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.
Rudolph W, Remane D, Wissenbach DK, Peters FT.Endophyte fungi (e.g. Epichloë ssp. and Neotyphodium ssp.) in symbiosis with pasture grasses (e.g. Festuca arundinacaea and Lolium perenne) can produce toxic alkaloids, which are suspected to be involved in equine diseases such as fescue toxicosis, ryegrass staggers, and equine fescue oedema. The aim of this study was, therefore, to develop and validate a quantification method for these and related alkaloids: ergocristine, ergocryptine, ergotamine, ergovaline, lolitrem B, lysergic acid, N-acetylloline, N-formylloline, peramine, and paxilline in horse serum. Horse serum samples (1.5mL) were wo...
Lacitignola L, Luca P, Santovito R, Comite MSD, Crovace A.Nutritional secondary hyperparathyroidism (NSH) is uncommon in horses. Aim of this report is evaluate an alternative therapeutic approach and provide more information on the diagnostic procedures, through detailed microscopic findings of the bone lesions pony with NSH. Administration of tiludronate along with a balanced diet can be used in a treatment protocol for ponies with NSH. This case report suggests that tiludronate can be used to ameliorate the clinical signs of NSH.
Tavassoli M, Jalilzadeh-Amin G, Fard VRB, Esfandiarpour R.The high incidence of equine gastrointestinal worms and their increased resistance against anthelmintics has encouraged research into the effectiveness of rational phytotherapy. This study investigates the in vitro anti-parasitic effects of extracts of Ferula asafoetida and Allium sativum, two native plants that are widespread in Iran on Strongylus spp. larvae. Faecal samples were collected from horses, examined by routine parasitology methods and positive samples were used for future examination. After incubation, the third-stage larvae were harvested by the Baermann technique. A hydroalcohol...
Cokelaere SM, Plomp SGM, de Boef E, de Leeuw M, Bool S, van de Lest CHA, van Weeren PR, Korthagen NM.Synovial inflammation is an important characteristic of arthritic disorders like osteoarthritis and rheumatoid arthritis. Orally administered non-steroidal anti-inflammatory drugs (NSAIDs) such as celecoxib are among the most widely prescribed drugs to manage these debilitating diseases. Intra-articular delivery in biodegradable in situ forming hydrogels overcomes adverse systemic effects and prolongs drug retention in the joint. In this study two formulations of celecoxib (40 mg/g and 120 mg/g) in a propyl-capped PCLA-PEG-PCLA triblock copolymer were sequentially evaluated in a multiple L...
Forni D, Cagliani R, Pontremoli C, Pozzoli U, Vertemara J, De Gioia L, Clerici M, Sironi M.Hepatitis C virus (HCV) belongs to the genus and is genetically heterogeneous, with seven major genotypes further divided into several recognized subtypes. HCV origin was previously dated in a range between ∼200 and 1000 years ago. Hepaciviruses have been identified in several domestic and wild mammals, the largest viral diversity being observed in bats and rodents. The closest relatives of HCV were found in horses/donkeys (equine hepaciviruses, EHV). However, the origin of HCV as a human pathogen is still an unsolved puzzle. Using a selection-informed evolutionary model, we show that the c...
Neudeck S, Kästner SBR, Wittenberg-Voges L, Rohn K, Hopster K.OBJECTIVE To determine global and peripheral perfusion and oxygenation during anesthesia with equipotent doses of desflurane and propofol combined with a constant rate infusion of dexmedetomidine in horses. ANIMALS 6 warmblood horses. PROCEDURES Horses were premedicated with dexmedetomidine (3.5 μg•kg, IV). Anesthesia was induced with propofol or ketamine and maintained with desflurane or propofol (complete crossover design) combined with a constant rate infusion of dexmedetomidine (7 μg•kg •h). Microperfusion and oxygenation of the rectal, oral, and esophageal mucosa were measured bef...
Kimmitt BA, Moore GE, Stiles J.OBJECTIVE To compare the efficacy of various concentrations and combinations of serum, EDTA, 3 tetracyclines, and N-acetylcysteine (NAC) for collagenase inhibition in an in vitro corneal degradation model. SAMPLE Grossly normal corneas from recently euthanized dogs and horses and fresh serum from healthy dogs and horses. PROCEDURES Serum was pooled by species for in vitro use. For each species, sections of cornea were dried, weighed, and incubated with clostridial collagenase (800 U/mL) in 5 mL of a 5mM calcium chloride-saline (0.9% NaCl) incubation solution and 500 μL of 1 of 19 treatments (...
