Risk factors associated with development of colitis in horses post-exploratory laparotomy.

BACKGROUND: Diagnosis of colitis has been shown to impact morbidity and mortality in hospitalised horses. There are no studies to date that describe the incidence of infectious colitis after exploratory laparotomy. OBJECTIVES: To investigate risk factors associated with the development of colitis and infectious colitis post-exploratory laparotomy. STUDY DESIGN: Retrospective case-control. METHODS: Medical records of equids admitted from 2011 to 2020 were reviewed. The primary outcome was a diagnosis of colitis following exploratory laparotomy. Bivariable associations between colitis and risk factors were assessed using the 2-sample t-test and Fisher's exact test. All risk factors were subjected to a backward elimination variable reduction algorithm within a logistic regression framework (p-value set to 0.05). Odds ratios and 95% confidence intervals were computed for the final model. RESULTS: A total of 504 equids were included in the study. Forty-two patients (8.3%) were diagnosed with postoperative colitis. Five patients were diagnosed with Salmonella spp. and two with Clostridioides difficile. The odds of postoperative colitis were higher among patients that had pelvic flexure enterotomy (OR = 3.7, 95% CI = 1.7-7.9, p = 0.001), postoperative leukopenia or leukocytosis (OR = 21.2, 95% CI = 9.7-46.7, p < 0.001), or plasma lactate 2.0-4.0 mmol/L (OR = 3.0, 95% CI = 1.3-6.7, p < 0.008). Patients diagnosed with colitis had a longer median length of hospitalisation (9 days; range 2-21) compared with patients without colitis (7 days; range 2-25). Patients with colitis had a survival to discharge rate similar to patients without colitis (95% compared to 93%). MAIN LIMITATIONS: Risk factors for infectious colitis could not be determined due to variation in testing protocols in this retrospective study and the low number of positive cases. CONCLUSIONS: Colitis as a postoperative complication does not negatively impact survival to discharge but is associated with longer hospitalisation. Pelvic flexure enterotomy, postoperative leukopenia or leukocytosis, and increased plasma lactate were identified as significant risk factors associated with colitis.

INTRODUCTION/CONTEXTE: Il a été démontré qu'un diagnostic de colite a un impact sur la morbidité et la mortalité des chevaux hospitalisés. Il n'y a aucune étude décrivant l'incidence de colites infectieuses suivant une laparotomie exploratrice. OBJECTIFS: Investiguer les facteurs de risque associés au développement de colites et de colites infectieuses en période post-opératoire suivant une laparotomie exploratrice. TYPE D'ÉTUDE: Étude de type rétrospective avec cas témoins. MÉTHODES: Les dossiers médicaux de chevaux admis entre 2011 et 2020 ont été utilisés. La résultante primaire était un diagnostic de colite suivant une laparotomie exploratrice. Les analyses bivariées entre colites et facteurs de risque ont été évalués par le biais d'un test de Fisher exact et un test de T à deux échantillons. Tous les facteurs de risque ont été sujet à un algorithme de réduction par élimination régressive des variables dans le cadre d'une régression logistique (valeur de p à 0.05). Les probabilités (odds ratio) et les intervalles de confiance à 95% ont été inclus dans le modèle final. RÉSULTATS: Au total, 504 chevaux ont été inclus dans l'étude. Quarante-deux patients (8.3%) ont reçu un diagnostic de colite post-opératoire. Cinq patients ont reçu un diagnostic de Salmonella spp. et deux, de Clostridioides difficile. Les chances de colites post-opératoires étaient plus élevées chez les patients ayant subi une entérotomie de la courbure pelvienne (OR = 3.7, 95% CI = 1.7-7.9, p = 0.0008), ayant souffert d'une leucopénie ou leucocytose (OR = 21.2, 95% CI = 9.7-46.7, p < 0.0001), ou ayant eu une valeur de lactate plasmatique de 2.0-4.0 mmol/L (OR = 3.0, 95% CI = 1.3-6.7, p < 0.0084). Les patients diagnostiqués avec une colite ont eu une durée d'hospitalisation médiane supérieure (9 jours; étendu 2-21) comparativement aux patients sans colite (7 jours; étendu 2-25). Il n'y avait pas de différence entre les patients avec et ceux sans colite, en ce qui a trait au taux de survie de congé hospitalier (95% comparé à 93%). LIMITES PRINCIPALES: Les facteurs de risque pour les colites infectieuses n'ont pas pu être identifié en raison de variations des protocoles de tests employés dans cette étude rétrospective et du faible nombre de cas positifs. CONCLUSIONS: Les colites en tant que complication post-opératoire n'ont pas d'impact négatif sur le taux de survie hospitaliser mais sont associées à une période d'hospitalisation de plus longue durée. Une entérotomie de la courbure pelvienne, une leucopénie ou leucocytose post-opératoire et une valeur élevée de plasma sanguin ont été identifiés comme facteurs de risque associés au développement de colite.

