Equine Disease Quarterly | EQUINE
(nocardioform) placentitis, increasing the total
percentage of infectious abortions to 55%.
Evaluation of the last four breeding seasons shows
that cases of mucoid placentitis and abortion of
undetermined cause have the most variation between
years. Abortions due to fungal infection, fetal
bacteremia, umbilical cord torsion, and fetal stress have
remained fairly stable. An increase in miscellaneous
causes of abortion and undetermined causes occurred
in 2018 and 2019. Miscellaneous causes include a variety
of conditions including congenital malformations, fetal
and maternal stress, cervical pole necrosis, fetal organ
necrosis or inflammation, hydrops and Potomac horse
fever. This increase may reflect normal variation between
years. Alternatively, monitoring and intervention for
early placentitis and vaccination for infectious cases
of abortion such as leptospirosis and EHV-1 may be
decreasing the incidence of these recognized diseases
and result in a corresponding increase in the percentage
of cases of abortion without an identified cause.
Abortions of undetermined cause increased each year
at 14.9% in 2016, 27.5% and 38.2% in 2017 and 2018
and peaking at 44% in 2019. Continued monitoring of
trends will help to determine the significance of these
variations.
Figure 1. Relationship between the number of nocardioform
placentitis cases seen by the UKVDL and average rainfall
(inches) in August and September preceding that foaling
season.
CONTACT
Alan Loynachan, DVM, PhD, DACVP, [email protected],
Rebecca Ruby, MSc, BVSc, DAVCP, [email protected], (859)
257-8283, University of Kentucky Veterinary Diagnostic Laboratory,
Lexington, Kentucky
Nocardioform Placentitis: A Continuing
Enigma
Nocardioform placentitis was first diagnosed in central
Kentucky in 1986 with subsequent increased case
incidences occurring in 1998, 1999, and 2011. Cases
of nocardioform placentitis have also been reported
sporadically in Florida, South Africa, Italy, and most
Figure 2. Relationship between the number of nocardioform
placentitis cases seen by the UKVDL and average temperature
(°F) in August and September preceding that foaling season
recently in New Zealand. Nocardioform placentitis
is characterized by late term abortions, premature
foals, neonatal deaths, and weak foals born at term.
Nocardioform placentitis may involve large regions of
• Volume 22 Issue 02 | June 2020 •
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