Hardefeldt LY, Gilkerson JR, Billman-Jacobe H, Stevenson MA, Thursky K, Browning GF, Bailey KE.Antimicrobial resistance is a public health emergency, placing veterinary antimicrobial use under growing scrutiny. Antimicrobial stewardship, through appropriate use of antimicrobials, is a response to this threat. The need for antimicrobial stewardship in Australian veterinary practices has had limited investigation. A 2016 survey undertaken to investigate antimicrobial usage patterns by Australian veterinarians found that antimicrobial dose rates were varied and often inappropriate. Doses of procaine penicillin in horses and cattle were often low, with 68% and 90% of respondents, respective...
Jiménez-Trejo F, Coronado-Mares I, Boeta M, González-Santoyo I, Vigueras-Villaseñor R, Arriaga-Canon C, Herrera LA, Tapia-Rodríguez M.Assisted reproductive techniques have been used on several domestic animals to preserve desirable traits in strains of high genetic and commercial value; however in equines its efficiency rate is relatively low. To increase the conception ratio in stallions, some research groups have used pharmacological treatments which promote sperm hyperactivation in order to increase male's fertility rates. In this way, our previous work suggests that serotonin (5-HT) could be a good pharmacological candidate that facilitates conception rate in domestic horses. 5-HT is a neurohormone involved in several re...
Lucas Castillo JA, Gozalo-Marcilla M, Werneck Fonseca M, Possebon FS, da Rosa AC, de Araujo Aguiar AJ.Information on appropriate protocols for sedation of Nordestino donkeys is scarce. Objective: To evaluate the sedative and cardiorespiratory effects of low doses of intravenous (i.v.) xylazine with and without acepromazine in 'Nordestino' donkeys. Methods: Seven healthy female Nordestino donkeys (150 ± 18 kg) were included in this blinded, randomised, crossover experiment. Methods: Four treatments were administered, consisting of two i.v. injections, at baseline (T0, 1st injection) and 15 min later (T15, 2nd injection). Treatments included acepromazine 0.05 mg/kg bwt + saline (AS), saline + x...
Sadikalay S, Reynaud Y, Guyomard-Rabenirina S, Falord M, Ducat C, Fabre L, Le Hello S, Talarmin A, Ferdinand S.Extended-spectrum beta-lactamases (ESBLs), especially those of the CTX-M type, represent a major public health problem throughout the world. Although the carriage of ESBL-producing Enterobacteriaceae (EPE) in feces of horses is now well recognized, little is known about the diversity of EPE after treatment of horses with antibiotics. We undertook this study to assess and follow the diversity of EP Escherichia coli isolated from horses after antibiotic treatment for an infection. Fecal samples from two horses treated and two that were untreated were tested for the presence of EPE on different d...
Wilson KA, Raisis AL, Drynan EA, Mosing M, Lester GD, Hayman J, Hosgood GL.To determine the agreement of invasive blood pressure measured in the facial, metatarsal and carotid arteries, and evaluate the effects of two haemodynamic conditions on agreement. Methods: Prospective randomized study. Methods: A group of eight horses aged 7 (4-23) years with a body weight of 493 ± 33 kg. Methods: Horses were anaesthetized and positioned in dorsal recumbency. Invasive blood pressure was measured simultaneously via catheters placed in the facial, metatarsal and carotid arteries. Cardiovascular function and agreement between arteries was assessed before and during administr...
Galvão A, Wolodko K, Rebordão MR, Skarzynski D, Ferreira-Dias G.In the present report we describe the involvement of transforming growth factor B1 (TGF) in functional regression and structural luteolysis in the mare. Firstly, TGF and its receptors activin-like kinase (ALK) 5 and TGF receptor 2 were identified in corpus luteum (CL) steroidogenic, endothelial and fibroblast-like cells. Also, TGF and ALK5 protein expression were shown to be increased in Mid-, and Late-CL (p < 0.05). Subsequently, using an in vitro model with Mid-CL cells, we studied the role of TGF on secretory activity and cell viability. Cell treatment with TGF decreased progesterone...
Sandbaumhüter FA, Vimercati S, Thormann W, Mevissen M.The anesthetic ketamine is often combined with analgesics and benzodiazepines in equine medicine. Therefore, drug-drug interactions are possible. Enzyme kinetics for ketamine N-demethylation were determined using equine CYP3A94, CYP3A95 and CYP3A97, and the effect of medetomidine, diazepam and methadone on the ketamine metabolism was studied in vitro. Ketamine was incubated with the CYPs or equine liver microsomes (ELM) alone or in presence of medetomidine, diazepam and/or methadone for different times. Norketamine levels were determined using enantioselective capillary electrophoresis (CE) wi...
