126
46TH
ANNUAL
CONGRESS
OF
THE
SAEVA
SKUKUZA
16-‐20
FEBRUARY
2014
alerted observers to possible cases of clinical infection. A set of duplicate nasal swabs
was again collected from each horse prior to departure from the sales complex. Any
horses that showed elevated rectal temperature (> 38.5 ºC) measured with a
Thermoval® rapid digital thermometer and, or a nasal discharge underwent a clinical
examination and serial nasal swab collection for qPCR analysis until departure.
Results
In 2011, two horses (from the E. Cape) showed molecular evidence of EHV-4
shedding and concurrent pyrexia during the sales period. The mean body
temperatures showed significant elevations overall and for each farm.
In 2013, no incidents of EHV-1 shedding and 21 incidents of EHV-4 shedding were
recorded from 13 (13.9%) horses; that ranged from one to four incidents per horse.
These animals originated from seven farms located as follows: W. Cape (n=3 farms;
6 horses), E. Cape (n=2 farms; 5 horses) and KZ-N (n=2 farms; 2 horses). At least
one incident of nasal discharge in 86 (95.6%) and pyrexia in 49 (54.4%) was observed
in the study population during the period of observation. In only a single horse was
there not a single incident of pyrexia or nasal discharge recorded. The distribution of
EHV-4 incidents by date showed that the first incidents were recorded on the
second day after arrival with a gradual increase in frequency being recorded towards
the end of the sales’ period.
Discussion
In the initial study in 2011, sales consignment of young Thoroughbreds was
associated with elevations in both physiological stress and body temperature, with
only limited shedding of EHV-4 observed. These findings did however support both
the variables and the sampling methods and justified a follow-up study to define the
prevalence o b6