Papers by Samuel Hurcombe
Journal of the American Veterinary Medical Association, 2015
Case Description-2 horses were examined for chronic nasal discharge secondary to unilateral guttu... more Case Description-2 horses were examined for chronic nasal discharge secondary to unilateral guttural pouch mycosis. Clinical Findings-Initial endoscopic examination of both horses confirmed the presence of a fungal plaque on the dorsomedial aspect of the medial compartment of the guttural pouch (auditory tube diverticulum) involving the internal carotid artery (ICA). No signs of hemorrhage or neurologic deficits were present at admission. Treatment and Outcome-Transarterial stainless steel coil embolization of the affected ICA was performed under general anesthesia, with fluoroscopic guidance. During treatment, an aberrant branch of the ICA, or a proposed bifid ICA, that anastomosed with the caudal cerebellar artery was identified. Occlusion of the distal (noncardiac) side of the aberrant branch was performed in both horses because of potential mycotic involvement at that level. Following treatment, resolution of the mycotic infection was observed in both horses; however, 1 horse developed neurologic signs compatible with unilateral caudal cerebellar artery ischemia on recovery from anesthesia; these signs resolved over the following 2 months. Clinical Relevance-Findings highlighted variability of the anatomy of the ICA in 2 horses that was identified during treatment for guttural pouch mycosis and identified caudal cerebellar artery infarction as a potential complication of treatment. Because of the size and pathway of both arterial branches, we suggest that the term bifurcation of the ICA is more appropriate than aberrant branching, as has been previously described in the literature. The information in this report may be of value to clinicians performing procedures involving the vasculature of the head and neck in horses.
Journal of the American Veterinary Medical Association, Jul 15, 2007
To determine clinical and clinicopathologic abnormalities in horses administered a blood transfus... more To determine clinical and clinicopathologic abnormalities in horses administered a blood transfusion and evaluate effects of blood transfusion on these variables. Retrospective case series. 31 adult horses that received > or = 1 blood transfusion. Procedures-Medical records of horses receiving a blood transfusion were reviewed to obtain clinical findings, laboratory test results before and after transfusion, adjunctive treatments, transfusion type and volume, response to transfusion, results of donor-recipient compatibility testing, adverse reactions, and outcome. 31 horses received 44 transfusions for hemorrhagic anemia (HG; n = 18 horses), hemolytic anemia (HL; 8), or anemia attributable to erythropoietic failure (EF; 5). Tachycardia and tachypnea were detected in 31 of 31 (100%) and 22 of 31 (71%) horses, respectively, before transfusion. The PCV and hemoglobin concentration were less than the reference range in 11 of 18 horses with HG, 8 of 8 horses with HL, and 5 of 5 horses with EF. Hyperlactatemia was detected in 16 of 17 recorded values before transfusion. Heart rate, respiratory rate, and PCV improved after transfusion, with differences among the types of anemia. Seventeen (54%) horses were discharged, 9 (29%) were euthanized, and 5 (16%) died of natural causes. Adverse reactions were evident during 7 of 44 (16%) transfusions, varying from urticarial reactions to anaphylactic shock. Abnormalities in clinical and clinicopathologic variables differed depending on the type of anemia. Colic, cold extremities, signs of depression, lethargy, tachycardia, tachypnea, low PCV, low hemoglobin concentration, and hyperlactatemia were commonly detected before transfusion and resolved after transfusion.
Journal of Veterinary Emergency and Critical Care, 2014
To describe a case of supraventricular tachycardia and sudden death in a horse following administ... more To describe a case of supraventricular tachycardia and sudden death in a horse following administration of flecainide acetate. An 8-year-old Hanoverian warmblood gelding was treated for chronic, naturally occurring, supraventricular tachycardia with digoxin, procainamide hydrochloride, quinidine sulfate, and flecainide acetate. After oral administration of flecainide, polymorphic ventricular tachycardia (torsades de pointes) and ventricular fibrillation developed, leading to cardiovascular collapse and death. Atrial fibrillation is the most commonly diagnosed dysrhythmia associated with poor performance in horses, while atrial tachycardia is rarely documented. Here, we describe a case of sudden death in a horse with atrial tachycardia following the oral administration of flecainide acetate, after the lack of response to other antiarrhythmic drugs. Information provided in this case report is new and will make clinicians aware of the potential complications of flecainide alone or in combination with other drugs, in horses with cardiac dysrhythmias.
