Neurologic Disorders of the Foal.

Neurologic disease of foals is a diagnostic and therapeutic challenge for veterinarians. Disease conditions such as neonatal encephalopathy are seen as well as developmental and congenital defects, bacterial infections, and trauma. Neonatal encephalopathy can be considered a "syndrome" with a variety of causes resulting in a similar clinical presentation. These causes can be categorized as maladaptation, hypoxic/ischemic encephalopathy, and metabolic abnormalities, all leading to signs of cerebral and brainstem disease. Spinal cord signs may occasionally be seen, but these signs are usually overshadowed by cerebral disease. Treatment in most cases involves supportive care and outcome is favorable in most cases.

Factors Associated with Veterinary Clinical Faculty Attrition.

Faculty attrition and recruitment for veterinary clinical faculty positions have been reported as significant problems in veterinary medical education. To investigate the factors that may be important in veterinary clinical faculty retention, the perceptions and views of veterinary clinical academic faculty were determined using a web-distributed electronic survey. Responses were dichotomized by whether the respondent had or had not left an academic position and were analyzed for their association with faculty attrition. A total of 1,226 responses were recorded, and results demonstrated that factors other than compensation were associated with veterinary clinical faculty attrition, including departmental culture, work-life balance, and recognition and support of clinical medicine by the administration. Forty-four percent of respondents who had held a faculty appointment reported leaving academia either voluntarily or for non-voluntary reasons such as failure to achieve tenure, retirement, or having their position closed. Attention to correcting deficiencies in workplace culture and professional rewards could be a beneficial means by which to decrease the faculty attrition rates currently observed in clinical academic veterinary medicine.

A decision-tree model of career choice for veterinarians in clinical residency programs.

OBJECTIVE: To identify factors that individuals in clinical residency training programs consider when making a choice for or against a career in academic clinical medicine. SAMPLE: 207 veterinarians in clinical residency programs. PROCEDURES: An online survey was distributed to 1,053 veterinarians participating in clinical residency training programs overseen by organizations recognized by the AVMA American Board of Veterinary Specialties. Results were compiled and decision factors were analyzed by means of principal component analysis to identify latent factors from the set of survey items. These factors were then used to construct a decision tree to predict respondents' choice of whether to enter academic medicine or private clinical practice. RESULTS: 207 (20%) responses were analyzed. Ninety-three of 194 (48%) respondents reported a desire to pursue a career in academic medicine, and 101 (52%) reported a desire to pursue a career in private clinical practice. Principal component analysis identified 14 items clustered on research, clinical teaching, classroom teaching, and clinical practice. A decision tree was constructed that resulted in an overall accuracy of 82% in predicting a resident's career choice of academic medicine versus private clinical practice. The construct of professional benefits had a negative effect on desiring a career in academic medicine, whereas the construct of professional priorities and having had a positive residency training experience had a positive effect on desiring a career in academic medicine. CLINICAL RELEVANCE: Understanding factors that attract and encourage residents who might have an aptitude and interest in academic medicine holds important implications for addressing the shortage of veterinarians entering academic medicine.

Investigating the Relationship Between Cardiac Function and Insulin Sensitivity in Horses: A Pilot Study.

Metabolic syndrome in humans is commonly associated with cardiovascular dysfunction, including atrial fibrillation and left ventricular diastolic dysfunction. Although many differences exist between human and equine metabolic syndrome, both of these conditions share some degree of insulin resistance. The aims of this pilot study were to investigate the relationship between insulin sensitivity and cardiac function. Seven horses (five mares, two geldings, aged 17.2 ± 4.2 years, weight 524 ± 73 kg) underwent insulin-modified frequently sampled intravenous glucose tolerance testing to determine insulin sensitivity (mean 2.21 ± 0.03 × 10-4 L/min/mU). Standard echocardiograms were performed on each horse, including two-dimensional, M-mode, and pulse-wave tissue Doppler imaging. Pearson and Spearman correlation analyses were used to determine the association of insulin sensitivity with echocardiographic measures of cardiac function in 5 horses. Insulin sensitivity was found to be significantly correlated with peak myocardial velocity during late diastole (r = 0.89, P = 0.0419), ratio between peak myocardial velocity in early and late diastole (r = -0.92, P = 0.0263), isovolumetric relaxation time (r = -0.97, P = 0.0072), and isovolumetric contraction time (ρ = -0.90, P = 0.0374). These preliminary data suggest that decreased insulin sensitivity is correlated with alterations in both systolic and diastolic function, as measured with tissue Doppler imaging (TDI). Due to the small sample size of this study, the relationship between insulin sensitivity and myocardial function in horses requires further investigation.

