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1.
J Vet Intern Med ; 36(2): 812-819, 2022 Mar.
Article En | MEDLINE | ID: mdl-35040515

BACKGROUND: Increased concentration of haptoglobin (Hp) in serum is associated with survival of critically ill humans and horses. High serum activity of liver-derived enzyme is associated with sepsis in children and foals. HYPOTHESIS/OBJECTIVES: Investigate whether admission serum Hp and glutamic dehydrogenase (GLDH) are associated with systemic inflammatory response syndrome (SIRS) and survival of sick calves. ANIMALS: One hundred two calves. METHODS: Retrospective cross-sectional study. Electronic medical records from all calves <30 days of age admitted to a teaching hospital for 8 years were reviewed. The signalment, clinicopathological findings, the presence of SIRS, final diagnosis, hospitalization time and outcome were recorded. A Cox proportional hazard ratio (HzR) were calculated to assess the association between clinicopathological variables and survival to discharge. RESULTS: Serum Hp concentrations were similar between SIRS (0.29 g/L; range, 0.05-3.6) and non-SIRS calves (0.22 g/L; range, 0-4.2; P = .62). GLDH activity was similar between SIRS (12 U/L; range, 1-1025) and non-SIRS calves (9 U/L; range, 2-137; P = .2). Absent suckle reflex (HzR: 6.44, 95% CI: 1.44-28.86), heart rate (HR) < 100 beats per minute (bpm; HzR: 12.2; 95% CI: 2.54-58.62), HR > 140 bpm (HzR: 3.59, 95% CI: 1.05-12.33), neutrophil count <1.7 × 109 /L (HzR: 7.36; 95% CI: 2.03-26.66) and increased gamma-glutamyl transferase activity (every 50-unit, HzR: 1.12; 95% CI: 1.03-1.21) were predictive of nonsurvival. CONCLUSIONS AND CLINICAL IMPORTANCE: The use of Hp and GLDH for prediction of survival in sick calves cannot be recommended at this time.


Haptoglobins , Systemic Inflammatory Response Syndrome , Animals , Animals, Newborn , Cattle , Cross-Sectional Studies , Liver , Retrospective Studies , Systemic Inflammatory Response Syndrome/veterinary , Transferases
2.
Can Vet J ; 62(7): 743-750, 2021 07.
Article En | MEDLINE | ID: mdl-34219784

The objective of this study was to describe the clinical findings, medical management, and outcomes of horses with sabulous cystitis, and to describe a high flow bladder lavage procedure in horses that are standing or under general anesthesia. The medical records of 13 horses diagnosed with sabulous cystitis via cystoscopy between 2013 and 2020 were reviewed. Geldings (92%) and Warmbloods (46%) were overrepresented. The most common presenting complaint was urinary incontinence (69%). Complete blood cell count, serum biochemistry profile and urine cytology results were non-specific. Six (46%) horses had various degrees of erosion, ulceration, and hemorrhage of the bladder mucosa. All horses were treated with bladder lavage either with standing sedation (n = 12) or general anesthesia (n = 2), as well as antimicrobials (54%), anti-inflammatory drugs (62%), bethanechol (15%), and phenazopyridine (15%). Most horses (85%) were discharged from the hospital, but only a small percentage (23%) was reported as having no urinary abnormalities on follow-up communication. Key clinical message: Copious bladder lavage with a high flow rate system could mitigate the acute clinical signs and improve the quality of life of horses with sabulous cystitis, but the prognosis for return to previous level of athletic performance and long-term survival is guarded.


