Pharmacology in horses involves the study and application of drugs and medications to diagnose, treat, and prevent diseases and conditions in equine species. This field encompasses the understanding of pharmacokinetics and pharmacodynamics specific to horses, including how drugs are absorbed, distributed, metabolized, and excreted by the equine body. Commonly studied pharmacological agents in horses include non-steroidal anti-inflammatory drugs (NSAIDs), antibiotics, sedatives, and anthelmintics. Research in equine pharmacology focuses on determining appropriate dosages, understanding drug interactions, and minimizing adverse effects. This page compiles peer-reviewed research studies and scholarly articles that investigate the efficacy, safety, and regulatory aspects of pharmacological interventions in equine veterinary practice.
Kuroda T, Knych HK, Noble GK, Minamijima Y, Leung GN, Nomura M, Mizobe F, Ishikawa Y, Kusano K, Toutain PL.Flunixin meglumine is widely used to manage pain and inflammation in horses, and its regulation requires robust pharmacokinetic analysis for harmonization. In this study, we conducted a meta-analysis of flunixin disposition using plasma and urine concentration data from 65 horses across four countries to robustly estimate pharmacokinetic parameters in setting screening limits (SLs) for controlling medications in horses. A population (POP) model was developed using nonlinear mixed-effects model analysis. The irrelevant plasma concentration (IPC) and irrelevant urine concentration (IUC) were det...
Thorn CA, Wilson DV, Wang S, Horne WA.Standing sedation is a safe and cost-effective alternative to general anesthesia in horses, but challenges include achieving adequate drug effect to block the stimulus response without inducing ataxia or recumbency. A benefit of midazolam has been reported in equine dental procedures. Seeking synergy, a combination of lower doses of several pharmacologic agents, including midazolam, may improve the quality of sedation while minimizing adverse effects. Bispectral index (BIS) correlates with sedation scores in human ICU patients, but the correlation between sedation scores and BIS has not been e...
El-Ghaly W, El Kamli T, Zaari Lambarki L, El Hamdani M, Lahkak FE, Benmoussa A, Balouch L, Bakkali F, Saffaj T, Jhilal F.The quality of quantitative results in bioanalysis requires not only a validated analytical method but also a rigorous estimation of measurement uncertainty. This study examines the challenges associated with the implementation of two distinct approaches in equine anti-doping control for the assessment of uncertainty associated with an ultra-high-performance liquid chromatography-high resolution mass spectrometry quantitative method for caffeine and lidocaine in horse urine. The bottom-up approach, based on the ISO Guide to the Expression of Uncertainty in Measurement (ISO GUM), was compared t...
Klinck M, Lovett A, Sykes B.Equine gastric ulcer syndrome (EGUS) refers to mucosal gastric disease in horses, including equine squamous gastric disease (ESGD) and equine glandular gastric disease (EGGD), which present as two distinct disease entities differing in pathophysiology and approach to disease management. Both diseases are a source of pain in affected horses, partly explaining why EGUS continues to receive substantial attention in the equine medical, welfare and equitation research sectors. There is a complex interplay between EGUS and a variety of physical and psychological stressors. Horses with EGUS are often...
Dufourni A, Demeyere M, Vernemmen I, Van Steenkiste G, Verhaeghe LM, van Loon G, Decloedt A.Administration of N-butylscopolammonium bromide (NBB) with metamizol sodium (NBBM) causes tachycardia and hypertension, and has been associated with accentuated cardiac murmurs. Objective: To evaluate the effect of a pharmacological challenge using NBBM on valvular regurgitation and cardiac murmurs in horses with aortic (AR) and mitral valve regurgitation (MR). Methods: Twenty Warmblood horses with AR and 20 with MR. Methods: Cardiac auscultation and two-dimensional (2D), M-mode, color flow, pulsed wave Doppler flow, and tissue Doppler echocardiography were performed with simultaneous ECG reco...
Thane K, Voth R, Klee R, Warnken T, Chukwu V, Frank N.Sodium-glucose cotransporter-2 inhibitors (SGLT2i) are promising treatments to manage hyperinsulinemia in horses with insulin dysregulation (ID). Objective: The SGLT2i velagliflozin decreases insulin concentration in horses with ID. Methods: Privately-owned adult horses (n = 37) with laboratory-confirmed ID (low-dose oral sugar test insulin concentration > 75 μIU/mL). Methods: Double-blind randomized placebo-controlled trial. Horses received placebo (n = 19) or velagliflozin 0.3 mg/kg PO q24h (n = 18) for 20 weeks (Study Period 1, SP1) immediately followed by a 20-week ope...