Equine insulin dysregulation causes tissue specific alterations of proinflammatory cytokines and acute phase proteins in a NF-kB independent manner.

Similar to human diabetes, equine metabolic syndrome (EMS) causes insulin dysregulation leading to debilitating sequela including laminitis. The pathophysiological mechanisms underlying EMS and laminitis are not well known. Therefore, using an insulin-resistant equine model, we hypothesized that insulin dysregulation induces an increased expression of inflammatory proteins in a tissue specific manner. Two groups of horses (n = -5/group) were categorized as insulin-resistant (IR) or insulin-sensitive (IS), using a frequently sampled intra-venous glucose tolerance test. Biopsies from skeletal muscle, and visceral and subcutaneous adipose tissues were collected in both groups. Protein expression was quantified via Western blotting in order to investigate HSP90, α 2 macroglobulin (A2M), Fibrinogen α, ß, γ isoforms as well as cytokines, including interleukin-1ß (IL-1ß) and interleukin-6 (IL-6), in muscle and adipose tissues. Protein expression of HSP90, A2M and IL1-ß was significantly greater in visceral adipose tissue of IR horses compared to IS horses. Fibrinogen (α and γ) expression was only significantly increased in subcutaneous adipose tissue of IR group compared to IS group. In contrast, no statistically significant difference in protein expression of proinflammatory cytokines and acute phase proteins was reported in skeletal muscle of IR vs. IS horses. Relative protein expression of total and phospho-NFκB protein expression was not statistically significantly changed in adipose tissues of IR horses compared to IS horses. In conclusion, proinflammatory cytokines and acute phase proteins were upregulated in adipose tissue, but not in skeletal muscle, through an NF-kB independent pathway. Insights from this study could reveal novel biomarkers and potential therapeutic targets for EMS.

Perceptions of training, self-efficacy, and mentoring among veterinary clinical specialty trainees.

OBJECTIVE: To determine the perceptions of training, self-efficacy, and mentoring among veterinary clinical specialty trainees on the basis of their career interest. SAMPLE: 207 veterinarians who were either in a residency training program or had recently (within 2 years) completed one in a specialty recognized by the American Board of Veterinary Specialties. PROCEDURES: An online survey was used to collect data about the respondents' perceived preparedness for an academic career, training emphasis, and mentoring received during training and demographic information. Results were compiled and compared by professional career interest (ie, academic medicine or private practice) and gender. RESULTS: Included respondents represented 20% (207/1,053) of those invited. Preferred career choice was academic medicine for 48% (93/194) of respondents and private clinical practice for 52% (101/194) and did not differ by gender. Respondents perceived their likelihood of success in an academic career as high, and these perceptions did not differ by gender or preferred career choice. Mean self-efficacy scores for teaching were high among all respondents for most but not all listed teaching skills and did not differ by gender or preferred career interest. Mean self-efficacy scores were low for formulating research hypotheses and designing studies. Perceptions of training emphasis indicated strong mentoring in the areas of clinical practice and teaching with less mentoring and training emphasis in multiple areas of research and academic activity. CONCLUSIONS AND CLINICAL RELEVANCE: Lower self-efficacy of veterinary clinical specialty trainees in aspects of academic career appeared to be related to training emphasis and mentoring. Enhancement of emphasis on the identified areas of weakness may improve the interest and success of trainees in an academic career.

Horses affected by EPM have increased sCD14 compared to healthy horses.

