Trimethoprim-sulfonamide: a valid antimicrobial treatment in foals?

Trimethoprim-sulfonamide (TMPS) combinations are widely used to treat a range of infectious diseases in horses, but some equine practitioners are reluctant to use them for treatment of both neonatal and older foals. Considering the emergence of increased antimicrobial resistance, the use of protected antimicrobials commonly prescribed to foals should be avoided and alternative first-line therapy considered, where appropriate. This review examines the characteristics and pharmacokinetics of TMPS and its suitability for treatment of foals. Data regarding dosage and route of administration are reported on the basis of recent publications in foals. The review intends to share significant information about the common infections that are most likely responsive to TMPS treatment in foals and, as such, where TMPS might be considered a suitable first-line therapeutic option.

Do post-surgical multiresistant urinary infections occur in horses? Case of unilateral pyelonephritis caused by extended-spectrum beta-lactamase-producing bacteria as a complication of cystotomy.

Pyelonephritis is a serious condition that is rarely described in horses. In contrast, urinary tract infections are common in humans and small animals, and multi-drug-resistant urinary infections are an emerging threat. In this report, we describe a horse with unilateral pyelonephritis caused by extended-spectrum beta-lactamase-producing bacteria belonging to the Enterobacter cloacae complex. [Correction added on 9 August 2023, after first online publication: The preceding sentence was corrected.] An 11-year-old Swedish warmblood gelding was diagnosed with a cystolith and a cystotomy through an open left para-inguinal approach was performed. Seven days after surgery the horse presented with pyrexia, dullness and colic. Diagnostic testing and renal transabdominal ultrasonography confirmed the presence of a right-sided pyelonephritis. Culture and antimicrobial susceptibility testing revealed a pure growth of extended-spectrum beta-lactamases-producing E. cloacae complex bacteria with resistance against beta-lactams, aminoglycoside and trimethoprim-sulphonamide classes. Treatment included prolonged oral antimicrobials according to susceptibility testing results (enrofloxacin), judicious use of non-steroidal anti-inflammatory drugs, fluid therapy and gastric ulcer prophylaxis. The horse recovered successfully and is currently in good health (follow-up of 5 years). Once the infection resolved, unilateral renal scarring occurred. Multidrug-resistant upper-urinary infections occur in horses and should be considered in a post-surgical patient that develops fever. Early diagnosis, urine bacterial culturing and antimicrobial susceptibility testing were crucial in this case to successful management.

Use of admission serum neutrophil gelatinase-associated lipocalin (NGAL) concentrations as a marker of sepsis and outcome in neonatal foals.

BACKGROUND: Equine neonatal sepsis can be challenging to diagnose and prognosticate. Neutrophil gelatinase-associated lipocalin (NGAL), a new marker of renal damage and inflammation, can potentially be helpful. OBJECTIVES: To evaluate NGAL in neonatal foals with sepsis, and assess its relation to outcome. ANIMALS: Foals ≤ 14 days, with admission blood analysis and stored serum. METHODS: NGAL was measured on stored serum from 91 foals. Foals were scored for sepsis and survival and categorized according to sepsis status (septic, sick non-septic, healthy, and uncertain sepsis status) and outcome groups (survivors and non-survivors). The septic foals were further sub-categorized according to severity (normal sepsis, severe sepsis and septic shock). A Kruskal-Wallis test was used to compare serum NGAL concentrations in survivors and non-survivors, in the sepsis status groups, and in the sepsis severity groups. Optimal cut-off values for serum NGAL concentrations to diagnose sepsis and outcome were determined with receiver operating characteristic (ROC) curves. NGAL was compared to creatinine and SAA. RESULTS: Median serum NGAL concentrations were significantly higher in septic than non-septic foals. However, serum NGAL concentrations did not differ between sepsis severity subgroups. Serum NGAL concentrations were significantly lower in survivors than in non-survivors. Optimal cut-off values of serum NGAL concentrations were 455 µg/L (sensitivity 71.4%, specificity 100%) and 1104 µg/L (sensitivity 39.3%, specificity 95.2%) for predicting sepsis and non-survival, respectively. NGAL correlated to SAA, but not to creatinine. NGAL performed similarly to SAA to diagnose sepsis. CONCLUSION: Serum NGAL concentrations may be useful for diagnosing sepsis and predicting outcome.

