I lost my first ferret to Aplastic Anaemia in her first season, don't make the mistakes I did. I was told there was no need to worry, she could take one season in oestrous (on heat), she could not. There seems to be much discussion as to the risks of a Jill remaining on heat and developing aplastic anaemia. First things first, Aplastic Anaemia is NOT BLEEDING TO DEATH. It is the loss of ability to produce new blood cells, not the loss of existing ones through bleeding. Aplastic anaemia will develop in a jill which is left in oestrous. It is the result of the jill having no effective mechanism to control the production of oestrogen with her body (a bit of a design fault in ferrets, or a human application outside design specification). As levels of oestrogen increase a whole catalogue of problems can occur, the most significant of which, in this case, is Hyper Oestrogenic Shock. This is manifest in 'shock' to the bone marrow (plus other structures) which is responsible for red blood cell production, aspects of immune response and regeneration, etc. As the bone marrow 'shocks', red blood cell production falls so a blood count will show a low cell count. If a jill were to be hit by hyper oestrogenic shock she will go down hill very quickly. I lost my first girl to Aplastic Anaemia as a result of hyper oestrogenic shock and she went from happy run around playful ferret, through two days of being not quite herself to dead, in about a week. Don't leave it to chance. If she has been oestrous for more than a few weeks then take her to the vet for an oestrogen suppressor injection. Spaying is the only long term solution but as breeding is a possible plan then this would be impossible. I left it too late. My girl was just a little off colour and a bit quieter than usual when I took her to the vet. By the time the first injection would have been having some effect, she was already dead. These injections are not instant in response, they take a few days to a week to make an impact and more than one may be required. Don't forget the roll bone marrow plays in immune response and system maintenance, if oestrous reaches stages of shock she will have little immune system left to defend herself. Pulling down oestrogen levels is only the start of treatment if she were to reach the stage of aplastic anaemia so try to stop this. Immune dysfunction, low blood count, damage to bone marrow are all issue which will result and each will slow the recovery from the next. I hope this help, I am a strong believer that acting early to prevent illness is a far superior technique to acting late to cure it. It's not as if the treatment requires you to wait, there will be no ill effects from early response, a late one could be catastrophic. Cc. [log in to unmask] Wayne (Lector, Priss and Bob (r.i.p. Lottie)) Wayne Gardner Dept. of Medical Physics United Leeds Teaching Hospitals NHS Trust [log in to unmask] [Posted in FML issue 3351]