b'YOUR GUIDE TO THE 2017 AAEP CONVENTION SPONSORED BY contagious disease, which is transmit-ted via the fecal-oral route, often occur at boarding facilities. But mortality rates are low.To better determine prevalence of and risk factors for coronavirus seropositivity, Pusterla tested blood serum samples from 5,247 healthy adult horses in 18 states us-ing an ELISA test. He found that:The overall seroprevalence of coronavi-rus was 9.4%;The highest seroprevalence was among horses from the Midwest;Seroprevalence among draft horses was higher than in other breeds; Seroprevalence was lowest among Thoroughbreds;As far as horse use, seroprevalence was highest in ranch/farm and breeding horses; and ISTOCK.COM There were no differences between agesDraft horses, horses from the Midwest, and those used for farming and ranching or breeding are and sexes. most at risk of contracting coronavirus.Coronavirus seroprevalence is associ-ated with region, herd size, animal den- found in soil. Grazing animals can ingesta temperature >103F, and a respiratory sity, and biosecurity measures (or a lackspores and become infected, but foals gen- rate 60 breaths per minute. thereof), he said. And that makes sense,erally get it after they inhale R. equi-ladenVaccinated mares showed significantly given the breed and horse use findings:particles. Treatment is prolonged and, so,higher anti-PNAG IgG (antibody) levels at Breeding and ranch/farm operationsin addition to risks of mortality, the dis- three weeks pre-foaling and on foaling day generally have large numbers of horses,ease has serious economic consequences.than on the day of first vaccination. The he added. And the Midwest has the high- Like many other bacterial pathogens,foals born to vaccinated mares had signifi-est percentage of drafts (30%) used asR. equi expresses the polysaccharide poly- cantly higher anti-PNAG IgG from birth farm or breeding animals. N-acetyl glucosamine (PNAG) on its sur- though Day 56 after birth, confirming the Pusterla noted, however, that he hadface. Study collaborators from Harvardantibodies were transferred to the foal via no information on farm managementMedical School created a candidate vac- passive transfer and colostrum ingestion. practices, how long horses had lived incine containing a fragment of syntheticWhen vets challenged the foals with a region, or the number of horses onPNAG attached to tetanus toxoidaR. equi, only one of the 12 born to vac-each premises. Still, he said he couldprotein veterinarians already administercinated mares developed pneumonia as confidently report that coronavirus sero- to protect horses against tetanusto de- compared to six out of the seven born to positivity is significantly associated withtermine its effectiveness against R. equi.the unvaccinated mares. That foal did not horses from the Midwest, draft horses,They gave the intramuscular vaccine torequire treatment, whereas the infected and ranch/farm and breeding uses. 12 pregnant mares six and three weeks be- foals from the control mares did.fore foaling, and saline to seven pregnantCohen said this research suggests Potential R. equi Vaccine Tested control mares at the same time points.that vaccinating mares against PNAG Rhodococcus equi (R. equi) is the mostWhen foals were approximately 28 dayseffectively protects foals against R. equi serious cause of pneumonia in 1- toold, the team infected them intrabronchi- pneumonia. He added that its unknown 4-month-old foals. It is expensive to treatally (i.e., via an endoscope through theif and when this vaccine will come on the and sometimes fatal, yet no vaccine totrachea into each of the large tubes thatmarket.hprotect against the pathogen exists.carry air to the lungs) with live, virulent R. Researchers from Texas A&Ms Collegeequi. They confirmed an R. equi pneu-of Veterinary Medicine and Biomedicalmonia diagnosis if they found ultrasono- eSciences considered if a newly developedgraphic evidence of abscesses in the lungs, vaccine given to pregnant mares couldmicroscopic evidence of bacterial infec- Visit TheHorse.com/AAEP2017protect their foals from R. equi pneumo- tion in tracheal lavage fluid consistentJapanese Vets Transferred MRSA tonia. Noah Cohen, VMD, MPH, PhD, Dipl.with bacterial pneumonia, and a positive Racehorses, TheHorse.com/40209ACVIM, professor of large animal internalculture for R. equi in the fluid. Also, foalsmedicine, presented their findings. had to display three or more of the follow-Quick Response Key in Equine Antimicrobial R. equi is a Gram-positive bacteriuming clinical signs: coughing, depression,Cases, TheHorse.com/40210A40 TheHorse.com/AAEP2017 AAEP Wrap-Up THE HORSEMarch 2018'