Hagyard Equine Medical Institute

Lexington, KY, United States

Hagyard Equine Medical Institute

Lexington, KY, United States

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Zabrecky K.A.,Purdue University | Zabrecky K.A.,Ohio State University | Slovis N.M.,Hagyard Equine Medical Institute | Constable P.D.,Purdue University | And 2 more authors.
Journal of Veterinary Internal Medicine | Year: 2015

Background: Accurate diagnostic markers for sepsis in neonatal foals are needed. Plasma C-reactive protein concentration (p[CRP]) and haptoglobin concentration (p[Hp]) are well-established biomarkers of infection in humans, but studies are lacking in foals. Hypotheses: p[CRP]) and p[Hp] are increased in septic foals compared to sick nonseptic and healthy control foals, and are predictive of survival. Animals: Eighty critically ill foals (40 septic, 40 sick nonseptic) and 39 healthy control foals <1 week of age. Methods: Multicenter, prospective observational clinical study. Venous blood was collected at admission from septic and sick nonseptic foals and from clinically healthy foals at 24 h of age. A diagnosis of sepsis was made based on positive blood culture or a sepsis score >11, and p[CRP] and p[Hp] were measured by using ELISA tests. Data were analyzed by using the Mann-Whitney U-test and forward stepwise multivariable linear regression. P < .05 was considered significant. Results: Plasma [CRP] was positively associated with age, serum globulin, adrenomedullin, and bilirubin concentrations, aspartate aminotransferase activity, glutamyl-transferase activity, band neutrophil count, and rectal temperature, and was increased in foals with toxic neutrophils, enterocolitis, colic, rib fractures and septic arthritis. Surprisingly, p[Hp] was lower in septic foals than in sick nonseptic foals. Neither p[CRP] or p[Hp] was predictive of survival in critically ill foals. Conclusions and Clinical Importance: Plasma [CRP] increases with inflammation in neonatal foals but is not indicative of sepsis. Single time point, admission sampling of p[CRP] and p[Hp] do not appear to be useful biomarkers for sepsis in foals. © 2015 The Authors.


Liepman R.S.,Ohio State University | Dembek K.A.,Ohio State University | Slovis N.M.,Hagyard Equine Medical Institute | Reed S.M.,Rood and Riddle Equine Hospital | Toribio R.E.,Ohio State University
Equine Veterinary Journal | Year: 2015

Reasons for performing study: Serum immunoglobulin (IgG) assessment in neonatal foals is considered standard care in equine hospitals to determine immunity and overall health. However, cut-off values of IgG to predict complete or partial failure of transfer of passive immunity (FTPI) were developed 30 years ago and are largely empirical with little prospective or statistical data to support their use or association with outcome. Objectives: To critically evaluate the traditional cut-off values of IgG in the assessment of FTPI (IgG <8g/l), determine the association between various degrees of FTPI and likelihood of nonsurvival and examine whether FTPI can be predicted by serum total protein (TP), albumin and globulin in hospitalised foals. Study design: Multicentre, cross-sectional study. Methods: We evaluated clinicopathological variables in 597 foals ≤7 days old from 3 equine hospitals including serum IgG, fibrinogen, TP and albumin concentrations. Foals were divided into 3 groups by diagnosis: healthy, sick nonseptic and septic. The aforementioned variables in addition to globulin concentrations were evaluated in a subset of 118 foals. Univariate, multivariate and multinomial logistic regression were used to compute odds ratios for nonsurvival in these foals. Results: Our findings support use of the traditional cut-off value of >8g/l as adequate transfer of passive immunity (ATPI). Odds of nonsurvival increased in proportion to lower IgG concentrations. Higher TP concentrations were associated with lower likelihood of FTPI; however, higher albumin concentrations were associated with a greater likelihood of FTPI. A regression equation was created to predict IgG in foals using serum proteins. Conclusions: Serum IgG values of <8g/l in hospitalised foals were proportionally associated with mortality. We recommend immediate assessment of IgG concentrations in hospitalised foals and those with FTPI should receive prompt immunotherapy. The summary is available in Chinese - see Supporting information. © 2015 EVJ Ltd.