Pharmacokinetics of multiple oral doses of acetaminophen in equine neonates.

OBJECTIVE: To determine the pharmacokinetics and clinical safety of acetaminophen after oral administration of 40 mg/kg q 12 hours or 60 mg/kg q 24 hours for 14 days. ANIMALS: 12 healthy light-breed neonatal foals. PROCEDURES: 6 foals received acetaminophen at 40 mg/kg q 12 hours and 6 foals received 60 mg/kg q 24 hours for 14 days. The study dates were January 31 to April 15, 2023. Physical examinations were performed daily. Plasma disposition of acetaminophen was determined after the first, mid-point drug administration. Hematology and biochemistry analysis was performed before the study, day 7, and the last day of drug administration. Plasma acetaminophen concentrations were determined by high-performance liquid chromatography. Plasma pharmacokinetic parameters were estimated using noncompartmental analysis. RESULTS: No statistically significant changes occurred on hematology or biochemistry profiles. Elevations in γ-glutamyl transferase (GGT) and sorbitol dehydrogenase (SDH) were noted in 4 foals at various time points. The maximum plasma concentration (Cmax) occurred within 2 hours for both doses. The 60 mg/kg dose resulted in a larger median Cmax (range) at 28 µg/mL (22-32) than the 40 mg/kg dose at 23 µg/mL (19-27). The median area under the concentration-vs-time curve from 0 to 8 hours (AUC0-8 hour [range]) was 100 h•µg/mL (82-100) at 40 mg/kg and 128 h•µg/mL (120-168) for 60 mg/kg. Trough concentrations decreased over time for both regimens. CLINICAL RELEVANCE: Foals tolerate oral acetaminophen at 40 mg/kg q 12 hours or 60 mg/kg q 24 hours. Further analgesic and antipyretic studies will help to delineate optimal dosage regimens of acetaminophen to treat foals.

Systemic calcinosis in a Quarter Horse gelding homozygous for a myosin heavy chain 1 mutation.

CASE DESCRIPTION: A 9-year-old Quarter Horse gelding was presented for lethargy, decreased appetite, polyuria and polydipsia (PU/PD), and severe muscle wasting suggestive of immune-mediated myositis. CLINICAL FINDINGS: The horse displayed lethargy, fever, tachyarrhythmia, inappetence, PU/PD, and severe epaxial and gluteal muscle wasting. Clinicopathologic findings were consistent with previously reported cases of systemic calcinosis in horses, including increased muscle enzyme activity, hyperphosphatemia, increased calcium-phosphorus product, hypoproteinemia, and an inflammatory leukogram. A diagnosis of systemic calcinosis was established by histopathologic evaluation of biopsy specimens from skeletal muscle, lung, and kidney. TREATMENT AND OUTCOME: Symptomatic treatment was complemented by IV treatment with sodium thiosulfate to reverse calcium-phosphate precipitation in soft tissue and PO aluminum hydroxide to decrease intestinal phosphorus absorption and serum phosphorus concentration. CLINICAL RELEVANCE: This is the first report in the veterinary literature of an antemortem diagnosis of systemic calcinosis in the horse that was successfully treated and had favorable long-term outcome.

Comparison of two glucose-monitoring systems for use in horses.

