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.
TURK RD, UECKERT BW, BELL RR.No signs of intoxication were seen in horses dosed with thiabendazole at either 200 mg. or 400 mg. per kg. body-weight. 17 horses were dosed with the drug at a level of 100 mg. per kg. These horses had a mean egg count of 1, 296 e.p.g. before treatment; all were negative for strongyle eggs by the 7th day after treatment. 3 of these horses were killed and few or no strongyles were found; an untreated control animal killed at the same time had many thousands of strongyle worms. Thiabendazole was effective when given either by stomach tube or when mixed in the feed.
BRAYE ET, HINSMAN EJ, RILEY WF.No horse receiving combined streptokinase, streptodornase, and human plasminogen alone in either 125,000-unit or 375,000-unit doses manifested any clinical reaction. Untoward reactions occurred in 2 horses receiving both the combined streptokinase, streptodornase, and human plasminogen (125,000 units), and chlortetracycline. The reaction was transitory and subsided without treatment.
DRUDGE JH, LELAND SE, WYANT ZN, ELAM GW, HUTZLER LB.In five horses dosed with polymethylenepiperazine at dose levels of 21, 51 or 106 mg. per Ib. body-weight clearance of ascarids was obtained with all dosages. The effect against oxyurids was much less marked and large numbers of immature worms were found at autopsy four days after treatment. About 85% of small strongyles were removed at dosages of 21 mg. per Ib. and above and about 50% of Strongylus vulgaris were removed at dosages of 51 mg. per Ib. and above. The drug was inactive against S. edentatus, Trichostrongylus axei, Habronema muscae and Strongyloides westeri. In another eight horses ...
Khan Y, El-Shalofy A, Kaps M, Gautier C, Aurich C.We aimed to determine associations between experimentally impaired uterine clearance or treatment with ecbolic drugs on luteal development in estrous mares after insemination. In a crossover design, eight mares were treated with saline (CON), clenbuterol (CLEN), oxytocin (OXY) and carbetocin (CARB) from the day of first insemination until 2 days after ovulation. Between treatments, the mares rested for one cycle. Estrous mares were examined for the presence of free intrauterine fluid by transrectal ultrasound. Endometrial swabs for cytology and bacteriology were collected on days 1 and 14. Blo...
Menzies-Gow NJ, Knowles EJ.Laminitis is a common and painful condition of the equine foot and approximately 90% of cases are associated with insulin dysregulation (ID) that is a central feature of the common endocrine disorder equine metabolic syndrome (EMS) and occurs in a subset of animals with pituitary pars intermedia dysfunction. Additional features of EMS include obesity, altered circulating concentrations of adipokines (particularly adiponectin and leptin) and hypertriglyceridaemia. Obesity, ID, hypoadiponectinaemia, hyperleptinaemia and an altered plasma lipid profile are also features of human metabolic syndrom...
Mita H, Kuroda T, Minamijima Y, Tamura N, Ohta M.Surgical-site infections (SSIs) at implant sites in horses are sometimes difficult to control with systemic antimicrobials. Because one of the likely reasons is insufficient antimicrobial concentrations, there is a need to increase these concentrations in and around the infected tissue. Marbofloxacin (MAR)-encapsulated microparticles (MAR-MPs) made of biodegradable poly (lactic-co-glycolic) acid are capable of sustained release in vitro. We examined the concentration of MAR in the subcutaneous tissue fluid at sites where MAR-MPs had been administered. On day 0, six 3- × 4-cm subcutaneous pock...
Lomnicka I, Dubey S, Waller P, Vora D, Dirikolu L.The screening of drugs in plasma and urine often requires initial extraction (such as liquid-liquid extraction and solid-phase extraction) before the samples are submitted to instrumental analyses. These extraction procedures are often laborious and time-consuming. 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 600-μL plasma aliquot, which is subjected to solid pha...
Bedogni G, Michelena LV, Seremeta K, Okulik N, Salomon C.Fenbendazole is an antiparasitic drug widely used in veterinary medicine to treat parasitic infections caused in animals like cattle, horses, sheep, and dogs. Recently, it has been repositioned as a potential alternative for cancer treatment. However, it is a highly hydrophobic molecule (0.9 ug/mL), which can compromise its dissolution rate and absorption. Thus, this work aimed to apply a nanotechnological approach to improve drug solubility and dissolution performance. Fenbendazole nanoparticles stabilized by different poloxamers were obtained by lyophilization without cryoprotectants. The be...