Equine protozoal myeloencephalitis (EPM) is a debilitating neurologic disease affecting horses across the Americas. Gaps in understanding the inflammatory immune response in EPM-affected horses create difficulties with diagnosis and treatment, subsequently negatively impacting the prognosis of affected horses. The purpose of the current study was to evaluate circulating levels of the inflammatory immune marker soluble CD14 (sCD14), in horses with EPM (n = 7) and determine if they differed from healthy neurologically normal horses (n = 6). Paired sera and cerebrospinal fluid (CSF) samples were analyzed for sCD14. Inclusion criteria for EPM horses consisted of the presence of neurologic signs consistent with EPM, Sarcocystis neurona surface antigens 2, 4/3 (SnSAG 2, 4/3) ELISA serum: CSF antibody ratio ≤ 100, and a postmortem diagnosis of EPM. Control horses were neurologically normal, healthy horses with SnSAG 2, 4/3 ELISA serum: CSF antibody ratios of > 100. Serum anti-Sarcocystis neurona antibodies indicate that healthy control horses were exposed to S. neurona but resistant to developing clinical EPM. EPM cases had significantly greater concentrations of sCD14 in CSF samples compared to control horses and increased serum sCD14 concentrations. A positive correlation between sCD14 serum and CSF concentrations was observed in EPM-affected horses but not healthy horses. Soluble CD14 is an inflammatory marker, and the study results suggest it is elevated in EPM patients. When performed in conjunction with clinical evaluation and standard antibody testing, there may be potential for sCD14 to be utilized as a correlate for EPM.

Multicenter case-control study of signalment, diagnostic features, and outcome associated with cervical vertebral malformation-malarticulation in horses.

OBJECTIVE: To compare signalment of horses with cervical vertebral malformation-malarticulation (CVM) with that of control horses and to describe results of clinical examination, diagnostic imaging and necropsy findings, and reported outcome in horses with CVM. DESIGN: Retrospective case-control study. ANIMALS: 270 horses with CVM and 608 control horses admitted to 6 veterinary hospitals from 1992 through 2007. PROCEDURES: Medical records of participating hospitals were reviewed to identify horses with CVM (ie, case horses) and contemporaneous control (non-CVM-affected) horses that were admitted for treatment. Signalment was compared between case horses and control horses. Results of clinical examination, laboratory and diagnostic imaging findings, necropsy results, and outcome were assessed for horses with CVM. RESULTS: Case horses were younger (median age, 2 years) than were control horses (median age, 7 years). Thoroughbreds, warmbloods, and Tennessee Walking Horses were overrepresented in the CVM group. Gait asymmetry and cervical hyperesthesia were frequently detected in horses with CVM. Vertebral canal stenosis and articular process osteophytosis were commonly observed at necropsy; agreement between the results of radiographic or myelographic analysis and detection of lesions at necropsy was 65% to 71% and 67% to 78%, respectively. Of 263 horses with CVM for which outcome was recorded, 1 died and 172 (65.4%) were euthanatized. CONCLUSIONS AND CLINICAL RELEVANCE: Odds of a diagnosis of CVM were greater in young horses and horses of specific breeds. Detection of gait asymmetry and cervical hyperesthesia were frequently reported in association with CVM. Accurate diagnosis of lesions associated with CVM by use of radiography and myelography can be challenging.

Evaluation of factors reported by veterinarians who chose not to enter clinical academic veterinary medicine.

OBJECTIVE: To identify factors that may have influenced veterinarians' decisions to not pursue careers in clinical academic veterinary medicine. SAMPLE: 363 board-certified veterinarians. PROCEDURES: An online survey, open from July 7 to July 21, 2015, was used to gather data from board-certified veterinarians who were members of ≥ 1 of the 22 specialty organizations recognized by the American Board of Veterinary Specialties of the AVMA. Responses from those who reported never to have held an academic appointment were included in the study. Results were compiled and analyzed by gender and clinical discipline. RESULTS: Approximately 10,000 board-certified veterinarians were solicited to participate in the survey, and 1,314 (13.1%) responded. Among those, 363 (27.6%) reported never having held an academic position. Females more commonly reported no interest in teaching (44/185 [23.8%]) and disagreement with the statement that compensation in academic medicine was too low (39/164 [23.8%]), compared with responses by males (24/158 [15.2%] and 22/148 [14.9%], respectively). The strongest magnitude of interrater agreement was for the paired survey statements regarding too much bureaucracy and excessive expectation for committee and administrative work (weighted κ, 0.569). CONCLUSIONS: Many factors contribute to veterinarians' decisions about whether to pursue careers in academic medicine, and results indicated that some factors may vary depending on gender or clinical discipline. Recognition of these factors may help guide academic leaders in devising strategies and programs to enhance veterinarians' interest in clinical academic medicine careers.