Breath Alcohol Test Results in Equine Veterinarians after Performing an Abdominal Ultrasound with Ethanol.

Transcutaneous abdominal ultrasonography using alcohol saturation is used in the diagnostic workup of a variety of conditions in horses. The duration of the examination and the amount of alcohol used in each case may vary depending on several factors. The aim of this study is to describe the breath alcohol test results obtained by veterinarians performing abdominal ultrasound on horses. Six volunteers were enrolled, after written consent, and a Standardbred mare was used for the whole study protocol. Each operator performed a total of 6 ultrasounds by pouring the ethanol solution from a jar or by spray application, for a duration of 10, 30, and 60 min. An infrared breath alcohol analyzer was used immediately after completing the ultrasonography and at 5-min intervals until a negative result was obtained. Positive results were obtained for 0-60 min after the procedure. A statistically significant difference was found between the groups that used more than 1000 mL, 300-1000 mL, and less than 300 mL of ethanol. No significant differences were observed between the type of ethanol administration and the time of exposure. Based on this study, equine vets who perform ultrasound on horses can test positive at the breath alcohol test for up to 60 min following ethanol exposure.

Transthoracic echocardiography and its limitations in the diagnosis of congenital supernumerary aortic valve in a Thoroughbred.

Aortic valve malformation is a common congenital abnormality reported in human medicine. The malformation is characterised by an increased or decreased number of cusps. Anatomical variations of the aortic valve that have been documented in humans include unicuspid, bicuspid, quadricuspid and quinticuspid valves. Two reports described a quadricuspid aortic valve in horses associated with either a ventricular septal defect (VSD) or tetralogy of Fallot. In this case report we describe the clinical and echocardiographic findings of a horse with a quadricuspid aortic valve as single congenital abnormality, referred with history of exercise intolerance and an episode of paroxysmal atrial fibrillation. Limitations and risks of misdiagnosis that can be encountered with transthoracic echocardiography are also discussed. The reported case highlights the importance of echocardiographic screening in asymptomatic patients as congenital heart disease can be present without obvious cardiac signs. As advanced imaging on the equine thorax is still far from future possibilities for adult horses, this report may help to reach an accurate diagnosis with similar cases.

Factors that influence owner consent for exploratory laparotomy in horses with colic in Australia and New Zealand.

BACKGROUND: Horse owners' motivators and barriers for consent to exploratory laparotomy are poorly understood. OBJECTIVES: To (1) determine the proportion of Australian and New Zealand horse owners who would consent to exploratory laparotomy and (2) identify motivators and barriers for consent. STUDY DESIGN: Cross-sectional survey. METHODS: A questionnaire was developed and distributed online. Descriptive statistics were calculated by tabulating respondents by their answers to whether they would consent to exploratory laparotomy. Univariate and multivariate analyses were used to identify variables associated with consenting to exploratory laparotomy. RESULTS: Two thousand two hundred horse owners participated with a 68.3% survey completion rate. Most were female (95.6%), and 18.7% stated they would consent to exploratory laparotomy, 55.2% would consider exploratory laparotomy and 26.1% would not consent to exploratory laparotomy being performed on their horse. Geographical location, intended use of the horse and perceptions regarding the cost and prognosis of exploratory laparotomy, as well as the previous experience of respondents significantly impacted the decision. Self-reported level of financial comfort, gender of respondents, number of horses owned and pre-existing relationship with nearest equine referral clinic did not impact the decision. Top motivators for exploratory laparotomy were high probability of survival, trust in hospital, emotional value of horse and the alternative being euthanasia. Top barriers for exploratory laparotomy were financial cost, uncertain outcome, welfare concern and age of the horse. MAIN LIMITATIONS: Self-selection bias and acquiescence in responses. CONCLUSIONS: Most respondents indicated that they would consider or consent to exploratory laparotomy. Several factors for owners to decide for exploratory laparotomy could be identified. Improved owner education regarding the positively reported survival rates for exploratory laparotomy would be beneficial.

