Fecal microbiota transplant for treatment of diarrhea in adult hospitalized horses-111 cases (2013-2018).

Background: Fecal microbiota transplant (FMT) is increasingly administered as part of the treatment of colitis in horses, yet there is little data as to its effectiveness. Aim: Retrospective evaluation of the effects of FMT on discharge status, fecal consistency, length of hospitalization, and improvement in clinical signs in horses hospitalized for diarrhea. Methods: Retrospective case-control study. Medical records of adult horses (>1 year old) that received at least one transfaunation treatment (2013-2018) in two referral hospitals were identified through a medical records database search. Medical records of contemporary adult horses with diarrhea who did not receive FMT at the same study centers were used as controls. Results: Control horses had statistically significant shorter hospitalization [7 (1-21)] as compared to the transfaunation group [12 (3-31)] ( p = 0.0006). There were no significant differences between groups in the number of days to the improvement of feces (p = 0.38), or in days to normalization of fecal consistency (p = 0.43), respiratory rate (p = 0.42), heart rate (p = 0.27), body temperature (p = 0.12), peripheral white blood cell count (p = 0.37), improvement in appetite (p = 0.81), or attitude (p = 0.06). There was also no significant difference in survival to discharge (transfaunation 28/37, 75.7%; control 56/74, 75.7%, p = 1.0). Conclusion: There were no significant advantages of performing FMTs in horses with diarrhea in this retrospective study. This highlights the need for prospective, randomized studies to evaluate the efficacy of FMT, as well as different formulations, in horses with colitis before this can become standard practice.

Retrospective evaluation of acute kidney injury in horses treated with nonnitrogenous bisphosphonates (2013-2020): 8 cases.

OBJECTIVE: To describe a population of horses with acute kidney injury (AKI) following administration of bisphosphonates including clinical signs, clinicopathologic data, treatment, and outcome. DESIGN: Retrospective study from August 2013 to July 2020. SETTING: Veterinary university teaching hospital. ANIMALS: Eight adult horses with AKI following administration of nonnitrogenous bisphosphonates. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Five horses received intramuscular clodronate (5/8; 62.5%) and 3 horses received intravenous tiludronate (3/8; 37.5%). Six horses (6/8; 75%) received concurrent nonsteroidal anti-inflammatory drugs. The most common initial presenting complaint was poor appetite (6/8; 75%), followed by abnormal urination (2/8; 25%). At the time of initial evaluation, the mean serum or plasma creatinine was 451.72 ± 190.06 µmol/L (5.11 ± 2.15 mg/dL) and BUN was 18.84 ± 8.85 mmol/L (52.75 ± 24.77 mg/dL). Five horses (5/6; 83.3%) had either an increased number of red blood cells (n = 4) or hemoprotein (n = 1) in the urine. All horses were treated with IV isotonic, balanced crystalloids either as a bolus, continuous rate infusion, or a combination of the 2. Seven horses (7/8; 87.5%) survived the initial episode of AKI and 1 horse (1/8; 12.5%) was euthanized. Of the 7 surviving horses, 2 horses (2/7; 28.5%) went on to develop chronic renal dysfunction. Warmblood breeds were overrepresented in the AKI group (P = 0.008; odds ratio: 11.5, 95% confidence interval: 1.8-72.1), when compared to horses that received bisphosphonates during the study period and did not develop AKI. CONCLUSIONS: Bisphosphonate administration, with or without concurrent nonsteroidal anti-inflammatory drugs, can be associated with AKI in horses. Serum creatinine should be monitored prior to and following bisphosphonate treatment to minimize this risk. Further evaluation of renal function is warranted in horses that develop clinical signs of poor appetite, lethargy, or altered urination in the days following bisphosphonate treatment.

Effects of a 10% dimethyl sulfoxide solution on radiocarpal joint amikacin pharmacokinetics during intravenous regional limb perfusion in standing sedated horses.

