Restoration of function following traumatic superior eyelid avulsion in a horse treated with advancement flap blepharoplasty (H-plasty) and subdermal hyaluronic acid filler.

OBJECTIVE: To describe the successful restoration of superior eyelid function in a horse following traumatic avulsion using an advancement flap blepharoplasty and subdermal hyaluronic acid filler. ANIMAL STUDIED: A 21-year-old American Paint Horse stallion who was attacked by a fellow stallion resulting in numerous traumatic injuries including avulsion of approximately 75% of the left superior eyelid. PROCEDURES: With standing sedation and locoregional anesthesia, the superior eyelid wound was debrided and an advancement flap blepharoplasty (H-plasty) and temporary tarsorrhaphy were performed. Routine healing of the surgical site occurred over the subsequent weeks, though lagophthalmos persisted. At 2 and 4 weeks post-operatively, 2.4% cross-linked hyaluronic acid was injected subdermally into the superior eyelid to attempt to improve corneal coverage. At 8 weeks post-operatively, a complete blink was restored and the cosmetic outcome was good. CONCLUSIONS: Injection of subdermal hyaluronic acid filler following eyelid injuries or blepharoplastic procedures that result in lagophthalmos can improve corneal coverage by the eyelids and allow for maintenance of a comfortable and visual eye.

Transcriptomic regulations of heat stress response in the liver of lactating dairy cows.

BACKGROUND: The global dairy industry is currently facing the challenge of heat stress (HS). Despite the implementation of various measures to mitigate the negative impact of HS on milk production, the cellular response of dairy cows to HS is still not well understood. Our study aims to analyze transcriptomic dynamics and functional changes in the liver of cows subjected to heat stress (HS). To achieve this, a total of 9 Holstein dairy cows were randomly selected from three environmental conditions - heat stress (HS), pair-fed (PF), and thermoneutral (TN) groups - and liver biopsies were obtained for transcriptome analysis. RESULTS: Both the dry matter intake (DMI) and milk yield of cows in the HS group exhibited significant reduction compared to the TN group. Through liver transcriptomic analysis, 483 differentially expressed genes (DEGs) were identified among three experimental groups. Especially, we found all the protein coding genes in mitochondria were significantly downregulated under HS and 6 heat shock proteins were significant upregulated after HS exposure, indicating HS may affect mitochondria integrity and jeopardize the metabolic homeostasis in liver. Furthermore, Gene ontology (GO) enrichment of DEGs revealed that the protein folding pathway was upregulated while oxidative phosphorylation was downregulated in the HS group, corresponding to impaired energy production caused by mitochondria dysfunction. CONCLUSIONS: The liver transcriptome analysis generated a comprehensive gene expression regulation network upon HS in lactating dairy cows. Overall, this study provides novel insights into molecular and metabolic changes of cows conditioned under HS. The key genes and pathways identified in this study provided further understanding of transcriptome regulation of HS response and could serve as vital references to mitigate the HS effects on dairy cow health and productivity.

Gender differences in research collaborations and academic advancement among veterinary medical college faculty.

OBJECTIVE: To examine patterns of collaborative research behavior by gender among veterinary academic faculty to determine whether differences exist in how men and women access resources as a contributing factor to the advancement gap. SAMPLE: 710 faculty from 23 veterinary medical colleges. PROCEDURES: An online questionnaire was sent through listservs at participating institutions and data were collected anonymously. Responses related to professional demographics, resources, collaboration, and elements of environmental culture were analyzed to identify associations among variables. Proportional odds logistic regression was utilized to examine the effect of gender on academic rank. RESULTS: Male and female faculty reported participating in collaborations at equal rates. Men were more likely to engage in research collaborations with other men. These collaborations were more common than collaborations between women or between women and men. Men had 47% higher odds of more advanced academic rank compared with women and controlling for relevant factors. While there was no difference in the value of startup packages listed by men and women, women were more likely to report gender as a disadvantage in accessing resources and opportunities. CLINICAL RELEVANCE: Research productivity is a main factor driving academic promotion. To improve gender equity in career advancement and to support scholarship among all faculty, the creation of institutional development programs focused on facilitating collaborations and resource sharing may be a strategic area for veterinary academic leaders to consider.

Plakoglobin and High-Mobility Group Box 1 Mediate Intestinal Epithelial Cell Apoptosis Induced by Clostridioides difficile TcdB.