Bergstrom TC, Sakai RR, Nieto JE.A mare was euthanized because of gastric rupture secondary to complete duodenal obstruction by 2 bezoars located in the pylorus and proximal duodenum. Infrared spectroscopy showed that the bezoars were composed of psyllium. The mare had been receiving treatment with a pelleted psyllium product at 4 times the recommended dosage. Veterinarians should be aware that treatment of colic in horses with pelleted psyllium products could be associated with gastric impaction. Rupture gastrique catastrophique secondaire à des pharmacobézoards de psyllium en boulettes chez un cheval. Une jument a été e...
The ultra long-acting β -adrenoceptor agonist olodaterol plus the ultra long-acting muscarinic antagonist tiotropium bromide are known to relax equine airways. In human bronchi combining these drugs elicits a positive interaction, thus we aimed to characterize this information further in equine isolated airways stimulated by electrical field stimulation (EFS) and using the Concentration-Reduction Index (CRI) and Combination Index (CI) equations. The drugs were administered alone and together by reproducing ex vivo the concentration-ratio delivered by the currently available fixed-dose combina...
Trachsel DS, Tejada MA, Groesfjeld Christensen V, Pedersen PJ, Kanters JK, Buhl R, Calloe K, Klaerke DA.The long QT syndrome (LQTS) is a channelopathy that can lead to severe arrhythmia and sudden cardiac death. Pharmacologically induced LQTS is caused by interaction between drugs and potassium channels, especially the K 11.1 channel. Due to such interactions, numerous drugs have been withdrawn from the market or are administered with precautions in human medicine. However, some compounds, such as trimethoprim-sulfonamide combinations are still widely used in veterinarian medicine. Therefore, we investigate the effect of trimethoprim-sulfadiazine (TMS), trimethoprim, sulfadiazine, and detomidine...
Tallmadge RL, Žygelytė E, Van de Walle GR, Kristie TM, Felippe MJB.Equine herpesvirus type 1 (EHV-1) is a ubiquitous and highly contagious pathogen that causes a range of disease severities with outbreaks of notable economic impact. Given the limitations in immune protection of current vaccines and the limited effectiveness of antiviral drugs on EHV-1 infections , improved treatment measures are needed to control disease. The use of drugs that alter the epigenetic state of herpes simplex virus genome has been shown to limit viral primary infection and reactivation both and . Therefore, we tested the hypothesis that maintaining a repressive epigenetic state o...
Ceriotti S, Consiglio AL, Casati L, Cremonesi F, Sibilia V, Ferrucci F.Increasing evidence suggests a role for ghrelin in the control of articular inflammatory diseases like osteoarthritis (OA). In the present study we examined the ability of ghrelin to counteract LPS-induced necrosis and apoptosis of chondrocytes and the involvement of GH secretagogue receptor (GHS-R)1a in the protective action of ghrelin. The effects of ghrelin (10-10 mol/L) on equine primary cultured chondrocytes viability and necrosis in basal conditions and under LPS treatment (100 ng/ml) were detected by using both acridine orange/propidium iodide staining and annexin-5/propidium iodide...
Aarsvold S, Solano M, Garcia-Lopez J.Systemic administration of gadolinium contrast medium is common in small animals to increase lesion conspicuity and determine vascularisation of lesions identified with magnetic resonance imaging (MRI); however, the large volume required for systemic administration limits its use in horses. Objective: The purpose of this study was to assess the feasibility of administering a low dose of contrast medium via venous regional limb perfusion. Methods: Prospective clinical study. Methods: Distal limbs of 26 horses (one limb per horse) were imaged with MRI before and after administration of 5 mL of g...
There are limited findings from low-powered studies based on few number of subjects with equine asthma. Furthermore, no studies have been performed to assess a meaningful clinically detectable impact of corticosteroids in equine asthma. Objective: To assess and compare the clinical effect of inhaled and systemic corticosteroids in equine asthma and identify a quantitative clinical score suitable to assess the Minimal Important Difference (MID), expressed as the Minimally Clinically Detectable Difference (MCDD). Methods: Pair-wise and network meta-analysis. Methods: Literature searches for stud...
Bowser JE, Costa LRR, Rodil AU, Lopp CT, Johnson ME, Wills RW, Swiderski CE.OBJECTIVE To evaluate the effect of 2 bronchoalveolar lavage (BAL) sampling techniques and the use of N-butylscopolammonium bromide (NBB) on the quantity and quality of BAL fluid (BALF) samples obtained from horses with the summer pasture endophenotype of equine asthma. ANIMALS 8 horses with the summer pasture endophenotype of equine asthma. PROCEDURES BAL was performed bilaterally (right and left lung sites) with a flexible videoendoscope passed through the left or right nasal passage. During lavage of the first lung site, a BALF sample was collected by means of either gentle syringe aspirati...