Adam E, Scollay M, Howard B, Taormina J, Hartmann P, Knych H.Levamisole is a regulated substance sometimes administered to racehorses to treat equine protozoal myelitis. Metabolites include compound II, aminorex, and pemoline. Aminorex and pemoline are Horseracing Integrity and Safety Authority-banned substances. Previous studies have examined single doses of the drug. This study examined the disposition of levamisole after 7 days of dosing. Methods: 6 healthy Thoroughbred geldings. Methods: Horses were treated with 500 mg (approx 0.91 to 1 mg/kg) of compounded levamisole hydrochloride paste PO every 12 hours for a total of 13 doses over 7 days. Serum a...
Philip M, Kal AKK, Subhahar MB, Karatt TK, Graiban FM, Ajeebsanu MM, Joseph M, Jose SV.Phosphodiesterase 4 (PDE4) inhibitors are a newer class of drugs that induce bronchodilation and have anti-inflammatory effects, making them susceptible to misuse as performance enhancers in competitive sports. Methods: This study explores the metabolic conversion of PDE4 inhibitor ibudilast in thoroughbred horses after oral administration and in vitro using equine liver microsomes and Cunninghamella elegans. A liquid chromatography-high resolution mass spectrometry method was used to postulate the plausible structures of the detected metabolites. Results: A total of 20 in vivo metabolites wer...
Kuroda T, Minamijima Y, Kinman CK, Takahashi Y, Ebisuda Y, Inoue K, Ishikawa H, Mita H, Tamura N, Nukada T, Toutain PL, Ohta M.Quinidine (QND) sulfate is an effective treatment for atrial fibrillation (AF) in horses, and several dosage regimens have been proposed to address its wide variability in response and potential adverse effects. The purpose of this study was to analyze the variability in plasma quinidine concentrations using population pharmacokinetics to determine an effective and safe dosage regimen for Thoroughbred horses. Unassigned: Six healthy Thoroughbred horses were treated with 20 mg/kg quinidine sulfate dihydrate (16.58 mg/kg QND base) administered PO or 5 mg/kg quinidine hydrochloride monohydr...
Kwak YB, Stambler I, Yoo HH, Yoon J.Red ginseng (RG), a traditional herbal remedy, has garnered attention owing to its diverse health benefits resulting from its complex composition. However, extensive research is needed to substantiate the efficacy of RG and understand the underlying mechanisms supporting these benefits. This study aimed to identify potential biomarkers and investigate the impact of RG on related metabolic pathways in horse plasma using liquid chromatography-mass spectrometry (LC-MS)-based metabolomics. Unassigned: Ten horses were divided into control and RG groups, with the latter administered RG at a dose of ...
Tuniyazi M, Tang R, Hu X, Zhang N.Laminitis is a serious health condition that can cause severe pain and lameness in horses. Due to lack of understanding of laminitis, treatments often fail to achieve the desired results. In recent years, we have begun to recognize that laminitis may involve a complex interaction between local and systemic inflammation. Dysbiosis of the gut microbiota has been linked in the development of systemic inflammation, and our previous findings suggest that the development of laminitis is closely linked to the production of harmful metabolites of the gut microbiota. In addition, it was found that loca...
Kwak YB, Seo SA, Kim M, Yoon J.Ethyl pyruvate (EP) has emerged as a promising compound with potential therapeutic benefits attributed to its anti-inflammatory and antioxidant properties. This study aimed to understand the effects of EP on plasma metabolites and immune cells in horses, utilizing advanced liquid chromatography-mass spectrometry (LC-MS)-based metabolomics, quantitative polymerase chain reaction (qPCR), and blood chemistry analyses. Our comprehensive analysis detected 2,366 ions, and 126 metabolites were accurately identified. Remarkably, EP administration induced significant changes in 28 metabolites at 1Â h a...
Elbourne M, Keledjian J, Cawley A, Fu S.Altrenogest, also known as allyltrenbolone, is a synthetic form of progesterone used therapeutically to suppress unwanted symptoms of estrus in female horses. Altrenogest affects the system by decreasing levels of endogenous gonadotrophin and luteinizing and follicle-stimulating hormones, which in turn decreases estrogen and mimics the increase of progesterone production. This results in more manageable mares for training and competition alongside male horses while improving the workplace safety of riders and handlers. However, when altrenogest is administered, prohibited steroid impurities su...