Cystite sableuse chez le cheval: 13 cas (2013­2020). L'objectif de cette étude était de décrire les résultats cliniques, la prise en charge médicale et les résultats des chevaux atteints de cystite sableuse, et de décrire une procédure de lavage de la vessie à haut débit chez les chevaux debout ou sous anesthésie générale. Les dossiers médicaux de 13 chevaux diagnostiqués avec une cystite sableuse par cystoscopie entre 2013 et 2020 ont été revus. Les hongres (92 %) et les Warmbloods (46 %) étaient surreprésentés. La plainte la plus fréquente était l'incontinence urinaire (69 %). Un hémogramme complet, le profil biochimique sérique et les résultats de cytologie urinaire n'étaient pas spécifiques. Six chevaux (46 %) présentaient divers degrés d'érosion, d'ulcération et d'hémorragie de la muqueuse de la vessie. Tous les chevaux ont été traités par lavage de la vessie soit avec sédation debout (n = 12) ou anesthésie générale (n = 2), ainsi que des antimicrobiens (54 %), des anti-inflammatoires (62 %), du béthanéchol (15 %) et de la phénazopyridine (15 %). La plupart des chevaux (85 %) sont sortis de l'hôpital, mais seul un petit pourcentage (23 %) a été signalé comme n'ayant aucune anomalie urinaire lors de la communication de suivi.Message clinique clé:Un lavage vésical abondant avec un système à débit élevé pourrait atténuer les signes cliniques aigus et améliorer la qualité de vie des chevaux atteints de cystite sableuse, mais le pronostic du retour au niveau antérieur de performance athlétique et de survie à long terme est réservé.(Traduit par Dr Serge Messier).


Cystitis , Horse Diseases , Urinary Incontinence , Animals , Cystitis/veterinary , Horse Diseases/therapy , Horses , Male , Quality of Life , Urinary Incontinence/veterinary
3.
J Equine Vet Sci ; 92: 103176, 2020 09.
Article En | MEDLINE | ID: mdl-32797798

The accuracy of using radiographs to diagnose cervical facet osteoarthritis (CFA) in horses is undetermined. Further investigation is required to determine the clinical significance of radiographic evidence of CFA, the prevalence of radiographic changes in horses without clinical signs, and the long-term efficacy of intra-articular CFA treatment. The objectives of this study is to compare degenerative changes of the cervical facet joints of the cervical vertebrae on radiographs of horses with clinical signs of CFA with healthy cohort-matched horses, to compare clinical findings between groups, and to obtain follow-up information on the long-term outcome in treated horses. This is a retrospective case-control cohort-matched comparison study of horses treated for cervical facet disease versus horses with no clinical signs of cervical facet disease. Horses diagnosed with CFA and treated with intra-articular injection of corticosteroids were included. Follow-up information on recovery from treatment was obtained via telephone survey of owners/trainers. Healthy horses with no clinical signs of CFA were matched to treated horses by breed, sex, age, and sport as the control group. Two blinded radiologists reviewed cervical spine radiographs for each horse and recorded CFA score and intravertebral/intervertebral measurements. Clinical and radiographic parameters were compared between treatment and control groups. There was a significant difference in CFA grades for C5-6 and C6-7 between horses with presence of clinical signs and healthy horses. However, interobserver agreement between radiologists for grading CFA was moderate and only 56% of values were identical for both observers. Atrophy of the neck was present on clinical examination in most cases in the treatment group. Dressage horses were overrepresented. Overall, 64% of horses returned to their previous level of performance after treatment. Clinical examination data collected for the treatment group were retrospective and were obtained by different clinicians. Eight owners/trainers were not able to be reached for the survey. There was a significant difference in CFA grades for C5-6 and C6-7 between horses with presence of clinical signs and healthy horses. Despite these statistical differences, the clinical diagnosis of CFA based on radiographic grading alone is questionable because of the lack of agreement between the radiologists. To strengthen the diagnosis, clinical signs of facet disease, in particular atrophy of the neck muscles, need to be present to make this diagnosis. Intra-articular corticosteroid injection was effective at allowing most treated horses to return to athletic use..


Horse Diseases , Animals , Case-Control Studies , Cervical Vertebrae/diagnostic imaging , Horse Diseases/diagnosis , Horses , Radiography , Retrospective Studies
4.
Can Vet J ; 60(7): 744-748, 2019 Jul.
Article En | MEDLINE | ID: mdl-31281192

The standard placement of a subpalpebral lavage system may not be feasible in some horses with eyelid disease. We describe placement of a commercially available, indwelling nasolacrimal lavage system that circumvents eyelid perforation. This novel approach provided for effective delivery of drugs to 1 horse with periocular and corneal disease.