Tavanaeimanesh H, Azarnoosh A, Ashar FS, Dehghan MM, Mohebbi Z, Akbarinejad V, Corley K.The choice of analgesic agents for the horse is limited, and many have side effects that can restrict their use for chronic and prolonged pain. Little information has been published on tramadol and acetaminophen use in the horse. The study evaluated the analgesic effects of coadministration of tramadol and acetaminophen compared to those of each drug individually in a crossover study. The study was performed on six healthy horses each infused with the following over 1 hour: control (normal saline), tramadol, acetaminophen, or both (acetaminophen and tramadol infused together). Nociception (usi...
Decloedt A, Broux B, De Clercq D, Deprez P, Van Steenkiste G, Vera L, Ven S, van Loon G.Based on its pharmacokinetic profile and electrophysiological effects in healthy horses, sotalol potentially could be used as a long-term PO antiarrhythmic drug in horses. Objective: To evaluate the effect of sotalol on heart rate (HR), QT interval, atrial fibrillatory rate, and success of cardioversion in horses with naturally occurring chronic atrial fibrillation (AF). Methods: Twenty-eight horses referred for transvenous electrical cardioversion of AF were treated with 2 mg/kg sotalol PO q12h for 3 days before cardioversion, and 13 horses underwent the same protocol without sotalol administ...
Calzetta L, Rogliani P, Pistocchini E, Mattei M, Cito G, Alfonsi P, Page C, Matera MG.Recurrent airway obstruction (RAO) is a main characteristic of horses with severe equine asthma syndrome. The presence of bacterial lipopolysaccharide (LPS) in the airways of horses is thought to play a crucial role in the clinical expression of this disorder. This study pharmacologically characterized the effect of LPS on the responsiveness of equine bronchial tissue. Equine isolated bronchi were incubated overnight with LPS (0.1-100 ng/ml) and then stimulated by electrical field stimulation (EFS). The role of capsaicin sensitive-sensory nerves (capsaicin desensitization treatment), neuroki...
Szydlarska J, Weiss C, Marycz K.Methyl-β-cyclodextrin (MβCD) is a cyclic oligosaccharide, commonly used as a pharmacological agent to deplete membrane cholesterol. In this study, we examined the effect of MβCD on adipose-derived mesenchymal stromal cells (ASCs) isolated form healthy horses (ASC) and from horses suffering from metabolic syndrome (ASC). We investigated the changes in the mRNA levels of the glucose transporter 4 (GLUT4) and found that MβCD application may lead to a significant improvement in glucose transport in ASC. We also showed that MβCD treatment affected GLUT4 upregulation in an insulin-independent m...
Lisowski ZM, Pirie RS, Blikslager AT, Lefebvre D, Hume DA, Hudson NPH.Post-operative ileus (POI) is a serious condition which any horse undergoing abdominal surgery is at risk of developing, leading to increased hospitalisation time and resulting costs. Advances in the understanding of the development of equine POI are mainly based on human and rodent literature, where manipulation-induced inflammation has been identified as a trigger, with activation of resident muscularis externa macrophages playing a crucial role in the pathophysiology. Despite many pharmacological trials in all species, there is no single completely successful treatment for POI, highlighting...
Bailly-Chouriberry L, Garcia P, Cormant F, Loup B, Popot MA, Bonnaire Y.Cobra (Naja naja kaouthia) venom contains a toxin called α-cobratoxin (α-Cbtx) containing 71 amino acids (MW 7821 Da) with a reported analgesic power greater than morphine. In 2013, the first analytical method for the detection of α-Cbtx in equine plasma was developed by Bailly-Chouriberry et al, allowing the confirmation of the presence of α-Cbtx at low concentrations (1-5 ng/mL or 130-640 fmol/mL) in plasma samples. To increase the method sensitivity and therefore to improve the detection of α-Cbtx in post-administration plasma samples, a nano-liquid chromatography-mass spectrometry/hi...
Gordon E, Stang BV, Heidel J, Poulsen KP, Cebra CK, Schlipf JW.To determine if corneal epithelial cell integrity is detrimentally affected by short-term administration of 1.0% morphine sulfate. Additionally, we sought to determine if topical 1.0% morphine applied to the equine cornea would result in ocular or systemic absorption. Methods: Six healthy horses. Methods: Morphine sulfate (1.0%) was applied topically to one eye every four hours for 72 h before horses were euthanized. Serum samples were collected at varying time points during the study and aqueous and vitreous humor were collected immediately after euthanasia. Morphine quantification in serum, ...