Factors associated with the risk of positive blood culture in neonatal foals presented to a referral center (2000-2014).

BACKGROUND: Bloodstream infections (BSI) are common in sick foals and increase foal morbidity and mortality when they occur. Recognition of risk factors for BSI could be an important means to limit their occurrence, but studies on this topic are limited. OBJECTIVES: Historical as well as maternal and foal physical examination findings will predict risk of BSI in neonatal foals. ANIMALS: Foals <14 days of age admitted to a referral equine hospital for care. METHODS: Retrospective case-control study with univariate and multivariable logistic regression analysis. RESULTS: Four hundred twenty-nine (143 cases and 286 controls) foals <14 days of age were studied. Risk of a foal having a BSI was increased in foals with umbilical disease (adjusted odds ratio [OR], 11.01; P = .02), hypoglycemia (adjusted OR, 13.51; P = .03), and the combined presence of umbilical disease and low hematocrit (adjusted OR, >999.99; P = .04). Factors not found to be risk factors for development of BSI included prematurity, hypothermia, abdominal disease, diarrhea, failure of passive transfer, and maternal uterine infection. CONCLUSIONS AND CLINICAL IMPORTANCE: Several historical and physical examination findings increase the risk of foals being blood culture positive at presentation to the hospital. This knowledge may aid early identification of blood culture status, thus aiding in treatment decisions.

Effects of coadministration of corn oil and ponazuril on serum and cerebrospinal fluid concentrations of ponazuril in horses.

BACKGROUND: Ponazuril is used for the treatment of equine protozoal myeloencephalitis (EPM). Coadministration of ponazuril with oil could result in higher serum and cerebrospinal fluid (CSF) concentrations of ponazuril. HYPOTHESIS: Coadministration of corn oil will result in higher serum and CSF concentrations of ponazuril than when ponazuril is administered alone. ANIMALS: Ten resident university-owned adult horses of either sex and >2 years of age. METHODS: Cohort study. Ponazuril oral paste (5 mg/kg BW; ponazuril treatment group (PON); n = 5), or ponazuril oral paste (5 mg/kg BW; ponazuril and oil treatment group (PONOIL; n = 5) coadministered with 2 oz of corn oil q24h for 21 days. Horses were treated once daily, for 21 days. Blood was collected on days 0, 7, 14, and 21 before dosing. In addition, CSF was collected on days 1, 7, 14, and 21. The concentration of ponazuril was determined in serum and CSF and results compared using repeated measures ANOVA. RESULTS: Coadministration of ponazuril with 2 oz of corn oil resulted in higher concentrations of ponazuril in serum (at steady state) than that found in horses given ponazuril alone (6.2 ± 0.9 mg/L versus 4.5 ± 1.0 mg/L; P = .004) (mean ± 1 SD). Cerebrospinal fluid concentrations of ponazuril were also greater in horses that received ponazuril and oil (0.213 mg/L ± 0.04 versus 0.162 ± 0.04 mg/L) (P = .03). CONCLUSIONS AND CLINICAL IMPORTANCE: Results suggest that coadministration of corn oil with ponazuril might enhance the effectiveness of treatment with ponazuril.

Differential Proteomic Expression of Equine Cardiac and Lamellar Tissue During Insulin-Induced Laminitis.