PLoS ONE, 2014
Background: Medical management of critically ill equine neonates (foals) can be expensive and lab... more Background: Medical management of critically ill equine neonates (foals) can be expensive and labor intensive. Predicting the odds of foal survival using clinical information could facilitate the decision-making process for owners and clinicians. Numerous prognostic indicators and mathematical models to predict outcome in foals have been published; however, a validated scoring method to predict survival in sick foals has not been reported. The goal of this study was to develop and validate a scoring system that can be used by clinicians to predict likelihood of survival of equine neonates based on clinical data obtained on admission.
Veterinary Dermatology, 2014
House dust mite (HDM) and storage mite (SM) stable fauna and their associated equine intradermal ... more House dust mite (HDM) and storage mite (SM) stable fauna and their associated equine intradermal test (IDT) threshold concentrations (TCs) for the midwestern region of the USA are unknown. To determine IDT TCs and serum IgE concentrations for two HDM and three SM species in clinically normal horses over two seasons, and to identify the mite taxa and habitats in a stable. Thirty-eight clinically normal horses. Threshold concentrations for HDMs and SMs were determined using IDT subjective measurements and a statistical model. An enzyme-linked immunosorbent assay was used to quantify serum IgE concentrations for the same mite species. A modified flotation method was used to identify morphologically HDMs and SMs. Subjective IDT TCs were as follows: 1:80,000 w/v for Dermatophagoides farinae in both seasons; 1:80,000 w/v in spring and 1:160,000 w/v in late summer for Dermatophagoides pteronyssinus; 1:40,000 w/v in spring and 1:20,000 w/v in late summer for Acarus siro; 1:20,000 w/v for Lepidoglyphus destructor in both seasons; and 1:20,000 w/v in spring and 1:10,000 w/v in late summer for Tyrophagus putrescentiae. Statistically significant associations for increased serum IgE and a positive IDT reaction were evident for D. farinae in the spring and D. pteronyssinus in both seasons. One mite from all four genera specific to this study was identified; however,two HDM and A. siro species were not detected.Conclusions and clinical importance – This study established HDM and SM IDT dilution concentrations for the horses in this region. Exposure to diverse acaridae fauna may contribute to the pathogenesis of equine allergic disease.
Veterinary Clinical Pathology, 2010
A 6-year-old female Rocky Mountain horse was presented for evaluation of draining tracts and dist... more A 6-year-old female Rocky Mountain horse was presented for evaluation of draining tracts and distal limb subcutaneous edema on the left front and left hind limbs that had been present for 2 weeks. Direct smears of fluid collected by fine-needle aspiration of subcutaneous fluid from both limbs were highly cellular with a predominance of eosinophils accompanied by numerous, moderately atypical, variably granulated mast cells. The cytologic diagnosis was mast cell tumor (MCT) with prominent eosinophilic infiltration with a differential diagnosis of eosinophilic granuloma. Histologic evaluation of surgical biopsies of lesions from both limbs was performed on sections stained with H&E, toluidine blue, and Luna stains. The histologic diagnosis was MCT, and staining with toluidine blue and Luna stains confirmed the presence of mast cells and eosinophils, respectively. In addition, the mast cells strongly expressed CD117. This is the first reported case of cutaneous mast cell neoplasia in a horse in which primary presenting complaints were draining tracts and distal limb subcutaneous edema involving multiple limbs. This case illustrates the utility of staining for CD117 expression in combination with traditional stains, such as toluidine blue and Luna, in differentiating MCTs from other eosinophilic lesions in horses.