OBJECTIVE: To determine the accuracy of 2 interstitial glucose-monitoring systems (GMSs) for use in horses compared with a point-of-care (POC) glucometer and standard laboratory enzymatic chemistry method (CHEM). ANIMALS: 8 clinically normal adult horses. PROCEDURES: One of each GMS device (Dexcom G6 and Freestyle Libre 14-day) was placed on each horse, and blood glucose concentration was measured via POC and CHEM at 33 time points and compared with simultaneous GMS readings. An oral glucose absorption test (OGAT) was performed on day 2, and glucose concentrations were measured and compared. RESULTS: Glucose concentrations were significantly correlated with one another between all devices on days 1 to 5. Acceptable agreement was observed between Dexcom G6 and Freestyle Libre 14-day when compared with CHEM on days 1, 3, 4, and 5 with a combined mean bias of 10.45 mg/dL and 1.53 mg/dL, respectively. During dextrose-induced hyperglycemia on day 2, mean bias values for Dexcom G6 (10.49 mg/dL) and FreeStyle Libre 14-day (0.34 mg/dL) showed good agreement with CHEM. CLINICAL RELEVANCE: Serial blood glucose measurements are used to diagnose or monitor a variety of conditions in equine medicine; advances in near-continuous interstitial glucose monitoring allow for minimally invasive glucose assessment, thereby reducing stress and discomfort to patients. Data from this study support the use of the Dexcom G6 and Freestyle Libre 14-day interstitial glucose-monitoring systems to estimate blood glucose concentrations in horses.

Blood thiamine (vitamin B1 ), ascorbic acid (vitamin C), and cortisol concentrations in healthy and ill neonatal foals.

BACKGROUND: Sepsis is common in foals and several treatments are used to facilitate recovery. Evidence in people suggests an association between low blood concentrations of thiamine, ascorbic acid, and cortisol and sepsis, with further evidence suggesting that administration of hydrocortisone, thiamine, and ascorbic acid may improve outcome. No information is available with regard to these treatments in foals. HYPOTHESIS/OBJECTIVES: To compare blood concentrations of thiamine, ascorbic acid, and cortisol in healthy and ill foals. ANIMALS: Fifteen healthy and 27 ill (septic and sick-nonseptic [SNS]) foals were evaluated at admission. Fewer healthy and ill foals were available for sampling at 72 and 120 hours. METHODS: Prospective study. Blood was collected from healthy foals at 12 (n = 15), 72 (n = 11), and 120 (n = 9) hours of age and from ill foals <48 hours old at admission (n = 27), 72 (n = 8), and 120 (n = 8) hours after presentation. Thiamine, ascorbic acid, and cortisol concentrations were measured in blood samples and compared between groups of foals. RESULTS: Blood concentrations of thiamine were significantly lower in septic compared to healthy foals at 72 (median, 1.72 ng/mL; P = .02) and 120 (median, 2.0 ng/mL; P = .04) hours after admission; blood concentrations of ascorbic acid also were significantly lower in septic compared to healthy foals at 72 (median, 4.4 µg/mL; P = .02) and 120 hours (median, 4.8 µg/mL; P = .03). Blood concentrations of ascorbic acid were lower in SNS compared to healthy foals at 72 (median, 6.9 µg/mL; P = .03) and 120 (median, 6.4 µg/mL; P = .04) hours after admission. Serum cortisol concentrations were significantly higher at admission in septic (median, 4.23 µg/dL) compared to SNS (median, 1.8 µg/dL; P = .01) and healthy (median, 2.2 µg/dL; P = .002) foals. CONCLUSIONS AND CLINICAL IMPORTANCE: A potential association exists between illness in foals and lower blood concentrations of thiamine and ascorbic acid during hospitalization. Additional studies are needed to examine a larger population of foals and determine the clinical impact of low vitamin concentrations, if any, on morbidity and mortality.

Dynein light chain regulates adaptive and innate B cell development by distinctive genetic mechanisms.