Placement nasolacrymal normograde d'un système de lavage oculaire pour le traitement des maladies de l'oeil des équidés. Le placement standard d'un système de lavage subpalpébral peut ne pas être réalisable chez certains chevaux atteints de maladies oculaires. Nous décrivons le placement d'un système de lavage nasolacrymal à demeure qui évite la perforation de la paupière. Cette approche innovatrice a permis d'administrer des médicaments à un cheval atteint de maladie périoculaire et cornéenne.(Traduit par Isabelle Vallières).


Corneal Diseases/veterinary , Eye Diseases/veterinary , Eyelid Diseases/veterinary , Horse Diseases , Animals , Horses , Therapeutic Irrigation/veterinary
5.
J Parasitol ; 105(1): 29-40, 2019 02.
Article En | MEDLINE | ID: mdl-30807709

Species in the genus Klossiella Smith and Johnson, 1902 are unique among the suborder Adeleorina because they are monoxenous in mammals exclusively, whereas all other reported members of the Adeleorina use invertebrates as definitive hosts. Unlike other coccidia, all members of the Adeleorina undergo syzygy, the association of microgamonts and macrogamonts before maturation to gametes and syngamy. After fertilization, many members of the Adeleorina produce thin-walled polysporocystic oocysts. Despite being biologically similar to other members of the Adeleorina, the phylogenetic placement of the genus Klossiella has been questioned based on its unique host affinity. In the present study, 2 cases of Klossiella equi were reported from the kidneys of horses in Ontario. Details of the life cycle as well as mitochondrial and nuclear 18S ribosomal DNA ( 18S rDNA) sequences were analyzed to provide both morphological and molecular evidence for the phylogenetic placement of K. equi. Initially, various stages of the life cycle were identified in histological slides prepared from the kidney tissue, and DNA was isolated from the infected tissue. Polymerase chain reaction and Sanger sequencing were used to generate a complete mitochondrial genome sequence (6,569 bp) and a partial 18S rDNA sequence (1,443 bp). The K. equi 18S rDNA sequence was aligned with various publicly available apicomplexan 18S rDNA sequences. This alignment was used to generate a phylogenetic tree based on Bayesian inference. Multiple K. equi stages were identified including meronts, microgamonts, and macrogamonts associating in syzygy as well as thin-walled oocysts in various stages of sporogonic development. The 18S rDNA sequence of K. equi positioned within the monophyletic Adeleorina clade. The mitochondrial genome of K. equi contained 3 coding sequences for cytochrome c oxidase I, cytochrome c oxidase III, and cytochrome b as well as various fragmented ribosomal sequences. These components were arranged in a unique order that has not been observed in other apicomplexan mitochondrial genomes sequenced to date. Overall, it was concluded that there were sufficient morphological and molecular data to confirm the placement of K. equi and the genus Klossiella among the Adeleorina. The biological and molecular data obtained from these cases may assist with future studies evaluating the prevalence and life history of this seemingly underreported parasite and better define the impact of K. equi on the health of domestic and wild equids.


Coccidiosis/veterinary , Eucoccidiida/classification , Horse Diseases/parasitology , Kidney Diseases/veterinary , Animals , Coccidiosis/epidemiology , Coccidiosis/parasitology , DNA, Ribosomal/chemistry , Electron Transport Complex IV/genetics , Eucoccidiida/genetics , Eucoccidiida/growth & development , Female , Genotyping Techniques/veterinary , Horse Diseases/epidemiology , Horses , Kidney/parasitology , Kidney Diseases/epidemiology , Kidney Diseases/parasitology , Life Cycle Stages , Male , Mitochondria/genetics , Multilocus Sequence Typing/veterinary , Ontario/epidemiology , Phylogeny , RNA, Ribosomal, 18S/genetics
6.
PLoS Genet ; 10(10): e1004712, 2014 Oct.
Article En | MEDLINE | ID: mdl-25340504

