Factors associated with survival in 148 recumbent horses

REASONS FOR PERFORMING STUDY

There are currently few data available on the prognosis and outcome of recumbent horses.

OBJECTIVES

To investigate the outcome of hospitalised horses that had been recumbent in the field or hospital and factors affecting their survival within the first 3 days of hospitalisation and survival after 3 days to hospital discharge.

STUDY DESIGN

Retrospective analysis of clinical records.

METHODS

Records of 148 horses admitted to the William R. Pritchard Veterinary Medical Teaching Hospital, University of California Davis from January 1995 to December 2010 with a history of recumbency or horses that became recumbent while hospitalised were evaluated. Exact logistic regression was used to assess the association between clinical parameters and survival within the first 3 days of hospitalisation and survival to hospital discharge after 3 days.

RESULTS

There were 109 nonsurvivors and 39 survivors. Multivariate analysis showed variables associated with an increased odds of death within the first 3 days of hospitalisation included duration of clinical signs prior to presentation, with horses showing clinical signs for over 24 h having increased odds of death (P = 0.043, odds ratio [OR] 4.16, 95% confidence interval [95% CI] 1.04-16.59), the presence of band neutrophils (P = 0.02, OR 7.94, 95% CI 1.39-45.46), the horse not using the sling (P = 0.031, OR 4.22, 95% confidence interval 1.14-15.68) and horses that were unable to stand after treatment (P<0.0001, OR 231.15, 95% CI 22.82-2341.33). Increasing cost was associated with lower odds of death (P = 0.017, OR 0.96, for each additional $100 billed, 95% CI 0.93-0.99).

CONCLUSIONS

This study demonstrates that the duration of clinical signs, response to treatment and the ability of horses to use a sling are associated with survival to hospital discharge for recumbent horses.

A racing start in life? The hurdles of equine feto-placental pathology

Significant progress has been made in understanding and monitoring the causes of equine abortion over past decades. However, not all in utero pathology results in abortion. It has long been recognised that some in utero pathology, such as twinning or chronic placentitis, can result in the birth of live but growth-retarded foals and there is historical evidence that birth weight may influence future athletic performance. Clinical experience (e.g. from twins) and experimental studies (pony-Thoroughbred embryo transfer) have highlighted the importance of reduced functional placental area in limiting growth in utero in horses. Many other nonfatal in utero pathologies (e.g. umbilical cord-related circulatory compromise) can potentially affect either placental function or other organ systems. Their influence on the short- and long-term health of the foal and its future athletic performance is in many cases poorly documented or understood. This review summarises the main causes of in utero pathology and reflects on how these may potentially affect the foal if born alive, highlighting the need for long-term studies on this important subject.

A review of foal diarrhoea from birth to weaning

Diarrhoea is among the most common clinical complaints in foals. Aetiologies, diagnostic testing and recommended interventions for specific causes of enterocolitis are summarised. Many mild to moderately affected foals can be managed in an ambulatory setting, while others will benefit from more intensive care at a referral centre.

Pharmacokinetics of intravenous ceftiofur sodium and concentration in body fluids of foals

The objectives of this study were to determine pharmacokinetics of intravenous (i.v.) ceftiofur in foals, to compare ultra-high performance liquid chromatography tandem mass spectometry (UPLC-MS/MS) and microbiologic assay for the measurement of ceftiofur concentrations, and to determine the minimum inhibitory concentration (MIC) of ceftiofur against common equine bacterial pathogens. In a cross-over design, ceftiofur sodium was administered i.v. to six foals (1-2 days-of-age and 4-5 weeks-of-age) at dosages of 5 and 10 mg/kg. Subsequently, five doses of ceftiofur were administered i.v. to six additional foals between 1 and 5 days of age at a dose of 5 mg/kg q 12 h. Concentrations of desfuroylceftiofur acetamide (DCA), the acetamide derivative of ceftiofur and desfuroylceftiofur-related metabolites were measured in plasma, synovial fluid, urine, and CSF by use of UPLC-MS/MS. A microbiologic assay was used to measure ceftiofur activity for a subset of plasma samples. Following i.v. administration of ceftiofur at a dose of 5 mg/kg to 1-2 day-old foals, DCA had a t(1/2) of 7.8 +/- 0.1 h, a body clearance of 74.4 +/- 8.4 mL/h/kg, and an apparent volume of distribution of 0.83 +/- 0.09 L/kg. After multiple i.v. doses at 5 mg/kg, DCA concentrations in CSF were significantly lower than concurrent plasma concentrations. Ceftiofur activity using a microbiologic assay significantly underestimated plasma concentrations of DCA. The MIC of ceftiofur required to inhibit growth of 90% of isolates of Escherichia coli, Pasteurella spp, Klebsiella spp, and beta-hemolytic streptococci was <0.5 microg/mL. Intravenous administration of ceftiofur sodium at the rate of 5 mg/kg every 12 h would provide sufficient coverage for the treatment of susceptible bacterial isolates.