INTRODUCTION/CONTEXTE: Les motivateurs et les obstacles derrières la décision des propriétaires d'autoriser ou pas une laparotomie exploratrice (LE) sur leurs chevaux demeurent mal compris. OBJECTIFS: (1) Déterminer la proportion des propriétaires de chevaux en Australie et Nouvelle-Zélande qui consentiraient à une LE et (2) identifier les motivateurs et obstacles contribuant à leur consentement. TYPE D'ÉTUDE: Étude transversale. MÉTHODES: Un questionnaire a été développé et distribué en ligne. Des statistiques descriptives ont été calculées en classifiant les répondants selon s'ils consentiraient ou non à une LE. Des analyses uni et multivariées ont été utilisées pour identifier les variables associées au consentement à la LE. RÉSULTATS: Deux milles deux cents propriétaires de chevaux ont participé et le taux de remplissage du sondage était de 68.3%. La majorité étaient des femmes (95.6%) et 18.7% donneraient leur consentement pour une LE, 55.2% considéraient une LE et 26.1% ne consentiraient pas à une LE pour leur cheval. La localisation géographique, la discipline du cheval et les perceptions relativement aux coûts et au pronostic pour une LE, de même que leurs expériences précédentes influenceraient la décision des participants de façon significative. La situation monétaire des participants (rapportés de leur plein gré), leur genre, le nombre de chevaux dont ils sont propriétaires et une relation pré-existante avec une clinique de référence à proximité n'influenceraient pas leur décision. Les motivateurs les plus importants pour le consentement à la LE étaient une chance de survie élevée, leur confiance envers le centre de référence, la valeur émotionnelle du cheval et les alternatives possibles à l'euthanasie. Les obstacles les plus flagrants étaient les coûts, une chance de survie incertaine, des préoccupations par rapport au bien-être du cheval et son âge. LIMITES PRINCIPALES: Biais de sélection et degré d'accord des réponses. CONCLUSIONS: La plupart des répondants consentiraient ou au moins considéraient une LE. Plusieurs facteurs influençant la décision des propriétaires ont pu être identifiés. Il est impératif pour les vétérinariares traitants d'éduquer les clients en ce qui concerne les taux de survie plus positifs suivant les laparotomies exploratrices.

Serum amyloid A as a marker to detect sepsis and predict outcome in hospitalized neonatal foals.

BACKGROUND: Serum amyloid A (SAA) has been reported to hold promise as diagnostic and prognostic marker in foals. This has not been investigated thoroughly. OBJECTIVES: Evaluate admission SAA concentrations as predictor of sepsis and outcome. ANIMALS: Five hundred and ninety hospitalized foals <14 days old. METHODS: Retrospective multicenter study. Foals were scored with sepsis and survival scores, grouped according to health category (septic, sick but nonseptic, uncertain sepsis status) and outcome; septic foals were further categorized according to severity (normal sepsis, severe sepsis, and septic shock). SAA was compared between groups using Mann-Whitney test and Kruskal-Wallis test. Receiver operating characteristic curves identified optimal SAA cut off values for detecting sepsis and predicting outcome. RESULTS: Admission SAA concentrations differed significantly between sick nonseptic foals (312.1 ± 685.4 mg/L) and septic foals (1079.7 ± 1254.5 mg/L) and increased with increasing sepsis score. SAA did not differ between sepsis severity groups. The optimal cut off for sepsis detection was 1050 mg/L (sensitivity 30.2%, specificity 90.7%). Admission SAA concentrations were lower in surviving (435.0 ± 723.6 mg/L) compared to nonsurviving foals (1062.7 ± 1440.1 mg/L) and decreased with increasing survival score. The optimal cut off for nonsurvival prediction was 1250 mg/L (sensitivity 22.1%, specificity 90.8%). CONCLUSIONS AND CLINICAL IMPORTANCE: SAA concentration was higher in septic foals and nonsurviving foals. Even though optimal cut offs for SAA to detect sepsis and predict outcome had low sensitivity, they had good specificity. SAA can therefore be used as a marker to rule out sepsis and nonsurvival.