Gasthuys F, De Moor A, Parmentier D.The cardiovascular changes induced by several sedatives were investigated in five ponies with a subcutaneously transposed carotid artery by means of cardiac output determinations (thermodilution technique), systemic and pulmonary artery pressure measurements (direct intravascular method) and arterial blood analysis (blood gases and packed cell volume). The cardiovascular depression (decrease in systemic blood pressure and cardiac output) was long lasting (greater than 90 min) after administration of propionylpromazine (0.08 mg/kg intravenous (i.v.)) together with promethazine (0.08 mg/kg i.v.)...
Carstensen H, Hesselkilde EZ, Haugaard MM, Flethøj M, Carlson J, Pehrson S, Jespersen T, Platonov PG, Buhl R.The atrial fibrillatory rate is a potential biomarker in the study of antiarrhythmic drug effects on atrial fibrillation (AF). The purpose of this study was to evaluate whether dose-dependent changes in the atrial fibrillatory rate can be monitored on surface electrocardiography (ECG) following treatment with dofetilide, ranolazine, and a combination of the two in an acute model of AF in horses. Eight horses were subjected to pacing-induced AF on 4 separate days. Saline (control), dofetilide, ranolazine, or a combination of dofetilide and ranolazine was administered in four incremental doses. ...
Gutiérrez JM, Tsai WC, Pla D, Solano G, Lomonte B, Sanz L, Angulo Y, Calvete JJ.A polyspecific antivenom is used in Central America for the treatment of envenomings by viperid snakes. This antivenom is generated in horses hyperimmunized with a mixture of venoms from Bothrops asper, Crotalus simus and Lachesis stenophrys. The present study analyzed the ability of this antivenom to neutralize the venoms of three Central American viperid species of the 'Porthidium group', i.e. Porthidium nasutum, Porthidium ophryomegas and Cerrophidion sasai, formerly classified as Cerrophidion godmani. In addition, the immunorecognition of the components of these venoms was assessed by immu...
Brooks MB, Divers TJ, Watts AE, Ness SL, Frye AH, Stokol T, Fubini SL.To evaluate the platelet activation response before and after treatment with clopidogrel in horses. Methods: 12 healthy adult mares. Methods: In a masked study, horses (6/group) were randomly allocated to alternately receive placebo or clopidogrel via nasogastric tube at a loading dose of 4 mg/kg followed by 2 mg/kg every 24 hours. Blood samples were collected before and 72 hours after initiation of treatment for ADP- and collagen-induced light transmission aggregometry; determination of closure time in collagen-ADP cartridges; modified thrombelastography for comparison of maximal amplitudes g...
Gargala G, Le Goff L, Ballet JJ, Favennec L, Stachulski AV, Rossignol JF.Sarcocystis neurona is an obligate intracellular parasite that causes equine protozoal myeloencephalitis (EPM). The aim of this work was to document inhibitory activities of nitazoxanide (NTZ, [2-acetolyloxy-N-(5-nitro 2-thiazolyl) benzamide]) and new thiazolides/thiadiazolides on S. neurona in vitro development, and investigate their structure-activity relationships. S. neurona was grown in bovine turbinate cell cultures. At concentrations varying from 1.0 to 5.0mg/L, nitazoxanide and 21 of 32 second generation thiazolide/thiadiazolide agents exerted a > or =95% maximum inhibition on S. neuro...
Stegelmeier BL, Colegate SM, Knoppel EL, Rood KA, Collett MG.Wild parsnip (Pastinaca sativa) has been associated with livestock and human photosensitization. An investigation of a natural occurrence of photosensitization of grazing horses identified wild parsnip as a possible cause. HPLC-MS and MS/MS analysis of this plant identified five furanocoumarins i.e., xanthotoxin, bergapten, isopimpinellin, imperatorin and a putative methoxyimperatorin. Goats fed this wild parsnip were largely unaffected. Xanthotoxin was not detected in the serum of parsnip-fed goats or in the serum of goats dosed orally or intravenous with purified xanthotoxin. Cutaneous appli...
McGowan CM, Neiger R.Trilostane, a competitive 3-beta hydroxysteroid dehydrogenase inhibitor, has been used successfully to control clinical signs and cortisol excess in canine pituitary dependent hyperadrenocorticism. Objective: Trilostane was evaluated for its efficacy in resolving clinical and clinicopathological abnormalities of equine Cushing's syndrome (ECS) and to assess its safety. Methods: Twenty horses (mean age 21 years) diagnosed with ECS were followed for 1 or 2 years. Affected horses received 0.4-1 mg/kg (mean 0.5 mg/kg) trilostane once daily. Results: Clinical signs assessed over 1 or 2 years, showe...