Endocrinopathic laminitis is pathologically similar to the multi-organ dysfunction and peripheral neuropathy found in human patients with metabolic syndrome. Similarly, endocrinopathic laminitis has been shown to partially result from vascular dysfunction. However, despite extensive research, the pathogenesis of this disease is not well elucidated and laminitis remains without an effective treatment. Here, we sought to identify novel proteins and pathways underlying the development of equine endocrinopathic laminitis. Healthy Standardbred horses (n = 4/group) were either given an electrolyte infusion, or a 48-h euglycemic-hyperinsulinemic clamp. Cardiac and lamellar tissues were analyzed by mass spectrometry (FDR = 0.05). All hyperinsulinemic horses developed laminitis despite being previously healthy. We identified 514 and 709 unique proteins in the cardiac and lamellar proteomes, respectively. In the lamellar tissue, we identified 14 proteins for which their abundance was significantly increased and 13 proteins which were significantly decreased in the hyperinsulinemic group as compared to controls. These results were confirmed via real-time reverse-transcriptase PCR. A STRING analysis of protein-protein interactions revealed that these increased proteins were primarily involved in coagulation and complement cascades, platelet activity, and ribosomal function, while decreased proteins were involved in focal adhesions, spliceosomes, and cell-cell matrices. Novel significant differentially expressed proteins associated with hyperinsulinemia-induced laminitis include talin-1, vinculin, cadherin-13, fibrinogen, alpha-2-macroglobulin, and heat shock protein 90. In contrast, no proteins were found to be significantly differentially expressed in the heart of hyperinsulinemic horses compared to controls. Together, these data indicate that while hyperinsulinemia induced, in part, microvascular damage, complement activation, and ribosomal dysfunction in the lamellae, a similar effect was not seen in the heart. In brief, this proteomic investigation of a unique equine model of hyperinsulinemia identified novel proteins and signaling pathways, which may lead to the discovery of molecular biomarkers and/or therapeutic targets for endocrinopathic laminitis.

Humoral immune responses in the horse after intrathecal challenge with ovalbumin.

BACKGROUND: Diagnosis of neuro-inflammatory conditions in the horse can be challenging. Current methods include evaluation of cerebrospinal fluid (CSF) for inflammation and determination of specific antibody status. The antibody index (AI) and Goldman-Witmer coefficient (C-value) can be used to aid in the interpretation. HYPOTHESIS: The null hypothesis to be tested was that the Al and C-values do not change in horses with neuroinflammation. ANIMALS: Twelve horses of various ages (3-17 years) and breeds (Thoroughbred, Thoroughbred cross, draft, and Arabian) were included in the study. METHODS: The study was designed as a prospective randomized study. All horses were immunized with ovalbumin in adjuvant, twice. Horses of Group 1 then were challenged by intrathecal (IT) injection of ovalbumin, whereas horses of Group 2 were challenged IM. The Al and C-values for ovalbumin and equine herpesvirus were calculated. RESULTS: The Al for ovalbumin increased up to 5.92 in horses after intrathecal challenge, and remained normal (<1) in horses challenged IM. The C-value for ovalbumin reached a peak of 7.48, whereas for equine herpesvirus it achieved a value of 2.69. The changes in ovalbumin C-value and AI were significantly different between days 20 and 30 in horses after intrathecal challenge at day 20 (P = .002 and .0005, respectively). CONCLUSIONS AND CLINICAL IMPORTANCE: The results confirm the value of the Al and C-value in the evaluation of neuroinflammation in the horse.

Effects of small- and large-volume resuscitation on coagulation and electrolytes during experimental endotoxemia in anesthetized horses.

BACKGROUND: Small-volume resuscitation (SVR) has been advocated in place of large-volume isotonic resuscitation for the treatment of endotoxemia in horses. The effects of this type of therapy during experimental endotoxemia on electrolytes and coagulation have not been evaluated in the horse. As part of a larger project, the objective of this study was to determine the effects of SVR (hypertonic saline solution [HSS] plus hetastarch [HES]) on coagulation and serum electrolytes concentration, and to compare SVR with large- and small-volume isotonic resuscitation during experimental endotoxemia in anesthetized horses. HYPOTHESIS: SVR does not affect coagulation parameters or serum electrolyte concentrations when compared with either small- or large-volume isotonic crystalloids. ANIMALS: Horses were randomly assigned to 1 of 3 groups. Under halothane anesthesia, endotoxemia was induced by administering 50 microg/kg Escherichia coli endotoxin i.v. The horses were treated for 30 minutes with 15 mL/kg of balanced polyionic crystalloid solution (control), 60 mL/kg of balanced polyionic crystalloid solution (ISO), or 5 mL/kg of HSS followed by 10 mL/kg HES (HSS-HES). METHODS: Prospective randomized trial. RESULTS: Significant differences in coagulation parameters were not found among the groups. Thrombocytopenia was severe in all 3 groups. Serum ionized calcium concentration significantly decreased from baseline in control and ISO groups but not in the HSS-HES group. CONCLUSIONS AND CLINICAL IMPORTANCE: These results suggest that the HSS-HES combination, at the dosage used in this study had no adverse effects on coagulation beyond those produced by endotoxemia. HSS-HES may have a protective effect against endotoxemia-induced ionized hypocalcemia.