Velarde PS, Cummings KJ, LaPointe C, Perkins GA.To assess the use of systemic antimicrobial agents in equine patients and identify areas where their use could be reduced. Unassigned: A retrospective study evaluating the electronic medical records for all equine visits in which systemic antimicrobials were given at a veterinary teaching hospital for 1 year (2021). Negative binomial regression analysis was used to evaluate factors associated with antimicrobial prescription rate. Unassigned: Systemic antimicrobials were prescribed for 33.5% (543 of 1,622) of equine visits. For most visits (89.1%), ≤ 3 antimicrobials were given. The antimicro...
Gomez DE, Johnson JP.Antimicrobial drug therapy in horses can lead to adverse effects across multiple body systems, with specific age groups, such as foals, at particular risk. Certain antimicrobial drugs, such as penicillins, aminoglycosides, macrolides, tetracyclines, and trimethoprim-sulfonamide combinations, are commonly implicated. This review explores the mechanisms behind these adverse reactions, emphasizing the importance of judicious antimicrobial drug use. This review also underscores the need for a centralized pharmacovigilance system to improve drug safety and adverse event reporting for veterinary med...
Bungărdean D, Pall E, Daradics Z, Popescu M, Tripon MA, Lupșan AF, Crecan CM, Morar IA, Nicolescu A, Bora FD, Marcus I.Musculoskeletal disorders are a major cause of lameness in horses, often necessitating innovative regenerative strategies to restore joint function and improve quality of life. This study investigated the effects of platelet-rich plasma (PRP), ozonized PRP, hyaluronic acid, paracetamol, and polyacrylamide hydrogel (NOLTREX) on the behavior of mesenchymal stem cells (MSCs) derived from equine synovial fluid. Synovial fluid samples were collected under strict cytological criteria to ensure viability, followed by in vitro expansion and phenotypic characterization of MSCs. Cultures were supplement...
Köhne M, Hüsch R, Peh E, Hirnet J, Tönissen A, Müsken M, Plötz M, Kittler S, Sieme H.Bacterial infections of the genital tract are a severe problem in equine reproduction. Biofilms produced by Klebsiella (K.) pneumoniae and Pseudomonas (P.) aeruginosa present further concerns in such cases as they can limit the success of antibiotic treatments. Alternative treatment approaches are urgently needed for treating bacterial equine genital tract infections and thus, reduce antibiotic use. The present study reports on the bactericidal efficacy of both, novel K. pneumoniae- and P. aeruginosa-specific phages, in a biofilm model and in conjunction with antibiotic drugs as tested in vitr...
Wilson KE, Davis JL.Adverse drug events (ADEs) are any harms caused by medical interventions used for treatment, prevention, or diagnosis. These events can happen due to human error or as unintended, harmful reactions to drugs when given at normal therapeutic doses. This review focuses on common ADEs associated with drugs frequently used in equine practice. Recognizing and understanding the manifestations of ADEs can help with early detection and more effective management, ultimately leading to better outcomes for equine patients. Additionally, knowledge of the potential harmful effects of drugs also aids in appr...
Cloteau C, Delcourt V, Loup B, Chabot B, Pescher M, Susdorf E, Kaabia Z, Garcia P, Popot MA, Le Bizec B, Dervilly G, Bailly-Chouriberry L.Biomarker identification by mass spectrometry represents a key step in the workflow of nontargeted metabolomic studies. Given the complexity of the data, this step, which must be carried out by a trained specialist, is time-consuming, and the biomarkers discovered are not always identified. While this stage is not an obstacle to the development of new screening and classification tools, it is nonetheless crucial to a better understanding of the results obtained. For this reason, the aim of this study was to perform structural elucidation of candidate biomarkers, which had previously been displ...
Olakojo TA, Akinniyi OO, Dansu EO, Adeoye AO, Adah O, Nwufoh OC, Adeoye BO, Oridupa OA, Saba AB.Dexamethasone is a common drug used in equine medicine, but when administered inappropriately, it can lead to serious health complications. There is a dearth of data on horse caregivers' knowledge, attitudes, and practices regarding dexamethasone use in Nigeria. Understanding current dexamethasone usage patterns is necessary for developing educational interventions which will then improve equine welfare. This study aimed to assess the knowledge, attitudes, and practices (KAP) of horse caregivers regarding dexamethasone use in Ibadan, Nigeria. A cross-sectional study was conducted amongst a tot...
Dubey S, Lomnicka I, Waller P, Vora D, Dirikolu L.The complexity of the drug market and the constant updating of drugs have been challenging issues for drug regulatory authorities. In this manuscript, a high-throughput automated assay based on Liquid Chromatography High Resolution Mass Spectrometry (LC-HRMS) suitable for use as an initial testing procedure covering multiple classes of compounds prohibited in horse racing is described. The assay requires a 250-μL urine aliquot, which is subjected to enzymatic hydrolysis followed by Biotage Isolute supported liquid extraction plates using Biotage Extrahera system, evaporation, and reconstituti...