OBJECTIVE: To determine the effect of a 10% dimethyl sulfoxide (DMSO) solution on the peak concentration (CMAX ) of amikacin in the radiocarpal joint (RCJ) during intravenous regional limb perfusion (IVRLP) compared with 0.9% NaCl. STUDY DESIGN: Randomized crossover study. ANIMALS: Seven healthy adult horses. METHODS: The horses underwent IVRLP with 2 g of amikacin sulfate diluted to 60 mL using a 10% DMSO or 0.9% NaCl solution. Synovial fluid was collected from the RCJ at 5, 10, 15, 20, 25, and 30 minutes after IVRLP. The wide rubber tourniquet placed on the antebrachium was removed after the 30 min sample. Amikacin concentrations were quantified by a fluorescence polarization immunoassay. The mean CMAX and time to peak concentration (TMAX ) of amikacin within the RCJ were determined. A one-sided paired t-test was used to determine the differences between treatments. The significance level was p < .05. RESULTS: The mean ± SD CMAX in the DMSO group was 1361.8 ± 593 µg/mL and in the 0.9% NaCl group it was 860 ± 481.6 µg/mL (p = .058). Mean TMAX using the 10% DMSO solution was 23 and 18 min using the 0.9% NaCl perfusate (p = .161). No adverse effects were associated with use of the 10% DMSO solution. CONCLUSION: Although there were higher mean peak synovial concentrations using the 10% DMSO solution no difference in synovial amikacin CMAX between perfusate type was detected (p = .058). CLINICAL SIGNIFICANCE: Use of a 10% DMSO solution in conjunction with amikacin during IVRLP is a feasible technique and does not negatively affect the synovial amikacin levels achieved. Further research is warranted to determine other effects of using DMSO during IVRLP.

Red blood cell distribution width to platelet ratio in neonatal foals with sepsis.

BACKGROUND: Rapid and accurate markers to aid diagnosis of sepsis are needed in neonatal foals. The CBC variable red blood cell distribution width (RDW) to platelet ratio (RPR) is associated with inflammatory response and linked to poor outcomes of sepsis in human patients. HYPOTHESIS: Explore the correlation of RPR with sepsis in neonatal foals and evaluate RPR predictive and prognostic value. ANIMALS: Three hundred seventeen hospitalized neonatal foals ≤7 days of age that had a CBC and physical exam performed at admission between 2012 and 2021. METHODS: Retrospective case-control study. Clinical records were used to calculate sepsis scores and define groups. Red blood cell distribution width to platelet ratio was calculated and compared between groups (septic vs nonseptic) based on Kruskal-Wallis and Wilcoxon signed-rank tests. A multivariate logistic regression model to predict sepsis was created. The cutoff for RPR was obtained based on the maximal Youden Index. The Kaplan-Meier method and the log-rank test were used to estimate survival curves and compare survival rates based on RPR. RESULTS: Red blood cell distribution width to platelet ratio was significantly higher in septic foals (Median = 0.099, confidence interval [CI] [0.093; 0.108]) than in sick nonseptic (0.085, CI [0.083; 0.089]) and healthy foals (0.081, CI [0.077; 0.086]; P < .0001). Red blood cell distribution width to platelet ratio was able to predict sepsis with high accuracy (AUC = 82.1%). The optimal RPR cutoff for sepsis was 0.09. CONCLUSIONS AND CLINICAL IMPORTANCE: Red blood cell distribution width to platelet ratio calculation is practical, inexpensive, and based on CBC-derived data. Calculation of RPR along with CBC can aid in the diagnosis of sepsis and estimation of outcome.

Effects of calcium supplementation to resuscitation fluids in endurance horses: A randomized, blinded, clinical trial.

BACKGROUND: The addition of calcium to resuscitation fluids is a common practice in horses, but studies evaluating the effects of calcium supplementation are limited. In healthy horses, decreases in heart rate and changes in serum electrolyte concentrations have been reported. HYPOTHESIS: Calcium gluconate administration at a rate of 0.4 mg/kg/min to eliminated endurance horses with metabolic problems will affect heart rate, gastrointestinal sounds, and serum electrolyte concentrations. ANIMALS: Endurance horses eliminated from the Tevis Cup 100-mile (160 km) endurance ride for metabolic problems and requiring IV fluid therapy were eligible. METHODS: Sixteen horses were randomly assigned to receive 0.4 mg/kg/min of calcium (23% calcium gluconate solution) over 1 hour diluted in 10 L of a non-calcium containing isotonic crystalloid (CAL group) or 10 L of a non-calcium containing isotonic crystalloid (CON group). Staff members administering the fluids were blinded to treatment group. Blood samples were collected and physical examinations performed before and after treatment. Heart rates were recorded every 15 min during fluid administration. Data were compared using 2-way analysis of variance (ANOVA) with repeated measures for continuous variables and Fisher's exact test for categorical variables. RESULTS: Calcium was associated with lower heart rates 45 min after starting the infusion (P = .002). Gastrointestinal sounds were less likely to improve in the calcium group compared with the control group (P = .005). An increase in plasma phosphorus concentration (P = .03) was associated with calcium administration. CONCLUSIONS: Intravenous calcium supplementation to endurance horses eliminated from competition after development of metabolic problems may decrease heart rate but impairs improvement in gastrointestinal sounds.