Mechanistic differences in the development and function of adaptive, high-affinity antibody-producing B-2 cells and innate-like, "natural" antibody-producing B-1a cells remain poorly understood. Here we show that the multi-functional dynein light chain (DYNLL1/LC8) plays important roles in the establishment of B-1a cells in the peritoneal cavity and in the ongoing development of B-2 lymphoid cells in the bone marrow of mice. Epistasis analyses indicate that Dynll1 regulates B-1a and early B-2 cell development in a single, linear pathway with its direct transcriptional activator ASCIZ (ATMIN/ZNF822), and that the two genes also have complementary functions during late B-2 cell development. The B-2 cell defects caused by loss of DYNLL1 were associated with lower levels of the anti-apoptotic protein BCL-2, and could be supressed by deletion of pro-apoptotic BIM which is negatively regulated by both DYNLL1 and BCL-2. Defects in B cell development caused by loss of DYNLL1 could also be partially suppressed by a pre-arranged SWHEL Igm-B cell receptor transgene. In contrast to the rescue of B-2 cell numbers, the B-1a cell deficiency in Dynll1-deleted mice could not be suppressed by the loss of Bim, and was further compounded by the SWHEL transgene. Conversely, oncogenic MYC expression, which is synthetic lethal with Dynll1 deletion in B-2 cells, did not further reduce B-1a cell numbers in Dynll1-defcient mice. Finally, we found that the ASCIZ-DYNLL1 axis was also required for the early-juvenile development of aggressive MYC-driven and p53-deficient B cell lymphomas. These results identify ASCIZ and DYNLL1 as the core of a transcriptional circuit that differentially regulates the development of the B-1a and B-2 B lymphoid cell lineages and plays a critical role in lymphomagenesis.

Measured and calculated variables of global oxygenation in healthy neonatal foals.

OBJECTIVE To assess multiple central venous and arterial blood variables that alone or in conjunction with one another reflect global oxygenation status in healthy neonatal foals. ANIMALS 11 healthy neonatal foals. PROCEDURES Central venous and arterial blood samples were collected from healthy neonatal foals at 12, 24, 36, 48, 72, and 96 hours after birth. Variables measured from central venous and arterial blood samples included oxygen saturation of hemoglobin, partial pressure of oxygen, lactate concentration, partial pressure of carbon dioxide, and pH. Calculated variables included venous-to-arterial carbon dioxide gap, estimated oxygen extraction ratio, ratio of partial pressure of oxygen in arterial blood to the fraction of inspired oxygen, bicarbonate concentration, base excess, and blood oxygen content. RESULTS Significant differences between arterial and central venous blood obtained from neonatal foals were detected for several variables, particularly partial pressure of oxygen, oxygen saturation of hemoglobin, and oxygen content. In addition, the partial pressure of carbon dioxide in central venous blood samples was significantly higher than the value for corresponding arterial blood samples. Several temporal differences were detected for other variables. CONCLUSIONS AND CLINICAL RELEVANCE Results of this study provided information about several variables that reflect global oxygenation in healthy neonatal foals. Values for these variables in healthy foals can allow for comparison with values for critically ill foals in future studies. Comparison of these variables between healthy and ill foals may aid in treatment decisions and prognosis of clinical outcome for critically ill foals.

Macrophage effector responses of horses are influenced by expression of CD154.

Reactive intermediates contribute to innate immunity by providing phagocytes with a mechanism of defense against bacteria, viruses and parasites. To better characterize the role of CD154 in the production of reactive intermediates, we cloned and expressed recombinant equine CD154 (reqCD154) in Chinese Hamster Ovary (CHO). In co-culture experiments, CHO cells ectopically expressing reqCD154 elicited superoxide production in monocyte-derived macrophages (MDM). Collectively, our results indicate that regulation of CD154 expression plays a role in innate host defenses.

The Transcription Factor ASCIZ and Its Target DYNLL1 Are Essential for the Development and Expansion of MYC-Driven B Cell Lymphoma.