Bentz BG, Maxwell LK, Erkert RS, Royer CM, Davis MS, MacAllister CG, Clarke CR.The purpose of the study reported here was to describe the bioavailability and pharmacokinetics of acyclovir after intravenous and oral administration to horses. Six healthy adult horses were used in a randomized cross-over study with a 3 x 3 Latin square design. Three treatments were administered to each horse: 10 mg of injectable acyclovir/kg of body weight in 1 L of normal saline delivered as an infusion over 15 minutes; 10 mg of acyclovir/kg in tablets by nasogastric intubation; and 20 mg of acyclovir/kg in tablets by nasogastric intubation. A 2-week washout period was provided between eac...
Kullmann A, Sanz M, Fosgate GT, Saulez MN, Page PC, Rioja E.Alpha-2 agonist-induced changes in packed cell volume (PCV), total solids (TS), selected biochemical parameters, and splenic thickness were investigated in horses. Four healthy mares were treated in a blinded, randomized, cross-over design with a dose of xylazine (0.5 mg/kg), romifidine (0.04 mg/kg), or detomidine (0.01 mg/kg) IV, and detomidine (0.02 mg/kg) IM. Hematology, TS, colloid osmotic pressure (COP), plasma osmolality; glucose, lactate, urea (BUN) and electrolyte concentrations; venous blood pH and ultrasonographic splenic thickness were evaluated at intervals for 300 min. Repeated me...
Urra JA, Villaroel-Espíndola F, Covarrubias AA, Rodríguez-Gil JE, Ramírez-Reveco A, Concha II.Dopamine is a catecholamine with multiple physiological functions, playing a key role in nervous system; however its participation in reproductive processes and sperm physiology is controversial. High dopamine concentrations have been reported in different portions of the feminine and masculine reproductive tract, although the role fulfilled by this catecholamine in reproductive physiology is as yet unknown. We have previously shown that dopamine type 2 receptor is functional in boar sperm, suggesting that dopamine acts as a physiological modulator of sperm viability, capacitation and motility...
Grobbel M, Lübke-Becker A, Alesík E, Schwarz S, Wallmann J, Werckenthin C, Wieler LH.A total of 417 isolates of Escherichia coli collected from five animal species/organ system combinations from swine [urinary/genital tract (UGT) incl. mastitis metritis agalactia syndrome], horses [genital tract (GT)] and dogs/cats [respiratory tract (RT), UGT and gastrointestinal tract (GIT)] were analysed quantitatively for their susceptibility against different antimicrobial agents by determination of minimum inhibitory concentrations. Regardless of which animal species the strains originated from, resistance appeared most frequently against sulfamethoxazole (18-59%), tetracycline (14-54 %)...
Mizen K, Woodman J, Boysen SR, Wagg C, Greco-Otto P, Léguillette R, Roy MF.Blood lactate concentration is a marker of tissue perfusion and helps guide therapeutic interventions in critically ill horses. In both humans and dogs, administration of corticosteroids can increase blood lactate concentration, leading to type B hyperlactatemia. This effect could be a consequence of the impact of corticosteroids on glucose metabolism. Objective: To investigate the effects of daily IM dexamethasone administration on blood lactate and glucose concentrations in horses. Methods: Nine healthy adult horses. Methods: A randomized, blinded, controlled, cross-over study design was use...
Simões J, Sales Luís JP, Tilley P.Severe equine asthma (SEA) syndrome is a chronic recurrent respiratory disease, common among adult horses. The disease occurs in genetically susceptible individuals after their exposure to organic dust. Thus, environmental management has proved essential in controlling airway challenge and disease exacerbation. This is a demanding process that can only be achieved through the horse owners' cooperation. One year after initial diagnosis of SEA in a group of 39 horses, owner compliance to an environmental management protocol was evaluated. The overall compliance to the protocol was poor and the h...
Caron JP, Gandy JC, Schmidt M, Hauptman JG, Sordillo LM.To compare the effects of triamcinolone acetonide (TA) and methylprednisolone acetate (MPA) on expression of selected chondrocyte genes in recombinant equine interleukin-1β (reIL-1β) stimulated articular cartilage explants. Methods: In vitro experiment. Methods: Horses (n = 6). Methods: Articular cartilage explants from 2- to 3- year-old horses were exposed to reIL-1β in the presence and absence of TA and MPA at 10(-7) and 10(-6) M. Resting levels of mRNA of anabolic and catabolic genes of chondrocyte origin were quantified using qPCR after 6- and 12-hour incubations. Genes of interest incl...