Prevalence of and risk factors associated with Salmonella shedding among equids presented to a veterinary teaching hospital for colic (2013-2018).

BACKGROUND: Gastrointestinal disease has been associated with shedding of Salmonella with previous studies demonstrating that horses with colic have a higher risk of acquiring and shedding Salmonella organisms. OBJECTIVES: The purpose of this study was to determine the prevalence of and risk factors associated with Salmonella shedding in a colic population at a referral clinic. STUDY DESIGN: Retrospective case-control study. METHODS: For each colic case that was positive for Salmonella (n = 56), two colic cases (n = 112) that tested negative for Salmonella, were enrolled as controls. Associations between variables and Salmonella shedding were identified using logistic regression. Univariate and multivariable models were developed pertaining to (1) presenting clinicopathological data and (2) clinical variables that developed during hospitalisation. RESULTS: Of the equids presenting with colic, 1585/1917 had a sample submitted for Salmonella testing. Of these, 56 were positive for Salmonella yielding a prevalence of 3.5%. Equids shedding Salmonella were more likely to present in July (odds ratio [OR] = 7.2; 95% confidence interval [CI] = 1.63-32.13; p = 0.009) and present with a history of fever (OR = 53.5; 95% CI = 2.57-1113.03; p = 0.01), increased lactate (OR = 1.6; 95% CI = 1.14-2.29; p = 0.007) and/or neutropenia (OR = 0.79; 95% CI = 0.65-0.97; p = 0.02). Hospitalised equids shedding Salmonella were more likely to be febrile (OR = 4.8; 95% CI = 1.47-15.8; p = 0.01) and 10 times more likely to develop reflux (OR = 10.1; 95% CI = 1.67-61.43; p = 0.01) compared to colic controls. MAIN LIMITATIONS: Retrospective nature of the study and bias inherent to the retrieval of data from medical records cannot be discounted. Classifying Salmonella status based on a single sample may have resulted in misclassification bias. CONCLUSIONS: The prevalence of Salmonella shedding in this colic population was low compared to earlier reports. Certain predictors such as the development of a fever or reflux in hospitalised colic cases were associated with Salmonella shedding and may help the clinician to promptly identify horses likely to shed; thus, helping institute effective use of barrier nursing precautions.

Prevalence of the RAPGEF5 c.2624C>A and PLOD1 c.2032G>A variants associated with equine familial isolated hypoparathyroidism and fragile foal syndrome in the US Thoroughbred population (1988-2019).

BACKGROUND: Equine familial isolated hypoparathyroidism (EFIH) and fragile foal syndrome (FFS) are both fatal recessive conditions reported in Thoroughbred foals. The causal variants for EFIH (RAPGEF5 c.2624C>A; EquCab3.0. chr4: g.54108297G>T) and FFS (PLOD1 c.2032G>A; EquCab3.0, chr2: g.39927817) were recently reported. Prevalence assessment for these variants in a large cohort of samples is needed to provide evidence-based recommendations for genetic testing. OBJECTIVES: To estimate the frequency of the EFIH and FFS variant alleles in the United States Thoroughbred population between 1988 and 2019, and determine whether these are recent mutations or are increasing in frequency due to current breeding practices. STUDY DESIGN: Population allele frequency study. METHODS: Genomic DNA from hair and serum samples were genotyped for the EFIH and FFS. Allele frequencies between cohorts, based on year of birth (1988-2000, n = 728) and (2001-2019, n = 1059), as well as across the seven geographical regions of the United States were compared by Fisher's Exact tests. RESULTS: EFIH and FFS allele frequencies were not significantly different between the two time points studied (0.008 and 0.004, respectively, in the older cohorts and 0.008 and 0.009 in most recent years). No EFIH or FFS homozygotes were detected. A sample from 1992 was identified as a carrier for EFIH and one from 1993 a carrier for FFS. Non-significant changes in geographical distribution of carriers for both traits were observed. MAIN LIMITATIONS: The earliest samples available for study were from foals born in 1988. CONCLUSIONS: The EFIH and FFS variants are present at low frequency in the United States Thoroughbred population but are not recent mutations. There is no evidence to support changes in allele frequency over time. However, given the closed studbook and breeding practices, continued monitoring of breed allele frequencies and genetic testing is recommended to avoid the mating of carriers and production of affected foals.