Clostridioides difficile infection (CDI) is the leading cause of antibiotic-associated intestinal disease, resulting in severe diarrhea and fatal pseudomembranous colitis. TcdB, one of the essential virulence factors secreted by this bacterium, induces host cell apoptosis through a poorly understood mechanism. Here, we performed an RNA interference (RNAi) screen customized to Caco-2 cells, a cell line model of the intestinal epithelium, to discover host factors involved in TcdB-induced apoptosis. We identified plakoglobin, also known as junction plakoglobin (JUP) or γ-catenin, a member of the catenin family, as a novel host factor and a previously known cell death-related chromatin factor, high-mobility group box 1 (HMGB1). Disruption of those host factors by RNAi and CRISPR resulted in resistance of cells to TcdB-mediated and mitochondrion-dependent apoptosis. JUP was redistributed from adherens junctions to the mitochondria and colocalized with the antiapoptotic factor Bcl-XL. JUP proteins could permeabilize the mitochondrial membrane, resulting in the release of cytochrome c. Our results reveal a novel role of JUP in targeting the mitochondria to promote the mitochondrial apoptotic pathway. Treatment with glycyrrhizin, an HMGB1 inhibitor, resulted in significantly increased resistance to TcdB-induced epithelial damage in cultured cells and a mouse ligated colon loop model. These findings demonstrate the critical roles of JUP and HMGB1 in TcdB-induced epithelial cell apoptosis. IMPORTANCE Clostridioides difficile infection (CDI) is the leading cause of hospital-acquired diarrhea. Toxins, especially TcdB, cause epithelial cell apoptosis, but the underlying cell death mechanism is less clear. Through an apoptosis-focused RNAi screen using a bacterium-made small interfering (siRNA) library customized to a human colonic epithelial cell model, we found a novel host factor, plakoglobin (γ-catenin), as a key factor required for cell apoptosis induced by TcdB. Plakoglobin targets and permeabilizes mitochondria after stimulation by TcdB, demonstrating a hitherto underappreciated role of this catenin family member in the apoptosis of intestinal epithelial cells. We also found a previously known cell death-related chromatin factor, HMGB1, and explored the inhibition of HMGB1 for CDI therapy in vivo.

Treatment and outcomes of two pigs treated for hemoabdomen secondary to splenic disease.

OBJECTIVE: To report the management and outcomes of two pigs undergoing emergency surgery for hemoabdomen secondary to splenic disease. STUDY DESIGN: Case report. ANIMAL: Two adult pigs with hemoabdomen and suspected splenic pathology. METHODS: Pigs were admitted for several clinical signs including lethargy, inappetence, vomiting, abdominal distention, hypothermia, and tachycardia. Abdominal ultrasound and abdominocentesis led to a diagnosis of hemoabdomen secondary to splenic disease. RESULTS: The spleen was confirmed as the source of hemorrhage during midline exploratory celiotomy in both pigs. Splenic rupture resulted from splenic vein thrombosis in one pig and splenic torsion in the other. Complications included intraoperative hemorrhage and intraabdominal adhesion formation. Four years following splenectomy, one pig was euthanized because of widespread small intestinal adhesions causing luminal obstruction, while the other pig was euthanized following a diagnosis of chronic myeloid leukemia. CONCLUSIONS: A ventral midline celiotomy provided adequate exposure for splenectomy. The procedure allowed resolution of signs in both pigs. Splenic pathology, such as vessel thrombosis or torsion, may result in splenic rupture and should be considered as a differential in pigs with hemoabdomen.

Small ruminant urinary obstruction: decision trees for treatment.

Urolithiasis is the most common cause of urinary tract disease in small ruminants and has significant economic and production impacts worldwide. Urolithiasis is multifactorial in origin and generally begins with the formation of cystoliths followed by urethral obstruction. The condition is most common in males. Clinical signs are variable depending on the severity of the obstruction. Uroliths can be calcium, struvite, or silicate based; however, struvite and amorphous magnesium calcium phosphate are the most common urolith types observed in small ruminants. Although urethral process (vermiform appendage) amputation is widely considered the first line of treatment, reobstruction is common within the first 36 hours. Surgical interventions such as temporary tube cystostomy, perineal urethrostomy (PU), modified proximal perineal urethrostomy, vesico-preputial anastomosis (VPA), and urinary bladder marsupialization (BM) are reported to carry an improved prognosis for long-term survival. PU carries a lower proportion of long-term success (> 12-month survival time) when compared with VPA and BM. Stoma stricture and urine scald are the most commonly observed surgical complications. Currently, the literature provides minimal direction for clinician decision-making in managing these cases while accounting for patient history, client financial ability, composition of calculi, and potential treatment complications. Small ruminant urinary obstructions are challenging and complicated conditions to treat, due to their multifactorial etiology, ruminant urogenital anatomy, and the variety of imperfect treatment options available. The purpose of this article this article is to provide veterinary practitioners with decision trees to guide management and treatment of urolithiasis in small ruminants.