Journal of Veterinary Internal Medicine, 2011
Background: Endocrine dysregulation of hormones of energy metabolism is well documented in critic... more Background: Endocrine dysregulation of hormones of energy metabolism is well documented in critically ill humans, but limited information exists in septic foals. The purpose of this study was to provide information on the hormonal response to energy metabolism in critically ill foals, focusing on insulin, glucagon, and leptin.
Journal of Veterinary Internal Medicine, 2009
Background: Disorders of calcium regulation are frequently found in humans with critical illness,... more Background: Disorders of calcium regulation are frequently found in humans with critical illness, yet limited information exists in foals with similar conditions including septicemia. The purpose of this study was to determine whether disorders of calcium exist in septic foals, and to determine any association with survival.
Journal of Veterinary Internal Medicine, 2008
Sepsis is an important cause for neonatal foal mortality. The hypothalamic-pituitary-adrenal axis... more Sepsis is an important cause for neonatal foal mortality. The hypothalamic-pituitary-adrenal axis (HPAA) responses to sepsis are well documented in critically ill humans, but limited data exist in foals. The purpose of this study was to evaluate the HPAA response to sepsis in foals, and to associate these endocrine changes with survival. Blood concentrations of arginine vasopressin (AVP), adrenocorticotropin hormone (ACTH), and cortisol will be higher in septic foals as compared with sick nonseptic and healthy foals. The magnitude of increase in hormone concentration will be negatively associated with survival. Fifty-one septic, 29 sick nonseptic, and 31 healthy foals of < or =7 days of age were included. Blood was collected at admission for analysis. Foals with positive blood culture or sepsis score > or =14 were considered septic. Foals admitted with disease other than sepsis and healthy foals were used as controls. AVP, ACTH, and cortisol concentrations were measured using validated immunoassays. AVP, ACTH, and cortisol concentrations were increased in septic foals. Septic nonsurvivor foals (n = 26/51) had higher plasma ACTH and AVP concentrations than did survivors (n = 25/51). Some septic foals had normal or low cortisol concentrations despite increased ACTH, suggesting relative adrenal insufficiency. AVP, ACTH, and cortisol concentrations were higher in sick nonseptic foals compared with healthy foals. Increased plasma AVP and ACTH concentrations in septic foals were associated with mortality. Several septic foals had increased AVP : ACTH and ACTH : cortisol ratios, which indicates relative adenohypophyseal and adrenal insufficiency.
Journal of Veterinary Internal Medicine, 2013
Background: The renin-angiotensin-aldosterone system (RAAS) and hypothalamic-pituitary-adrenal ax... more Background: The renin-angiotensin-aldosterone system (RAAS) and hypothalamic-pituitary-adrenal axis (HPAA) and their interactions during illness and hypoperfusion are important to maintain organ function. HPAA dysfunction and relative adrenal insufficiency (RAI) are common in septic foals. Information is lacking on the RAAS and mineralocorticoid response in the context of RAI in newborn sick foals.
Journal of Veterinary Emergency and Critical Care, 2012
To determine whether direct intra-abdominal pressures (IAP) and calculated direct abdominal perfu... more To determine whether direct intra-abdominal pressures (IAP) and calculated direct abdominal perfusion pressures (APP) are location dependent within the abdomen of standing horses. We hypothesize that IAP will be increased and calculated APP will be decreased at a ventral abdominal location (V) when compared to values obtained from the left (LFl) or right flank (RFl). Prospective experimental design. University-based equine research facility. Seven healthy adult horses, 4 geldings and 3 mares. Measurements of direct IAP obtained from the RFl, LFl, and V locations via abdominal cannulation and direct arterial blood pressures obtained via catheterization of the transverse facial artery were obtained in fasted, standing, unsedated horses. APP was calculated for each location by the subtraction of IAP from the mean arterial pressure. Differences between sites of measurement for IAP, APP, and their gradients were calculated and compared by ANOVA and t-tests. Mean flank IAP measurements were subatmospheric and negative compared to ventral IAP values (LFl = -3 mm Hg, RFl = -5 mm Hg, V = 25 mm Hg; P < 0.001 between each flank and the ventral location). Ventrum APP was lower than flank APP (V = 82 mm Hg; LFl = 106 mm Hg; RFl = 108 mm Hg; P = 0.029 between each flank and the ventral location). Gradient calculations between sites showed the IAP increased and APP decreased from dorsal to ventral (P < 0.05) and from right to left (P = 0.004) within the abdomen. IAP and calculated APP are location dependent. These data provide new information regarding abdominal pressure profiles in standing healthy adult horses.