Investigation of high gamma-glutamyltransferase syndrome in California Thoroughbred racehorses.

BACKGROUND: Increases in serum gamma-glutamyltransferase (GGT) activity have been reported in Thoroughbred (TB) racehorses and associated with maladaptation to training but the underlying etiology remains unknown. HYPOTHESIS/OBJECTIVES: Classify the etiology of high GGT syndrome in racing TBs by assessment of pancreatic enzymes, vitamin E concentrations, and both a candidate gene and whole genome association study. We hypothesized that a genetic variant resulting in antioxidant insufficiency or pancreatic dysfunction would be responsible for high GGT syndrome in TBs. ANIMALS: A total of 138 California racing TBs. Amylase: n = 31 affected (serum GGT activity ≥60 IU/L), n = 52 control (serum GGT activity <40 IU/L). Lipase: n = 19 affected, n = 35 control. Serum α-tocopherol concentrations: n = 32 affected, n = 46 control. Genome-wide association study (GWAS): 36 affected, 58 control. Whole genome sequencing: n = 5 affected, n = 5 control. METHODS: Biochemical and vitamin analytes were compared among cohorts. A GWAS was performed and a subset of TBs underwent whole genome sequencing to interrogate candidate genes and positional genetic regions. RESULTS: Serum lipase and amylase activity and α-tocopherol concentrations did not differ between groups. No genetic variants were identified in 2 candidate genes (UGT1A1 and GGT1) that associated with the phenotype. Four single nucleotide polymorphisms (SNPs) approached a suggestive association with the phenotype (P = 2.15 × 10-5 ), defining a 100 kb region on chromosome 5 surrounding cluster of differentiation 1a (CD1A1), a transmembrane gene related to the major histocompatibility complex. CONCLUSIONS AND CLINICAL IMPORTANCE: An underlying genetic etiology may exist for high GGT syndrome in racing TBs, similar to genetic disorders in humans.

Breed Distribution and Allele Frequencies of Base Coat Color, Dilution, and White Patterning Variants across 28 Horse Breeds.

Since domestication, horses have been selectively bred for various coat colors and white spotting patterns. To investigate breed distribution, allele frequencies, and potential lethal variants for recommendations on genetic testing, 29 variants within 14 genes were investigated in 11,281 horses from 28 breeds. The recessive chestnut ea allele in melanocortin 1 receptor (MC1R) (p.D84N) was identified in four breeds: Knabstrupper, Paint Horse, Percheron, and Quarter Horse. After filtering for relatedness, ea allele frequency in Knabstruppers was estimated at 0.035, thus illustrating the importance of testing for mate selection for base coat color. The Rocky Mountain Horse breed had the highest allele frequency for two of the dilution variants under investigation (Za.f. = 0.32 and Cha.f. = 0.026); marker-assisted selection in this breed could aid in the production of horses with desirable dilute coats with less severe ocular anomalies caused by the silver (Z) allele. With regard to white patterning, nine horses homozygous for the paired box 3 (PAX3) splashed white 2 (SW2) allele (p.C70Y) and six horses homozygous for the KIT proto-oncogene, receptor tyrosine kinase (KIT) sabino 1 (SB1) allele (ECA3g.79544206A>T) were identified, thus determining they are rare and confirming that homozygosity for SW2 is not embryonic lethal. The KIT dominant white 20 (W20) allele (p.R682H) was identified in all but three breeds: Arabian (n = 151), Icelandic Horse (n = 66), and Norwegian Fjord Horse (n = 90). The role of W20 in pigmentation across breeds is not well understood; given the different selection regimes of the breeds investigated, these data provide justification for further evaluating the functional role of this allele in pigmentation. Here, we present the largest dataset reported for coat color variants in horses to date, and these data highlight the importance of breed-specific studies to inform on the proper use of marker-assisted selection and to develop hypotheses related to pigmentation for further testing in horses.

Seasonal variation of endogenous adrenocorticotropic hormone concentrations in healthy non-geriatric donkeys in Northern California.