Novel Board Game versus Active Case-Based Discussion to Teach Final-Year Veterinary Students the Diagnostic Approach to Clinical Cases.

Traditional lectures, where students listen passively, often do not reflect the complexity of real-life decision-making situations. Furthermore, modern students are using online devices for daily activities, and this has a challenging side effect for educators, as many people these days can only maintain their focus if topics are discussed in concise and engaging ways. For these reasons, there is growing interest in the use of games for educational purposes. The aim of this study was to introduce a board game based on the Clue game for final-year veterinary students during their practical activity in large animal medicine. This type of learning process was compared with a classical case-based discussion and evaluated via a survey delivered to the students to both test their acquired knowledge and obtain their evaluation of the activity. A total of 49 students were enrolled in this study. While the board game was evaluated significatively better than the traditional class, no statistically significant differences were observed for the answers given to questions assessing their veterinary skills. The proposed game requires few resources other than a case-based visual materials and analyses from clinical patients, a board, two dice, and some imagination to create cases at the appropriate level for students' knowledge. We conclude that this board game-based activity represents innovative techniques to teach clinical approaches in an interactive way with the same utility as a traditional class but is more enjoyable for the students.

Co-Occurrence of Multidrug Resistant Klebsiella pneumoniae Pathogenic Clones of Human Relevance in an Equine Pneumonia Case.

The global epidemiology of multidrug resistant Klebsiella pneumoniae, a serious threat to both animal and human health, is dominated by the spread of pathogenic clones, each separately evolving via acquisition of transferable antibiotic resistance or niche-specific virulence determinants. In horses, K. pneumoniae infection can lead to severe respiratory illness. Here, we characterized multiple isolates recovered from bronchial aspirates of a mare with pneumonia refractory to antibiotics. First, we used a combination of standard microbiology, bacteriophage cross-susceptibility and antibiotic resistance testing to profile the infecting K. pneumoniae population. The genomes of isolates with distinct fingerprints (pulsed-field gel electrophoresis) and unique combined bacteriophage/antibiotic profiles were then further analyzed using whole-genome sequencing. Adhesion to human epithelial cells and biofilm production were also measured as virulence indicators. Although it is commonly expected for one clone to dominate an infection episode, we identified five coexisting multidrug resistant K. pneumoniae sharing the same niche. One was a novel sequence type (ST4656), while the other four were all members of emerging human pathogenic clonal groups (ST307, ST628, ST893 and ST392). These isolates did not display significant differences from one another in terms of virulence or resistance and differed only in plasmid content from isolates implicated in severe human infections, with equal potential to prolong duration and severity of infection when sharing the same niche. This study highlights the importance of more precise surveillance and detection measures to uncover bacterial heterogeneity, reminding us that the "single clone" concept is not an absolute in invasive bacterial infections. IMPORTANCE Multidrug resistant Klebsiella pneumoniae are agents of life-threatening infections in animals and humans, with several multidrug resistant clones causing outbreaks of disease worldwide. It is generally accepted that only one clone will be dominant in an infection episode. In this study, we investigated K. pneumoniae isolates from a horse with severe pneumonia and demonstrated co-occurrence of multiple sequence types previously identified as emerging human pathogens. The equine isolates are not significantly different from one another in terms of virulence or resistance, with equal potential to prolong duration and severity of infection, and are indistinguishable from isolates recovered from humans, except for plasmid content. Our study highlights how the "one dominant clone" concept is not an absolute in severe infection, illustrating the need for improved diagnostics to track heterogeneity of infection, and reinforces the importance of cross-monitoring of environmental and human reservoirs of multidrug resistant pathogens.