Journal of Veterinary Emergency and Critical Care, 2012
To document whether presumptive bacterial translocation (PBT) occurs in horses with small intesti... more To document whether presumptive bacterial translocation (PBT) occurs in horses with small intestinal strangulation (SIS). Prospective clinical cohort study. University tertiary care facility. Thirty-six adult horses with SIS (clinical cases) and 10 adult horses without gastrointestinal disease (control cases). Sterile collection and bacterial culture of samples from peripheral venous blood, mesenteric venous blood, mesenteric lymphatic tissue, and intestinal aspirates from horses with SIS and control horses without gastrointestinal disease. Five of 36 (13.8%) horses with SIS had at least 1 sample yield a positive result. Shorter SIS bowel segments were more likely to yield a positive culture result. (P < 0.01). Two of 10 of control horses had positive culture results with different bacterial species identified compared to horses with SIS. Antimicrobial usage did not influence bacterial culture status (P = 0.31). There were no differences between culture-positive and culture-negative horses with SIS regarding admission, clinical, or clinicopathologic variables. PBT occurs in normal horses and in horses with SIS. Bacterial genera differed between groups. A low incidence of PBT occurs in horses with SIS suggesting postoperative morbidity in some cases may be due to other factors.
Journal of Veterinary Emergency and Critical Care, 2012
To determine the predictive value of serum concentrations of total protein (sTP), albumin (sAlb),... more To determine the predictive value of serum concentrations of total protein (sTP), albumin (sAlb), and globulin (sGlob) measured by automated calorimetric assays to estimate serum immunoglobulin G (sIgG) concentrations in neonatal foals and identify failure of transfer of passive immunity when compared to turbidoimmunometric assay determinations of sIgG. Retrospective and prospective analysis of laboratory data. University tertiary care facility. Group 1 (retrospective): foals (n = 45) ≤7 days of age in which sIgG, sGlob, sAlb, and sTP concentrations were measured on an automated chemistry analyzer. Group 2 (prospective): foals (n = 31) ≤7 days of age with same laboratory data collected used to validate equations generated from group 1 foals. Spearman rank correlations between measured sIgG and serum protein concentrations were performed. When significant correlation was found, sIgG was estimated using an sGlob simple linear regression and estimated using a sGlob, sTP, and sAlb multiple linear regression. Comparisons between estimated and measured sIgG was performed using Kruskal-Wallis testing. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated to identify foals with sIgG < 8.0 g/L [<800 mg/dL]. sIgG was correlated with sGlob, sTP, and sAlb (ρ = 0.8, 0.6, and -0.3, respectively; P < 0.05). Estimated sIgG and measured sIgG were not different (P > 0.9). In group 1 foals, the sensitivity, specificity, positive predictive value, and negative predictive value were 73%, 76%, 73%, and 83%, respectively, for sGlob, and 90%, 76%, 75%, and 90%, respectively, for multiple proteins estimated sIgG identification of failure of transfer of passive immunity. Test qualities were improved in group 2 foals. Serum protein concentrations may be used to estimate sIgG concentrations in newborn foals. Further investigation using a larger sample size is needed to validate this methodology of assessing humoral immunity in neonatal foals.