Factors associated with outcome following treatment of horses with septic tenosynovitis: 51 cases (1986-2003).

OBJECTIVE: To identify factors associated with outcome (ie, survival and return to function) following treatment of horses with septic tenosynovitis. DESIGN: Retrospective case series. ANIMALS: 51 horses with septic tenosynovitis. PROCEDURES: Information was obtained from medical records and through follow-up conversations with owners. Factors analyzed for an association with outcome included affected limb, etiology, duration of clinical signs prior to examination, presence of complications, primary treatment, secondary treatments, number of surgical procedures, and hospitalization time. RESULTS: Concurrent complications were identified in 41 (80%) horses. The primary treatment consisted of through-and-through lavage in 26 (51%) horses, tenoscopy in 20 (39%), and tenosynoviotomy combined with lavage in 5 (10%). Forty (78%) horses were discharged, and 37 (73%) survived at least 1 year after surgery; 21 of the 37 (57%) returned to their previous or a higher level of performance. Percentages of horses that survived 1 year after discharge and percentages that returned to their intended use did not vary significantly among treatments. Horses with tendon rupture or sepsis of an adjacent joint were significantly less likely to survive. Horses with tendon injury or pannus were significantly less likely to return to their intended use. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that various factors were associated with outcome in horses with septic tenosynovitis. However, surgical technique was not found to be associated with survival rate or rate of return to intended use.

A multicenter case-control study of risk factors for equine protozoal myeloencephalitis.

OBJECTIVE: To identify risk factors for equine protozoal myeloencephalitis (EPM) among horses examined at 11 equine referral hospitals. DESIGN: Case-control study. ANIMALS: 183 horses with EPM, 297 horses with neurologic disease other than EPM (neurologic controls), and 168 horses with non-neurologic diseases (non-neurologic controls) examined at 11 equine referral hospitals in the United States. PROCEDURES: A study data form was completed for all horses. Data were compared between the case group and each of the control groups by means of bivariate and multivariate polytomous logistic regression. RESULTS: Relative to neurologic control horses, case horses were more likely to be > or = 2 years old and to have a history of cats residing on the premises. Relative to non-neurologic control horses, case horses were more likely to be used for racing or Western performance. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that cats may play a role in the natural epidemiology of EPM, that the disease is less common among horses < 2 years of age relative to other neurologic diseases, and that horses used for particular types of competition may have an increased risk of developing EPM.

Cardiovascular and pulmonary effects of hetastarch plus hypertonic saline solutions during experimental endotoxemia in anesthetized horses.

BACKGROUND: Small volume resuscitation has been advocated as a beneficial therapy for endotoxemia in horses but this therapy has not been investigated in a prospective manner. The objective of this study was to determine the cardiopulmonary effects of small-volume resuscitation using hypertonic saline solution (HSS) plus Hetastarch (HES) during experimental endotoxemia in anesthetized horses. HYPOTHESIS: Treatment of horses with induced endotoxemia using HES-HSS does not alter the response of various cardiopulmonary indices when compared to treatment with either small- or large-volume isotonic crystalloid solutions. ANIMALS: Eighteen healthy horses were randomly assigned to 1 of 3 groups. Anesthesia was maintained with halothane. Endotoxemia was induced by administering 50 microg/kg of Escherichia coli endotoxin IV. The horses were treated over 30 minutes with 15 mL/kg of balanced polyionic crystalloid solution (control), 60 mL/kg of balanced polyionic crystalloid solution (ISO), or 5 mL/kg of HSS followed by 10 mL/kg of HES (HSS-HES). METHODS: Prospective randomized trial. RESULTS: Cardiac output (CO) after endotoxin infusion increased significantly (P < .05) from baseline in all groups, whereas mean central venous pressure increased significantly (P < .05) in the ISO group only. Mean pulmonary artery pressure increased from baseline (P < .05) in horses treated with isotonic fluids and HSS-HES. There was no effect of treatment with HSS-HES on CO, systemic vascular resistance (SVR), mean arterial pressure, blood lactate concentrations, or arterial oxygenation. CONCLUSIONS AND CLINICAL IMPORTANCE: The use of HSS-HES failed to ameliorate the deleterious hemodynamic responses associated with endotoxemia in horses. The clinical value of this treatment in horses with endotoxemia remains unconfirmed.