How MYC promotes the development of cancer remains to be fully understood. Here, we report that the Zn(2+)-finger transcription factor ASCIZ (ATMIN, ZNF822) synergizes with MYC to activate the expression of dynein light chain (DYNLL1, LC8) in the murine Eµ-Myc model of lymphoma. Deletion of Asciz or Dynll1 prevented the abnormal expansion of pre-B cells in pre-cancerous Eµ-Myc mice and potentiated the pro-apoptotic activity of MYC in pre-leukemic immature B cells. Constitutive loss of Asciz or Dynll1 delayed lymphoma development in Eµ-Myc mice, and induced deletion of Asciz in established lymphomas extended the survival of tumor-bearing mice. We propose that ASCIZ-dependent upregulation of DYNLL1 levels is essential for the development and expansion of MYC-driven lymphomas by enabling the survival of pre-neoplastic and malignant cells.

IL-10 mediates plasmacytosis-associated immunodeficiency by inhibiting complement-mediated neutrophil migration.

BACKGROUND: Plasmacytosis (ie, an expansion of plasma cell populations to much greater than the homeostatic level) occurs in the context of various immune disorders and plasma cell neoplasia. This condition is often associated with immunodeficiency that causes increased susceptibility to severe infections. Yet a causative link between plasmacytosis and immunodeficiency has not been established. OBJECTIVE: Because recent studies have identified plasma cells as a relevant source of the immunosuppressive cytokine IL-10, we sought to investigate the role of IL-10 during conditions of polyclonal and neoplastic plasmacytosis for the regulation of immunity and its effect on inflammation and immunodeficiency. METHODS: We used flow cytometry, IL-10 reporter (Vert-X) and B cell-specific IL-10 knockout mice, migration assays, and antibody-mediated IL-10 receptor blockade to study plasmacytosis-associated IL-10 expression and its effect on inflammation and Streptococcus pneumoniae infection in mice. ELISA was used to quantify IL-10 levels in patients with myeloma. RESULTS: IL-10 production was a common feature of normal and neoplastic plasma cells in mice, and IL-10 levels increased with myeloma progression in patients. IL-10 directly inhibited neutrophil migration toward the anaphylatoxin C5a and suppressed neutrophil-dependent inflammation in a murine model of autoimmune disease. MOPC.315.BM murine myeloma leads to an increased incidence of bacterial infection in the airways, which was reversed after IL-10 receptor blockade. CONCLUSION: We provide evidence that plasmacytosis-associated overexpression of IL-10 inhibits neutrophil migration and neutrophil-mediated inflammation but also promotes immunodeficiency.

Defining the Systemic Inflammatory Response Syndrome in Equine Neonates.

Defining and describing the systemic inflammatory response syndrome (SIRS) and sepsis facilitated recognition and investigation of the complex disease processes involving the host response to infection and trauma. Over the years a variety of definitions of SIRS have been examined and applied to numerous research studies to improve critical care in both human and veterinary clinical practice. This article summarizes the history of the development of the SIRS definition, outlines the pathophysiologic processes that are involved in SIRS, and provides a specific definition for use in foal medicine.

Effects of administration of a synthetic low molecular weight/low molar substitution hydroxyethyl starch solution in healthy neonatal foals.

This study compared the effects of IV administration of isotonic fluid therapy and colloidal fluid therapy in healthy neonatal foals. Fifteen healthy neonatal foals were used in a randomized blinded prospective clinical study. Foals were randomly assigned to receive a bolus of 20 mL/kg of tetrastarch (TES) or balanced crystalloid solution. Vital parameters, colloid osmotic pressure (COP), and various clinicopathologic variables were assessed prior to infusion and at various time points up to 120 h after infusion. The treatment group (TES) had a significant increase in both COP and percentage increase in COP at 1 and 3 h. The COP was significantly lower than baseline at 3 h in the control group. No significant changes were observed in coagulation parameters in either group. Tetrastarch was effective in increasing COP for 3 h after infusion and had no notable adverse clinical effects in this group of healthy foals. Further studies are warranted regarding optimal dosing and effects in clinically ill foals.

