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Hypothalamic–pituitary–adrenal axis (HPAA) dysfunction has been associated with sepsis and mortality in foals. Most studies have focused on cortisol, while other steroids have not been investigated. The objectives of this study were to characterise the adrenal steroid and steroid precursor response to disease and to determine their association with the HPAA response to illness, disease severity, and mortality in hospitalised foals. All foals ( n = 326) were classified by two scoring systems into three categories: based on the sepsis score (septic, sick non-septic [SNS] and healthy) and the foal survival score (Group 1: 3–18%; Group 2: 38–62%; Group 3: 82–97% likelihood of survival). Blood concentrations of adrenocorticotropic hormone (ACTH) and steroids were determined by immunoassays. ACTH–cortisol imbalance (ACI) was defined as a high ACTH/cortisol ratio. Septic foals had higher ACTH, cortisol, progesterone, 17α-OH-progesterone, pregnenolone, and androstenedione concentrations as well as higher ACTH/cortisol, ACTH/progesterone, ACTH/aldosterone, and ACTH/DHEAS ratios than SNS and healthy foals ( P < 0.01). Foals with DHEAS of 0.4–5.4 ng/mL were more likely to have ACI (OR = 2.5). Foals in Group 1 had higher ACTH, aldosterone, progesterone, and cortisol concentrations as well as ACTH/cortisol, ACTH/progesterone, and ACTH/DHEAS ratios than foals in Groups 2 and 3 ( P < 0.01). High progesterone concentrations were associated with non-survival and the cutoff value below which survival could be predicted was 23.5 ng/mL, with 75% sensitivity and 72% specificity. In addition to cortisol, the response to the stress of illness in foals is characterised by the release of multiple adrenal steroids. DHEAS and progesterone were good predictors of HPAA dysfunction and outcome in hospitalised foals. [ABSTRACT FROM AUTHOR]

Reason for performing study Foals stand and walk immediately after birth, but insight into the subsequent longitudinal development of their gait kinetics in the early juvenile phase and the possible influence of osteochondrosis thereon is lacking. Objectives To quantify gait kinetics in foals during the first half year of life, taking into account their osteochondrosis status. Study design Prospective, cohort study performed at a single stud farm. Methods Pressure plate measurements at walk and trot from 11 Dutch Warmblood foals during the first 24 weeks of life were used to determine body mass normalised peak vertical force, normalised vertical impulse and stance duration. Coefficients of variation of peak vertical force and stance duration were used as measures for gait maturity. Radiographs of tarsocrural and femoropatellar joints were taken at age 4-6 weeks and after 6 months to check for osteochondrosis. A linear mixed model was used to determine the effects of age, limb, presence of osteochondrosis and speed on gait parameters. Results Mean walking and trotting velocity increased over time as did stance duration and normalised vertical impulse, normalised peak vertical force values however remained relatively constant. During the first weeks of their life only the coefficient of variation of stance duration decreased significantly, while the coefficient of variation of peak vertical force did not. None of the foals was visibly lame, but the presence of osteochondrosis resulted in a temporarily but significantly reduced normalised peak vertical force. Main limitations This study is a relatively small sample size of one breed from a single stud farm. A stand-alone pressure plate was used and body mass was estimated rather than measured. Conclusions Despite being precocious, foals need time to mature their gait. During growth, velocity at walk and trot increases, but normalised peak vertical force remains relatively constant. Although not visibly lame, a temporary reduction in normalised peak vertical force was detected in osteochondrosis positive foals using a pressure plate. [ABSTRACT FROM AUTHOR]

Synovial sepsis represents a major cause of morbidity and mortality in foals; however, there are no studies focusing on foals particularly at risk during the first 2 months of life. Our objective was to analyse outcome in foals aged <2 months with haematogenous septic arthritis and to identify prognostic factors and compare the effects of two different lavage procedures on outcome. Sixty foals with synovial sepsis were used for our retrospective study in which medical records, online data and telephone interviews were utilised to analyse prognostic factors, and determine short- and long-term survival and athletic performance of foals treated at Evidensia Equine Specialist Hospital, Helsingborg, between 2008 and 2014. Overall survival to discharge was 80% (48/60). Time to long-term follow-up ranged from 6 months to 6.5 years. Forty/60 (67%) horses survived long-term. Four/8 (50%) of the nonsurvivors at long-term follow-up had been subjected to euthanasia due to sequelae of joint sepsis. Of the long-term survivors, 37/40 (92.5%) achieved athletic soundness. Overall long-term outcome for athletic soundness was 37/60 (62%). Prognostic factors based on historical, clinical or laboratory data, or the use of through-and-through needle lavage compared to endoscopic lavage as the first procedure, could not be identified. The present study demonstrates a more favourable prognosis than previously reported, with 80% of foals with synovial sepsis surviving to discharge, and approximately 60% achieving athletic soundness. However, the study was limited by a small population size, which may account for the failure to verify statistically significant prognostic factors. [ABSTRACT FROM AUTHOR]