We constructed a 400K WG tiling oligoarray for the horse and applied it for the discovery of copy number variations (CNVs) in 38 normal horses of 16 diverse breeds, and the Przewalski horse. Probes on the array represented 18,763 autosomal and X-linked genes, and intergenic, sub-telomeric and chrY sequences. We identified 258 CNV regions (CNVRs) across all autosomes, chrX and chrUn, but not in chrY. CNVs comprised 1.3% of the horse genome with chr12 being most enriched. American Miniature horses had the highest and American Quarter Horses the lowest number of CNVs in relation to Thoroughbred reference. The Przewalski horse was similar to native ponies and draft breeds. The majority of CNVRs involved genes, while 20% were located in intergenic regions. Similar to previous studies in horses and other mammals, molecular functions of CNV-associated genes were predominantly in sensory perception, immunity and reproduction. The findings were integrated with previous studies to generate a composite genome-wide dataset of 1476 CNVRs. Of these, 301 CNVRs were shared between studies, while 1174 were novel and require further validation. Integrated data revealed that to date, 41 out of over 400 breeds of the domestic horse have been analyzed for CNVs, of which 11 new breeds were added in this study. Finally, the composite CNV dataset was applied in a pilot study for the discovery of CNVs in 6 horses with XY disorders of sexual development. A homozygous deletion involving AKR1C gene cluster in chr29 in two affected horses was considered possibly causative because of the known role of AKR1C genes in testicular androgen synthesis and sexual development. While the findings improve and integrate the knowledge of CNVs in horses, they also show that for effective discovery of variants of biomedical importance, more breeds and individuals need to be analyzed using comparable methodological approaches.


20-Hydroxysteroid Dehydrogenases/genetics , DNA Copy Number Variations/genetics , Genome , Horses/genetics , Animals , Base Sequence , Breeding , Comparative Genomic Hybridization , Humans
7.
Can Vet J ; 53(6): 670-2, 2012 Jun.
Article En | MEDLINE | ID: mdl-23204589

A 6-hour-old alpaca was presented for evaluation of respiratory difficulty. As part of routine surveillance, methicillin-resistant Staphylococcus aureus (MRSA) was identified from a nasal swab taken upon admission to the hospital. No signs of MRSA infection were noted. The MRSA strain recovered was a human epidemic clone that has been associated with horses. Methicillin-resistant S. aureus colonization can occur in camelids, and the potential animal and public health risks require consideration.


Camelids, New World/microbiology , Infectious Disease Transmission, Vertical/veterinary , Methicillin-Resistant Staphylococcus aureus , Pregnancy Complications, Infectious/veterinary , Staphylococcal Infections/veterinary , Animals , Animals, Newborn , Fatal Outcome , Female , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Pregnancy , Staphylococcal Infections/transmission
8.
Can Vet J ; 53(1): 83-5, 2012 Jan.
Article En | MEDLINE | ID: mdl-22753970

An 82-cm fragment of nasogastric tube was removed from the stomach of an adult horse under standing sedation by use of an endoscope and electrocautery snare. This is the first report of successful non-surgical removal of a nasogastric tube fragment from the stomach of a horse.


Foreign Bodies/veterinary , Gastroscopy/veterinary , Horse Diseases/surgery , Intubation, Gastrointestinal/veterinary , Animals , Electrocoagulation/veterinary , Female , Foreign Bodies/surgery , Gastroscopy/methods , Horses , Intubation, Gastrointestinal/adverse effects , Polyurethanes , Stomach , Treatment Outcome
9.
Am J Vet Res ; 72(9): 1193-203, 2011 Sep.
Article En | MEDLINE | ID: mdl-21879977

