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Rabbits/Spay surgery question


QUESTION: Dear Dr. Krempels,

I have a question regarding my new 3-month-old rex bunny. I took her to the vet (someone on the HRS recommendation list) and we had a pre-spay blood work done. I was just informed that her liver enzymes were slightly elevated and that she had prolonged clotting.

Her vet said that the elevated liver enzymes may be due to her still growing (we use Yesterday's News for her litter), and the prolonged clotting may be a result of her squirming when they took the blood sample. Our current plan is to re-do the blood test in a month time to confirm this.

I was wondering,

1) Why would her squirming give that kind of result?

2) If the blood clotting is an issue, is it likely genetic? and,

3) Because the risk of cancer is high in females, are there any alternative treatments that can be done if spay surgery is not an option?

Thank you,

ANSWER: Dear Kira,

Yes, a struggling bunny can make taking a blood sample difficult, and it can cause the sample to clot.  I doubt this is a genetic condition of your bunny.  And yes, she's quite young to be spayed.

I wait until a female bunny is a year old before spaying.  This way, her estrogen can do its work in skeletal development, and her risk of bone density loss will be decreased.  Though the minute those ovaries come out, bone density will decrease.  It's just a physiological fact.

(We have begun a pilot program in which we take out only the uterus and leave the ovaries.  It's not for everyone, as the natural, hormone-based behaviors remain intact.  But it's going to help prevent bone density loss in our trial bunnies, which we're already seeing.)

I would wait a few months, let her mature, and then try again.  You do have some time.

Hope this helps.


---------- FOLLOW-UP ----------

QUESTION: Hi Dr. Krempels,

Thank you, yes, that does help! We were planning on having her spayed closer to 6 months but did her blood test early since we were already there for a general health exam (I was under the impression that if the blood results were okay, then there wouldn't be a need to re-test before surgery).

This might be a silly question, but is there a big difference between spaying at 6 months old versus a year old?

If I understood your response, when the ovaries come out their bone density will decrease. I thought rabbits were considered mature at 7 months. By waiting until 1 year of age, does the "risk of bone density loss" from the estrogen outweigh the "bone density loss" from the ovaries?


Dear Kira,

Spaying at a year gives her that much more time to develop her skeleton, which is not fully mature at 6 months.  At a year, she should be pretty much done growing, but have not yet developed the intraperitoneal fat that can make a spay surgery more challenging in older female bunnies.

No matter what age she is when you remove her ovaries, the bone density loss will begin as soon as she is spayed.  It's a gradual process, but it's no different from a human who has an ovariohysterectomy.  We mammals all suffer the same problems when we lose our estrogen.

So in short, it's better to wait as long as you can (until she's done growing), if possible.



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Dana Krempels, Ph.D.


I've lived with companion rabbits for more than 35 years, and consider them members of my family. I can answer any questions about the biology and health of rabbits, from the commonplace to the unusual. But please note:

RULE #1:

Find a rabbit vet at for immediate help, and don't risk your bunny's life by spending time asking questions online! If you can't get in touch with your vet, read these Emergency Sick Bunny Instructions.

If you have found a wild baby rabbit, please read these EMERGENCY INSTRUCTIONS FOR WILD BABY RABBITS and then use this link to FIND A LOCAL WILDLIFE REHABILITATOR who can give you the right advice.

RULE #2:
Help me help you! Please make your subject line informative if you have an urgent question. then LET ME KNOW IN THE SUBJECT LINE so I can give your question highest priority over non-urgent questions. If you don't do this, then I can't guarantee timely assistance!

For all the best, most accurate rabbit health, care and behavior information, visit The House Rabbit Society.


I have been rescuing and rehabilitating domestic and wild rabbits for about 30 years. I have written articles for many rabbit rescue publications, as well as for the veterinary journal, Exotic DVM. I own EtherBun, the internet's largest listserve dedicated to health, care, and behavior of domestic rabbits.

Houserabbit Adoption, Rescue, and Education, Inc. (H.A.R.E., Inc.) president National House Rabbit Society (Board member)

Exotic DVM
Warren Peace (Journal of the House Rabbit Society of Miami)
Various newsletters of the House Rabbit Society, nationwide

Ph.D - Biology
B.S. - Biology
B.A. - English

Awards and Honors
Lightspan Academic Excellence Award for web site on rabbit health and biology

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