Journal of Veterinary Diagnostic Investigation, 2009
A 2-year-old Quarterhorse was evaluated for chronic diarrhea and weight loss of 5 weeks duration ... more A 2-year-old Quarterhorse was evaluated for chronic diarrhea and weight loss of 5 weeks duration after numerous diagnostic tests failed to identify an underlying cause. Historically, the horse was housed at pasture where human household waste vehicles were routinely cleaned and the effluent could run onto the field. Physical examination revealed poor body condition and frequent high-volume diarrhea. Diagnostic testing for Salmonella spp., endoparasites, Cryptosporidium spp., Clostridium spp., and diffuse infiltrative bowel disease were negative. Rectal tissue histopathology failed to identify Mycobacterium spp., spirochetal organisms, or submucosal infiltration with cells. Rectal tissue biopsy and a fresh fecal sample identified numerous Campylobacter organisms with microaerobic culture. Molecular testing revealed the species as Campylobacter fetus subsp. fetus as a possible organism associated with large bowel disease in this filly. The organism was sensitive to fluoroquinolone antimicrobials in vitro. The filly responded transiently to therapy, forming discrete fecal balls after 72 hr of treatment. At 5 months follow-up, the horse had gained weight, was alert and responsive, but reverted back to having soft ''cow-pie'' feces. Reculture of the feces at 9 months failed to identify any Campylobacter organisms. To the authors' knowledge, this is the first report to identify C. fetus subsp. fetus from feces and tissue of a horse with the use of molecular methods. This organism could play a role in the etiology of chronic diarrhea in horses.
Journal of the American Veterinary Medical Association, 2008
A 2-year-old Thoroughbred filly was evaluated because of hemorrhage from the vulva and suspected ... more A 2-year-old Thoroughbred filly was evaluated because of hemorrhage from the vulva and suspected hematuria of 5 days' duration. A primary coagulopathy was ruled out on the basis of results of hematologic testing. Vaginoscopy and cystoscopy revealed a large bleeding mass in the bladder that extended into the vagina, causing marked obliteration of normal urogenital structures and difficulty in urination. Histologic examination of endoscopic and surgical biopsy specimens revealed a poorly differentiated neoplasia likely of mesenchymal origin. Chronic suppurative cystitis caused by Streptococcus zooepidemicus was also diagnosed. The tumor continued to grow despite treatment with doxorubicin and, within 45 days, was causing substantial discomfort and stranguria. Given the grave prognosis, the horse was euthanized. At necropsy, the tumor was found to have caused widespread destruction of the urinary bladder and to have invaded the broad ligament of the uterus. The mass was identified as a poorly differentiated leiomyosarcoma on the basis of results of histologic examination and immunohistochemical staining for alpha-actin. Findings suggested that leiomyosarcoma should be considered in the differential diagnosis when examining horses with urogenital bleeding.
Journal of the American Veterinary Medical Association, 2007
To determine clinical and clinicopathologic abnormalities in horses administered a blood transfus... more To determine clinical and clinicopathologic abnormalities in horses administered a blood transfusion and evaluate effects of blood transfusion on these variables. Retrospective case series. 31 adult horses that received > or = 1 blood transfusion. Procedures-Medical records of horses receiving a blood transfusion were reviewed to obtain clinical findings, laboratory test results before and after transfusion, adjunctive treatments, transfusion type and volume, response to transfusion, results of donor-recipient compatibility testing, adverse reactions, and outcome. 31 horses received 44 transfusions for hemorrhagic anemia (HG; n = 18 horses), hemolytic anemia (HL; 8), or anemia attributable to erythropoietic failure (EF; 5). Tachycardia and tachypnea were detected in 31 of 31 (100%) and 22 of 31 (71%) horses, respectively, before transfusion. The PCV and hemoglobin concentration were less than the reference range in 11 of 18 horses with HG, 8 of 8 horses with HL, and 5 of 5 horses with EF. Hyperlactatemia was detected in 16 of 17 recorded values before transfusion. Heart rate, respiratory rate, and PCV improved after transfusion, with differences among the types of anemia. Seventeen (54%) horses were discharged, 9 (29%) were euthanized, and 5 (16%) died of natural causes. Adverse reactions were evident during 7 of 44 (16%) transfusions, varying from urticarial reactions to anaphylactic shock. Abnormalities in clinical and clinicopathologic variables differed depending on the type of anemia. Colic, cold extremities, signs of depression, lethargy, tachycardia, tachypnea, low PCV, low hemoglobin concentration, and hyperlactatemia were commonly detected before transfusion and resolved after transfusion.