Elevated plasma adrenocorticotropic hormone (ACTH) is often used to diagnose pituitary pars intermedia dysfunction (PPID) in horses. The hormone naturally increases in the fall in horses, and donkeys have been found to have higher ACTH concentrations than horses. However, circannual variation of ACTH has not been assessed in donkeys. The objective of the study was to establish seasonal variation of basal plasma ACTH concentrations over the course of a year in clinically healthy, non-geriatric donkeys. It was hypothesized that donkey ACTH concentrations would be higher than those reported in horses without PPID in all seasons, and that, similarly to horses, ACTH concentrations would further increase in the fall months. Twenty-six healthy adult donkeys (10 standards, 16 miniatures), a median (range) of 6 (2-13) years of age, were included. Donkeys were housed at a single location. Serial plasma samples were obtained monthly for 12 months. Plasma ACTH concentrations were determined by immunoassay. Data are presented as median (range), with a P-value < 0.05 considered significant. ACTH concentrations were lowest in the winter and spring [12.8 (5.0-73.6) pg/ml and 12.5 (2.8-62.6) pg/ml, respectively], with an increase in the summer [53.2 (29.7-305.0) pg/ml], and peak in the fall [77.1 (12.4-319.0) pg/ml]. ACTH concentrations were highest in the month of September [122.0 (41.7-319.0) pg/ml]. Donkey ACTH concentrations were higher than equine reference ranges from May through November but showed similar circannual variation with dramatic increases in the fall months. Species-specific reference ranges are necessary for accurate interpretation of endocrinopathy screenings in donkeys.

Closure of a patent ductus arteriosus in a 2-week-old llama cria using an Amplatz canine duct occluder.

A two-week-old female llama cria was brought to the UC Davis Large Animal Hospital for evaluation of a cardiac murmur and suspected syncopal episodes. A grade IV/VI left basilar continuous murmur was present on cardiac auscultation. Echocardiography revealed a left-to-right shunting patent ductus arteriosus (PDA), mild left ventricular enlargement, scant pericardial effusion, and a suspected persistent left cranial vena cava. The PDA was successfully closed with an Amplatz canine duct occluder. Mild mitral regurgitation was present on echocardiography performed 7 d following PDA occlusion. No syncopal episodes were observed in hospital prior to or following PDA occlusion. At approximately 1 mo following PDA closure, a grade I/VI left apical systolic murmur was present and the cria's body condition was improved. Key clinical message: Patent ductus arteriosus closure is achievable in New World camelids using interventional cardiology which provides a minimally invasive treatment option for valuable or companion animals. Since interventional cardiac catheterization is commonly performed in small animal species, veterinary cardiologists are well-equipped to apply these skills to camelids.

Fermeture d'un canal artériel persistant chez un lama cria âgé de 2 semaines à l'aide d'un obturateur de conduit canin Amplatz. Une femelle lama cria âgée de deux semaines a été amenée à l'UC Davis Large Animal Hospital pour l'évaluation d'un souffle cardiaque et d'épisodes syncopaux suspectés. Un souffle continu basilaire gauche de grade IV/VI était présent à l'auscultation cardiaque. L'échocardiographie a révélé une persistance du canal artériel avec perméabilité de gauche à droite (PDA), une légère hypertrophie ventriculaire gauche, un léger épanchement péricardique et une suspicion de veine cave crâniale gauche persistante. Le PDA a été fermé avec succès avec un obturateur de conduit canin Amplatz. Une régurgitation mitrale légère était présente sur l'échocardiographie réalisée 7 jours après l'occlusion du PDA. Aucun épisode de syncope n'a été observé à l'hôpital avant ou après l'occlusion du PDA. Environ 1 mois après la fermeture du PDA, un souffle systolique apical gauche de grade I/VI était présent et l'état corporel du cria s'était amélioré.Message clinique clé :La fermeture brevetée du canal artériel est réalisable chez les camélidés du Nouveau Monde en utilisant la cardiologie interventionnelle qui offre une option de traitement peu invasive pour les animaux de valeur ou de compagnie. Étant donné que le cathétérisme cardiaque interventionnel est couramment pratiqué chez les petites espèces animales, les cardiologues vétérinaires sont bien équipés pour appliquer ces compétences aux camélidés.(Traduit par Dr Serge Messier).

Increasing tourniquet number has no effect on amikacin concentration within the radiocarpal joint in horses undergoing intravenous regional limb perfusion.