Yates AC, Stewart AA, Byron CR, Pondenis HC, Kaufmann KM, Constable PD.To determine the effects of sodium hyaluronate (HA) in combination with methylprednisolone acetate (MPA) on interleukin-1 (IL-1)-induced inflammation in equine articular cartilage pellets. Methods: Chondrocytes collected from 7 horses euthanatized for problems unrelated to the musculoskeletal system. Methods: Chondrocyte pellets were treated with medium (negative control); medium containing IL-1 (positive control); or medium containing IL-1 with MPA only (0.05 or 0.5 mg/mL), HA only (0.2 or 2 mg/mL), or MPA (0.05 or 0.5 mg/mL) and HA (0.2 or 2 mg/mL) in combination. Proteoglycan (PG) synthesis...
Cuming RS, Abarca EM, Duran S, Wooldridge AA, Stewart AJ, Ravis W, Babu RJ, Lin YJ, Hathcock T.To determine in vitro release profiles, transcorneal permeation, and ocular injection characteristics of a voriconazole-containing thermogel suitable for injection into the subconjunctival space (SCS). In vitro release rate of voriconazole (0.3% and 1.5%) from poly (DL-lactide-co-glycolide-b-ethylene glycol-b-DL-lactide-co-glycolide) (PLGA-PEG-PLGA) thermogel was determined for 28 days. A Franz cell diffusion chamber was used to evaluate equine transcorneal and transscleral permeation of voriconazole (1.5% topical solution, 0.3% and 1.5% voriconazole-thermogel) for 24 hours. Antifungal activit...
Murray RC, DeBowes RM, Gaughan EM, Zhu CF, Athanasiou KA.Intra-articular corticosteroids are widely used as anti-inflammatory agents for symptomatic management of arthritis, but their administration with concurrent exercise remains controversial. Biochemical and morphologic analysis of treated cartilage has revealed conflicting results, but previous biomechanical assessment has not been undertaken. Objective: To compare the biomechanical properties of intra-articular methylprednisolone acetate (MPA) and diluent treated cartilage in treadmill exercised horses. Methods: Eight 2-year-old female horses had MPA or diluent administered into contralateral ...
Stahl J, Braun M, Siebert J, Kietzmann M.A water based combination of 0.1% octenidine dihydrochloride and 2% 2 - phenoxyethanol is registered in many European countries as an antiseptic solution (octenisept®) for topical treatment with high antimicrobial activity for human use, but octenidine based products have not been registered for veterinary use yet. The aim of the present study was to investigate whether octenidine dihydrochloride or 2 -phenoxyethanol, the two main components of this disinfectant, permeate through animal skin in vitro. Therefore, permeation studies were conducted using Franz-type diffusion cells. 2 ml of the t...
Elfenbein JR, Sanchez LC, Robertson SA, Cole CA, Sams R.To evaluate the effects of detomidine on visceral and somatic nociception, heart and respiratory rates, sedation, and duodenal motility and to correlate these effects with serum detomidine concentrations. Methods: Nonrandomized, experimental trial. Methods: Five adult horses, each with a permanent gastric cannula weighing 534 +/- 46 kg. Methods: Visceral nociception was evaluated by colorectal (CRD) and duodenal distension (DD). The duodenal balloon was used to assess motility. Somatic nociception was assessed via thermal threshold (TT). Nose-to-ground (NTG) height was used as a measure of sed...
Sheldon SA, Aleman M, Costa LRR, Santoyo AC, Howey Q, Madigan JE.Trigeminal-mediated headshaking results from low-threshold firing of the trigeminal nerve resulting in apparent facial pain. Magnesium may have neuroprotective effects on nerve firing that potentially dampen signs of neuropathic pain. This hypothesis has not been investigated in horses with trigeminal-mediated headshaking. Objective: To investigate head-shaking behavior in affected horses after IV magnesium sulfate infusion. Methods: Six geldings with trigeminal-mediated headshaking. Methods: Prospective randomized crossover study. Horses were controlled for diet and infused IV with 5% dextros...
Shepard EM, Heggem H, Juda GA, Dooley DM.Potential inhibitory effects of the clinically utilized monoamine oxidase inhibitor tranylcypromine (TCP) on mammalian, plant, bacterial, and fungal copper-containing amine oxidases have been examined. The following enzymes have been investigated: human kidney diamine oxidase (HKAO), bovine plasma amine oxidase (BPAO), equine plasma amine oxidase (EPAO), pea seedling amine oxidase (PSAO), Arthrobacter globiformis amine oxidase (AGAO), and Pichia pastoris lysyl oxidase (PPLO). Only BPAO, EPAO, and AGAO were found to lose significant levels of activity when incubated with varying amounts of TCP....