Infectious agents detected in the feces of diarrheic foals: a retrospective study of 233 cases (2003-2008)

Background: Diarrhea is common in foals but there are no studies investigating the relative prevalence of common infectious agents in a population of hospitalized diarrheic foals.

Objectives: To determine the frequency of detection of infectious agents in a population of hospitalized foals with diarrhea and to determine if detection of specific pathogens is associated with age, outcome, or clinicopathologic data.

Animals: Two hundred and thirty‐three foals ≤ 10 months of age with diarrhea examined at a referral institution.

Methods: Retrospective case series. Each foal was examined for Salmonella spp., viruses, Clostridium difficile toxins, Clostridium perfringens culture, C. perfringens enterotoxin, Cryptosporidium spp., and metazoan parasites in feces collected at admission or at the onset of diarrhea.

Results: At least 1 infectious agent was detected in 122 foals (55%). Rotavirus was most frequently detected (20%) followed by C. perfringens (18%), Salmonella spp. (12%), and C. difficile (5%). Foals < 1 month of age were significantly more likely to be positive for C. perfringens (odds ratio [OR] = 15, 95% confidence interval [CI] = 3.5–66) or to have negative fecal diagnostic results (OR = 3.0, 95% CI = 1.7–5.2) than older foals. Foals > 1 month of age were significantly more likely to have Salmonella spp. (OR = 2.6, 95% CI = 1.2–6.0), rotavirus (OR = 13.3, 95% CI = 5.3–33), and parasites (OR = 23, 95% CI = 3.1–185) detected compared with younger foals. Overall 191 of the 223 foals (87%) survived. The type of infectious agent identified in the feces or bacteremia was not significantly associated with survival.

Conclusions and Clinical Importance: In the population studied, foals with diarrhea had a good prognosis regardless of which infectious agent was identified in the feces.

Relationships between early foal health, future performance and their dams reproductive health

The objectives of this study were to investigate: (i) relationships between early foal health and their dams' reproductive health at mating/conception as well as after parturition and (ii) health status during early foal life and its association with performance as an adult. The study included 35 foals showing clinical symptoms indicating septicaemia, sometimes in combination with other disturbances, within their first 18 h postpartum (Group I). Eighty-eight foals that were healthy during their first few days of life were used as control (Group II). All foals were born in the same region of Sweden and during the same period, and were expected to become performance athletes based upon the pedigree of their parents. Cytological and bacteriological examination of uterus at the time of mating/insemination at which the foal was conceived, revealed no difference between dams of Group I and Group II foals. Within 2-3 days after parturition, 29% and 4% of dams (p < 0.001) of Group I and Group II foals had metritis, respectively. At 30 days post-parturition, 64% of the dams of Group I foals and 32% of the dams of Group II foals (p = 0.002) had cytological indication of endometritis, and 57% of the dams of Group I foals and 21% of the dams of Group II foals (p < 0.001) showed bacterial growth upon culture. Altogether 29% of the Group I foals and 7% of the Group II foals were killed or died before 2 years of age (p = 0.001). The majority of the remaining Group I foals were poor performers and some were used just for pleasure riding. It is hypothesized that (i) mares--delivering foals that compromised within their first 18 h postpartum--might have suffered from an ascending infection during late gestation and (ii) health status during early foal life might be associated with their performance as adult.