Chronic Renal Failure-Causes, Clinical Findings, Treatments and Prognosis.

Chronic kidney disease (CKD) is rare in horses with an overall prevalence reported to be 0.12%. There is often a continuum from Acute Kidney Injury (AKI) to CKD, and patients with CKD may be predisposed to episodes of AKI. The most common clinical signs are non-specific with weight loss, polyuria/polydipsia and ventral edema. Less common clinical signs are poor appetite and performance, dull hair coat, oral ulcerations, gastro-intestinal ulceration, gingivitis, dental tartar and diarrhea. Rarely, horses may develop forebrain signs. Creatinine increases when at least 2/3 of kidney function have been lost and a more accurate assessment of kidney function is an estimated glomerular filtration rate measuring iohexol clearance time combined with protein content in the urine. Tubulointerstitial disease and glomerulonephritis are common causes of chronic kidney disease together with pyelonephritis and nephrolithiasis. Dietary changes and avoiding nephrotoxic drugs are key in slowing down the degenerative process.

Perioperative lung ultrasonography in healthy horses undergoing general anesthesia for elective surgery.

BACKGROUND: Lung ultrasound (LUS) is poorly evaluated in horses, especially perioperatively. OBJECTIVES: (1) Describe LUS findings in healthy horses before and after general anesthesia (GA), (2) evaluate if GA induces ultrasonographic changes in healthy horses, (3) suggest a LUS scoring system, (4) identify horse variables that are associated to LUS changes after anesthesia. ANIMALS: Twenty-five healthy adult horses undergoing elective surgery. METHODS: Prospective hypothesis-driven observational study. LUS findings were recorded before anesthesia, 5 minutes in recovery, 15 minutes, 2H, 3H, 4H, 6H, and 24H after anesthesia in 8 lung regions. Clinical data were collected perioperatively. RESULTS: There was a significant increase in amount of I-lines (10.8 ± 8.7 vs 15.28 ± 8.19), B-lines (3.2 ± 3.5 vs 8.72 ± 4.86), and coalescent B-lines (0.04 ± 0.2 vs 1.12 ± 1.45) after anesthesia compared to before anesthesia, and a significantly higher LUS score 2H after anesthesia (4.92 ± 8.40) compared to before anesthesia (0.9 ± 1.8; P = .02). The maximal LUS score after anesthesia was correlated to total procedure time (Pearson r = 0.4, P = .05; Spearman r = 0.44, P = .03) and was significantly higher in horses with abnormal cardiorespiratory values during anesthesia (P = .005). CONCLUSIONS: LUS changes can be induced by GA in healthy horses. This study did not investigate if and which LUS findings indicate lesions, however, this information can aid clinicians to identify pulmonary complications after anesthesia.

Neutrophil Gelatinase-Associated Lipocalin in Synovial Fluid from Horses with and without Septic Arthritis.