OBJECTIVE: To determine whether IV regional limb perfusion (IVRLP) performed in the cephalic vein with a wide rubber tourniquet (WRT) applied proximal and distal to the carpus results in a higher peak concentration (Cmax) of amikacin in the radiocarpal joint (RCJ), compared with the Cmax for IVRLP using a single WRT proximal to the carpus. ANIMALS: 7 healthy adult horses. PROCEDURES: Horses underwent IVRLP using standing sedation with 2 g of amikacin sulfate diluted to 60 mL by use of saline (0.9% NaCl) solution in the cephalic vein with 2 different tourniquet techniques; proximal WRT (P) and proximal and distal WRT (PD). Synovial fluid was collected from the RCJ at 5, 10, 15, 20, 25, and 30 minutes after IVRLP. Tourniquets were removed after the 30-minute sample was collected. Blood samples from the jugular vein were collected at 5, 10, 15, 20, 25, 29, and 31 minutes after IVRLP. Amikacin concentration was quantified by a fluorescence polarization immunoassay. Median peak concentration (Cmax) of amikacin and time to maximum drug concentration (Tmax) within the RCJ were determined. RESULTS: Median peak concentration in the RCJ was 1331.4 µg/mL with technique P and 683.1 µg/mL with technique PD. Median Tmax occurred at 30 minutes with technique P and 25 minutes with technique PD. No significant (Cmax, P = 0.18; Tmax, P = 0.6) difference in amikacin Cmax or Tmax between techniques was detected. CLINICAL RELEVANCE: Placement of 2 WRTs offers no advantage to a single proximal WRT when performing IVRLP to deliver maximal amikacin concentrations to the RCJ using IVRLP.

Fecal PCR testing for detection of Clostridium perfringens and Clostridioides difficile toxin genes and other pathogens in foals with diarrhea: 28 cases.

Clostridium perfringens and Clostridioides difficile cause significant morbidity and mortality in foals. Antemortem diagnosis of C. perfringens infection has been complicated by a paucity of tests available for toxin detection. Fecal PCR panels have assays for a variety of C. perfringens toxin gene sequences as well as for several other foal gastrointestinal pathogens. We evaluated results of a comprehensive fecal diarrhea PCR panel in 28 foals that had been presented to a referral hospital because of diarrhea. Sixteen (57%) foals were positive for C. perfringens and/or C. difficile toxin gene sequences on fecal PCR, including 3 foals positive for NetF toxin. These foals were younger (p = 0.0029) and had higher hematocrits (p = 0.0087), hemoglobin (p = 0.0067), and red blood cell concentrations (p = 0.028) than foals with diarrhea that tested negative for clostridial toxins. The foals had lower total protein concentrations (p = 0.045) and were more likely to have band neutrophils on a CBC (p = 0.013; OR: 16.2). All 3 foals with NetF toxin gene sequences detected in feces survived to discharge, indicating that diarrhea caused by NetF toxigenic C. perfringens isolates is not uniformly fatal.

Association of globulin concentrations with prognosis in horses with lymphoma.

Introduction: Lymphoma is the most common hemopoietic neoplasia in horses. Common clinicopathologic abnormalities in equine lymphoma include hyperglobulinemia, hypoalbuminemia, hyperfibrinogenemia, anemia, thrombocytopenia and lymphocytosis. Hypoglobulinemia has been reported in other species with lymphoma, however it has not been well-described in horses. The objectives of this study were to examine the prevalence of hypoglobulinemia in equine lymphoma, and to identify prognosis and clinicopathological abnormalities associated with serum globulin concentrations. Methods: Ninety-six horses with lymphoma were investigated in this retrospective study. Patients were allocated into groups based on serum globulin concentration. Survival analysis was performed to determine risk factors associated with globulin concentration and outcome. Results: Nineteen horses were hypoglobulinemic (≤2.1 g/dL), 63/98 were normoglobulinemic (2.2-4.3 g/dL), and 16/98 were hyperglobulinemic (≥4.4 g/dL). Hyperglobulinemia was associated with a higher anion gap (P = 0.0005), lower bicarbonate (P = 0.006), sodium (P = 0.03) and chloride concentrations (P = 0.002), and higher total protein than hypoglobulinemic horses (P < 0.0001). For location, 37% of horses with mucocutaneous lymphoma were hypoglobulinemic, compared to none in the hyperglobulinemic group (P = 0.02). Survival times were significantly different between low, normal and high globulin groups (P = 0.0002, median [range] survival times: 333 [1-3792], 43 [1-4,001] and 4 [1-129] days, respectively). Significant risk factors for shortened time to death were hyperglobulinemia (HR 2.4, P = 0.02), T cell lymphoma (HR 3.5, P < 0.0001), and multicentric (HR 3.1, P = 0.0008) and mediastinal (HR 6.4, P = 0.006) forms of lymphoma. Lack of chemotherapy was associated with shortened survival time (HR 4.5, P < 0.0001). B cell lymphomas (P < 0.0001) and mucocutaneous lymphoma location (P < 0.0001) were associated with longer survival times. Discussion: Serum globulin concentrations are associated with location of lymphoma, clinicopathologic abnormalities, and survival times in equine lymphoma.