Background Previous reports reveal variation in the cellular composition of equine bronchoalveolar lavage fluid ( BALF). Objectives The purpose of this study was to compare the profiles of BALF from horses to assess age-related differences. Serial BALF samples were collected from the same individuals over a one-year period to identify changes in individual animals as they aged. Methods Collection of BALF was performed on horses aged one week and one, 2, 6, and 12 months. Total nucleated cell count ( TNCC), protein concentration, and cytology were assessed. Longitudinal analysis was performed and compared to healthy adults. Results Foals at one week and 6 months of age had significantly higher TNCC than adults (medians: 320/μL, 285/μL, and 90/μL, respectively); no differences in total protein were found. Foals at one month had the highest proportion of macrophages (median: 87.3%), differing significantly from both yearlings and adults (medians: 45.5% and 48.7%, respectively). Foals aged one week and one month had significantly lower proportions of lymphocytes than yearlings and adults (medians: 3.2% and 4.7% vs 43.2% and 45.8%, respectively). Eosinophil percentage was lowest in foals aged one week, one month, and 2 months (median: 0.0%) and highest in foals aged 6 months (median: 2.2%). Mast cell percentages were highest in yearlings and adults (medians: 2.2% and 3.3%, respectively) and neutrophil percentage was highest in foals aged one week (13.7%). Conclusions Cytologic profiles of BALF from foals and adult horses differed considerably. Significant changes in TNCC and percentages of lymphocytes, macrophages, and eosinophils occurred with age. [ABSTRACT FROM AUTHOR]

A 5-week-old American Miniature filly was referred due to intermittent neurological signs of 4 weeks' duration. Clinicopathological findings showed increased ammonia and bile acids in venous blood samples. Abdominal ultrasonography detailed a portosystemic shunt (PSS). The foal underwent laparotomy and operative mesenteric portovenography, which further defined the PSS as extrahepatic portocaval in configuration. The PSS was occluded and intraoperative portovenography confirmed successful shunt occlusion. The foal made a good recovery from surgery and had a successful showing career until she succumbed to colic just over 3 years after surgery. [ABSTRACT FROM AUTHOR]

Panniculitis is a rare disease in horses. As the name characterizes, it is an inflammation of the fat tissue. The dimension of this inflammation can be various. The aetiology of panniculitis is not entirely clarified until now. In this case report panniculitis is described based on a three weeks old islandic foal. There was a progredient impairment of the general condition at the stable. Based on this the foal has been referred to the horse hospital. Noticeable symptoms in this case were painful, rough swellings in the subcutaneous tissue located in the region of the Ligamentum nuchae, above both eyes, cheeks and of the ventral abdomen. Furthermore there were symmetrical and fluctuating swellings on the croup. Other clinical symptoms were progredient impairment of the general condition, no nursing, stiff gait and recumbency. The pathohistological examinations have been performed from biopsies and collected fluid from lesions as well as by use of autopsy. Findings were necrotic changes of the adipose tissue. There have been necrotic lipocytes as well as inflammatory infiltrates in form of neutrophil granulocytes. In this case the initiated therapy with Meloxicam, Cefquinom, Tocopherolacetat and Sodiumselenite showed no improvement. Finally the foal had to be euthanised because of poor prognosis. In general the prognosis in case of panniculitis has to be scored cautiously. Successful treatments worked out with substitution of vitamin E and selenium in combinition with corticosteroids. A success of this treatment can only be seen in a longer period of time up to several months. [ABSTRACT FROM AUTHOR]

Fractures of the scapula are uncommon and the majority of these involve the supraglenoid tubercle in young horses 2 years of age or less. Scapula fractures of the neck or body are rare. Comminuted scapula fractures have been diagnosed in racing breeds (Thoroughbreds and Quarter Horses) and a review of the literature on the different fracture types and their management is presented in this article. The best prognosis for soundness is given for horses treated surgically. The different techniques for surgical management are described here and comments made with reference to nonsurgical management. A residual gait deficit may persist in some horses because of involvement of the suprascapular nerve at the time of injury, during surgery and follow-up period, the severity of which depends on the degree of nerve trauma. [ABSTRACT FROM AUTHOR]

Guttural pouch mycosis (GPM) is a rare disorder in foals and should be considered as a differential in a foal presenting with dysphagia. This manuscript describes the medical management of 2 Thoroughbred foals (age 2 and 4 months) that presented with dysphagia secondary to presumptive mucosal penetration and damage by the fungal hyphae to the glossopharyngeal and hypoglossal nerves, and the pharyngeal branch of the vagus nerve. Successful treatment of the GPM was achieved with the use of systemic itraconazole and topical miconazole. The mycotic lesions resolved, but both foals continued to have residual cranial nerve deficits, which included an acquired left laryngeal paralysis ( Foal A), and residual dysfunction of the glossopharyngeal, hypoglossal and vagus nerves resulting in a weak swallow reflux and transient dysphagia ( Foal B). [ABSTRACT FROM AUTHOR]

This report describes the successful surgical repair of a transverse, displaced scapula fracture in a foal. A 3.5 mm locking compression plate (LCP) was used on either side of the spine of the scapula. The suprascapular nerve was apparent upon dissection as it passed directly over the fracture line and care was taken to leave it intact, although the fracture line itself caused some irritation. The foal recovered without long-term nerve damage and is sound at 1.5 years post surgery. [ABSTRACT FROM AUTHOR]