Surgery of the Equine Urinary Tract.

Urinary surgery in the horse may be challenging. More straightforward procedures, such as urinary bladder or urachal defects, do not usually require specialized equipment or imaging, although laboratory work is helpful. Congenital or acquired conditions of the ureters or kidneys may necessitate advanced diagnostic work-ups including advanced imaging /or and minimally invasive procedures. Some surgery of the lower urinary tract is done in the sedated, standing adult horse. Surgery involving the kidney typically requires general anesthesia. Laparoscopy and associated tools are frequently used. Although many of the surgical procedures discussed are quite involved, they are becoming more commonplace.

Laparoscopic inguinal herniorrhaphy with barbed suture in a ram.

A 7-month-old Hampshire ram, with no history of trauma or breeding, was referred for treatment of acute, unilateral scrotal swelling. Physical examination revealed a moderately sized, soft, left-sided, non-reducible swelling of the proximal scrotum and mild swelling of the scrotal neck. Ultrasound evaluation of the scrotum revealed morphologically normal testicles and a mild accumulation of free fluid in the left vaginal tunic. Unilateral, laparoscopic inguinal herniorrhaphy under general anesthesia was performed. The herniated omentum was reduced and barbed suture was used to imbricate the internal inguinal ring and the vaginal ring. No recurrence of herniation was reported 5 months after surgery. Key clinical message: Laparoscopic inguinal herniorrhaphy with barbed suture can be a safe and effective means of scrotal hernia resolution in a ram. When performed by a competent surgeon experienced in laparoscopy, this treatment for inguinal and scrotal herniation may minimize post-operative pain, provide a rapid return to function, and preserve normal testicular and scrotal anatomy.

Herniorraphie inguinale laparoscopique avec suture barbelée chez un bélier. Un bélier Hampshire âgé de 7 mois, sans antécédent de traumatisme ou de reproduction, a été vu pour traitement d'un gonflement unilatéral aigu du scrotum. L'examen physique a révélé une tuméfaction modérée, molle, du côté gauche, non réductible du scrotum proximal et une légère tuméfaction du col scrotal. L'examen échographique du scrotum a révélé des testicules morphologiquement normaux et une légère accumulation de liquide libre dans la tunique vaginale gauche. Une herniorraphie inguinale unilatérale laparoscopique sous anesthésie générale a été réalisée. L'épiploon hernié a été réduit et une suture barbelée a été utilisée pour imbriquer l'anneau inguinal interne et l'anneau vaginal. Aucune récidive de hernie n'a été rapportée 5 mois après la chirurgie.Message clinique clé:La herniorraphie inguinale laparoscopique avec suture barbelée peut être un moyen sûr et efficace de résolution de la hernie scrotale chez un bélier. Lorsqu'il est effectué par un chirurgien compétent et expérimenté en laparoscopie, ce traitement des hernies inguinales et scrotales peut minimiser la douleur postopératoire, permettre un retour rapide à la fonction et préserver l'anatomie testiculaire et scrotale normale.(Traduit par Dr Serge Messier).

Surgical treatment of uterine neoplasia in 13 production size pigs with a comparison to pot-bellied pigs.