Lizarraga I, Castillo-Alcala F.Donkeys have contributed to the development and livelihoods of humans for almost 7,000 years. They have been used for traction and transportation, kept as pets, utilized in animal-assisted therapies, or farmed as food-producing animals. Over the past two decades, significant progress has been made in bridging the knowledge gap in veterinary medicine between donkeys and horses. Veterinary practitioners are now more aware that donkeys have important behavioral, anatomical, and physiological characteristics that distinguish them from horses. These peculiarities should be considered when treating ...
Ajeebsanu MM, Koshy SA, Karakka Kal AK, Subhahar MB, Karatt TK, Philip M.Suzetrigine, a recently approved Na1.8 sodium channel blocker, shows strong potential in the treatment of neurological, psychiatric, and pain-related conditions. Its peripheral selectivity enables effective pain management while avoiding central nervous system complications and addiction risks linked to opioid use. Following FDA approval in January 2025, concerns have emerged regarding its possible misuse for performance enhancement in sports, highlighting the need for reliable detection tools in doping control. Methods: An analytical procedure was designed and validated to detect suzetrigine ...
Massardi E, Gaudenzi G, Carra S, Oldani M, Rybinska I, Persani L, Vitale G.Cushing's disease (CD) is a rare neuroendocrine disorder caused by ACTH-secreting pituitary adenomas, presenting significant diagnostic and therapeutic challenges. Given the evolutionary conservation of the hypothalamic-pituitary-adrenal axis, this review explores the translational value of spontaneous CD forms in dogs, horses, cats, small mammals, and rats, as well as of experimental models in mice, rats, and zebrafish. Dogs are the most studied, showing strong molecular and clinical similarities with human CD, making them valuable for preclinical drug and diagnostic research. While equine an...
Darby S, DeNotta S, Gomez DE.This report describes a case of ivermectin toxicosis in a 4-day-old thoroughbred colt successfully treated with intravenous lipid emulsion (ILE) without complications. This case supports the use of ILE as a safe and effective therapy for the management of lipophilic drug toxicosis in foals. Key clinical message: Ivermectin toxicosis, though rare in equine neonates, can occur following accidental overdose and induces severe neurologic signs. In this case, ILE administration resulted in rapid neurologic improvement and complete recovery without adverse effects, supporting its use as a safe and e...
Chaimbeul SF, Rodrigues NNP, Thurston DD, Scoggin KE, Janes J, Jacobs CA, MacLeod JN, Stone AV, Menarim BC.Synovitis resolution is critical for joint homeostasis and prevents the progression of osteoarthritis (OA). Treatments like NSAIDs and intra-articular corticosteroids relieve symptoms by blocking pro-inflammatory mediators, but also impair the production of pro-resolving mediators, contributing to the likelihood of chronic synovitis. PPARγ signaling is an essential mechanism of synovitis resolution, which is decreased in OA tissues. To evaluate the potential of PPARγ agonists to promote pro-resolving pathways, equine macrophages cultured in autologous, normal, or inflamed synovial fluid ( = ...
Carroll AT, Reed RA, Berghaus LJ, McNabney D, Knych HK.To investigate the effect of cannabidiol (CBD) on thermal and mechanical thresholds and physiologic variables in horses. Unassigned: 6 horses (3 geldings and 3 mares) were enrolled in a prospective, randomized, masked crossover design from March 18 through May 3, 2025. Horses received 3.48 mg/kg CBD oil or placebo (sesame oil) orally every 24 hours for 3 days. Thermal and mechanical thresholds were determined at baseline and 4 and 12 hours after treatment administration on each day. Physiologic variables, including heart rate, respiratory rate, and rectal temperature, were recorded at the same...
Arantes JA, Rabelo IP, Bermudes L, Lacerenza MD, Mendes RP, Corrêa RR, Yamada DI, Valadão CAA, Dória RGS.This study aimed to compare the sedation quality and cardiorespiratory and behavioral effects of detomidine administered intravenously, either in intermittent boluses or as a continuous rate infusion, with butorphanol in horses pre-medicated with acepromazine for odontoplasty procedures. Unassigned: A prospective clinical study was conducted with fifteen adult horses randomly assigned to two groups: Bolus group (BG, = 7) and Infusion group (IG, = 8). Both groups received acepromazine premedication, followed by detomidine administration (bolus or infusion). Butorphanol was administered either...