OBJECTIVE: To evaluate influence of electrode position on cardioversion energy (CE; energy delivered in the shock at which cardioversion was achieved) during transvenous electrical cardioversion (TVEC) in horses with atrial fibrillation. ANIMALS: 37 horses with atrial fibrillation (41 cardioversion events). PROCEDURES: Records were reviewed to identify horses that underwent TVEC for treatment of atrial fibrillation. Signalment and CE were recorded. Electrode positions in the right atrium and pulmonary artery were identified on intraoperative radiographs. An orthogonal coordinate space was created, and electrode y- and z-axis coordinates and shadow lengths were determined. Trigonometric modeling was used to estimate x-axis electrode positions that resulted in observed shadows. Postmortem casts of catheterized horses were used to assess electrode paths and anatomic relationships. Model assumptions were tested by use of these and a theoretical data set. Relationships between signalment, electrode position, and CE were assessed via multivariate analysis. RESULTS: Sex and y-axis differences between electrode positions were significant predictors of CE. Population stratification based on examination of residuals improved model strength; populations differed in z-axis variables and in CE. Decreasing distance between electrodes and pulmonary artery electrode positions ventral to the right atrium were associated with increased CE. Agreement between estimated and actual x-axis coordinates was poor. CONCLUSIONS AND CLINICAL RELEVANCE: Optimal electrode positioning can reduce the energy requirement for successful TVEC and may eventually support application of TVEC under short-term IV anesthesia and potentially increase chances of treatment response. Further investigation into these relationships is warranted.


Atrial Fibrillation/veterinary , Cardiac Catheterization/veterinary , Electric Countershock/methods , Electrodes/veterinary , Heart Atria , Animals , Atrial Fibrillation/physiopathology , Atrial Fibrillation/therapy , Cardiac Catheterization/instrumentation , Electric Countershock/instrumentation , Electric Countershock/veterinary , Female , Heart Atria/physiopathology , Horse Diseases/physiopathology , Horse Diseases/therapy , Horses , Male , Models, Biological , Pulmonary Artery/physiopathology , Regression Analysis , Retrospective Studies , Sex Factors
10.
J Am Vet Med Assoc ; 231(8): 1225-30, 2007 Oct 15.
Article En | MEDLINE | ID: mdl-17937553

OBJECTIVE: To describe management of anesthesia for transvenous electrical cardioversion (TVEC) in horses and report perianesthetic complications. DESIGN: Retrospective case series. ANIMALS: 62 horses with atrial fibrillation and without underlying cardiac disease and 60 horses without atrial fibrillation. PROCEDURES: Medical records of horses with atrial fibrillation anesthetized for TVEC were reviewed, as were records of horses without atrial fibrillation anesthetized for magnetic resonance imaging (MRI). The TVEC group horses were compared with MRI group horses for incidence of intraoperative bradycardia and use of inotropic drugs. Data obtained included patient signalment, weight, duration of anesthesia, heart rate and arterial blood pressure during anesthesia, anesthetic drugs administered, mode of ventilation, perioperative complications, and quality of recovery. RESULTS: The TVEC group horses were > 1 year of age and were predominantly Standardbreds. The TVEC group horses underwent a total of 76 anesthetic episodes. For 40 (52.6%) anesthetic episodes, horses received xylazine only for premedication, and for 26 (34.2%) anesthetic episodes, horses received xylazine and butorphanol. Induction of anesthesia consisted of ketamine administration in various combinations with diazepam and guaifenesin for 74 (97.4%) anesthetic episodes and ketamine alone for 2 (2.6%). Bradycardia in horses was encountered during 15 of 76 (19.7%) anesthetic episodes. Minor signs of possible postanesthetic myopathy occurred following 6 (7.9%) anesthetic episodes. No significant difference was found between TVEC and MRI group horses regarding incidence of bradycardia and inotropic drug administration. CONCLUSIONS AND CLINICAL RELEVANCE: Short-duration anesthesia for TVEC of atrial fibrillation in horses without underlying cardiac disease was a safe procedure.