OBJECTIVES: The primary objective of this study was to describe the clinical management and surgical treatment of production size pigs (PrdP) with uterine neoplasia. A secondary objective was to compare tumor diagnoses as well as short- and long-term survival between PrdP and a published report of pot-bellied pigs (PBP) following surgical intervention. STUDY DESIGN: Retrospective clinical study. ANIMALS OR SAMPLE POPULATION: Client-owned PrdP (n = 13) treated with exploratory celiotomy ±ovariohysterectomy for uterine neoplasia. METHODS: Medical records from a university hospital were reviewed for historical treatment, presenting complaint, clinical signs, diagnostics, surgical intervention, pathology, and outcome. An online owner survey was performed for follow-up. The novel PrdP cohort was compared to a previously published PBP cohort for differences in tumor diagnoses, surgical complications, and survival. Descriptive statistics, Fischer's exact tests and odds ratios were reported. RESULTS: PrdP were affected by uterine leiomyoma (4/11), leiomyosarcoma (2/11), adenoma (1/11), adenocarcinoma (3/11), and carcinosarcoma (1/11) with no difference in tumor types between PrdP and PBP. PrdP surviving to hospital discharge (6/13) survived at least 1 year postoperatively, with median follow-up of 16 months (14-60 months). PrdP were less likely than PBP to survive in the short-term despite similar frequencies of marked intraoperative hemorrhage. PrdP and PBP had comparable rates of long-term survival following hospital discharge. CONCLUSION: PrdP are afflicted by similar uterine neoplasia diagnoses as PBP, but they have lower rates of short-term survival to hospital discharge with surgical treatment. CLINICAL SIGNIFICANCE/IMPACT: PrdP have a guarded prognosis for survival to hospital discharge when operated for uterine neoplasia.

Assessment and Revision of the Veterinary Internship and Residency Matching Program Standardized Letter of Reference.

The Veterinary Internship and Residency Matching Program (VIRMP) recently revised its electronic standardized letter of reference (SLOR) to improve the quality and usefulness of the data obtained from it and to enhance the relevance of non-cognitive and cognitive candidate attributes assessed. We used a stepwise process including a broad survey of SLOR readers and writers, analysis of past SLORs, and a multi-wave iterative revision that included key stakeholders, such as residency and internship program directors from academia and private practice. Data from the SLOR survey and analysis of past SLOR responses identified opportunities to improve applicant differentiation, mitigate positive bias, and encourage response consistency. The survey and other analytics identified and confirmed performance domains of high relevance. The revised SLOR assesses four performance domains: knowledge base and clinical skills, stress and time management, interpersonal skills, and personal characteristics. Ratings within the revised SLOR are predominantly criterion-referenced to enhance discernment of candidate attributes contained within each domain. Questions assessing areas of strength and targeted mentoring were replaced with free-text boxes, which allow writers to comment on positive and neutral/negative ratings of attributes within domains. Minor revisions were made to certain questions to enhance readability, streamline responses, or address targeted concerns identified in the SLOR survey or stakeholder review. The revised SLOR was deployed in the 2020 VIRMP; data from a survey of writers (n = 647) and readers (n = 378) indicate that the redesign objectives were achieved.

Higher body mass index may increase the risk for the development of incisional complications in horses following emergency ventral midline celiotomy.

BACKGROUND: Obesity is common in the equine population and it has been associated with increased surgical morbidity and mortality in humans. The effect of increased body mass index (BMI) on the incidence of surgical site infections has not been investigated in horses. OBJECTIVES: To determine whether horses with increased body fat, as estimated by BMI, are more likely to develop post-operative complications, particularly incisional complications, following emergency ventral midline celiotomy. STUDY DESIGN: Retrospective, multi-institutional clinical study. METHODS: Medical records of horses >2 years old presenting with colic that underwent ventral midline celiotomy between January 2010 and September 2018 with follow-up of a minimum of 30 post-operative days were reviewed. Extracted data included signalment, operative details and outcome. BMI was calculated by dividing the patient's weight (kg) by the withers height squared (m2 ). RESULTS: In all, 287 horses fit inclusion criteria. Incisional complication prevalence was 23.7%. Horses with incisional complications had a higher BMI (median 203.6 kg/m2 , IQR = 191.5-217.4) compared with those without (median 199.1 kg/m2 , IQR = 184.7-210.2) (P = .03). Multi-variable analysis of the effects of age, sex, breed and presence of metabolic disease on the association between BMI and risk of incisional complications, identified a tendency towards increased risk with a higher BMI, but statistical significance decreased to P = .07. Breed had an association with BMI (P < .01), but not with incisional complication risk. MAIN LIMITATIONS: BMI as an estimate of body fat has limitations. Retrospective studies with reliance on owners reporting data and complete medical records is imperfect. When the data were subjected to multi-variable analysis, the trend towards an increased incidence of incisional complications in horses with higher BMI persisted but it was not statistically significant. CONCLUSION: Higher BMI may increase the risk for the development of incisional complications in horses following emergency ventral midline celiotomy.