The objective of this study was to assess the placental vasculature and microcotyledons in pregnant mares with chronic laminitis. Twenty-six pregnant mares were enrolled in the study, 13 had chronic laminitis (Laminitis Group) and 13 were healthy mares (Healthy Group). Arterial systolic pressure and heart rate were measured in the last 30 days of gestation. After foaling, the fetal membranes were grossly evaluated and samples were harvested for histopathologic examination. All mares had digitalized images taken from chorioallantois for histomorphometry analyses (software-NIH ImageJ). Images were assessed for: (i) arterioles from the allantoic region: total and lumen vascular diameter and vascular wall thickness; (ii) microcotiledonary and capillary area/field. Mares in the Laminitis Group showed hypertension, shorter gestational length, lower placental weight and lower birthweight (p < 0.05) foal in comparison with mares in the Healthy Group. Laminitis mares had a reduction of vascular lumen diameters in the uterine body and pregnant horn (p < 0.05), vascular wall thickening in the pregnant horn (p < 0.05) and smaller capillary area/field in the microcotyledons of uterine body and pregnant horn (p < 0.05). In conclusion, pregnant mares with chronic laminitis presented signs of hypertension syndrome, and vascular abnormalitities in placental vessels such as reduction in the vascular lumen and capillary area in the microcotyledones, and thickening of the vascular wall. Foals born from mares with chronic laminitis showed lower birth weight and shorter gestation lengths. [ABSTRACT FROM AUTHOR]

The purpose of this study is to investigate the presence of IL-4, IL-8, IL-13 and IFN-γ in equine colostrum and in foals’ serum. Samples were obtained from 14 mares and their healthy foals. Soon after parturition, 10 ml of colostrum was collected, filtered, centrifuged and frozen until assayed. Blood samples were obtained from each foal at birth (TO) and again after 24 h (T24), after which they were frozen until assayed. Serum IgG was measured at 24 h of age with an immunoturbidimetric quantitative method. Cytokine concentration was determined using commercially available ELISA tests. Statistical analyses revealed a significant difference in serum concentration of IL-4 at T0 and at T24 (p < 0.05) and a significant correlation between the serum IL-4 at T24 and colostral IL-4. These results suggest the absorption of IL-4 from colostrum. The presence of IL-8 in the pre-suckle foal’s serum may be due to an endogenous production. With the exception of two samples, there was no IL-13 detected in the foals’ serum at birth and remained undetectable in 8/14 samples after 24 h. This cytokine was also undetectable in four colostrum samples, where its concentration showed a wide range and a high standard deviation. IFN-γ was present in both the colostrum and in the foals serum at birth. [ABSTRACT FROM AUTHOR]

Foals are dependent on a milk-based diet for the first 3-4 months of life. If they are orphaned during this period they require appropriate nutritional and behavioural management to allow them to develop into sound, well-grown horses and ponies with well established normal behavioural patterns. In order to meet these needs it is necessary to understand the metabolic requirements of the foal and the composition of mares' milk. Usually managing these foals requires short-term, emergency feeding of the foal while a long-term option is sought. Long-term options include use of a foster mare, induction of lactation in a parous, barren mare or hand rearing with suitable equine company. It is important to monitor growth and development of these foals to ensure that over the long term their nutritional needs are being met to allow normal growth and development. [ABSTRACT FROM AUTHOR]

The negative impact of equine dystocia on hematological and serum biochemical profile of neonatal foals remains unknown, particularly in heavy draft horses that show high incidence of dystocia. This study aimed to reveal the hematological and serum biochemical profile of the foals born in normal delivery and examine the effect of dystocia on blood properties in heavy draft newborn foals. In the normal birth group (n = 23), stage II labor was <30 minutes, with spontaneous or assisted delivery with mild traction by one or two people. In the dystocia group (n = 13), stage II labor was ≥30 minutes, with strong traction by more than three people or mechanical tools with or without correcting fetal displacement. Blood samples were collected from the jugular vein at 0, 1, and 12 hours and 1 and 2 days after foaling. Red blood cells, hemoglobin concentration, and packed cell volume remained significantly lower in the dystocia group than in the normal birth group. The white blood cell count was significantly higher in dystocia foals (1 day: P < .05). Dystocia foals had significantly higher cortisol (1 hour: P < .05), urea nitrogen (1 hour: P < .05), and creatine kinase activities (1 hour: P < .01, 12 hours: P < .05). This study revealed that dystocia foals were more likely to be affected by anemia, physical stress, and muscle damage than normal birth foals. [ABSTRACT FROM AUTHOR]

In equestrian sports, many riders and trainers prefer either male or female horses because of the sex-specific characteristics. Many sex-related differences do not depend on gonadal activity but are suggested to be established much earlier in life. Readiness for birth depends on timely maturation of the fetus which is necessary to adapt to the challenges of extrauterine life. We hypothesized that horse foals already show sex-related differences during neonatal adaptation. Foaling itself, behavior of the foals after birth, salivary cortisol concentration, and heart rate variability (root mean square of successive RR differences [RMSSDs]) were investigated in healthy warmblood foals (male n = 28, female n = 34). Gestation length differed significantly between colts and fillies (338.5 ± 1.5 days and 334.3 ± 1.1 days, P < 0.05). Duration of stage II of parturition was not affected by sex of the foal (male 13.6 ± 1.3, female 13.4 ± 1.5 minutes). In female foals, the intervals from birth to the first attempt to stand (14.2 ± 1.2 minutes) and to first standing (42.7 ± 2.7 minutes) were shorter than in male foals (first attempt to stand 18.9 ± 1.8 minutes, P < 0.05, first standing 51.2 ± 3.3 minutes, P < 0.05). Male and female foals did not differ significantly with regard to the time of first suckling after birth (male 119.1 ± 8.1, female 106.7 ± 7.8 minutes). Concentration of cortisol in saliva increased for 1 hour after the birth of the foal and decreased thereafter ( P < 0.001) but did not differ significantly between sexes. Heart rate increased in male and female foals within 30 minutes after birth and decreased continuously thereafter ( P < 0.001), whereas the heart rate variability parameter RMSSD decreased within 1 hour after birth and increased thereafter ( P < 0.001). Neither for heart rate nor RMSSD were significant differences between male and female foals seen. In conclusion, sex influences some behavior of horse foals during neonatal adaptation. Despite a longer gestation length of males, adaptation to the extrauterine environment is slightly but significantly delayed in this sex due to the prolonged time interval for the first attempt to rise and first standing. [ABSTRACT FROM AUTHOR]