Changes in electrolyte concentrations and hydration status in endurance horses following transport and an overnight stay prior to competition.

OBJECTIVE: To evaluate changes in electrolyte concentrations and hydration status that take place in endurance horses prior to the start of a competition and determine whether these changes would be associated with elimination. ANIMALS: 19 horses entered in the 2016 Tevis Cup 100-Miles (160 km) One-Day Western States Trail Ride. PROCEDURES: Heparinized blood samples were collected at 5 time points: prior to transport to the ride (T0), during check-in the day before the ride (T1), 1 to 2 hours before the start of the ride (T2), at the 15-km mark (T3), and at the 55-km mark (T4). Packed cell volume and plasma sodium, potassium, chloride, urea nitrogen, glucose, bicarbonate, and total protein concentrations were determined and compared across time points and between finishers and nonfinishers. RESULTS: Signif icant differences were detected among plasma sodium, potassium, and urea nitrogen concentrations measured prior to the start of the ride (ie, T0, T1, and T2). For all variables except chloride and bicarbonate concentrations, significant differences were detected between values obtained prior to the start of the ride and values obtained during the ride (ie, T3 and T4). Only bicarbonate concentration at the 15-km mark of the ride was significantly associated with finishing status. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that significant changes in plasma sodium, potassium, and urea nitrogen concentrations can occur in endurance horses during transport to a competition and when horses are stabled overnight before an event. Additionally, a lower bicarbonate concentration following a steep climb early during the ride was associated with subsequent elimination.

Antimicrobial Selection for the Equine Practitioner.

Antimicrobial drugs play an important, often central, role in the therapeutic management of mature horses and foals with a variety of illnesses, including those requiring critical care. Antimicrobial use must be based on rational principles involving thorough patient evaluation and sound clinical judgment that indicate a high likelihood that the patient has a bacterial infection and that antimicrobials are indicated to promote recovery. The aim of antimicrobial treatment is to inflict an insult on infecting bacteria sufficient to kill the organism or render it susceptible to inactivation by natural host defenses or the local microenvironment without adversely affecting the patient.

Bacterial meningitis after dental extraction in a 17-year-old horse.

Dental extractions in horses may result in bacteremia, which can lead to systemic complications. Bacterial meningitis following oral cheek tooth extractions in a 17-year-old Thoroughbred gelding is described in this report. The bacterial meningitis was confirmed by histopathology. The gelding was presented for evaluation of intermittent fever, loose feces, and mild colic signs which started 5 days after cheek tooth extraction. This case illustrates a rare complication associated with oral tooth extraction in a horse and highlights the unusual presenting features of meningitis. Key clinical message: Bacterial meningitis secondary to oral cheek tooth extraction should be considered as differential diagnosis; particularly in cases with the development of pyrexia a few days after the procedure.

Méningite bactérienne après extraction dentaire chez un cheval de 17 ans. Les extractions dentaires chez les chevaux peuvent entraîner une bactériémie, ce qui peut amener des complications systémiques. Un cas de méningite bactérienne à la suite d'extractions buccales de dents jugales chez un hongre pur-sang de 17 ans est décrite dans ce rapport. La méningite bactérienne a été confirmée par histopathologie. Le hongre a été présenté pour évaluation d'une fièvre intermittente, de selles molles et de signes de coliques légers qui ont commencé 5 jours après l'extraction de la dent jugale. Ce cas illustre une complication rare associée à l'extraction dentaire orale chez un cheval et met en évidence des caractéristiques inhabituelles de la méningite.Message clinique clé :La méningite bactérienne secondaire à l'extraction buccale des dents jugales doit être considérée comme un diagnostic différentiel, en particulier dans les cas de développement d'une pyrexie quelques jours après l'intervention.(Traduit par Dr Serge Messier).

Equine antimicrobial therapy: Current and past issues facing practitioners.