Surgical treatment of chronic penile prolapse in Vietnamese pot-bellied pigs: 5 cases (2016-2017).

OBJECTIVE: To describe the surgical treatment and short- and long-term outcome of young pot-bellied pigs with penile prolapse. STUDY DESIGN: Short case series. ANIMALS: Five young castrated Vietnamese pot-bellied pigs. METHODS: Five Vietnamese pot-bellied pigs presented with penile prolapse of several weeks duration. No other abnormalities were found at physical examination. Under general anesthesia, phallopexy with or without combined urethropexy was performed successfully in all cases. RESULTS: All pigs were discharged from the hospital. One pig required a second urethropexy the day after the initial surgery to improve positioning of the penis in the prepuce. Long-term outcome was available in 4 cases. Penile prolapse resolved in the 4 cases available for follow-up, and the owners were satisfied with the cosmetic outcome of the procedure. CONCLUSION: Penile prolapse was successfully corrected in 5 pot-bellied pigs by using 2 different phallopexy techniques. The procedure was combined with urethropexy in 3 pigs. Long-term outcome was excellent in the 4 cases available for follow-up. CLINICAL IMPACT: This is the first report describing the use of phallopexy with or without urethropexy for successful treatment of penile prolapse in young pot-bellied pigs. Two different phallopexy techniques were effectively used in this report. The etiology of penile prolapse in pot-bellied pigs remains unknown.

Clinical features, treatment, and outcome in goats with thymomas: 13 cases (1990-2014).

OBJECTIVE To determine the anatomic location and clinical signs of thymoma in goats and long-term outcomes in a subset of goats treated by tumor excision. DESIGN Retrospective case series. ANIMALS 13 goats with a histologic diagnosis of thymoma at the Cornell University Hospital for Animals between 1990 and 2014. PROCEDURES Medical records of goats with thymoma were reviewed and data were evaluated regarding signalment, clinical signs, diagnostic imaging results, thymoma size, treatment, and outcome. Follow-up information was obtained via contact with the owners and review of medical records. RESULTS 8 goats had a mediastinal mass, 4 had a palpable ventral cervical mass, and 1 had both types of masses. Median age at the time of diagnosis was 9.5 years (range, 3 to 12 years). Goats with a mediastinal mass had respiratory distress or marked tachypnea. Six goats were treated surgically, including all 5 with a ventral cervical mass. All 5 goats with a ventral cervical mass survived with no tumor recurrence for ≥ 1 year after excision. Only 2 goats with a mediastinal mass survived to hospital discharge. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that the prognosis for goats following excision of ventral cervical thymomas was favorable, whereas goats with mediastinal thymomas appeared more likely to have severe clinical signs and a guarded prognosis.

Tumor collision of uterine adenocarcinoma and leiomyosarcoma in a goat.

An aged mixed-breed goat doe was presented with a 9-mo history of serosanguineous vaginal discharge. Vaginal speculum examination revealed serosanguineous discharge but otherwise no abnormalities. Transrectal ultrasonography showed normal ovaries and multifocal cystic lesions within the uterus. Ovariohysterectomy was recommended because of a strong suspicion of neoplasia. Multiple, non-resectable masses were noted in and around the uterus intraoperatively, and euthanasia was elected. Autopsy revealed multiple masses within the uterus, cervix, and lung parenchyma. Histologically, the masses within the uterus represented a likely collision tumor of primary adenocarcinoma and leiomyosarcoma. Our report highlights the importance of obtaining biopsy samples of all masses because the lesions described showed significantly different biological behavior. This information is vital to guide treatment and prognosis.

Laparoscopic-guided compared to skilled instructor support for student rectal examination training using live horses in the veterinary curriculum.

OBJECTIVES: To evaluate the veterinary student learning outcome of 2 methods of equine rectal examination training. STUDY DESIGN: Randomized prospective study. SAMPLE POPULATION: Veterinary students (3rd and 4th year; n = 40) and practicing equine veterinarians (n = 10). METHODS: Year 1: Group 1 (n = 11) and Group 2 students (n = 10) received skilled instructor (SI) and laparoscopic-guidance (LG), respectively, during rectal exam instruction. All students were tested on rectal identification of 4 abdominal organs. Year 2: One group of students (n = 19) was trained and subsequently tested using each technique, first SI, followed by LG. Subjective evaluation of laparoscopy as a teaching tool was achieved with veterinary students and equine practitioners. RESULTS: A significantly greater percentage of students having LG compared to SI were able to correctly identify the left kidney (Year 1) and the spleen, cecum, and right ovary (Year 2). A significantly greater proportion of LG trained students in years 1 and 2 (100% and 95%, respectively) were also able to identify 75% of organs compared with SI (27% and 21%, respectively). Both students and veterinarians uniformly provided favorable feedback for LG in teaching rectal palpation skills. CONCLUSION: The LG method of equine rectal examination instruction resulted in improved learning for identification of several key abdominal organs compared with SI.