Menzies-Gow NJ.Pituitary pars intermedia dysfunction (PPID) is a common, slowly progressive, neurodegenerative disorder of the older horse. Oxidative damage to the hypothalamic periventricular neurons results in loss of dopaminergic inhibition of the pars intermedia region of the pituitary gland. Consequently, there is increased production of the pro-opiomelanocortin (POMC)-derived hormones normally produced by this region, as well as initial melanocyte hypertrophy and hyperplasia, followed by adenomatous change. Clinical signs that are highly suggestive of the disease are generalised and regional hypertrich...
Maldonado Moreno N, Alves Moreira J, Araujo De Oliveira L, Sanches Gontijo A, Castilho Baldi ML, Rocha Wenceslau R, Beier SL.A multimodal approach is recommended to optimize perioperative pain control in animals, although opioid use in horses remains limited due to the risks of central nervous system (CNS) stimulation and reduced intestinal motility. A group of 19 healthy, male, mixed-breed horses were divided into two groups and medicated with acepromazine (0.05 mg kg) and detomidine (10 µg kg), with methadone (0.05 mg kg) (ADM) or saline (ADS) administered intravenously (IV). Physiological variables, intestinal motility, gastric distention, and facial pain (EQUUS-FAP) were evaluated one day before (DB), before th...
Bombardi C, Salamanca G, Tagliavia C, Grandis A, Zamith Cunha R, Gramenzi A, De Silva M, Zannoni A, Chiocchetti R.The amygdala is composed of several nuclei, including the lateral nucleus which is the main receiving area for the input from cortical and subcortical brain regions. It mediates fear, anxiety, stress, and pain across species. Evidence suggests that the endocannabinoid system may be a promising target for modulating these processes. Cannabinoid and cannabinoid-related receptors have been identified in the amygdala of rodents, carnivores, and humans, but not in horses. This study aimed to investigate the gene expression of cannabinoid receptors 1 (CB1R) and 2 (CB2R), transient receptor potential...
Lowndes CR, Boyle AG, Kulp J, Stefanovski D, Davis JL, van Eps A.To characterize the effects of pioglitazone (2 mg/kg, PO, either q 24 h [PIO-SID] or q 12 h [PIO-BID]) in equids with severe hyperinsulinemia. Unassigned: 17 client-owned equids with severe resting hyperinsulinemia (> 100 µIU/mL) were assigned to PIO-SID or PIO-BID in a prospective cohort study with rolling enrollment over an 11-month study period (December 13, 2022, to November 17, 2023). Basal insulin, total and high-molecular-weight adiponectin concentrations, and plasma pioglitazone concentrations were measured over 70 days. Oral sugar tests (OSTs) were performed on days 0 and 28. Results...
Mountessou BYG, Mouafon IL, Maharjan R, Tchamgoue J, Tiani GLM, Dibouloul P, Choudhary MI, Kouam SF.Four previously undescribed phenazine-derived pigments (1-4), along with seventeen known compounds, were isolated from a strain cultured on solid rice medium. Structural elucidation of the new compounds was achieved through extensive spectroscopic analysis, while known compounds were identified by comparison with literature data. The antimicrobial and cytotoxic activities of the isolated compounds were assessed. Compounds 2, 5, and 11 exhibited weak antifungal activity against at 200 μM, while compounds 5, 6, 11, 12, 15, and 20 demonstrated moderate antibacterial effects against at the sam...
Blanton A, Glass KG, Bayer J, Baetge C, Watanabe R, Sampson SN, Lépiz M, Moreno K, Ida KK.Pregabalin reduces excitatory neurotransmitter release and is used for anxiolysis in humans, cats, and horses. The effects of pregabalin on equine recovery following isoflurane anaesthesia are unknown. Objective: To determine if pre-anaesthetic oral pregabalin influences recovery time and/or quality from isoflurane anaesthesia in horses undergoing elective magnetic resonance imaging (MRI) of the appendicular skeleton. Methods: Retrospective cohort study. Methods: Anaesthetic and recovery data from 52 healthy horses in which pregabalin (PG) was administered and 76 control horses (CG) undergoing...
Bacon EK, Finno CJ, Donnelly CG, Haase B, Knych HK, Velie BD.Clinical assessments of equine sedation typically rely on subjective observations, the accuracy of which is paramount to the safety of equine veterinary procedures. Methods: To assess the degree in which subjective clinical sedative evaluations reflect pharmacokinetic measurements of equine drug metabolism, xylazine hydrochloride, an alpha-2 adrenoreceptor agonist, was administered to 36 horses of varying breed and age at a dosage of 0.5 mg/kg body weight. Subjective clinical parameters were scored at 5-, 15-, 30-, 45- and 60-minutes post xylazine administration and included responsiveness to ...