Equine Veterinary Journal, 2012
Reasons for performing study: Dysphagia due to pharyngeal dysfunction occurs in human neonates an... more Reasons for performing study: Dysphagia due to pharyngeal dysfunction occurs in human neonates and is associated with prematurity and hypoxic episodes. This syndrome probably occurs in neonatal foals but has not been reported. Objectives: The objectives of this study were to describe 1) a series of neonatal foals with dysphagia due to pharyngeal dysfunction; 2) the progression, treatment and resolution of the dysphagia; 3) the comorbidities; and 4) the prognosis for life and athleticism for affected foals. Methods: Records from 3 referral equine hospitals were reviewed from neonatal foals with dysphagia of pharyngeal origin. Inclusion criteria were a normal to strong suckle, dysphagia evidenced by milk at the nostrils after nursing the dam, and endoscopic examination of the airway. Foals with mechanical reasons for dysphagia, botulism or hyperkalaemic periodic paralysis were not included. Results: Sixteen neonatal foals qualified for the study. Eight (50%) were premature and/or diagnosed with hypoxic ischaemic encephalopathy. Twelve (75%) had aspiration pneumonia. Fifteen foals were discharged alive from the hospital, nursing the mare with no evidence of dysphagia (n = 14), or mild dysphagia (n = 1), a mean Ϯ s.d. of 7 Ϯ 6 days (median = 6.3 days, range 0-22 days) after hospital admission. One foal was subjected to euthanasia in hospital. Follow-up information was available for 14 animals. Thirteen of 16 (81%) were alive and included one yearling and 12 horses >2 years old. Seven of the 14 (50%) were racing, training or in work, and 6 horses were pets, breeding animals or had unknown athletic status. Two had laryngeal deficits. One foal was subjected to euthanasia within weeks of discharge from the hospital due to aspiration pneumonia. Conclusion: Dysphagia related to pharyngeal dysfunction occurs in equine neonates and can resolve, but may require days to weeks of supportive care. Prognosis for life is favourable and for athleticism fair.
Equine Veterinary Journal, 2012
Reasons for performing the study: Hypothalamic-pituitary-thyroid (HPT) axis dysfunction is associ... more Reasons for performing the study: Hypothalamic-pituitary-thyroid (HPT) axis dysfunction is associated with morbidity and mortality in critically ill people. To date, investigations of HPT axis in critically ill foals are limited. Objectives: To document the occurrence of low thyroid hormone concentrations (presumptive nonthyroidal illness syndrome; NTIS) in critically ill newborn foals and investigate whether NTIS is associated with severity of disease and outcome. Hypothesis: NTIS occurs frequently in foals with sepsis and is associated with sepsis score and outcome. Reverse T3 (rT3) concentrations will be increased in septic foals and highest in nonsurvivors. Methods: Thyroid hormones (total and free thyroxine [TT4 and fT4], total and free tri-iodothyronine [TT3 and fT3], reverse T3 [rT3]) were prospectively measured in healthy, sick nonseptic and septic foals. Clinical and laboratory information was retrieved from the medical records. Hormones were measured by validated radioimmunoassays. Results: Concentrations of all thyroid hormones except rT3 (P = 0.69) were decreased in septic and sick nonseptic foals (P<0.01). Reductions in hormone concentrations were associated with an increased sepsis score (P<0.01). Nonsurviving septic foals had lower TT4, fT4, TT3 and fT3 concentrations than surviving septic foals (P<0.01). rT3 concentrations were higher in nonsurviving septic premature foals than surviving septic premature foals (P<0.05). Conclusions: NTIS (euthyroid sick syndrome) is frequently observed in critically ill and premature foals, and associated with severity of disease and mortality. Potential relevance: More research is needed to better understand the mechanism of this finding and determine whether manipulation of the HPT axis or thyroid replacement therapy could be beneficial.