Anesthesia/veterinary , Atrial Fibrillation/veterinary , Electric Countershock/veterinary , Horse Diseases/therapy , Age Factors , Anesthesia/adverse effects , Animals , Atrial Fibrillation/therapy , Electric Countershock/methods , Electrocardiography/veterinary , Female , Horses , Magnetic Resonance Imaging/veterinary , Male , Retrospective Studies , Safety , Treatment Outcome
11.
Cloning Stem Cells ; 9(1): 118-29, 2007.
Article En | MEDLINE | ID: mdl-17386019

Animal models have played an important part in establishing our knowledge base on reproduction, development, and the occurrence and impact of chromosome abnormalities. Translocations involving the X chromosome and an autosome are unique in that they elicit sex-dependent infertility, with male carriers rendered sterile by synaptic anomalies during meiosis, whereas female carriers conceive but repeatedly abort. Until now the limited access to relevant fetal oocytes has precluded direct study of meiotic events in female carriers. Because somatic cell nuclear transfer (SCNT) circumvents meiotic problems associated with fertility disturbances in translocation carriers, we used SCNT to generate embryos, fetuses, and calves from a cell line derived from a deceased subfertile X-autosome translocation carrier cow to study the meiotic configurations in carrier oocytes. Data from 33 replicates involving 2470 oocyte-donor-cell complexes were assessed for blastocyst development and of these, 42 blastocysts were transferred to 21 recipients. Fourteen pregnancies were detected on day 35 of gestation. One of these was sacrificed for ovary retrieval on day 94 and three went to term. Features of oocytes from the fetal ovary and from the newborn ovaries were examined. Of the pachytene spreads analyzed, 16%, 82%, and 1.5% exhibited quadrivalent, trivalent/univalent, and bivalent/univalent/univalent structures, respectively, whereas among the diakinesis/metaphase I spreads, 16% ring, 75% chain, and 8.3% bivalent/bivalent configurations were noted, suggesting that the low fertility among female carriers may be related to synaptic errors in a predominant proportion of oocytes. Our results indicate that fibroblasts carrying the X-autosome translocation can be used for SCNT to produce embryos, fetuses, and newborn clones to study such basic aspects of development as meiosis and to generate carriers that cannot easily be reproduced by conventional breeding.


Cattle Diseases , Genetic Diseases, X-Linked , Infertility, Female , Meiosis , Models, Biological , Nuclear Transfer Techniques , Sex Chromosome Aberrations , Animals , Cattle , Cattle Diseases/genetics , Female , Genetic Diseases, X-Linked/genetics , Infertility, Female/genetics , Infertility, Female/veterinary , Pregnancy , Sex Chromosome Aberrations/veterinary
12.
J Am Vet Med Assoc ; 229(1): 104-10, 2006 Jul 01.
Article En | MEDLINE | ID: mdl-16817724

CASE DESCRIPTION: 4 racehorses were examined because of markedly abnormal behavior following administration of fluphenazine decanoate. CLINICAL FINDINGS: Clinical signs included restlessness, agitation, profuse sweating, hypermetria, aimless circling, intense pawing and striking with the thoracic limbs, and rhythmic swinging of the head and neck alternating with episodes of severe stupor. Fluphenazine was detected in serum or plasma from all 4 horses. The dose of fluphenazine decanoate administered to 3 of the 4 horses was within the range (25 to 50 mg) routinely administered to adult humans. TREATMENT AND OUTCOME: In 2 horses, there was no response to IV administration of diphenhydramine hydrochloride, but the abnormal behavior in these 2 horses appeared to resolve following administration of benztropine mesylate, and both horses returned to racing. The other 2 horses responded to diphenhydramine administration. One returned to racing. The other was euthanized because of severe neurologic signs, respiratory failure, and acute renal failure. CLINICAL RELEVANCE: Findings indicate that adverse extrapyramidal effects may occur in horses given fluphenazine decanoate. These effects appear to be unpredictable and may be severe and life threatening. Use of fluphenazine decanoate as an anxiolytic in performance horses is not permitted in many racing and horse show jurisdictions, and analytic procedures are now available to detect the presence of fluphenazine in serum or plasma.