Effects of clopidogrel on horses with experimentally induced endotoxemia.

OBJECTIVE: To evaluate the effects of clopidogrel on clinical and clinicopathologic variables in healthy horses with experimentally induced endotoxemia. ANIMALS: 12 adult mares. Procedures-Horses were assigned with a randomization procedure to receive clopidogrel (4 mg/kg, once, then 2 mg/kg, q 24 h; n = 6) or a placebo (6) through a nasogastric tube. After 72 hours of treatment, horses received lipopolysaccharide (LPS; 30 ng/kg, IV). Heart rate, respiratory rate, rectal temperature, CBC variables, plasma fibrinogen concentration, serum tumor necrosis factor-α concentration, plasma von Willebrand factor concentration, and measures of platelet activation (including ADP- and collagen-induced platelet aggregation and closure times, thrombelastography variables, and results of flow cytometric detection of platelet membrane P-selectin, phosphatidylserine, and microparticles) were determined at various times before and after LPS administration by investigators unaware of the treatment groups. Statistical analyses were performed with repeated-measures ANOVA. RESULTS: 4 of 6 clopidogrel-treated horses had significant decreases in ADP-induced platelet aggregation before and after LPS administration. Heart rate increased significantly after LPS administration only for the placebo group. No significant differences were detected between groups for CBC variables, closure time, and plasma concentration of fibrinogen or serum concentration of tumor necrosis factor-α, and no clinically relevant differences were detected for other hemostatic variables. CONCLUSIONS AND CLINICAL RELEVANCE: In this study, administration of LPS did not induce platelet hyperreactivity in horses on the basis of measures of platelet adhesion, aggregation, degranulation, and procoagulant activity. Administration of clopidogrel was associated with variable platelet antiaggregatory activity and attenuated some clinical signs of endotoxemia.

Surgical treatment of 4 horses for cryptorchidism caused by failure of regression of the cranial suspensory ligament of the testis.

OBJECTIVE: To report surgical management of 4 horses with cryptorchidism caused by failure of regression of the cranial suspensory ligament (CSL). STUDY DESIGN: Retrospective case series. ANIMALS: Cryptorchid horses (n = 4). METHODS: Horses with unilateral or bilateral cryptorchidism caused by failure of regression of the CSL were treated by removing the retained testes through a standing laparoscopic approach (2), flank laparotomy (1), or paramedian celiotomy (1). After identification of the retained testis attached to the caudal pole of the kidney by the CSL, the vascular pedicle and ductus deferens were ligated and removed. RESULTS: Two horses had bilateral cryptorchidism and 2 horses had unilateral cryptorchidism. Standing laparoscopic cryptorchidectomy was performed successfully in 2 horses and in 2, the retained testes were removed using a flank or paramedian celiotomy. All testes were located in the dorsal aspect of the abdomen just caudal to the kidney and had a well-developed CSL. All horses recovered successfully from surgery. CONCLUSIONS: Failure of regression of the CSL is an uncommon cause of cryptorchidism in horses; however, affected horses can be treated using surgical approaches that facilitate exploration of the dorsocaudal aspect of the abdomen.

Accumulation of amikacin in synovial fluid after regional limb perfusion of amikacin sulfate alone and in combination with ticarcillin/clavulanate in horses.