Reasons for performing study Neonatal encephalopathy is the most common neurological abnormality identified in neonatal foals, but its clinical course has been rarely characterised. Objectives To describe factors associated with nonsurvival in a population of foals diagnosed with neonatal encephalopathy. Study design Retrospective cross-sectional clinical study. Methods Cases were selected from equine neonatal (≤14 days of age) admissions between 1996 and 2007. Multivariable logistic regression was used to identify clinical parameters, laboratory variables and therapeutic interventions associated with nonsurvival. Results A total of 94 foals were included in the study. Median age at admission was 12 h (range 0-96 h). The most frequently identified clinical signs included abnormal udder seeking (59%), abnormal suckle (55%), inability to stand (42%), abnormal gastrointestinal motility (37%), abnormal consciousness (34%) and seizure activity (22%). Overall, 75 (79.8%) foals survived to be discharged from the hospital and 19 foals died or were subjected to euthanasia. Variables significantly associated with nonsurvival in the multivariable model were serum total calcium concentration, serum activity of alkaline phosphatase, recumbency, number of concurrent diseases, and use of vasopressors/inotropes. The model correctly classified 92.0% of cases. Conclusions Overall survival was good and similar to previous reports. Vasopressors/inotropes were the only therapeutic intervention associated with nonsurvival, suggesting that persistent hypotension is associated with nonsurvival in the current population. Foals with concurrent disease, high total calcium and low alkaline phosphatase at admission, and that were recumbent or required treatment with vasopressors/inotropes during hospitalisation, were significantly less likely to survive. [ABSTRACT FROM AUTHOR]

Reasons for performing study Failure of transfer of passive immunity (FTPI) in foals is associated with a risk of infection and death. The current diagnostic gold standard is quantification of immunoglobulins using radial immunodiffusion (IgG-RID). Routine diagnosis is often performed using semi-quantitative tests. Concentrations of serum electrophoretic gamma globulins (EGG) and total globulins may be useful to assess , but few studies have investigated their use. Objectives To assess agreement between IgG-RID and EGG and evaluate the accuracy of total globulin concentration to diagnose based on both IgG-RID and EGG. Study design Prospective study. Methods A total of 360 serum samples were harvested at 6-24 h post natum from 60 German Warmblood foals. Concentrations of EGG, IgG-RID and total globulin (calculated from total proteins and albumin) were measured. Agreement between EGG and IgG-RID was assessed using Bland-Altman plots and Passing-Bablok regression. The accuracy of total globulin concentration was assessed using rank correlation and ROC curve analysis. Results Good agreement was found with slightly lower EGG than IgG-RID concentrations (Bland-Altman systemic bias -1.9 g/l) which was more pronounced at higher concentrations (regression equation: IgG-RID = -0.78 + 1.28 × EGG). Correlations between total globulin concentration and EGG and total globulin concentration and IgG-RID were 0.93 and 0.79, respectively. The area under the curve was 0.982 and 0.952 for EGG <4 and <8 g/l and 0.953 and 0.899 for IgG-RID <4 and <8 g/l. Sensitivities and specificities of total globulin concentration in the diagnosis of were comparable to those of commonly used screening tests, but cut-offs could be selected to achieve sensitivities of >95% with 71.2% (IgG-RID) and 90.5% (EGG) specificity for <4 g/l and >90% with 66.0% (IgG-RID) and 87.9% (EGG) specificity for <8 g/l. Conclusions There is good agreement between EGG and IgG-RID, with slightly more conservative estimates of immunoglobulins obtained using EGG. Total globulins may be a useful and economic quantitative screening test with cut-offs achieving high sensitivities, but analyser-specific cut-offs may be necessary. [ABSTRACT FROM AUTHOR]

Equine laryngeal dysplasia ( ELD) is a congenital disorder caused by hypoplasia or aplasia of the structures derived from the fourth and possibly sixth branchial arches. The severity of the clinical signs varies widely, and depends on which structures are involved and the extent of the defect. In most cases, affected horses present with abnormal respiratory noise during exercise and poor performance. Manifestation of the disease in foals is very rare. This case report describes an unusual presentation of ELD in a neonatal foal. The foal presented with severe respiratory distress and weakness. Equine laryngeal dysplasia was suspected on endoscopy and later confirmed on post mortem examination of the larynx. To the best of our knowledge, this is the first report describing ELD as a cause of respiratory distress in a neonatal foal. [ABSTRACT FROM AUTHOR]