Antipsychotic Agents/adverse effects , Extrapyramidal Tracts/drug effects , Fluphenazine/analogs & derivatives , Horse Diseases/chemically induced , Nervous System Diseases/veterinary , Animals , Antipsychotic Agents/therapeutic use , Behavior, Animal/drug effects , Benztropine/therapeutic use , Diphenhydramine/therapeutic use , Fatal Outcome , Female , Fluphenazine/adverse effects , Fluphenazine/therapeutic use , Horses , Male , Nervous System Diseases/chemically induced , Treatment Outcome
13.
Can Vet J ; 47(1): 65-6, 2006 Jan.
Article En | MEDLINE | ID: mdl-16536231

An inflammatory aural polyp was identified in a 1-year-old standardbred filly, which presented with otorrhea and head rubbing. The polyp was removed by traction-avulsion, and the filly showed no subsequent signs of otorrhea. Aural polyps have not been reported in horses, but they are commonly seen in companion animals and humans.


Ear Diseases/veterinary , Horse Diseases/diagnosis , Polyps/veterinary , Animals , Ear Diseases/diagnosis , Ear Diseases/pathology , Ear Diseases/surgery , Female , Horse Diseases/pathology , Horse Diseases/surgery , Horses , Inflammation/veterinary , Polyps/diagnosis , Polyps/pathology , Polyps/surgery , Treatment Outcome
14.
J Vet Intern Med ; 19(5): 695-702, 2005.
Article En | MEDLINE | ID: mdl-16231714

Conventional treatment of equine atrial fibrillation (AF) involves administration of quinidine salts. Most uncomplicated cases respond to treatment, but pharmacologic cardioversion involves a range of adverse effects, and some horses are unable to tolerate medication. A study was undertaken to develop transvenous electrical cardioversion (TVEC) as an alternative treatment. Safety issues and catheter placement techniques with catheter-integrated cardioversion electrodes were investigated, and responses to shock application were evaluated. After the premortem catheterization of elective-euthanasia horses, no tissue abnormalities were detected at postmortem examination. To evaluate the response to the application of shocks and appropriate electrode positions, an electrical cardioversion of research horses in chronic AF was then attempted. After catheterization of the right atrium (RA) and pulmonary artery through the right jugular vein, horses were placed under general anesthesia. Biphasic, truncated exponential shock waves were delivered at incremental energies until cardioversion was achieved or until a maximum energy of 300 J was reached. Five treatment events were applied to 3 horses, with cardioversion achieved in one of the treatment events. No adverse effects of cardioversion attempts or general anesthesia were observed. The procedure was then applied to 8 client-owned horses, with cardioversion achieved in 7. No adverse responses to appropriately delivered shocks were observed. No antiarrhythmic medications were administered to any horse at any stage. Catheter design and placement technique evolved throughout the study, with combined ultrasonography and pressure guidance proving most effective in achieving appropriate electrode placement. Results suggest TVEC, as applied in the present study, is a safe, effective, and realistic therapeutic option for equine AF.


Atrial Fibrillation/veterinary , Cardiac Catheterization/veterinary , Electric Countershock/veterinary , Horse Diseases/therapy , Anesthesia, General/adverse effects , Anesthesia, General/methods , Anesthesia, General/veterinary , Animals , Atrial Fibrillation/therapy , Electric Countershock/adverse effects , Electric Countershock/methods , Electrocardiography/veterinary , Electrodes/veterinary , Horses , Safety , Treatment Outcome
15.
J Vet Cardiol ; 7(2): 109-19, 2005 Nov.
Article En | MEDLINE | ID: mdl-19083326

Electrical cardioversion of atrial fibrillation is a well-established technique for restoration of sinus rhythm in humans. While transthoracic cardioversion is more commonly used, transvenous electrical cardioversion (TVEC) has been reported as having higher efficacy at substantially lower energy levels. In horses, treatment of atrial fibrillation has essentially been limited to the administration of quinidine salts either orally or intravenously. TVEC provides an alternative to quinidine salts, especially for those animals in which quinidine is neither effective nor tolerated. The present report details this technique in horses, discusses possible complications of the procedure, and provides guidance for successful outcome. Still and video images are used to illustrate details with regard to TVEC techniques in horses. Please view supplemental material for the videos.