Neutrophil gelatinase-associated lipocalin (NGAL) has been suggested to be a highly sensitive and specific marker of joint infection in humans. The aim of the study was to investigate NGAL concentrations in synovial fluid (SF) from horses with septic synovitis, horses without septic synovitis, and horses with uncertain status. NGAL was measured in 177 admission samples obtained from 152 horses. From a subset of horses (n = 35), additional samples obtained sequentially over the course of treatment were available. Concentrations of NGAL were significantly higher in septic synovitis (n = 47 samples) than in samples classified as non-septic (n = 103) or samples with uncertain status (n = 27), with median NGAL concentrations in the three groups being 1236, 16.8, and 266.4 µg/L, respectively. NGAL discriminated nearly perfectly between septic and non-septic (area under the receiver operating characteristic curve 0.98, 95% confidence interval 0.95-1.00). The optimal cut-off value for maximal sensitivity (87.2%) and specificity (75.0%) to discriminate septic samples from those with uncertain status was 444.6 µg/L, with an area under the receiver operating characteristic curve of 0.85 (95% confidence interval 0.74-0.93). Concentrations declined over time in horses undergoing treatment. NGAL is a novel biomarker that seems to have great potential for identifying septic synovitis and for monitoring the response to treatment of synovial infection in horses.

Effect of exercise on serum neutrophil gelatinase-associated lipocalin concentration in racehorses.

Serum neutrophil gelatinase-associated lipocalin (sNGAL) is a marker of renal injury, and its concentrations are affected by inflammation. Therefore, it could serve as a useful biomarker of disease or fitness in high-level competition. However, it has not yet been determined if sNGAL concentrations are affected by exercise. The aim of this study was to determine whether concentrations of equine sNGAL were affected by 1000 m galloping as the form of exercise used in the study. Pre- and post-gallop sNGAL, serum amyloid A, and creatinine concentrations were evaluated in 14 healthy Thoroughbred racehorses. The results showed that short, high-intensity exercise did not significantly affect sNGAL concentrations in healthy horses (P = .42), and no significant difference was found in either creatinine or serum amyloid A before and after galloping (P > .05). Therefore, it was determined that sNGAL was not influenced by the type of exercise used in the study and could have the potential to be used as a routine laboratory screening tool in horses even after strenuous exercise. Future research should clarify its use in a larger population and a broader range of equine sport disciplines, including endurance-related exercise.

An Oligosaccharide Rich Diet Increases Akkermansia spp. Bacteria in the Equine Microbiota.

Some oligosaccharides induce growth of anti-inflammatory bacterial species and induce regulatory immunity in humans as well as animals. We have shown that the equine gut microbiota and the immune-microbial homeostasis largely stabilize within the first 50 days of life. Furthermore, we have previously established that certain bacterial species in the equine gut correlated with regulatory immunity. Accordingly, we hypothesized that an oligosaccharide rich diet fed to foals during the first 50 days would increase the abundance of bacterial species associated with regulatory immunity, and that this would influence immune responses in the foals. Eight pregnant mares and their foals were fed an oligosaccharide rich diet from 4 weeks before expected parturition until 49 days post-partum. Six mares and foals served as control. Fecal microbiota from mares and foals was characterized using 16S rRNA gene amplicon high throughput sequencing. On Day 49 the test foals had significantly higher abundances of Akkermansia spp. Blood sampled from the foals in the test group on Day 7, 28, and 49 showed non-significant increases in IgA, and decreases in IgG on Day 49. In BALB/cBomTac mice inoculated with gut microbiota from test and control foals we found increased species richness, increased relative abundance of several species identified as potentially anti-inflammatory in horses, which were unclassified Clostridiales, Ruminococcaceae, Ruminococcus, Oscilospira, and Coprococcus. We also found increased il10 expression in the ileum if inoculated with test foal microbiota. We conclude that an oligosaccharide diet fed to foals in the "window of opportunity," the first 50 days of life, increases the abundance of anti-inflammatory species in the microbiota with potentially anti-inflammatory effects on regulatory immunity.

Effect of three different needle holders on gastrointestinal anastomosis construction time and bursting pressure in equine jejunal segments.