Cortisol is a key anti-inflammatory hormone that increases in bacterial sepsis and circulates predominantly bound to cortisol binding globulin (CBG). Only unbound cortisol was believed to be biologically active, but recent evidence suggests that CBG-bound cortisol also regulates inflammation. The objective of this study was to evaluate the effects of free and CBG-bound cortisol on equine neutrophil function ex vivo . We hypothesized that CBG would enhance cortisol-mediated suppression of neutrophil pro-inflammatory responses. Neutrophils isolated from 8 foals and 6 adult horses were exposed to Staphylococcus aureus antigen (SAA) alone and with hydrocortisone (HC), CBG, or both (CBG + HC). Inflammatory cytokine (TNF-α, IL-8) and reactive oxygen species (ROS) production were measured and compared among stimulants and between ages with linear mixed-effects models. CBG and CBG + HC inhibited ROS production induced by SAA in both foal and horse neutrophils, maintaining it at levels comparable to baseline production (P ≤ 0.060–0.907). TNF-α production was not significantly different among stimulants (P = 0.284). CBG + HC significantly (P ≤ 0.016) increased IL-8 production by neutrophils in response to SAA in both foals and adults, although the response of foals was significantly greater than that of adults (P < 0.001). These findings suggest that CBG directly modulates equine neutrophil responses, but the effects are cytokine- and age-specific. [ABSTRACT FROM AUTHOR]

In neonatology, blood gas analysis is a useful tool in the evaluation of the health of newborns and plays a key role in early detection of critically ill subjects. Because blood gas analysis parameters have not previously been studied in any depth in donkey foals, this study was performed on 16 healthy Martina Franca donkey foals born after an uncomplicated delivery. Arterial and venous blood samples were collected at 5 minutes and at 12, 24, 72, and 96 hours of age. Blood gas analysis was performed by a portable analyzer, measuring arterial and venous total carbon dioxide, carbon dioxide partial pressure (pCO 2 ), oxygen partial pressure (pO 2 ), oxygen saturation (sO 2 ), bicarbonate, base excess (BE), pH, and lactate (LT). Lower blood pH values, pO 2 and sO 2 , and a higher level of lactate were found at birth in comparison with subsequent sampling times. This moderate acidotic profile disappeared at 12 hours, when all the parameters became constant until the end of the study period. As expected, significant differences between arterial and venous blood gas parameters related to the oxygenation, such as pO 2 and sO 2 , and partially carbon dioxide partial pressure were found, whereas total carbon dioxide, pH, BE, and LT were comparable in arterial and venous blood samples. For these latter parameters, the highly significant correlation between arterial and venous findings suggests that venous samples could be an acceptable alternative to the arterial sample for blood gas analysis in newborn donkey foals, when the oxygenation status of the patient is not the first goal of patient analysis. [ABSTRACT FROM AUTHOR]

Emergency care of the equine neonate is often a stressful situation and with multiple disease processes ongoing a quick decision must be made as to whether to refer or treat in the field. The initial care can be broken down into manageable steps and this article will discuss the initial assessment, primary intensive care, ongoing care of the non-critical neonate and reasons for referral. If referral is deemed appropriate and a financially viable option, the costs and prognosis should be discussed with the owners prior to transport. [ABSTRACT FROM AUTHOR]

Reasons for performing study There is a paucity of information regarding the association between common disorders and outcome over time in a large population of ill equine neonates. Objectives To describe the relative frequency of neonatal disorders in a large population of foals admitted to a neonatal intensive care unit, to determine the disorders and factors associated with nonsurvival and determine if the outcome of ill neonatal foals has improved over time. Study design Retrospective study. Methods Cases were selected from equine neonatal (≤14 days of age) admissions between 1982 and 2008. Multivariable logistic regression was used to identify the disorders, clinical parameters and laboratory variables associated with nonsurvival or natural death and assess survival over time after accounting for potential confounding variables. Results A total of 1065 foals were included in the study. Overall, 775 of 1065 (72.8%) foals survived to be discharged from the hospital and 290 (27.2%) foals were nonsurvivors. Age at admission, sepsis score, proportion of foals with positive blood cultures and proportion of survivors were significantly different (P<0.001) between primary disease categories. Variables retained in the multivariable model for nonsurvival included positive blood culture, neutrophils <2.28 × 109/l, temperature ≤37.6°C, bicarbonate, PCO2, presence of infectious orthopaedic disorders and sepsis score. The adjusted odds of survival for foals admitted in the 2000s were approximately 3.4 (95% CI = 1.9-6.0, P<0.001) times higher than that of foals admitted in the 1980s. Conclusions Primary disorders, sepsis, temperature, acid base status and neutropenia are the main factors that affect outcome in this population of equine neonates. The survival of foals admitted to a neonatal intensive care unit has increased dramatically over a 26 year period. [ABSTRACT FROM AUTHOR]

The vitamin D receptor (VDR)-vitamin D axis modulates pulmonary immunity in people but its role in equine immunity is unknown. Bacterial pneumonia causes high morbidity/mortality in foals and alveolar macrophages (AMφ) are important for pulmonary defenses. Age-related variations in vitamin D -mediated function of AMφ might contribute to the foal's susceptibility to pneumonia. Our aim was to assess the impact of age on equine vitamin D metabolism and VDR expression in AMφ. AMφ and plasma was collected from healthy foals (2, 4 and 8 weeks old) and adult horses (once). AMφ VDR expression was determined via RT-qPCR and plasma vitamin D metabolites quantified via immunoassays. Data were analyzed with linear mixed models. Inactive-vitamin D metabolite concentrations were lowest in foals at 2 weeks and lower at 2 and 4 weeks compared to adults (P < 0.001). Active-vitamin D metabolite concentrations were higher in foals than adults (P < 0.05). VDR expression was detected in AMφ in all animals and was highest in 2-week-old foals. Vitamin D metabolism and AMφ VDR expression are impacted by age in horses. This may have immunological consequences in foals given the key role that the VDR-vitamin D axis has in pulmonary immunity in other species. [ABSTRACT FROM AUTHOR]

