intestinal lymph nodes. Thoracic radiographs may
show an interstitial pattern and nodules.
Affected tissues, such as skin, oral mucosa, rectal
mucosa, liver, and intestine, should be biopsied.
Histopathology confirms chronic, fibrosing
inflammatory reaction with infiltrates composed of
lymphocytes, plasma cells, and eosinophils seen in
multiple organs. In some tissues, the eosinophilic
infiltrates form granulomas.
Treatment is symptomatic, including systemic
broad-spectrum antibiotics, anthelmintics, and
corticosteroids. Prolonged therapy may be necessary,
and some relapses have been reported. Use of the
antineoplastic drug hydroxyurea has had limited
success; the thiopurine antimetabolite azathioprine
has also been suggested as a potentially effective
treatment.
A positive response to treatment shows as improved
demeanor, weight gain, reduced pruritus, and
resolution of diarrhea.
The prognosis for horses with MEED is poor, and
affected horses are generally euthanized due to lack
of response to treatment. Survival and resolution
of clinical signs has been reported, however, so
treatment should be attempted.
CONTACT:
Dr. Rachael Conwell
[email protected]
EquiMed Referrals Ltd
Tadcaster, North Yorkshire, United Kingdom
Progress Toward New Biomarkers for the Diagnosis of Bacterial Placentitis in Mares
Placentitis is a common cause of late-pregnancy
abortion in mares and poses a significant threat to fetal
and neonatal viability. Bacterial agents commonly
associated with the occurrence of placentitis include
Streptococcus equi subspecies zooepidemicus,
Escherichia coli, Klebsiella pneumoniae, Pseudomonas
aeruginosa, Leptospira spp, nocardioform bacteria
(Crossiella equi, Amycolatopsis spp) and others. Except
for leptospiral and nocardioform placentitis, most
cases of bacterial placentitis are thought to originate
due to bacterial invasion via the cervix. Therefore,
these cases of ascending placentitis usually start at
the cervical star and spread from there. Infection of
the placenta results in subsequent infection of the
fetus and in the release of prostaglandins from the
inflamed placenta, which ultimately leads to abortion
or delivery of a premature foal with bacterial sepsis.
8
Effective treatment of placentitis requires early
diagnosis prior to the appearance of clinical signs,
such as premature udder development with
or without the streaming of milk and/or vulvar
discharge.
Currently, ultrasonographic evaluation of the
placenta is used to detect early cases of placentitis
and to implement treatment to prevent abortion
an