Equine antimicrobial therapy has advanced over time with the availability of increasing pharmacokinetic and pharmacodynamic studies in horses, allowing for greater evidence-based clinical decision-making. However, many challenges to optimal antimicrobial therapy remain and further research is needed to address these areas. There are a limited number of approved antimicrobials for use in horses, which creates a need for compounded preparations for clinicians. Extra-label drug use is commonplace in equine practice, which warrants continual education of veterinarians about policies and updates. Performance and competitive horses have their own unique concerns when it comes to antimicrobial use and drug testing. In keeping with the use of a broader range of antimicrobials over time, antimicrobial resistance is emerging as an important issue facing veterinary medicine, including equine practice. Another challenge is that of drug interactions and adverse drug events for which there are little scientific data available for horses, especially for critically important diseases such as Rhodococcus equi infection. Finally, much progress has been made in the availability of equine-specific antimicrobial susceptibility break points. These aid clinicians in interpreting culture and susceptibility results and antimicrobial selection. Even with these advances, continuing education and further research are needed in this area.

Clinical and biochemical factors associated with survival in equids attacked by dogs: 28 cases (2008-2016).

BACKGROUND: Trauma from dog attacks has been associated with mortality rates as high as 23% in some species. However, the prognosis and clinical features of this type of injury have not been described in equids. HYPOTHESES/OBJECTIVES: To describe survival rate, signalment, clinical features, and biochemical results in equids presented for emergency care after presumed dog attacks. We hypothesized there would be differences between survivors and nonsurvivors. ANIMALS: A total of 28 equids presented for presumed dog attacks from 3 referral centers. METHODS: A retrospective study was performed using data from 3 hospitals between 2008 and 2016. Survival was defined as survival at 14 days postdischarge. Variables were compared between survivors and nonsurvivors using a t test, Mann-Whitney U test, or Fisher's exact test as appropriate. RESULTS: Overall mortality rate was 21%. Ponies and miniature horses represented 16/28 (57%) of the animals in the study. Full-sized equids had a lower risk of nonsurvival as compared to smaller patients (odds ratio = 0.02; 95% confidence intervals = 0.00-0.27; P < .005). Animals with lower body temperatures had increased risk for nonsurvival (P = .0004). Increased admission blood lactate concentrations (P = .003) and decreased serum total protein concentrations (P = .006) were associated with nonsurvival. CONCLUSIONS: The mortality rate in equids attacked by dogs was similar to what is reported for other veterinary species. Smaller equids and those with increased admission blood lactate concentration, lower body temperature, and lower total serum protein concentrations were less likely to survive.

Immune-mediated haemolytic anaemia and thrombocytopenia in 25 adult equids: 1997-2016.

BACKGROUND: Information concerning clinical presentation, conditions associated with immune-mediated haemolytic anaemia (IMHA) and thrombocytopenia (IMTP) and outcome in equids is lacking. Previous case reports suggest that immune-mediated disease and neoplasia are associated. OBJECTIVES: Characterise the clinical presentation, clinicopathologic data, underlying conditions, treatment and outcome of IMHA and IMTP cases in equids. We hypothesise that IMHA with concurrent thrombocytopenia occurs more often than IMHA or IMTP alone, and that neoplasia is commonly associated with these immune diseases and cases frequently have a poor prognosis. STUDY DESIGN: Retrospective case-control study. METHODS: Medical records were reviewed from 1997 to 2016. Twenty-five equids were diagnosed with IMHA, IMTP or IMHA with thrombocytopenia by Coombs test or flow cytometry. Controls were equids presented for nonimmune-mediated disease immediately prior to and after study animals. Fisher's exact test was used to compare between groups for categorical variables (P < .05). Results reported as odds ratios (OR) and 95% confidence intervals (CI). Unpaired t test and Mann-Whitney test were used to compare between groups for continuous variables (P < .05). RESULTS: Neoplasia incidence was significantly higher in the study population (28%) versus controls (8%) (P = .04). Equids with primary disease were more likely to survive to discharge than equids with secondary disease (8/9 vs 7/16; P = .03; OR = 13.3; 95% CI: 1.3-134.7). Survivors had a significantly lower blood urea nitrogen (BUN) than those that died or were subjected to euthanasia (survivors, 6.1 ± 2.5 mmol/L vs nonsurvivors, 9.9 ± 3.1 mmol/L P = .003). The odds of short-term mortality were higher in horses presenting with increased BUN (OR = 19.5; 95% CI, 1.8-214.1; P = .009). MAIN LIMITATIONS: Retrospective nature of the study, small case numbers and limited long-term follow-up. CONCLUSIONS: Primary IMHA/IMTP cases have a reasonable prognosis and warrant treatment. Secondary cases have a poor prognosis, and are frequently associated with cancer. BUN may have utility as a prognostic indicator for IMHA/IMTP cases.