PubMed | Ohio State University, Hagyard Equine Medical Institute, Rood and Riddle Equine Hospital and Auburn University
Type: Journal Article | Journal: Equine veterinary journal | Year: 2016

Critically ill foals often present to veterinary hospitals with impaired organ perfusion which can be demonstrated by increased blood L-lactate concentrations. As a compensatory mechanism to low blood pressure and electrolyte abnormalities, aldosterone and arginine vasopressin (AVP) are released to restore organ perfusion and function. Several studies have investigated the ability of blood L-lactate concentrations to predict severity of disease and outcome in critically ill human patients, adult horses and foals. However, information on the aldosterone and AVP response to hypoperfusion and its association with L-lactate concentrations in neonatal foals is limited.To determine the association between clinical hypoperfusion and endocrine markers of reduced tissue perfusion in normo- and hypoperfused foals.Prospective, multicentre, cross-sectional observational study.Blood samples were collected on admission from 72 clinically hypoperfused, 110 normoperfused (73 hospitalised and 37 healthy) foals of 4 days of age. Foals were considered clinically hypoperfused if they had L-lactate concentrations 2.5mmol/l and one of the 3 following findings: heart rate >120 beats/min, packed cell volume (PCV) >0.44l/l or azotaemia (increased creatinine and blood urea nitrogen [BUN]). Blood concentrations of aldosterone and AVP were determined by radioimmunoassays.Aldosterone, AVP, creatinine and BUN concentrations and heart rate, PCV and blood osmolality were higher in clinically hypoperfused compared with normoperfused foals (P<0.05). Risk of hypoperfusion increased with the presence of hypothermic extremities (OR = 5.26) and with each one unit increase in albumin concentrations (OR = 3.5) (P<0.05). The proposed admission L-lactate cut-off value above which nonsurvival could be reliably predicted in hospitalised foals was 10.6mmol/l with 82% of sensitivity and 74% of specificity.Hyperaldosteronaemia and hypervasopressinaemia as well as hypothermic extremities and increased albumin concentrations are potent predictors of hypoperfusion in hospitalised foals.


Burton A.J.,University of Georgia | Giguere S.,University of Georgia | Sturgill T.L.,University of Georgia | Berghaus L.J.,University of Georgia | And 5 more authors.
Emerging Infectious Diseases | Year: 2013

Macrolide and rifampin resistance developed on a horse breeding farm after widespread use was instituted for treatment of subclinical pulmonary lesions in foals. Resistance occurred in 6 (24%) of 25 pretreatment and 8 (62%) of 13 (62%) posttreatment isolates from affected foals. Drugresistant isolates formed 2 distinct genotypic clusters.


Petersen M.R.,Copenhagen University | Skive B.,Copenhagen University | Christoffersen M.,Copenhagen University | Lu K.,Hagyard Equine Medical Institute | And 3 more authors.
Veterinary Microbiology | Year: 2015

Endometritis in horses caused by Streptococcus equi subspecies zooepidemicus (S. zooepidemicus) may be underdiagnosed due to traditional diagnostic methods lacking sensitivity and specificity. We serendipitously identified a bacterial growth medium (bActivate) that appeared capable of inducing growth of dormant S. zooepidemicus, which subsequently allowed detection by standard diagnostics. To assess the effect of bActivate we compared its ability to activate dormant S. zooepidemicus in a group of potentially infected subfertile mares with phosphate-buffered saline (PBS). All mares had to test negative for S. zooepidemicus on a low-volume uterine lavage, be negative on endometrial cytology and without clinical signs of endometritis to be included in the investigation. The mares were instilled with bActivate or PBS in the uterus. Growth of S. zooepidemicus was induced by bActivate in 64% (16/25) and PBS in 8% (1/12) of the mares, respectively (p < 0.002). In vitro studies supported that some strains of S. zooepidemicus were able to form persister cells tolerating 32-times of the minimal inhibitory concentration of penicillin compared to normal growing cells. Persister cells had not acquired penicillin resistance, but seemed to tolerate the antimicrobial due to dormancy. This is, to our knowledge, the first description of controlled growth induction of dormant bacteria from a subclinical infection. Moreover we demonstrated how endometritis can origin from a reservoir of dormant bacteria residing within the endometrium, and not only as an ascending infection. Further studies should aim at determining the prevalence of dormant S. zooepidemicus, impact of activation on diagnostic and treatment efficacy, uterine health and mare fertility. © 2015 Elsevier B.V.


