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  Discussion on Elevated Progesterone & Stallionish behaviour
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New Member:
Ross1954

Posted on Thursday, Jan 23, 2003 - 11:29 pm:

5yo mare who has displayed agrressive/unruly behaviour for 8 weeks plus increasing ongoing 'seasonal' behaviour. After 4 weeks similar behaviour ultrasound exam revealed normal sized ovaries + large follicle due to cycle based on palpatation. Given regumate. No/minimal difference in behaviour. Blood test 2 weeks (6 weeks from first behaviour problems) later revealed elevated progesterone levels (10x normal)accompanying stallionish behaviour- yet no visible sign of ovarion cyst. I note previous references but wonder how long before physical presence is detected. Vet has recommended waiting a further 8 weeks before repeating ultrasound to determine which ovary / whether cyst. Is the any more recent data on diagnosis & treatment. Any other cause of high progesterone? Does cost of inhibin test improve probability of correct diagnosis?
Moderator:
DrO

Posted on Friday, Jan 24, 2003 - 9:28 am:

Welcome to The Advisor Ross,
Usually depressed progesterone levels are noted with ovarian granulosa cell tumors, so I am uncertain why yours are elevated, what were the actual values? I wonder if the test might cross react with the Regumate a progesterone analog. If uncertain run the test again after having been off the Regumate a couple of weeks. A persistant corpus luteum is a cause of high levels of progesterone. The article is pretty current and yes demonstrating high inhibin levels will improve the chance you have a GCT, this is discussed in the article.
DrO
Member:
Ross1954

Posted on Thursday, Jan 30, 2003 - 6:44 pm:

I was 'misinformed' re the hormone tested. After checking directly with the vet, the mare was tested for testosterone (not progesterone)4 days after ultrasound & palpation when soft 4cm follicle detected. Reading was 1.6nmol/lt against a base/normal reading of .17nmol/lt. With a reading this high and ignoring the possibility of tumor on both ovaries (accounting for same size) should there be some physical presence detectable to account for this level of testosterone? If not...how long? At what point in time are you able to determine that in the absence of any measurable difference in ovary size there may be tumours on both ovaries?
Moderator:
DrO

Posted on Friday, Jan 31, 2003 - 4:04 am:

Why would you ignore the possiblility of GCT as this would be about the only likely cause of this. The article explains about the tumors appearances (Equine Diseases » Reproductive Diseases » Trouble Settling Mares & Stallion Infertility » Abnormal Heat Cycles (Estrus)
Granulosa Cell Tumors in Mares).
DrO
Member:
Ross1954

Posted on Sunday, Feb 2, 2003 - 7:07 pm:

It is not that I am ignoring GCT - its just that there are no detectable physical evidence and am curious as to this aspect with such high testosterone reading. The advice received is wait 8 weeks - ultrasound to see if there is anything "visible". Whilst there may be no alternative I guess I am concerned that if there is no physical difference @ 8 weeks between the ovaries - what then? Does one operate on the basis that it must be GCT and further assume that it must involve both ovaries ? Is 8 weeks too long / long enough? Thanks for your help and patience!

Moderator:
DrO

Posted on Monday, Feb 3, 2003 - 6:47 am:

As you are in Australia and in the middle of the normal breeding season I think that is plenty long to wait. If there is no ultrasound proof of which ovary has the tumor, repeat the hormone assays just to be sure and if it were me, I would go after the larger one first, all other things being equal.
DrO
Member:
Ross1954

Posted on Monday, Feb 3, 2003 - 6:43 pm:

Thanks for the advice. I note in your article on GCT reference to "As often as not the enlarged ovary may have a single cyst or solid mass suggestive of a large follicle... " As a '4cm follicle' was detected by ultrasound I wondered wehther in fact this could be the tumour? How similarly in ultrasound appearance or 'feel' are they likely to be (ie. could one be mistaken for the other)?
Moderator:
DrO

Posted on Tuesday, Feb 4, 2003 - 8:23 am:

Only if it persists.
DrO
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