Jantunen N, Raekallio M, Obrochta B, Tapio H, Gracia Calvo L, Rivera Pöyhönen R, Hagman K, Karikoski N.To assess the effects of a 4 hour detomidine constant rate infusion (CRI) with and without a vatinoxan CRI on energy metabolism and urine composition. Methods: Randomized, blinded, crossover study. Methods: Eight Finnhorses, 587 (550-620) kg [median (range)] and 13 (4-16) years old. Methods: Horses were administered an intravenous (IV) detomidine loading dose (0.01 mg kg) followed by 240 minutes CRI (0.015 mg kg hour) (DET) and the same detomidine protocol combined with an IV vatinoxan loading dose (0.15 mg kg) and CRI (0.05 mg kg hour) (DET+VAT). Blood samples for glucose, insulin, non-esteri...
Tarillion M, Hertzsch R, Richter A.Since 28.01.2022, veterinary medicinal products must be used in accordance with the conditions of authorization (Regulation (EU) 2019/6, Article 106). This entails further restrictions on therapeutic freedom, e. g., with regard to dose deviations. To date, there is no data available in equine medicine on the scope of off-label use as any use deviating from the expert information for antibiotics, on the basis of which the feasibility of implementing the new regulations in Germany can be assessed.To collect data on the off-label use of antibiotics, a Germany-wide anonymous online survey was th...
Patnaik A, Chau V, Li F, Montelaro RC, Wills JW.The only retrovirus protein required for the budding of virus-like particles is the Gag protein; however, recent studies of Rous sarcoma virus (RSV) and human immunodeficiency virus have suggested that modification of Gag with ubiquitin (Ub) is also required. As a consequence, the release of these viruses is reduced in the presence of proteasome inhibitors, which indirectly reduce the levels of free Ub within the cell. Here we show that the budding of equine infectious anemia virus (EIAV) from infected equine cells is largely unaffected by these drugs, although use of one inhibitor (MG-132) re...
Harder A, Schmitt-Wrede HP, Krücken J, Marinovski P, Wunderlich F, Willson J, Amliwala K, Holden-Dye L, Walker R.There are three major classes of anthelmintics for veterinary use: the benzimidazoles/prebenzimidazoles, the tetrahydropyrimidines/imidazothiazoles, and the macrocyclic lactones. In nematodes, there are five targets for the existing anthelmintics: the nicotinergic acetylcholine receptor which is the target of tetrahydropyrimidines/imidazothiazoles and indirectly that of the acetylcholineesterase inhibitors; the GABA receptor which is the target of piperazine, the glutamate-gated chloride channel as the target of the macrocyclic lactones, and beta-tubulin as the target of prebenzimidazoles/benz...
DrugCentral monitors new drug approvals and standardizes drug information. The current update contains 285 drugs (131 for human use). New additions include: (i) the integration of veterinary drugs (154 for animal use only), (ii) the addition of 66 documented off-label uses and iii) the identification of adverse drug events from pharmacovigilance data for pediatric and geriatric patients. Additional enhancements include chemical substructure searching using SMILES and 'Target Cards' based on UniProt accession codes. Statistics of interests include the following: (i) 60% of the covered drugs are...
Higgins AJ, Lees P.Arachidonic acid is a polyunsaturated fatty acid covalently bound in esterified form in the cell membranes of most body cells. Following irritation or injury, arachidonic acid is released and oxygenated by enzyme systems leading to the formation of an important group of inflammatory mediators, the eicosanoids. It is now recognised that eicosanoid release is fundamental to the inflammatory process. For example, the prostaglandins and other prostanoids, products of the cyclooxygenase enzyme pathway, have potent inflammatory properties and prostaglandin E2 is readily detectable in equine acute in...
Guardabassi L, Apley M, Olsen JE, Toutain PL, Weese S.Optimization of antimicrobial treatment is a cornerstone in the fight against antimicrobial resistance. Various national and international authorities and professional veterinary and farming associations have released generic guidelines on prudent antimicrobial use in animals. However, these generic guidelines need to be translated into a set of animal species- and disease-specific practice recommendations. This article focuses on prevention of antimicrobial resistance and its complex relationship with treatment efficacy, highlighting key situations where the current antimicrobial drug product...
Beretta C, Garavaglia G, Cavalli M.We report on the inhibitory activity of the NSAIDs meloxicam, carprofen, phenylbutazone and flunixin, on blood cyclooxygenases in the horse using in vitro enzyme-linked assays. As expected, comparison of IC50 indicated that meloxicam and carprofen are more selective inhibitors of COX-2 than phenylbutazone and flunixin; meloxicam was the most advantageous for horses of four NSAIDs examined. However at IC80, phenylbutazone (+134.4%) and flunixin (+29.7%) had greater COX-2 selectivity than at IC50, and meloxicam (-41.2%) and carprofen (-12.9%) had lower COX-2 selectivity than at IC50. We therefor...