OBJECTIVES: To determine the effect of regional limb perfusion (RLP) with amikacin sulfate alone and in combination with ticarcillin/clavulanate on synovial fluid concentration and antimicrobial activity of amikacin. SAMPLE POPULATION: Experimental study. METHODS: RLP with amikacin alone (A; 2.5 g) or amikacin and ticarcillin/clavulanate (AT; 2.5 g amikacin, 7 g ticarcillin/clavulanate) was performed with a tourniquet placed at mid-antebrachium in standing, sedated horses. Perfusate blood was collected immediately after injection and again before tourniquet release. Blood from the jugular vein was collected before tourniquet release. Synovial fluid from the middle carpal joint was collected 0, 30, and 60 minutes after tourniquet release. Amikacin concentration and antimicrobial activity of synovial fluid against Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, and Pseudomonas aeruginosa were determined. RESULTS: There was significantly lower amikacin concentration in the middle carpal joint synovial fluid of group AT compared with group A at 30 minutes (AT = median 4.4 µg/mL, IQR 3.0-11.2 µg/mL; A = 17.5 µg/mL, 6.6-80.1 µg/mL) and 60 minutes (AT = median 4.6 µg/mL, IQR 3.1-8.1 µg/mL; A = 15.0 µg/mL, 6.7-61.7 µg/mL) after tourniquet release. Zones of inhibition for ticarcillin-resistant Klebsiella pneumoniae from group AT were significantly smaller than group A from synovial fluid at 30 and 60 minutes after tourniquet release and in the perfusate serum before tourniquet release. CONCLUSIONS: The combination of amikacin with ticarcillin/clavulanate during RLP resulted in significantly lower amikacin synovial concentration and antimicrobial activity on amikacin susceptible and ticarcillin resistant cultures compared with amikacin alone.

Effects of clopidogrel on the platelet activation response in horses.

OBJECTIVE: To evaluate the platelet activation response before and after treatment with clopidogrel in horses. ANIMALS: 12 healthy adult mares. PROCEDURES: In a masked study, horses (6/group) were randomly allocated to alternately receive placebo or clopidogrel via nasogastric tube at a loading dose of 4 mg/kg followed by 2 mg/kg every 24 hours. Blood samples were collected before and 72 hours after initiation of treatment for ADP- and collagen-induced light transmission aggregometry; determination of closure time in collagen-ADP cartridges; modified thrombelastography for comparison of maximal amplitudes generated by kaolin, reptilase, and reptilase plus ADP activation; and flow cytometric tests to detect platelet fibrinogen binding, P-selectin expression, and phosphatidylserine externalization before and after ex vivo stimulation with thrombin, convulxin, thrombin with convulxin, and calcium ionophore. RESULTS: Clopidogrel administration induced a significant decrease in mean aggregation response to 5 µM and 10 µM ADP stimulation; however, 2 horses had resistance to clopidogrel's inhibitory action. Significant differences after clopidogrel treatment were not found in any other tests of platelet function. CONCLUSIONS AND CLINICAL RELEVANCE: Assays using commercially available reagents were configured to measure different variables of the platelet activation response; however, clopidogrel's platelet inhibitory action was only detected by ADP-induced light transmission aggregometry. Results also suggested that horses, like humans, have interindividual variability in response to clopidogrel that may influence the drug's clinical efficacy as an antiplatelet agent.

Spiral colon impaction in juvenile alpacas: 12 cases (2006-2010).

OBJECTIVE: To describe clinical signs and treatment outcomes for juvenile alpacas with spiral colon impaction (SCI). DESIGN: Retrospective case series. Animals-12 juvenile (< 6 months old) camelids with SCI. PROCEDURES: Crias with SCI were identified by searching the medical records database of the Cornell University Equine and Farm Animal Hospital. A keyword-based search method was used. Inclusion required confirmation of SCI on the basis of surgical or necropsy findings. History, signalment, examination findings, diagnostic test results, medical treatments, and surgical reports as well as short- and long-term outcomes were reviewed. Peritoneal fluid parameters were compared with those of age-matched comparison crias in which SCI was suspected but ruled out at necropsy or exploratory celiotomy. RESULTS: 12 crias with confirmed SCI were identified. Common clinical signs included lethargy and diarrhea. Abdominal distention was observed in 9 crias. In 3 crias, a mass in the region of the spiral colon was palpated. Seven crias underwent peritoneal fluid analysis; compared with age-matched comparison crias, SCI-affected crias had higher peritoneal fluid nucleated cell counts and nucleated cell count-to-total protein concentration ratios. A ventral midline celiotomy was performed in 9 crias; 7 underwent an enterotomy, and 2 underwent transmural infusion of saline (0.9% NaCl) solution with manual breakdown of ingesta; 3 of these crias survived for at least 6 months. CONCLUSIONS AND CLINICAL RELEVANCE: Crias with SCI that were not resolved by medical management had a poor prognosis. During celiotomy, transmural infusion of saline solution with manual breakdown of ingesta provided a less invasive alternative to enterotomy.