The authors aimed to determine the plasma melatonin concentration in mares and their new-born foals in the early post-partum period. Blood samples were collected from the jugular vein of 53 mare-foal pairs within twelve hours after parturition. Plasma melatonin levels were measured by ELISA. The melatonin concentration, adjusted for the moment of parturition using a generalised linear model, was 34.58 pg mL-1 in mares. It was significantly lower (27.63 pg mL-1) in the new-born foals. However, the melatonin concentration declined differently by the end of the twelve hours, it decreased less in the offspring than in the mothers. An artificial light supplementation at the end of gestation reduced the melatonin concentration both in mares and their foals by about 10 pg mL-1, compared to the controls. An elevated melatonin production may be related to preparation of mares for parturition and ensures the chances of survival of offspring, therefore the melatonin may reach its peak at the moment of foaling regardless of its actual time. The effect of low melatonin concentration in new-born foals might be associated with the foal's health and subsequent performance. The need to monitor the melatonin concentration in the offspring justifies further studies.

Background: Forelimb extensor tendon rupture (ETR) in foals is sparsely documented., Objectives: To describe clinical and imaging findings, treatment details, and long-term outcome in foals with ETR., Study Design: Multicentre retrospective case-series., Methods: Clinical record review of foals with ETR, presented to Faculty of Veterinary Medicine at Ghent University (Belgium), the Clinic for Horses at the University of Veterinary Medicine Hannover (Germany), and Rossdales Equine Hospital (UK) between 2009-2021. Long-term outcome based on structured telephone interview with the owner at the university hospitals and on future ratings from a public racing results archive at Rossdales Equine Hospital., Results: Eight foals (28%; 95%CI: 11.7%-44.3%) presented with ETR only, whereas 21 foals (72%; 95%CI: 55.7%-88.3%) presented with ETR and concurrent flexural limb deformity foals with ETR only were older (median 20 days; Interquartile range [IQR] 13-22) than foals with ETR and flexural limb deformity (median five days; IQR 3-11; p = 0.001). Treatment included medical support, immobilization, and box rest. Hospitalisation time was longer for foals with ETR and flexural limb deformity (median 26 days; IQR 16-44) than for ETR-only foals (median 11 days; IQR 6-16; p = 0.03). Total rehabilitation time was longer for foals with ETR and flexural limb deformity (median 58 days; IQR 42-91) than for foals without flexural limb deformity (median 32 days; IQR 12-39; p = 0.03). Six foals (21%; 95%CI: 6.3%-35.7%) were euthanased within seven months: three because of problems with limb protraction and progressive flexural limb deformity. Long-term follow-up (>18 months) was available for two cases with ETR only, and seven cases with ETR and flexural limb deformity. Both ETR-only foals had a positive cosmetic outcome but only one a positive functional outcome. Foals with ETR and concurrent flexural limb deformity suffered limitations regarding cosmetic appearance (5/7 negative) and limb function (7/7 negative)., Main Limitations: Small sample size, retrospective study, and no clinical follow-up., Conclusions: ETR is a rare condition in this sample of foals treated under hospital conditions often requiring prolonged care, especially with concurrent flexural limb deformity. Further research should investigate potential associations with future athletic performance., (© 2022 EVJ Ltd.)

Background: Equine granulocytic anaplasmosis (EGA) is a common disease in adult horses, but clinical disease in foals is rarely reported. The relationship between equine maternal and neonatal antibodies to Anaplasma phagocytophilum is unclear., Hypothesis/objectives: That mares in an endemic region would be seropositive for A. phagocytophilum and that mare and foal serum IgG concentrations for A. phagocytophilum would correlate. Additionally, we hypothesized that foal IgG concentrations for A. phagocytophilum acquired by passive immunity would decline by 6 months of age., Animals: Twenty-two healthy mare-foal pairs., Methods: This prospective observational study investigated serum IgG concentrations specific for A. phagocytophilum in mares and foals using an immunofluorescent antibody test (IFA). The association between foal titer (as a binary variable) and age in months was assessed using a mixed-effects logistic regression., Results: A positive correlation between newborn foal antibody titers and mare titers was identified at both the pre-foaling (τ a  = 0.38, τ b  = 0.50, P = .009) and foaling timepoints (τ a  = 0.36, τ b  = 0.47, P = .01). In A. phagocytophilum seropositive neonates, it was unlikely that a positive titer would be detected by 3 months of age (OR = 0.002, P = .02, 95% CI: 0.00001-0.38). Three out of 20 foals seroconverted between 3 and 6 months of age., Conclusions and Clinical Importance: Transfer of specific passive immunity to A. phagocytophilum occurred in 80% of foals born to seropositive mares and declined by 3 months of age. A. phagocytophilum infection should be considered in foals displaying clinical signs consistent with EGA., (© 2023 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals LLC on behalf of American College of Veterinary Internal Medicine.)