Lyons ET, Tolliver SC, Drudge JH.Small strongyles are highly prevalent in horses and can be found worldwide. Even though over 50 species of these parasites have been described, about 10 species comprise the bulk of the total number present in horses. Efforts to control small strongyles and other equine internal parasites have been undertaken for many years. Some of the early medications and control measures provided questionable activity against endoparasites; whether effective or not, they could be detrimental to the horse. Beginning in the early 1900s, scientific effort was used to evaluate activity of antiparasitic compoun...
Rizk MA, El-Sayed SA, Terkawi MA, Youssef MA, El Said el Sel S, Elsayed G, El-Khodery S, El-Ashker M, Elsify A, Omar M, Salama A, Yokoyama N....A rapid and accurate assay for evaluating antibabesial drugs on a large scale is required for the discovery of novel chemotherapeutic agents against Babesia parasites. In the current study, we evaluated the usefulness of a fluorescence-based assay for determining the efficacies of antibabesial compounds against bovine and equine hemoparasites in in vitro cultures. Three different hematocrits (HCTs; 2.5%, 5%, and 10%) were used without daily replacement of the medium. The results of a high-throughput screening assay revealed that the best HCT was 2.5% for bovine Babesia parasites and 5% for equ...
Brideau C, Van Staden C, Chan CC.To determine potency and selectivity of nonsteroidal anti-inflammatory drugs (NSAID) and cyclooxygenase- (COX-) specific inhibitors in whole blood from horses, dogs, and cats. Methods: Blood samples from 30 healthy horses, 48 healthy dogs, and 9 healthy cats. Methods: Activities of COX-1 and COX-2 were determined by measuring coagulation-induced thromboxane and lipopolysaccharide-induced prostaglandin E2 concentrations, respectively, in whole blood with and without the addition of various concentrations of phenylbutazone, flunixin meglumine, ketoprofen, diclofenac, indomethacin, meloxicam, car...
Guedes AG, Morisseau C, Sole A, Soares JH, Ulu A, Dong H, Hammock BD.A 4-year old, 500 kg Thoroughbred female horse diagnosed with bilateral forelimb laminitis and cellulitis on the left forelimb became severely painful and refractory to non-steroidal anti-inflammatory therapy (flunixin meglumine on days 1, 2, 3 and 4; and phenylbutazone on days 5, 6 and 7) alone or in combination with gabapentin (days 6 and 7). Methods: Pain scores assessed independently by three individuals with a visual analog scale (VAS; 0 = no pain and 10 = worst possible pain) were 8.5 on day 6, and it increased to 9.5 on day 7. Non-invasive blood pressure monitoring revealed severe hyper...
Nielsen MK.Anthelmintic resistance is reported in equine nematodes with increasing frequency in recent years, and no new anthelmintic classes have been introduced during the past 40 years. This manuscript reviews published literature describing anthelmintic resistance in cyathostomins, Parascaris spp., and Oxyuris equi with special emphasis on larvicidal efficacy against encysted cyathostomin larvae and strongylid egg reappearance periods (ERP). Resistance to benzimidazoles and pyrimidines is highly prevalent in cyathostomin populations around the world, and macrocyclic lactone resistance has been docume...
Scepek S, Coorssen JR, Lindau M.Using the patch-clamp technique, we studied the role of protein phosphorylation and dephosphorylation on the exocytotic fusion of secretory granules with the plasma membrane in horse eosinophils. Phorbol 12-myristate 13-acetate (PMA) had no effect on the amplitude and dynamics of degranulation, indicating that the formation of fusion pores is insensitive to activation of protein kinase C (PKC). Fusion pore expansion, however, was accelerated approximately 2-fold by PMA, and this effect was abolished by staurosporine. Elevating intracellular Ca2+ to 1.5 microM also resulted in a 2-fold accelera...
MacAllister CG, Morgan SJ, Borne AT, Pollet RA.The relative toxicity of phenylbutazone, flunixin meglumine, and ketoprofen was studied in healthy adult horses. Sixteen horses were randomly assigned to receive 10 ml of physiologic saline solution, or ketoprofen (2.2 mg/kg of body weight), flunixin meglumine (1.1 mg/kg), or phenylbutazone (4.4 mg/kg) IV, every 8 hours, for 12 days. Results of CBC, serum biochemical analyses, and fecal occult blood tests were monitored. On day 13, all horses were euthanatized and complete necropsy examinations were performed. Mean CBC values remained within normal limits for all groups. Phenylbutazone-treated...