Slovis N.M.,Hagyard Equine Medical Institute | Elam J.,Hagyard Equine Medical Institute | Estrada M.,IDEXX Laboratories | Leutenegger C.M.,IDEXX Laboratories
Equine Veterinary Journal | Year: 2014

Reasons for performing study: Diarrhoea caused by infectious agents is common in foals but there is no comprehensive molecular work-up of the relative prevalence of common agents and appearance of coinfections. Objectives: To determine the prevalence of 9 infectious agents in gastrointestinal (GI)-diseased and healthy foals with ages ranging from 1 to 20 weeks of age and to what degree coinfections are associated with clinical signs of GI disease. Study design: Retrospective controlled observational study. Methods: The population consisted of 88 Thoroughbred foals aged 2 days to 17 weeks born on 32 different studfarms in Kentucky. Healthy (n = 37) and GI-diseased (n = 51) foals were identified based on clinical presentation. Faecal samples were analysed for 9 infectious agents by real-time PCR: equine rotavirus, equine coronavirus, Clostridium difficile toxins A & B, Neorickettsia risticii, Clostridium perfringens alpha toxin, Lawsonia intracellularis, Rhodococcus equi, Cryptosporidium spp., and Salmonella spp. Salmonella was also cultured from overnight selenite enrichment broth. Results: The prevalence of infectious pathogens under study was between 0% (Lawsonia intracellularis) and 34.6% (equine rotavirus). The overall prevalence for any infectious agent was 63.2% in the GI-diseased group and 43.2% in the healthy group. Coinfections were significantly more frequent in the sick group (15 monoinfections vs. 22 coinfections) than in the healthy group (12 vs. 4, respectively, P = 0.0002). Six of the 8 infectious agents were associated with the GI-diseased group, the other 2 were not (equine coronavirus and R.equi). Conclusions: The use of panels rather than individual tests in combination with quantitative toxin gene analysis enables detection of coinfections significantly associated with risk of disease. Several infectious diseases previously not tested for or considered unimportant were found at high prevalence and require further investigation. © 2013 EVJ Ltd.


Cohen N.D.,Texas A&M University | Slovis N.M.,Hagyard Equine Medical Institute | Giguere S.,University of Georgia | Baker S.,Hagyard Equine Medical Institute | And 2 more authors.
Journal of Veterinary Internal Medicine | Year: 2015

Background: Macrolide-resistant isolates of Rhodococcus equi are emerging, prompting the search for clinically effective alternative antimicrobials. Hypothesis: The proportion of foals with ultrasonographic evidence of pneumonia presumed to be caused by R. equi that had a successful outcome when administered gallium maltolate (GaM) PO would not be more than 10% inferior (ie, lower) than that of foals receiving standard treatment. Animals: Fifty-four foals with subclinical pulmonary abscesses among 509 foals at 6 breeding farms in Kentucky. Methods: Controlled, randomized, prospective noninferiority study. Foals with ultrasonographic lesions >1 cm in diameter (n = 54) were randomly allocated to receive per os either clarithromycin combined with rifampin (CLR+R) or GaM, and followed up for 28 days by daily physical inspections and weekly (n = 1 farm) or biweekly (n = 4 farms) thoracic ultrasound examinations by individuals unaware of treatment-group assignments. Treatment success was defined as resolution of ultrasonographically identified pulmonary abscesses within 28 days of initiating treatment. Noninferiority was defined as a 90% confidence interval for the observed difference in CLR+R minus GaM that was ≤10%. Results: The proportion of GaM-treated foals that resolved (70%; 14/20) was similar to that of foals treated with CLR+R (74%; 25/34), but we failed to demonstrate noninferiority for GaM relative to CLR+R; however, GaM was noninferior to CLR+R treatment when results from a noncompliant farm were excluded. Conclusions and Clinical Importance: Gallium maltolate is not inferior to macrolides for treating foals with subclinical pneumonia. Use of GaM might reduce pressure for macrolide-resistance in R. equi. © 2015 The Authors.