Background: Foals that develop pulmonary ultrasonographic lesions on Rhodococcus equi (R. equi) endemic farms are treated with antibiotics because those at risk of developing clinical pneumonia (~20%) cannot be recognised early. Candidate biomarkers identified using metabolomics may aid targeted treatment strategies against R. equi., Objectives: (1) To describe how foal ageing affects their plasma metabolome (birth to 8 weeks) and (2) to establish the effects that experimental infection with Rhodococcus equi (R. equi) has on foal metabolome., Study Design: Experimental study., Methods: Nine healthy newborn foals were experimentally infected with R. equi as described in a previous study. Foals were treated with oral antibiotics if they developed clinical pneumonia (n = 4, clinical group) or remained untreated if they showed no signs of disease (n = 5, subclinical group). A group of unchallenged foals (n = 4) was also included in the study. By the end of the study period (8 weeks), all foals were free of disease. This status was confirmed with transtracheal wash fluid evaluation and culture as well as thoracic ultrasonography. Plasma metabolomics was determined by GC-MS weekly for the study duration (8 weeks)., Results: Foals' plasma metabolome was altered by ageing (birth to 8 weeks) and experimental infection with R. equi as demonstrated using multivariate statistical analysis. The intensities of 25 and 28 metabolites were altered by ageing and infection (p < 0.05) respectively. Furthermore, 20 metabolites changed by more than 2-fold between clinical and subclinical groups., Main Limitations: The number of foals is limited. Foals were experimentally infected with R. equi., Conclusions: Ageing and R. equi infection induced changes in the plasma metabolome of foals. These results provide an initial description of foal's plasma metabolome and serve as background for future identification of R. equi pneumonia biomarkers., (© 2022 EVJ Ltd.)

Background: Acetaminophen is a common analgesic and antipyretic drug used in human medicine and might be an alternative to nonsteroidal anti-inflammatory drugs for treating pain and pyrexia in foals. The pharmacokinetics and safety of differing doses of acetaminophen have not been investigated in foals., Objectives: To determine the plasma pharmacokinetics and any changes in haematology and biochemistry profiles following oral administration of single doses of acetaminophen at 10, 20, and 40 mg/kg to foals., Study Design: Randomised cross-over pharmacokinetic study., Methods: Six Quarter Horse (two colts and four fillies) foals received 10, 20, and 40 mg/kg acetaminophen orally once. Haematology and biochemistry profiles were performed before and 7 days after each drug administration. Blood samples were collected over 64 h after drug administration and were used to quantify plasma acetaminophen concentrations by liquid chromatography. Pharmacokinetic parameters were determined using compartmental analysis., Results: Median (range) acetaminophen plasma concentrations were 4.4 (1.8-5.1), 6.3 (2.6-12.6), and 14 (7.3-18) μg/ml for the 10, 20, and 40 mg/kg doses, respectively. Median acetaminophen area under the concentration versus time curve (AUC) 0-∞ ranged from 25 (11-32), 41 (22-74), and 105 (82-142) h × μg/ml for the 10, 20, and 40 mg/kg doses, respectively. Dose-normalised maximal concentrations and AUC 0-∞ values were similar across dose concentrations (p > 0.05). Median terminal half-life for all doses was 2.7-2.8 h. Haematology and biochemistry profiles were normal except for blood urea nitrogen and alkaline phosphatase concentrations., Main Limitations: Foals were growing throughout the study, starting at 1 month and ending at 3 months. Deposition of drugs changes with age. The sample size was small and only single doses were evaluated. No liver biopsies were performed., Conclusion: Plasma disposition of acetaminophen after a single oral dose of 10, 20, and 40 mg/kg to 1-3-month-old foals varies greatly with the dose. The analgesic and antipyretic effect in foals is unknown., (© 2022 The Authors. Equine Veterinary Journal published by John Wiley & Sons Ltd on behalf of EVJ Ltd.)

Colic is a common presenting complaint in foals. Unfortunately, evaluation of foals with colic can be difficult due to the common clinical presentation of acute abdominal pain attributable to a wide variety of disorders and a broad range of etiologies. Similar to foals, colic is one of the most common diseases of pregnant and periparturient mares. Several conditions are unique or occur more commonly in broodmares. This article reviews the most commonly encountered types of colic events in neonatal foals and periparturient mares, how to correctly diagnose these conditions, as well as details concerning appropriate medical management and/or surgical intervention., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: Upper respiratory disease was reported over many seasons in Arabian foals on a single stud farm in the Middle East. Affected foals were noted to have mucopurulent nasal discharge, cough, fever and tachypnea. All affected foals had been empirically treated with a macrolide and rifampicin, by the referring veterinarian without improvement. On endoscopic examination, all affected foals had significant guttural pouch empyema (GPE)., Objectives: (1) To document a previously unreported presentation of guttural pouch empyema (GPE) in a family of juvenile Arabian foals; (2) To document the cytological and microbial composition of the empyema; (3) To identify clinical signs significantly correlated with the presence of GPE, as predictors for the need for guttural pouch (GP) endoscopy; (4) To demonstrate successful resolution of the identified syndrome with mechanical GP lavage and evidence based antimicrobial use, improving antibiotic stewardship and the one-health approach to respiratory disease in this demographic of foals., Methods: Evaluation and scoring of clinical signs, upper airway endoscopy and thoracic ultrasound were performed in 14 affected foals and 10 age-matched controls, followed by comparative tracheal and guttural pouch sputum culture and cytological evaluation. Therapeutic GP lavage was performed and response to therapy monitored., Results: GPE, cranioventrally distributed ultrasonographic lesions and opportunistic pathogen infection suggested a primary lesion of GPE with aspiration of GP discharge into the lungs. GP lavage resolved the empyema and associated clinical signs in all cases., Conclusions: Cytological examination of tracheal and guttural pouch aspirates revealed a neutrophilic exudate with lipid-laden phagocytes, suggestive of engulfed milk. Bacteriology revealed a high prevalence of Streptococcus equi ssp. zooepidemicus admixed with other opportunistic pathogens. Streptococcus equi ssp. equi was not isolated in any case., (© 2023 The Authors. Veterinary Medicine and Science published by John Wiley & Sons Ltd.)