Atta EH, Dias DS, Marra VL, de Azevedo AM.The best antithymocyte globulin preparation for first-line immune suppression in patients with severe aplastic anemia is still not clear. The aim of this study was to compare hematological response and overall survival in patients submitted to horse or rabbit antithymocyte globulin as first-line treatment for severe aplastic anemia. We retrospectively compared 71 consecutive patients with severe aplastic anemia, classified according to the antithymocyte globulin preparation. Analyses included variables related to patients and to immune suppression. Forty two patients (59.1%) received horse and...
van der Kraan PM.Osteoarthritis (OA) is the most common joint disease but an effective pharmacological therapy has not been developed yet. To identify targets for treatment and ways to interfere with OA development and progression both spontaneous and induced OA models are still needed. In this narrative review it is discussed what variables can be identified that lead to variation in OA animal model studies. Literature was screened (Pubmed) with the following terms; OA animal models in combination with species, age, strain, gender/sex, housing, diet, fighting, circadian rhythm, transgenic. Relevant articles ...
Perkins GA, Lamb S, Erb HN, Schanbacher B, Nydam DV, Divers TJ.Plasma ACTH levels have been variable in horses with a positive clinical response for therapy for equine Cushing's Disease (ECD). Therefore, our purpose was to determine the value of monitoring plasma adrenocorticotropin (ACTH) levels during treatment of equine Cushing's disease (ECD) with either cyproheptadine (n = 32) or pergolide (n = 10). First, we validated the chemiluminescent ACTH assay (specificity, precision, accuracy, intra-assay and interassay variations) and tested methods of handling the whole blood from the time of collection to when the ACTH was assayed. The sensitivity and spec...
Iyer U, Kadambi VJ.Antibody drug conjugates (ADCs) consist of an antibody attached to a cytotoxic drug by means of a linker. ADCs provide a way to couple the specificity of a monoclonal antibody (mAb) to the cytotoxicity of a small-molecule drug and, therefore, are promising new therapies for cancer. ADCs are prodrugs that are inactive in circulation but exert their cytotoxicity upon binding to the target cancer cell. Earlier unsuccessful attempts to generate ADCs with therapeutic value have emphasized the important role each component plays in determining the efficacy and safety of the final ADC. Scientific adv...
Bullone M, Lavoie JP.Human asthma is a complex and heterogeneous disorder characterized by chronic inflammation, bronchospasm and airway remodeling. The latter is a major determinant of the structure-function relationship of the respiratory system and likely contributes to the progressive and accelerated decline in lung function observed in patients over time. Corticosteroids are the cornerstone of asthma treatment. While their action on inflammation and lung function is well characterized, their effect on remodeling remains largely unknown. An important hindrance to the study of airway remodeling as a major focu...
Yamashita K, Tsubakishita S, Futaok S, Ueda I, Hamaguchi H, Seno T, Katoh S, Izumisawa Y, Kotani T, Muir WW.The cardiovascular effects of medetomidine, detomidine, and xylazine in horses were studied. Fifteen horses, whose right carotid arteries had previously been surgically raised to a subcutaneous position during general anesthesia were used. Five horses each were given the following 8 treatments: an intravenous injection of 4 doses of medetomidine (3, 5, 7.5, and 10 microg/kg), 3 doses of detomidine (10, 20, and 40 microg/kg), and one dose of xylazine (1 mg/kg). Heart rate decreased, but not statistically significant. Atrio-ventricular block was observed following all treatments and prolonged wi...
Wang ZW, Nara M, Wang YX, Kotlikoff MI.The effects of sulfhydryl reduction/oxidation on the gating of large-conductance, Ca(2+)-activated K+ (maxi-K) channels were examined in excised patches from tracheal myocytes. Channel activity was modified by sulfhydryl redox agents applied to the cytosolic surface, but not the extracellular surface, of membrane patches. Sulfhydryl reducing agents dithiothreitol, beta-mercaptoethanol, and GSH augmented, whereas sulfhydryl oxidizing agents diamide, thimerosal, and 2,2'-dithiodipyridine inhibited, channel activity in a concentration-dependent manner. Channel stimulation by reduction and inhibit...
Scott Weese J.Antimicrobial resistance (AMR) is an emerging problem in companion animals, because of difficult-to-treat infections, possible pressure to use antimicrobials that are important in human medicine, and potential zoonotic transmission. The extent and importance of AMR in companion animals are poorly understood, in part because of limited surveillance; however, it is clear that resistance is problematic in many pathogens and commensals, including staphylococci, enterococci, Escherichia coli and Salmonella.
de Grauw JC, van de Lest CH, Brama PA, Rambags BP, van Weeren PR.Meloxicam is a commonly used nonsteroidal anti-inflammatory drug in equine practice, but little is known about its in vivo effects on joint inflammation and cartilage turnover. Objective: To study the effects of meloxicam on biomarkers of inflammation, matrix metalloproteinase (MMP) activity, and cartilage biomarkers in joints with experimental synovitis. Methods: In a 2-period cross-over study, synovitis was induced at T = 0 h in the L or R intercarpal joint of 6 horses by intraarticular injection of 0.5 ng lipopolysaccharide (LPS). Horses received once daily meloxicam (0.6 mg/kg bwt per os) ...