Effets de l'administration d'une solution de substitution synthétique d'amidon hydroxyéthylé de faible poids moléculaire/faible molarité chez des poulains néonataux en santé. Cette étude a comparé les effets de l'administration IV d'une fluidothérapie isotonique et d'une fluidothérapie colloïdale chez des poulains néonataux en santé. Quinze poulains néonataux ont été utilisés dans une étude clinique prospective randomisée. Les poulains ont été assignés au hasard pour recevoir un bolus de 20 mL/kg de tétra-amidon (TEA) ou d'une solution cristalloïde équilibrée. Les paramètres vitaux, la pression osmotique colloïdale (POC) et diverses variables clinicopathologiques ont été évalués avant l'infusion et à divers moments jusqu'à 120 heures après l'infusion. Le groupe de traitement (TEA) a subi une hausse importante de la POC et une augmentation du pourcentage de POC à 1 et 3 heures dans le groupe témoin. Aucun changement significatif n'a été observé dans les paramètres de coagulation des deux groupes. Le tétra-amidon a été efficace pour l'augmentation de la POC pendant 3 heures après l'infusion et il n'a pas eu d'effets cliniques négatifs notables dans ce groupe de poulains en santé. De nouvelles études sont justifiées concernant le dosage optimal et les effets chez les poulains cliniquement malades.(Traduit par Isabelle Vallières).

Bacterial isolates, antimicrobial susceptibility patterns, and factors associated with infection and outcome in foals with septic arthritis: 83 cases (1998-2013).

OBJECTIVE: To determine clinical characteristics, clinicopathologic data, and bacterial culture and antimicrobial susceptibility results associated with septic arthritis in foals ≤ 180 days old. DESIGN: Retrospective case series. ANIMALS: 83 foals with septic arthritis. PROCEDURES: Medical records at 2 teaching hospitals between 1998 and 2013 were searched to identify those for foals ≤ 180 days old with confirmed infection of ≥ 1 synovial structure. Data extracted from the records included signalment, clinicopathologic information, bacteriologic culture and antimicrobial susceptibility results, and outcome. Data were analyzed for all foals as a single population and for foals stratified into 3 age groups (≤ 7 days, 8 to 30 days, and 31 to 180 days). RESULTS: Mean ± SD age of all foals was 18.2 ± 25 days (range, 0 to 180 days). The median number of joints affected per foal was 2 (range, 1 to 10 joints). Forty-seven of 83 (56.6%) foals survived to discharge from the hospital. Seventy antemortem synovial fluid samples underwent bacteriologic culture, of which 60 (85.7%) yielded growth. Of the 72 bacterial isolates identified, 45 (62.5%) were gram negative and 27 (375%) were gram positive. Survival rate was positively associated with plasma fibrinogen concentration and negatively associated with number of affected joints. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated the frequency with which certain bacterial agents were isolated from septic joints, which may be beneficial for the empirical treatment of septic arthritis in foals. Also, the positive association between survival rate and plasma fibrinogen concentration may have prognostic value in a clinical setting.

Effects of intravenous administration of polymyxin B in neonatal foals with experimental endotoxemia.

OBJECTIVE: To evaluate the effect of IV administration of polymyxin B on clinical and serum biochemical variables in foals with experimental endotoxemia. DESIGN: Prospective experimental study. ANIMALS: 14 healthy neonatal foals. PROCEDURES: Foals were randomly assigned to a treatment or control group and were administered a single dose of lipopolysaccharide (0.5 µg/kg [0.23 µg/lb]) IV over 30 minutes. The treatment group received polymyxin B (6,000 U/kg [2,727 U/lb], IV) immediately after completion of lipopolysaccharide infusion; the control group was administered an equal volume of saline (0.9% NaCl) solution. Subsequent doses of polymyxin B or saline solution were administered IV at 8 and 16 hours. Blood was collected at various time points, and outcome variables, including heart rate, respiratory rate, rectal temperature, attitude score, WBC count, neutrophil count, lymphocyte count, monocyte count, platelet count, Hct, blood lactate concentration, blood glucose concentration, serum tumor necrosis factor-α concentration, and plasma thromboxane B2 concentration, were measured. Urine was collected prior to and after experimentation to determine whether nephrotoxicosis was associated with treatment. RESULTS: The treatment group had significantly lower blood lactate concentration and serum tumor necrosis factor-α and plasma thromboxane B2 concentrations and had higher blood glucose concentrations and better attitude scores, compared with the control group, at various time points during the study. No other significant differences and no evidence of overt nephrotoxicosis were detected. CONCLUSIONS AND CLINICAL RELEVANCE: Administration of polymyxin B IV in healthy neonatal foals challenged with lipopolysaccharide attenuated some clinical and serum biochemical derangements associated with endotoxemia.