BACKGROUND: Equine small intestinal resection and anastomosis is a procedure where optimizing speed, without compromising integrity, is advantageous. There are a range of different needle holders available, but little is published on the impact surgical instrumentation has on surgical technique in veterinary medicine. The objectives of this study were to investigate if the needle holder type influences the anastomosis construction time, the anastomosis bursting pressure and whether the bursting pressure is influenced by the anastomosis construction time. Single layer end-to-end jejunojejunal anastomoses were performed on jejunal segments harvested from equine cadavers. These segments were randomly allocated to four groups. Three groups based on the needle holder type that was used: 16.5 cm Frimand (Group 1), 16 cm Mayo-Hegar (Group 2) or 20.5 cm Mayo-Hegar (Group 3) needle holders. One (Group 4) as control without anastomoses. Anastomosis construction time was recorded. Bursting pressure was determined by pumping green coloured fluid progressively into the lumen whilst recording intraluminal pressures. Maximum pressure reached prior to failure was recorded as bursting pressure. Construction times and bursting pressures were compared between needle holder, and the correlation between bursting pressure and construction time was estimated. RESULTS: Construction times were not statistically different between groups (P = 0.784). Segments from Group 2 and Group 3 burst at a statistically significantly lower pressure than those from Group 4; P = 0.031 and P = 0.001 respectively. Group 4 and Group 1 were not different (P = 0.125). The mean bursting pressure was highest in Group 4 (189 ± 61.9 mmHg), followed by Group 1 (166 ± 31 mmHg) and Group 2 (156 ± 42 mmHg), with Group 3 (139 ± 34 mmHg) having the lowest mean bursting pressure. Anastomosis construction time and bursting pressure were not correlated (P = 0.792). CONCLUSIONS: The tested needle holders had a significant effect on bursting pressure, but not on anastomosis construction time. In an experimental setting, the Frimand needle holder produced anastomoses with higher bursting pressures. Further studies are required to determine clinical implications.

Blood glucose and subcutaneous continuous glucose monitoring in critically ill horses: A pilot study.

This pilot prospective study reports the feasibility, management and cost of the use of a continuous glucose monitoring (CGM) system in critically ill adult horses and foals. We compared the glucose measurements obtained by the CGM device with blood glucose (BG) concentrations. Neonatal foals (0-2 weeks of age) and adult horses (> 1 year old) admitted in the period of March-May 2016 with clinical and laboratory parameters compatible with systemic inflammatory response syndrome (SIRS) were included. Glucose concentration was monitored every 4 hours on blood samples with a point-of-care (POC) glucometer and with a blood gas analyzer. A CGM system was also placed on six adults and four foals but recordings were successfully obtained only in four adults and one foal. Glucose concentrations corresponded fairly well between BG and CGM, however, there appeared to be a lag time for interstitial glucose levels. Fluctuations of glucose in the interstitial fluid did not always follow the same trend as BG. CGM identified peaks and drops that would have been missed with conventional glucose monitoring. The use of CGM system is feasible in ill horses and may provide clinically relevant information on glucose levels, but there are several challenges that need to be resolved for the system to gain more widespread usability.

Influence of clinical and experimental intra-articular inflammation on neutrophil gelatinase-associated lipocalin concentrations in horses.

