the concentration that is recommended for pet rabbits.”

 http://homepage.mac.com/exoticdvm/.Public/vol%206-2.pdf