Use of a multivariable model to estimate the probability of discharge in hospitalized foals that are 7 days of age or less.

OBJECTIVE: To create a mathematical model to assist in early prediction of the probability of discharge in hospitalized foals < or= 7 days old. STUDY DESIGN: Prospective study. ANIMALS: 1,073 foals. PROCEDURES: Medical records from 910 hospitalized foals < or = 7 days old for which outcome was recorded as died or discharged alive were reviewed. Thirty-four variables including historical information, physical examination findings, and laboratory results were examined for association with survival. Variables associated with being discharged alive were entered into a multivariable logistic regression model. Accuracy of the model was validated prospectively on data from 163 foals. RESULTS: Factors in the final model included age group, ability to stand, presence of a suckle reflex, WBC count, serum creatinine concentration, and anion gap. Sensitivity and specificity of the model to predict live discharge were 92% and 74%, respectively, in the retrospective population and 90% and 46%, respectively, in the prospective population. Accuracy of an equine clinician's initial prediction of the foal being discharged alive was 83%, and accuracy of the model's prediction was 81%. Combining the clinician's prediction of probability of live discharge with that of the model significantly increased (median increase, 12%) the accuracy of the prediction for foals that were discharged and nonsignificantly decreased (median decrease, 9%) the accuracy of the predication for nonsurvivors. CONCLUSIONS AND CLINICAL RELEVANCE: Combining the clinician's initial predication of the probability of a foal being discharged alive with that of the model appeared to provide a more precise early estimate of the probability of live discharge for hospitalized foals.

In vivo pretreatment with PGG-glucan fails to alter cytokine mRNA expression of equine peripheral blood mononuclear cells exposed to endotoxin ex vivo.

Twelve healthy horses were assigned to treatment or control groups. Treated horses received PGG-Glucan[ED-1] (1 mg/kg, IV) 24 hours prior to peripheral blood mononuclear cell (PBMC) isolation. PBMCs were isolated and incubated in the presence of lipopolysachharide (LPS). At 0, 6, 12, 24 and 48 hours messenger RNA (mRNA) was extracted. Reverse transcription polymerase chain reaction (PCR) was performed and cytokine mRNA expression for tumor necrosis factor alpha (TNFalpha), interleukin 1beta (IL-1beta), interleukin 10 (IL-10) and interferon gamma (IFN-gamma) determined using real time PCR. A significant effect of LPS stimulation over time was seen on TNFalpha, IL-1beta, IL-10 and IFN-gamma production. No significant difference was observed between the PGG-Glucan treatment group and control cells at any time point.

Antigen-specific antibodies in cerebrospinal fluid after intramuscular injection of ovalbumin in horses.

Eighteen normal horses were assigned to 1 of 3 treatment groups to investigate the effects of IM or intrathecal (IT) administration of ovalbumin on serum and cerebrospinal fluid (CSF) antibody production. Horses of group 1 were injected intramuscularly with ovalbumin and adjuvant, while horses in treatment groups 2 and 3 received ovalbumin intrathecally or intravenously, followed by IM injection as in group 1. Serum and CSF antibody titers were tested in group I every 30 days for 4 months, while serum and CSF were collected in group 2 and 3 horses at postvaccination day 60. Horses of group 1 (IM) developed a serum antibody titer that peaked at postadministration day 60 (1:24,320 +/- 7,680) (mean +/- I SEM). Anti-ovalbumin antibodies were detected in CSF, and titers paralleled that of the serum, although at a much lower concentration (peak, 1:166 +/- 87). Horses of groups 2 and 3 developed significantly (P = .02) lower serum titers (1:720 and 1:2,067, respectively), but the difference in CSF titers did not achieve statistical significance (P = .06). The results confirm that antigen-specific antibody can be found in the CSF of horses in which antigen is not administered intrathecally. This may affect the interpretation of CSF analysis in diseases such as equine protozoal myeloencephalitis. Further, the findings suggest that IT injection of the soluble antigen ovalbumin induces a state of antigenic tolerance in the horse. The clinical significance of this finding remains unknown at this time.