López-Sanromán FJ, Gómez Cisneros D, Varela del Arco M, Santiago Llorente I, Santos González M.The aim of the present study was to quantify by accelerometry the trotting pattern of adult horses sedated with two different doses of acepromazine, in order to assess the use of this drug in equine lameness evaluations. Methods: Seven mature horses were used and three treatments were administered to each horse: saline solution, acepromazine (0.01 mg/kg), and acepromazine (0.02 mg/kg). The portable gait analyzer used consisted of three orthogonal accelerometers that measure accelerations along the dorsoventral, longitudinal, and lateral axes. Baseline values were obtained and after treatment, ...
Suarez-Mier G, Giguère S, Lee EA.The objectives of the present study were to determine and compare the pulmonary disposition of azithromycin, clarithromycin, and erythromycin in foals. A single dose (10 mg/kg) of azithromycin, clarithromycin, or erythromycin was administered intragastrically to six healthy 1- to 3-month-old foals using an orthogonal design. Activity of the drugs was measured in serum, pulmonary epithelial lining fluid (PELF), and bronchoalveolar lavage (BAL) cells by use of a microbiologic assay. Peak drug activity in PELF was significantly higher in foals treated with clarithromycin (48.96+/-13.26 microg/mL)...
Martinez PS, Whitley RD, Plummer CE, Richardson RL, Hamor RE, Wellehan JFX.To examine the relationship between Minimum Inhibitory Concentration (MICs) and response to therapy of 6 Fusarium spp. and 5 Aspergillus fumigatus isolated from equine ulcerative keratitis cases. Methods: Fungi were identified by morphology and Internal Transcribed Spacer (ITS) polymerase chain reaction (PCR) with sequencing and evaluated at the University of Texas Fungal Testing Laboratory for susceptibility to three azole antifungals (miconazole, voriconazole, posaconazole), natamycin, and two echinocandins (anidulafungin, caspofungin). A Mann-Whitney rank sum test was used for the compariso...
Kruluc P, Nemec A.Clinically, the use of detomidine and butorphanol is suitable for sedation and deepening of analgosedation. The aim of our study was to establish the influence of detomidine used alone and a butorphanol-detomidine combination on brain activity and to evaluate and compare brain responses (using electroencephalography, EEG) by recording SEF90 (spectral edge frequency 90%), individual brain wave fractions (beta, alpha, theta and delta) and electromyographic (EMG) changes in the left temporal muscle in standing horses. Ten clinically healthy cold-blooded horses were divided into two groups of five...
Fillion G, Beaudoin D, Rousselle JC, Jacob J.Glial cell membrane fractions were prepared using glial cells preparations isolated from horse brain striatum. [3H]5-HT binding was measured by the filtration technique and the adenylate cyclase activity determined by measuring the cAMP production using a radioimmunoassay. Serotonin binds to glial membrane fractions with an affinity corresponding to a dissociation constant Kd = nM. The corresponding site is serotoninergic specific: [3H]5-HT binding is inhibited by 5-HT agonists (5 OH NM-DMT, 5-MeOHT, 5-MeOH-DMT, NN-DMT) or antagonists (cinanserine, cyproheptadine, methysergide, LSD) and not (o...
Prieto D, Hernández M, Rivera L, García-Sacristán A, Simonsen U.The distribution of neuropeptide Y (NPY)-immunoreactive (IR) nerves, as well as the functional effects of NPY and the Y1- and Y2-receptor agonists, [Leu31,Pro34]NPY and NPY(13-36), respectively, have been investigated in vitro in both visceral and arterial smooth muscle of the horse intravesical ureter. NPY-IR nerve fibres were widely distributed along the entire length of the ureter, although the intravesical part was the most richly innervated region, and the only one where NPY-IR ganglion cells were found. NPY (10(-7) M) did not affect either basal tone or spontaneous rhythmic contractions ...
Risberg ÅI, Ranheim B, Krontveit RI, Lervik A, Haga HA.To compare cardiac index and oxygen extraction at equivalent depths of anaesthesia between isoflurane-anaesthetized horses and horses anesthetized with isoflurane and dexmedetomidine CRI. Methods: Sequential, blinded, randomized, balanced, crossover study. Methods: Eight horses weighing a mean ± standard deviation of 478 ± 58 kg. Methods: Horses were premedicated with 0.03 mg kg(-1) acepromazine intramuscularly (IM) and 8 μg kg(-1) dexmedetomidine intravenously (IV). Anaesthesia was induced with 2.5 mg kg(-1) ketamine and 0.1 mg kg(-1) midazolam IV and maintained with isofluran...
