Dear Mike:
>The first line on the page says that adrenal tumors cause excess cortisol.
>It's my understanding that serum cortisol levels are rarely elevated in
>ferrets with adrenal disease.
 
That page is a bit confusing.  In the first section, it says that adrenal
tumors result in excessive cortisol secretion, which is true in dogs and
cats, and in a low number of ferret cases.  Further down the page under
physiology, they say that in ferrets, the operating hormone is indeed
estrogen.  Probably the y could clear it up by stating that at the outset.
 
>Further down the page it shows a picture of an enlarged spleen and says
>something about a biopsy to determine whether or not it is "normal
>enlargement, called hypersplenism..." whoa, I thought normal enlargement
>was called splenomegaly and hypersplenism is a specific condition.  To
>paraphrase "Ferrets, Rabbits and Rodents..." hypersplenism causes a
>deficiency of one of the blood elements as a result of excessive
>destruction by the spleen.
 
You are correct - simple enlargement is splenomegaly.  Hypersplenism is
a pathologic condition where blood elements are destroyed by the liver.
However, hypersplenism really does not occur in the ferret (there was one
case reported incorrectly in the ferret literature about fifteen years ago.
The true cause of splenomegaly is splenic production of immature red and
white blood cells by the spleen in response to chronic inflammation.
However, in ferrets, these cells generally do not complete their maturation
process and are restricted to the spleen, which grows and grows, and grows
some more!  Destruction of blood elements is really not part of the
equation.
 
I do like the page overall, with one exception.  In the diseases page, they
have a section on "liver cancer".  the implication is that this is a common
problem, as the other sections are on adrenal disease and insulinoma.
However, liver cancer, outside of lymphosarcoma, is fairly rare.  In this
page, they do not identify the cause of the "cancer" outside of showing a
bloody, swollen section of liver.  I would hope that ferret owners would
not get the take home message that the liver is a common site of neoplasia
in ferrets, because it isn't.  I see too many misinterpretations of liver
enzymes as it is!
 
With kindest regards,
 
Bruce Williams, DVM, DACVP
[Posted in FML issue 3179]