OBJECTIVE: To investigate neutrophil gelatinase-associated lipocalin (NGAL) concentrations in serum and synovial fluid (SF) from horses with joint inflammation. STUDY DESIGN: Experimental studies and retrospective clinical study. SAMPLE POPULATION: Serum and SF samples were available from healthy horses (n = 19), clinical cases, and horses with experimental joint inflammation. Clinical cases included horses with (n = 10) or without (n = 10) septic arthritis. Experimental intra-articular inflammation was induced by lipopolysaccharide (LPS; n = 7, severe inflammation), lidocaine (n = 6, moderate inflammation), or mepivacaine (n = 6, mild inflammation). METHODS: Availability of samples was based on approval from the local ethical committee and from the Danish Animal Experiments Inspectorate. Neutrophil gelatinase-associated lipocalin was measured with a previously validated enzyme-linked immunosorbent assay. Repeated-measurements one- and two-way analysis of variance and correlation analysis were used to analyze NGAL concentrations and white blood cell counts (WBC). RESULTS: After injection of LPS or lidocaine, SF NGAL concentrations increased 343- (P = .0035) and 60-fold (P = .0038) relative to baseline, respectively. Serum NGAL also increased in both groups (P < .05) but to lower concentrations than in SF. Concentrations were higher after injection of lidocaine SF NGAL than after injection of mepivacaine (P < .05) at 6 and 12 hours. Synovial fluid concentrations of NGAL were higher in horses with septic arthritis than in the nonseptic group (P = .0070) and in healthy controls (P = .0071). Concentrations of NGAL correlated with WBC in SF (P < .0001, R2 = 0.49) and in blood (P = .0051, R2 = 0.27). CONCLUSION: Neutrophil gelatinase-associated lipocalin concentrations increased in SF in response to experimentally induced and naturally occurring joint inflammation. Synovial fluid NGAL concentration correlated with WBC and, thus, seems to reflect intensity of joint inflammation. CLINICAL SIGNIFICANCE: Neutrophil gelatinase-associated lipocalin may prove to be a useful biomarker of joint inflammation and infection in horses.

Ascending aortic aneurysm associated with tetralogy of Fallot in an adult mare.

Congenital heart disease is relatively uncommon in horses. Only three reports exist that describe a tetralogy of Fallot in adult horses. Whereas in humans the presence of congenital heart disease constitutes a risk factor for developing aortic aneurysms, their association has never been reported in horses. Here, we present a case with a large ascending aortic aneurysm as a complication of a tetralogy of Fallot in an adult mare. The mare was referred with sustained tachycardia and a 5 days history of mild intermittent colic, depression, inappetence and weight loss. Echocardiography was used to characterize the cardiac abnormalities and aortic root dilation. Due to the poor prognosis, the mare was euthanized and post-mortem examination further characterized the abnormalities. At least four factors contributed in this case to the development of aortic haematoma: congenital disease, mucoid extracellular matrix accumulation vasa vasorum dysfunction and inflammatory/degenerative lesions in the aorta's intima. Although colic is primarily caused by gastrointestinal issues, cardiac disease should be suspected in cases with sustained tachycardia, even in absence of murmurs or arrhythmias. Despite the fact that congenital abnormalities are usually detected in foals, they may sometimes remain unnoticed for several years.

Evaluation of Dynamic Structural Disorders in the Upper Airways and Applied Rein Tension in Healthy Dressage Horses During Riding in Different Gaits and Head-Neck Positions.

Flexion of the horse's head and neck during dressage riding reduces the pharyngeal lumen with the risk of increased upper airway resistance and upper airway obstructions. According to the Fédération Equestre Internationale, hyperflexion is achieved through force, whereas the position low-deep-round is nonforced. The objectives of this study were to evaluate (1) applied rein tension and (2) dynamic structural disorders in the upper airways in dressage horses in different gaits and different head-neck positions (HNPs). Overground endoscopy (OGE) and rein tension were evaluated in 13 clinically healthy and high-performance Warmblood dressage horses while being ridden in a standardized program comprised of four different gaits (halt, walk, trot, and canter) and in four HNPs (unrestrained, competition frame, hyperflexion, and low-deep-round). All included horses were able to achieve the desired HNPs. The HNP low-deep-round showed significantly lower rein tension than competition frame (P < .001) and hyperflexion (P < .001). An association was found between dynamic structural disorders in the upper airway tract evaluated by OGE and head-neck flexion, but this association was not linked to the degree of flexion. The HNP hyperflexion was neither associated with greater rein tension nor severe dynamic structural disorders than the HNP competition frame. This study confirms that low-deep-round is a nonforced position, in contrast to hyperflexion. Further studies are needed to evaluate whether dynamic structural disorders are a result of flexion or if the degree of flexion has an impact.