Equine Veterinary Journal, 2014
Resistance to the somatotropic axis and increases in ghrelin concentrations have been documented ... more Resistance to the somatotropic axis and increases in ghrelin concentrations have been documented in critically ill human patients, but limited information exists in healthy or sick foals. To investigate components of the somatotropic axis (ghrelin, growth hormone and insulin-like growth factor-1 [IGF-1]) with regard to energy metabolism (glucose and triglycerides), severity of disease and survival in critically ill equine neonates. It was hypothesised that ghrelin and growth hormone would increase and IGF-1 would decrease in proportion to severity of disease, supporting somatotropic axis resistance, which would be associated with severity of disease and mortality in sick foals. Prospective multicentre cross-sectional study. Blood samples were collected at admission from 44 septic, 62 sick nonseptic (SNS) and 19 healthy foals, all aged &lt;7 days. Foals with positive blood cultures or sepsis scores ≥12 were considered septic, foals with sepsis scores of 5-11 were classified as SNS. Data were analysed by nonparametric methods and multivariate logistic regression. Septic foals had higher ghrelin, growth hormone and triglyceride and lower IGF-1 and glucose concentrations than healthy foals (P&lt;0.01). Sick nonseptic foals had higher growth hormone and triglycerides and lower IGF-1 concentrations than healthy foals (P&lt;0.05). Growth hormone:IGF-1 ratio was higher in septic and SNS foals than healthy foals (P&lt;0.05). Hormone concentrations were not different between septic nonsurvivors (n = 14) and survivors (n = 30), but the growth hormone:IGF-1 ratio was lower in nonsurvivors (P = 0.043). Somatotropic axis resistance, characterised by a high growth hormone:IGF-1 ratio, was frequent in sick foals, associated with the energy status (hypoglycaemia, hypertriglyceridaemia) and with mortality in septic foals. A functional somatotropic axis appears to be important for foal survival during sepsis. Somatotropic resistance is likely to contribute to severity of disease, a catabolic state and likelihood of recovery.
Equine Veterinary Journal, 2014
Intraoperative assessment of colonic viability can be challenging and largely subjective. Objecti... more Intraoperative assessment of colonic viability can be challenging and largely subjective. Objective methods are often impractical. Viability is related to re-establishment of colonic perfusion; particularly microvascular perfusion. This study evaluated the utility of dark-field microscopy (DFM) of the colonic serosa as an objective method of assessing microperfusion. To measure microvascular perfusion indices (MPI) of the pelvic flexure serosa in horses with surgical colonic lesions and correlate these with macroperfusion indices (MaPI) and histomorphometry. Prospective, clinical, case-control study. Control horses and horses with colonic volvulus (LCV), displacement, and/or simple obstruction undergoing surgery had DFM video loops performed on the pelvic flexure. Total vessel density, perfused vessel density, proportion of perfusion vessels and microvascular flow index were calculated from video analysis. Macroperfusion indices (arterial blood pressure and heart rate) were recorded. Histomorphometry was used to determine a mucosal injury score. Differences between lesions for MPI, MaPI and histomorphometry were compared using ANOVA or Kruskal-Wallis statistic. Spearman correlations between MPI with MaPI were performed. Linear regression was used to assess the relationship between MPI and histomorphometry. P&lt;0.05 was significant. Horses with LCV had lower perfused vessel density, proportion of microvascular perfusion vessels and flow index than horses with nonstrangulating obstructions and control horses. Macroperfusion indices were not correlated with MPI but MPI were correlated with histomorphometry. Dark-field microscopy is achievable in the operating room and can quantify MPI from the colonic serosa in different colonic lesions. Macroperfusion indices were not related with colonic MPI. Microvascular perfusion indices can predict the severity of histopathological change at the pelvic flexure. Derangements of MPI may be more useful indicators of colonic pathology and viability and offer a more objective assessment of intestinal injury than subjective methods. Further study is needed to determine the utility of DFM in predicting survival in horses with LCV.
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Papers by Samuel Hurcombe