Sousa LN, Winter IC, Varela DD, Luvison EZ, Guzmán JFC, Machado AMV, Figueiredo RDV, Pena GT, Dos Santos ACS, Faleiros RR, Carvalho AM.The present study involved seven horses in a randomized crossover clinical trial to evaluate the effect of lidocaine on horses with induced endotoxemia. Horses received intravenous lidocaine (1.5 mg/kg bolus, followed by 0.05 mg/kg bwt/min) or placebo (0.9% sodium chloride at the same manner) one hour before LPS administration (0.03 μg/kg, IV infusion over 30 min). We monitored clinic and hematologic parameters, abdominal auscultation, ultrasound, and pain over time. No relevant clinical differences existed between treatments regarding peristalsis, abdominal pain, or any other parameters befo...
Mersich I, Bishop RC, Diaz Yucupicio S, Nobrega AD, Austin SM, Barger AM, Fick ME, Wilkins PA.Coagulopathy is common in equine critical illness, with its early recognition being crucial for patient management and prognosis. In vitro viscoelastic (VE) hypercoagulability with decreased RCM/PCV has been demonstrated in dogs but not horses. Our objective was to evaluate the effects of acepromazine-induced (0.1 mg/kg IV) decreased RCM on VE and plasma coagulation parameters using a prospective interventional study of eight adult horses. Complete blood count (CBC), fibrinogen, prothrombin time (PT), partial thromboplastin time (PTT), packed cell volume (PCV), total solids (TS), and VCM Vetâ„...
Jargielo MM, Kritchevsky JE, Bertin FR.Pergolide, labeled for the treatment of pituitary pars intermedia dysfunction, is 90% protein bound and might cause a decrease in blood thyroid hormone concentrations by displacing them from binding proteins. This study investigated the effect of pergolide on the equine thyroid function. Methods: This was an analytic, observational, cohort study. Six horses (17 to 24 years old and 530 to 599 kg) received 1 mg of pergolide mesylate orally once a day from days 1 to 6. Total T4 (tT4) was measured daily from day 0 to 11 (before, during, and after pergolide treatment). Thyrotropin-releasing hormone...
So YM, Kwok WH, Ching CCW, Wong COL, Wan TSM, Ho ENM.Anabolic-androgenic steroids (AAS) are banned substances in both human and equine sports. They are often administered intramuscularly to horses in esterified forms for the purpose of extending their duration of action. As such, the detection of intact esters of endogenous steroids in hair is particularly advantageous, as it can provide unequivocal proof of their external origin. Compared with urine and blood matrices, hair in general allows a longer detection window as long as the administered drug can be incorporated into hair and has not degraded. This can be useful in doping control of equi...
Equine asthma, a prevalent chronic inflammatory condition affecting the equine population, significantly compromises the performance and quality of life in affected horses. Inhaled corticosteroids (ICS) are often the first-line pharmacological intervention due to their potent anti-inflammatory properties. This meta-analysis investigates the clinical efficacy of ICS in treating equine asthma, emphasizing the number needed to treat (NNT) and the likelihood of achieving a clinical response. A comprehensive literature search identified relevant studies comparing ICS with placebo (PCB) controlled t...
Wang Z, Li Y, Xi X, Zou Q, Zhang Y.In this paper, a novel molecularly imprinted polymer membrane modified glassy carbon electrode for electrochemical sensors (MIP-OH-MWCNTs-GCE) for epinephrine (EP) was successfully prepared by a gel-sol method using an optimized functional monomer oligosilsesquioxane-AlO sol-ITO composite sol (ITO-POSS-AlO). Hydroxylated multi-walled carbon nanotubes (OH-MWCNTs) were introduced during the modification of the electrodes, and the electrochemical behavior of EP on the molecularly imprinted electrochemical sensors was probed by the differential pulse velocity (DPV) method. The experimental conditi...
Reed RA, Carroll AT, Dantino SC, Quandt JE, Barletta M, Sakai DM.To determine the influence of xylazine infusion on survival to discharge and describe the associated intraoperative requirement for isoflurane, use of positive inotropes and vasopressors, and recovery time in horses undergoing exploratory laparotomy. Methods: Retrospective cohort study. Methods: A total of 352 horses. Methods: Medical records of horses undergoing anesthesia for exploratory laparotomy from January 2018 to December 2023 were reviewed. Data collected included survival to discharge, results of diagnostic tests, end tidal isoflurane concentration (FE'Iso), use of vasopressors/inotr...
The AnalystJanuary 23, 2025
doi: 10.1039/d4an01501k
Göktaş EF, Kabil E, Söylemez Yeşilçimen E, Dirikolu L.Various technical methodologies are required to accurately detect substances of different chemical and pharmacological properties in biological samples, which are increasing in number and variety daily. Therefore, laboratories where many samples and different factors are analyzed simultaneously need methods with easy sample preparation, short analysis times and low analysis costs. In this study, the objective was to scan substances susceptible to chemical degradation, amenable to analysis without hydrolysis, and exhibiting short-term stability by employing a straightforward, expeditious, and c...