Barrett E.J.,Auburn University | Rodgerson D.H.,Hagyard Equine Medical Institute
Veterinary Surgery | Year: 2014

Objective: To describe an ultrasound assisted arthroscopic approach for removal of non-articular basilar sesamoid fragments in Thoroughbred yearlings. Animals: Thoroughbred yearlings (n=7). Methods: Basilar sesamoid fragments identified during pre-sale radiographic examination were removed using a palmar/plantar arthroscopic approach to the fetlock joint and ultrasonographic guidance. Complete fragment removal was confirmed by ultrasonography and radiography. Results: Basilar sesamoid fracture fragments were localized and removed successfully using rongeurs and a radiofrequency probe for soft tissue dissection of the fragment. Complete fragment removal was confirmed by ultrasonography and radiography. No intra- or postoperative complications occurred. At 6-8 months follow-up, no fragments or bony proliferation at the base of the sesamoid was observed. Conclusions: Ultrasonographic guidance can be used to facilitate localization, dissection, and confirmation of removal of basilar fragments of the proximal sesamoid bone. © 2014 by The American College of Veterinary Surgeons.


Toth B.,Purdue University | Slovis N.M.,Hagyard Equine Medical Institute | Constable P.D.,Purdue University | Taylor S.D.,Purdue University
Journal of Veterinary Internal Medicine | Year: 2014

Background: Bacterial sepsis remains a leading cause of morbidity and mortality in neonatal foals, but accurate diagnostic and prognostic markers are lacking. Adrenomedullin (AM) is a polypeptide with diverse biologic effects on the cardiovascular system that increases in septic humans and laboratory animals. Hypotheses: Plasma AM concentration (p[AM]) is increased in septic neonatal foals compared to sick nonseptic and healthy control foals, and p[AM] is predictive of survival in septic neonatal foals. Animals: Ninety critically ill (42 septic, 48 sick nonseptic) and 61 healthy foals <1 week of age. Methods: A prospective observational clinical study was performed. Venous blood was collected from critically ill foals at admission and from healthy foals at 24 hours of age. Critically ill foals were categorized as septic or sick nonseptic based on blood culture results and sepsis score. Plasma [AM] was measured by using a commercially available ELISA for horses. Data were analyzed by using the Mann-Whitney U-test and P < .05 was considered significant. Results: Plasma [AM] was not significantly different between septic and sick nonseptic foals (P = .71), but critically ill foals had significantly increased p[AM] compared to healthy controls (P < .0001). In critically ill foals, p[AM] was not predictive of survival (P = .051). A p[AM] cutoff concentration of 0.041 ng/mL provided a test sensitivity of 91% and specificity of 54% to predict illness. Conclusions and Clinical Relevance: Plasma [AM] shows promise as a marker of health in neonatal foals, but p[AM] increases nonspecifically during perinatal illnesses and is not necessarily associated with sepsis. © 2014 by the American College of Veterinary Internal Medicine.


Romero A.,Hagyard Equine Medical Institute | Rodgerson D.H.,Hagyard Equine Medical Institute | Fontaine G.L.,Hagyard Equine Medical Institute
Canadian Veterinary Journal | Year: 2010

A 3-year-old Thoroughbred was presented for evaluation of hematuria post exercise. On physical examination, an enlarged kidney was identified, as well as serum biochemical abnormalities such as an elevated creatine kinase (CK) and hypoalbuminemia. The kidney was removed laparoscopically and a nephroblastoma was identified.

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