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36 TheHorse.com THE HORSE October 2015 the push of a plunger at a distant catheter port on his neck. But even with this handy tool complications can arise, so British researchers took a closer look at which factors lead to its failure. Gayle Hallowell, MA, VetMB, PhD, CertVA, Dipl. ACVIM, ACVECC, PFHEA, MRCVS, of the Uni- versity of Nottingham, and colleagues studied 14 years of SPL records from the University of London's Royal Veterinary College. They examined various data points in each horse, ranging from age and ophthalmic condition to catheter position and clinician experience. The team collated data from 138 SPL catheters in 135 horses aged 6 days to 30 years old. The overall mean SPL com- plication rate among these animals was 15.9%. Hallowell noted that the clinician complication rate was lowest for medi- cine residents (10%), when compared with interns (42%), medicine clinicians (27%), and surgeons (16%). The stage-of-training results could have more to do with the type of case each group generally works with than procedure skill. "Medicine clinicians were more likely to put catheters in difficult cases, or clinicians and the residents just put more in, whereas surgeons put them into the horses under anesthesia in very clean conditions," she said. Hallowell et al. also determined that while 12.8% of cases developed complica- tions related to upper eyelid SPL place- ment, 22.2% experienced complications associated with lower eyelid placement; boarded clinicians were more likely to place catheters in the lower eyelid. The approach with the fewest compli- cations also appeared to be associated with the longest treatment times and the most efficacy for medicating: "There was better distribution of fluorescein (stain used to ascertain defects in the eye sur- face) when administered dorsally (via the upper eyelid) than ventrally (through the lower one) in horses with SPL catheters," said Hallowell. Theoretically, medication will distribute the way the dye does. For those horse owners concerned about the expense of long-term hospital- ization, there's good news: "There was no difference in complication rates in horses with subpalpebral lavage catheters whether maintained at home or in hospi- tal," said Hallowell, and duration of SPL use didn't influence complication rate. The clinician's chosen medication can make a difference, however: Horses on antimicrobials had complication rates of 13.2%, as opposed to 25% in those not re- ceiving antimicrobials. Among horses not receiving plasma, 13% developed compli- cations, whereas that figure rose to 30.4% with SPL administration of plasma. All told, "data favors upper eyelid place- ment" for SPL, said Hallowell. "Use of topical antimicrobials appeared protective against complications, and plasma should only be administered when indicated, as it increased the likelihood of complications. "I think the big take-home message is spend a little money on these catheters early on," she said, "rather than waiting to put them in when horses have become difficult … especially for conditions that will need long-term treatment." Separate Salmonella Shedders Brandy A. Burgess, DVM, MSc, PhD, Dipl. ACVIM, ACVPM, assistant professor in Epidemiology & Infection Control at Virginia-Maryland College of Veterinary Medicine, and colleagues at Colorado State University and a Kentucky hospital recently studied the factors associated with shedding multi-drug-resistant (MDR) Salmonella enterica and what effect it might have on previously hospitalized horses and their stablemates. The team scoured medical records of horses having fecal cultures for S. enterica as part of a surveillance program from January 2011 to December 2012 and contacted owners for long-term outcomes of those cases. Study horses included 94 culture-positive and 279 culture-negative animals from 199 farms. They found that: ■ Horses with diarrhea during hospital- ization were more likely to shed Salmo- nella than those without diarrhea. ■ Hospitalized horses with reduced feed intake were more likely to shed MDR strains than those with normal intake. ■ "A culture-positive hospitalized horse going back home did not affect whether stablemates had abnormal feces that year," Burgess said. ■ Salmonella shedding was not associated with risk of death or diarrhea one year post-hospital-discharge in the affected horse and was also not associated with hospitalization in stablemates. ■ However, horses that received a higher level of care (indicative of increased disease severity) were more likely to die during the one-year follow-up period as compared to horses at a lower level of care, irrespective of culture status. This is good news for owners of horses that have tested positive or been hospital- ized for Salmonella, but Burgess em- phasized it is not a hall pass for relaxing biosecurity measures on the farm. "Manage horses shedding Salmonella separately from other resident horses and to employ rigorous personal and envi- ronmental hygiene," said Burgess. These include such steps as housing them in a space separate from other horses and that can be easily cleaned and disinfected, us- ing separate cleaning tools and outer gar- ments when tending to horses returning from the hospital, and employing rigorous footwear and hand hygiene practices. Burgess also stressed that these "study results should be interpreted in light of the infection control practices employed on participating farms, which commonly included horse segregation and the use of separate cleaning tools." h ABOUT THE AUTHOR Stephanie L. Church is The Horse's editor in chief, and Erica Larson is the news editor. ACVIMForum Manage horses shedding Salmonella separately from other resident horses." DR. BRANDY BURGESS Data favors upper eyelid placement for subpal- pebral lavage. STEPHANIE L. CHURCH