Blood culture is considered the gold standard test for documenting bacteraemia in patients with suspected bacterial sepsis in veterinary and human medicine. However, blood culture often fails to yield bacterial growth even though the clinical picture is strongly suggestive of bacterial sepsis, or contaminating organisms can overgrow the true pathogen, making accurate diagnosis and appropriate management of this life-threatening condition very challenging. Methodology for collecting blood cultures in equine medicine, and even in human hospitals, is not standardised, and many variables can affect the yield and type of microorganisms cultured. Microbiological culture techniques used in the laboratory and specific sample collection techniques, including volume of blood collected, aseptic technique utilised, and the site, timing and frequency of sample collection, all have substantial impact on the accuracy of blood culture results. In addition, patient-specific factors such as husbandry factors, the anatomical site of the primary infection, and changing microflora in different geographic locations, also can impact blood cultures. Thus, blood cultures obtained in practice may not always accurately define the presence or absence of, or specific organisms causing, bacteraemia in horses and foals with suspected sepsis. Erroneous blood culture results can lead to inappropriate antimicrobial use, which can result in poor outcomes for individual patients and contribute to the development of antimicrobial resistance in the patient's microflora and the environmental microcosm. This review summarises current indications and methodology, and specific factors that may be optimised, for equine blood culture, with particular focus on available literature from neonatal foals with suspected bacterial sepsis. To standardise and optimise blood culture techniques in horses and foals, future research in this area should be aimed at determining the optimal volume of blood that should be collected for culture, and the ideal site, timing, and frequency of sample collection., (© 2022 The Authors. Equine Veterinary Journal published by John Wiley & Sons Ltd on behalf of EVJ Ltd.)

Arthrodesis was achieved in two foals through the placement of three 4.5 mm cortical lag screws. Two screws were placed in a standard transarticular fashion from the dorsal aspect of P1 (glide hole) to the palmar aspect of P2 (thread hole). A third transarticular lag screw was placed from the dorsal aspect of P2 (glide hole) to the palmar aspect of P1 (thread hole). Both foals were comfortable and considered suitable for light work. Crossed transarticular lag screw fixation of P1 and P2 in cases of PIPJ arthrodesis in foals is a simple and useful method offering good stability for fusion and future athletic soundness.

The effect of sex on carcass measurement, physico-chemical properties, nutritional value and sensory characteristics of foal meat slaughtered at 15 months was investigated. Twelve foals (six females and six males) from an extensive production system in freedom regimen were used for this study. Sex had no statistical influence on carcass measurements, chemical composition, colour parameters, textural properties, amino acid content and sensory characteristics. In contrast, there was a clear effect on the fatty acid profile of longissimus dorsi. Slaughter weight was not significantly (P > 0.05) different between sexes, although higher values were observed in male group compared with female group (194 v. 184 kg). As a consequence, this trend affected carcass weight being slightly (P > 0.05) heavier in the male group than in the female group. On the other hand, cooking loss samples from males showed significantly higher values than those from females (21.50% v. 14.96%, P < 0.05). From a nutritional point of view, the n-6/n-3 ratio in both sexes was within the recommended range for the human diet and this ratio was ostensibly different between the sexes (1.83 v. 1.36, P < 0.05, for male and female, respectively) and it showed a strong correlation (r = −0.91, P < 0.01) with C18:3n-3 content.

Five foals were admitted with history of unilateral lameness and hoof dragging during walking. Clinical examination revealed jerky movement during locomotion and toe dragging of affected limb. On basis of clinical examination, animals were diagnosed with upward patellar fixation. Surgical management of all five foals was carried out by medial patellar ligament desmotomy. Immediately after desmotomy, all five foals walking normally without any lameness and recovered fully. [ABSTRACT FROM AUTHOR]

Highlights • Joint development is not related to the number of extracellular vesicles (EVs) in synovial fluid (SF). • EV numbers in SF do not resemble typical biomarker patterns of the dynamic joint metabolism in growing foals. • Functional analyses of EVs may still reveal differences between juvenile and mature EVs in healthy SF. Abstract Extracellular vesicle (EV) concentration, characteristics and function in equine synovial fluid (SF) during normal growth and development has not previously been studied. Isolation of EVs was performed in SF from three healthy foals and two adult horses by differential ultracentrifugation (10,000 g and 200,000 g); EVs were purified by sucrose density gradient floatation and analysed by high-resolution flow cytometry (FCM), buoyant density and western blotting. Additionally, repeated biomarker analysis of sulphated glycosaminoglycans (GAG), matrix metalloproteinase (MMP), C-terminal crosslinked telopeptide type II collagen (CTX-II), collagenase cleaved neopeptide type II collagen (C2C) was performed in SF from 10 foals and six adult horses. In contrast with the quantitative EV profile, the biomarker profile in SF from juvenile joints was substantially different from that in SF from adult animals. However, there were qualitative differences in the high-resolution FCM scatter plots. Future in-depth functional analyses may reveal differences between juvenile and mature EVs in SF. [ABSTRACT FROM AUTHOR]