Page 527 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

502 CHAPTER 2

VetBooks.ir CHRONIC DEGENERATIVE stromal, periglandular or perivascular; lymphatic
ENDOMETROSIS
stasis; uterine sacculation; transluminal adhesions;
Definition/overview glandular nests; and glandular or lymphatic cysts
(Fig. 2.112).
Chronic degenerative endometrosis is a term used to
describe a wide range of histopathological changes Management
found particularly in the endometrium of older mares. Evidence-based effective treatments for this group
of conditions have not been described, but most
Aetiology/pathophysiology therapies are aimed at inducing a superficial endo-
Chronic degenerative endometrosis is degenerative metrial inflammation and tissue loss. It is postu-
and progressive in nature and generally there is no lated that as the tissue regenerates itself, it will be in
evidence of active inflammation, although there are a better histopathological state than before. Some
infiltrates of lymphocytes, plasma cells and macro- of the therapies have the potential to cause irre-
phages. It is a feature of older mares, although the versible damage to the uterus and elsewhere in the
onset is individually specific, and is a sign of uterine tract and so should be used carefully. Mechanical
‘wear and tear’, ageing and cyclic hormonal effects. uterine curettage and uterine lavage with caustic
substances have been used with variable success. All
Clinical presentation can lead to intrauterine, cervical and vaginal adhe-
The degenerative changes are seen in older mares sions. These therapies should only be used after all
that have difficulty in conceiving and repeatedly other conventional therapies have been tried. After
return to oestrus, suffer early embryonic loss or treatment, a follow-up uterine biopsy at 1 month
pregnancy failure, or carry foals to term that are should be taken to assess response. All affected
dysmature. Older maiden mares that have had a suc- mares require breeding and post-breeding tech-
cessful athletic career may also demonstrate these niques to minimise contamination and optimise
changes on biopsy outside of the degree expected for conception chances.
their age, and this may explain their poor fertility.
Prognosis
Diagnosis The prognosis is guarded to poor depending on the
The major histopathological changes seen on endo- degree of histological changes and the response to
metrial biopsy are: fibrosis, which can be diffuse and therapy.

2.112

Fig. 2.112 Histopathology of an
endometrial biopsy from a mare with
chronic endometrial degeneration showing
a glandular cyst.