17.
Can Vet J ; 44(6): 469-73, 2003 Jun.
Article En | MEDLINE | ID: mdl-12839240

West Nile virus encephalomyelitis was diagnosed in 28 horses presented to the Ontario Veterinary College Veterinary Teaching Hospital between August 20 and October 15, 2002. The age range of affected horses was 5 months to 20 years (mean 6.9 years, median 6 years). Clinical signs were highly variable. Duration of hospitalization ranged from < 1 to 12 days (mean 5 days, median 5.4 days). Overall, 16 of the 28 (57%) horses were discharged and, of the 14 from which follow-up information was available, 13 (93%) were reported to be clinically normal 4 to 6 weeks following discharge, while the other horse had markedly improved. This pathogen is emerging as an important cause of neurological disease in Canada.


Disease Outbreaks/veterinary , Encephalomyelitis/veterinary , Horse Diseases/diagnosis , West Nile Fever/veterinary , Animals , Diagnosis, Differential , Encephalomyelitis/diagnosis , Encephalomyelitis/epidemiology , Female , Horse Diseases/epidemiology , Horse Diseases/virology , Horses , Male , Ontario/epidemiology , West Nile Fever/diagnosis , West Nile Fever/epidemiology , West Nile virus/pathogenicity
18.
Am J Vet Res ; 63(11): 1545-50, 2002 Nov.
Article En | MEDLINE | ID: mdl-12428665

OBJECTIVE: To identify and characterize motilin receptors in equine duodenum, jejunum, cecum, and large colon and to determine whether erythromycin lactobionate competes with porcine motilin for binding to these receptors. SAMPLE POPULATION: Specimens of various segments of the intestinal tracts of 4 adult horses euthanatized for reasons unrelated to gastrointestinal tract disease. PROCEDURE: Cellular membranes were prepared from smooth muscle tissues of the duodenum, jejunum, pelvic flexure, and cecum. Affinity and distribution of motilin binding on membrane preparations were determined by use of 125I-labeled synthetic porcine motilin. Displacement studies were used to investigate competition between 125I-labeled synthetic porcine motilin and erythromycin lactobionate for binding to motilin receptors in various segments of bowel. RESULTS: Affinity of 125I-labeled synthetic porcine motilin for the equine motilin receptor was estimated to be 6.1nM. A significantly higher number of motilin receptors was found in the duodenum than in the pelvic flexure and cecum. The jejunum had a significantly higher number of motilin receptors than the cecum. Erythromycin lactobionate displacement of 125I-labeled porcine motilin from the equine motilin receptor did not differ significantly among various segments of bowel. CONCLUSIONS AND CLINICAL RELEVANCE: Motilin receptors were found in the duodenum, jejunum, pelvic flexure, and cecum of horses. The highest number of motilin receptors was in the duodenum, and it decreased in more distal segments of bowel. Erythromycin lactobionate competed with motilin binding in the equine gastrointestinal tract. This suggests that 1 of the prokinetic actions of erythromycin in horses is likely to be secondary to binding on motilin receptors.


Digestive System/metabolism , Erythromycin/analogs & derivatives , Erythromycin/metabolism , Gastrointestinal Agents/metabolism , Horses/metabolism , Motilin/metabolism , Muscle, Smooth/physiology , Animals , Binding, Competitive , Erythromycin/pharmacology , Gastrointestinal Agents/pharmacology , In Vitro Techniques , Receptors, Gastrointestinal Hormone/metabolism , Receptors, Neuropeptide/metabolism
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