Evaluation of a point-of-care portable analyzer for measurement of plasma immunoglobulin G, total protein, and albumin concentrations in ill neonatal foals.

OBJECTIVE: To compare the diagnostic performance of a point-of-care (POC) analyzer with that of established methods for the measurement of plasma IgG, total protein, and albumin concentrations in neonatal foals. DESIGN: Evaluation study. ANIMALS: 100 neonatal foals < 7 days of age. Procedures-Plasma IgG, total protein, and albumin concentrations were measured with a POC analyzer via an immunoturbidimetric method. Corresponding measurements of plasma IgG, total protein, and albumin concentrations were measured by means of automated biochemical analyzers via automated immunoturbidimetric, biuret, and bromocresol green dye-binding assays, respectively (standard laboratory methods). RESULTS: The sensitivity and specificity of the POC analyzer for detection of failure of passive transfer of immunity (FPTI) in foals were 80.7% and 100%, respectively, when FPTI was defined as a plasma IgG concentration < 400 mg/dL and were 75.9% and 100%, respectively, when FPTI was defined as a plasma IgG concentration < 800 mg/dL. The POC analyzer overestimated plasma albumin concentrations and, to a lesser extent, plasma total protein concentrations, compared with values determined with the standard laboratory methods. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested the POC analyzer was acceptable for determination of plasma IgG and total protein concentrations in ill foals. The POC analyzer overestimated plasma albumin concentration such that its use was clinically unacceptable for the determination of that concentration. The POC analyzer provided timely measurements of plasma IgG concentrations, which is necessary information for the assessment of passive transfer of maternal antibodies to neonatal foals.

Episodic blindness and ataxia in a horse with cholesterinic granulomas.

An 11-year-old Oldenburg mare presented following three episodes of acute, transient blindness, ataxia, and disorientation within the preceding 7 months. Clinical improvement, including return of vision, occurred within 1 week of initiating corticosteroid therapy for each of the three episodes. However, mild right-sided miosis was a consistent finding on ophthalmic examinations. Routine clinicopathologic testing revealed no significant abnormalities, and testing of cerebral spinal fluid for selected infectious diseases was unrewarding. Computed tomography of the brain demonstrated a hyperattenuating mass with peripheral mineralization in the rostroventral aspect of each lateral ventricle. The mare was euthanized due to a guarded to poor prognosis. On histopathology, the masses consisted of clusters of cholesterol clefts admixed with leukocytes, mineral deposits, and connective tissue. Cholesterinic granulomas of the lateral ventricles and hydrocephaly were diagnosed. Cholesterinic granulomas should be considered a differential diagnosis in horses presenting for intermittent blindness.

Intestinal ischemia-reperfusion injury in horses: pathogenesis and therapeutics.

This article discusses the potential role of oxidative injury to the intestinal tract of horses and the therapeutic approaches that have been investigated to decrease cellular damage secondary to ischemia-reperfusion (IR) injury. Equine colic is a major concern for horse owners and veterinary practitioners. Strangulating and obstructive lesions of the small and large intestines commonly require intervention in patients via exploratory celiotomy. However, the application of information from experimentally induced IR injury in horses to clinical cases of naturally occurring equine colic is not clear. Thus, while the exact mechanisms and clinical significance of intestinal IR are being defined and may be matters of academic debate, a review of the available information may provide knowledge of potential underlying pathophysiologic mechanisms contributing to intestinal injury in equine colic. This information may allow clinicians to offer additional therapeutic strategies for horses with strangulating obstruction of the small or large intestine. Further clinical study of the therapeutic options for horses with naturally occurring disease is warranted.