Apparent excessive calcium in diet

Question

Sludge?   This is the third time I've noticed in my bun's urine "sludge"-type material. After Googling, I've found so much conflicting information on what foods are high in calcium. I've noticed some congruity however, such as kale, dandelion greens, alfalfa, etc. Bunbun is approximately 6 months old. I took her to the only vet in my area who sees rabbits; but they aren't specialists. The nearest specialist is several hours away. I can take her if need be. Thus far I am trying to restrict her excess calcium intake (but not overly so!). There is evidence of calcium carbonate in her urine. She has free access to fresh, clean water. Bunbun gets a minimum of 5 hours free play per day and usually up to 8-10 hours. She's an indoor pet and my youngest cat has adopted her and thinks she's her child (grooms her, they play, etc). I suppose I'm looking for a straight answer on the calcium content of greens (and fruits, but she gets them as a treat), for a 2.3 lb bun. If I see sludge again, I will take her to the vet for sure, so should I ask for a blood calcium test? We have 4 cats and we take excellent care of our companions. Bunbun is a rescue, too. (They all are). Bunbun is a member of our family (2 kids as well) and I want her to live a long, happy and healthy life. Thank you for your time and consideration. (She peed in her Timothy hay dish, which I also give an occasional sprinkle of dried rabbit grains, hence the "things that are food items").

Kind Regards,
Remy

Answer
Hi Remy

Sorry it's taken me so long to reply, I could have sworn I did but it must not have sent properly.

Rabbits do naturally excrete calcium in their urine, that is normal. I do recommend a vet investigate actual sludgy muck in the urine though, if the rabbit is developing bladder or kidney stones that may need operations.

Have a read of these two links on the urinary tract and calcium problems:
http://www.bio.miami.edu/hare/urinary.html
http://www.rabbitwelfare.co.uk/resources/content/info-sheets/calcium.htm

With the diet, they don't need any kind of "grain" type food and struggle to digest seeds. A handful of proper rabbit pellets such as Oxbow or Science Selective is a good supplement, but avoid "junior" pellets as they will have higher calcium content as they are designed for growing rabbits.

There are a lot of veggies that are high in calcium, or oxalates, this is a guinea pig website but has a good vegetable chart with calcium listed. Although note that some of these veggies are not suitable for rabbits
http://www.guinealynx.info/diet_vegs.html
Some herbs are also higher in calcium including parsley (listed on the link above), especially curly leaf.

Definitely avoid alfalfa hay and stick to meadow or timothy hay. Although the calcium content of those will vary too depending on when they've been cut in the field.

I hope the links above are useful!

Cat