Guo W, Li Z, Mao W, Liu X, Yang Y, Yu J, Yang H, Gao R.Flunixin meglumine (FM) is commonly used in painful conditions in horses; however, it may contribute to equine gastric ulcer syndrome (EGUS). Some veterinarians combine omeprazole (OME) and FM to reduce EGUS risk. However, the efficacy and safety of this combination in Mongolian horses with chronic lameness remain unknown. Objective: To investigate the changes in lameness and EGUS scores in Mongolian horses through the comparison of three treatment strategies: FM, FM + OME and placebo treated control (CON) and to assess the effects of these treatments on gastric fluid pH, serum total prote...
Kemp KL, Yuen NKY, Skinner JE, Bertin FR.Phenylbutazone is prescribed to manage pain caused by hyperinsulinemia-associated laminitis. Phenylbutazone reduces glucose and insulin concentrations in horses with insulin dysregulation (ID) but the underlying mechanism of action is unknown. Objective: Investigate the effect of phenylbutazone on tissue insulin sensitivity in horses. It is hypothesized that the reduced glucose and insulin concentrations in horses with ID receiving phenylbutazone are mediated by a higher tissue insulin sensitivity. Methods: Fifteen light breed horses, including seven with ID. Methods: Randomized cross-over stu...
Guzmán JFC, Gontijo AS, Melgaço ES, Faria SA, Baldi MLC, Sousa LN, Wenceslau RR, Fantini P, Xavier ABDS, Beier SL.Morphine has significant clinical and analgesic effects in horses, but its impact on the gastrointestinal tract requires further understanding. This study assessed the analgesic and gastrointestinal effects of morphine in horses undergoing elective orchiectomy in the quadrupedal position. Thirty uncastrated male horses were randomly assigned to three groups: orchiectomy without morphine and sedation protocol (OSM), orchiectomy with morphine and sedation protocol (OM), and administration of morphine alone in the absence of orchiectomy (M). The anesthetic protocol involved acepromazine (0.05 mg/...
Gorenberg EB, Slack J, Stefanovski D, Theiss D, Hopster K.Dobutamine is a first-line therapy for hypotension in anaesthetised horses, but the effects on haemodynamic parameters in standing and anaesthetised horses are not well studied. Objective: To investigate the effects of dobutamine in escalating dosages on haemodynamic performance in awake and anaesthetised horses. Methods: Randomised cross-over experimental study. Methods: Six healthy adult horses were enrolled, including both standing and isoflurane-anaesthetised experiments with 1-week washout. Heart rate, mean arterial pressure (MAP), central venous pressure, pulmonary arterial pressure, and...
Obrochta B, Tapio H, Raekallio M, Gracia Calvo LA, Pöyhönen RR, Hagman K, Jantunen N, Karikoski N.Sedation in horses is typically achieved using alpha-2 adrenoceptor agonists, although their use is associated with multiple side effects. A peripheral alpha-2 adrenoceptor antagonist, vatinoxan, can alleviate many of these. Objective: To evaluate the effects of vatinoxan infusion on gastrointestinal motility, sedation, and antinociception in horses sedated with detomidine infusion. Methods: Randomised, blinded cross-over in vivo experiments. Methods: Eight horses were given two 4-h infusions: detomidine (0.01 mg/kg + 0.015 mg/kg/h IV) (DET) and a combination of detomidine and vatinoxa...
Kintz P, Baudry M, Gheddar L.Trazodone, a medicine registered for human, is a serotonin agonist-antagonist. At low dose, the drug is sedative due to its antagonist properties. At high dose, it is an agonist with anxiolytic and antidepressant actions. Trazodone can be administered to the horse to reduce anxiety. However, according to the anti-doping rules for horses, the presence of trazodone in blood or urine is considered as a violation which will produce a suspension of both the athlete and the horse as the drug is listed banned on the International Federation of Horseracing Authorities prohibited substances list. As a ...
Pain management in horses plays a pivotal role in the therapeutic approach to several diseases. Horses have cannabinoid receptors at the level of dorsal root ganglia, blood vessels, and synoviocytes that can be up or down- regulated by inflammatory conditions, justifying the possible efficacy of exogenous cannabinoids (i.e., phytocannabinoids) in managing several painful pathologies in this animal species. However, the current use of supplements containing cannabidiol (CBD) in equines is based on anecdotal evidence, without the support of sufficient pharmacokinetic studies. In humans, the conc...