Nielsen MK, Reinemeyer CR, Donecker JM, Leathwick DM, Marchiondo AA, Kaplan RM.Anthelmintic resistance is becoming increasingly prevalent among equine nematode parasites. The first reports documenting resistance were published in the 1960s, just a short time after introduction of the first modern anthelmintics phenothiazine and thiabendazole. Several factors are known to influence development of resistance, but evidence specific to equine parasites is limited. Most current knowledge and applications have been extrapolated from research with trichostrongylid parasites of sheep. The number of cyathostomin species co-infecting horses adds to the complexity of investigating ...
Clegg PD, Strassburg S, Smith RK.Injuries to tendons are common in both human athletes as well as in animals, such as the horse, which are used for competitive purposes. Furthermore, such injuries are also increasing in prevalence in the ageing, sedentary population. Tendon diseases often respond poorly to treatment and require lengthy periods of rehabilitation. The tendon has a unique extracellular matrix, which has developed to withstand the mechanical demands of such tensile-load bearing structures. Following injury, any repair process is inadequate and results in tissue that is distinct from original tendon tissue. There ...
Zhao S, McDermott PF, White DG, Qaiyumi S, Friedman SL, Abbott JW, Glenn A, Ayers SL, Post KW, Fales WH, Wilson RB, Reggiardo C, Walker RD.Three hundred and eighty Salmonella isolates recovered from animal diagnostic samples obtained from four state veterinary diagnostic laboratories (AZ, NC, MO, and TN) between 2002 and 2003 were tested for antimicrobial susceptibilities and further characterized for bla(CMY) beta-lactamase genes, class 1 integrons and genetic relatedness using PFGE. Forty-seven serovars were identified, the most common being S. Typhimurium (26%), S. Heidelberg (9%), S, Dublin (8%), S. Newport (8%), S. Derby (7%), and S. Choleraesuis (7%). Three hundred and thirteen (82%) isolates were resistant to at least one ...
Harlow BE, Lawrence LM, Flythe MD.Antibiotics are important to equine medicine, but antibiotic-associated diarrhea (AAD) can lead to poor performance and even mortality. AAD is attributed to disruption of the hindgut microbiota, which permits proliferation of pathogenic microbes. The goal of this study was to evaluate the effects of common antibiotics on cellulolytic bacteria, lactobacilli, and AAD-associated pathogens in the feces of healthy horses. Fifteen horses were assigned to three treatment groups (blocked by age and sex): control (no antibiotics), trimethoprim-sulfadiazine (PO), or ceftiofur (IM). Fecal samples (n=8 pe...
England GC, Clarke KW, Goossens L.The sedative effects of a new alpha 2-adrenoceptor agonist, romifidine, were compared with those of xylazine and detomidine. Five horses were treated with two doses of romifidine (40 micrograms/kg body weight and 80 micrograms/kg body weight), two doses of detomidine (10 micrograms/kg body weight and 20 micrograms/kg body weight) and one dose of xylazine (1 mg/kg body weight) given by intravenous injection using a Latin-square design. The dose of 80 micrograms/kg romifidine appeared equipotent to 1 mg/kg xylazine and 20 micrograms/kg detomidine, although at these doses both xylazine and detomi...
Walshe N, Duggan V, Cabrera-Rubio R, Crispie F, Cotter P, Feehan O, Mulcahy G.The interactions between parasitic helminths and gut microbiota are considered to be an important, although as yet incompletely understood, factor in the regulation of immunity, inflammation and a range of diseases. Infection with intestinal helminths is ubiquitous in grazing horses, with cyathostomins (about 50 species of which are recorded) predominating. Consequences of infection include both chronic effects, and an acute inflammatory syndrome, acute larval cyathostominosis, which sometimes follows removal of adult helminths by administration of anthelmintic drugs. The presence of cyathosto...
England GC, Clarke KW.In recent years the usefulness of the alpha 2 adrenoceptor agonist drugs has been recognized in equine practice. Several agents have become available and are now licensed for use in a number of countries. The principle actions of all alpha 2 adrenoceptor agonists are similar, in that they produce a reduction in heart rate and alteration of heart rhythm, an initial hypertension followed by a prolonged hypotension, a decrease in the cardiac output and respiratory depression. For clinical purposes, these agents produce sedation and analgesia, they are useful for premedication and markedly potenti...
