Respiratory rate in horses refers to the number of breaths a horse takes per minute and is a vital physiological parameter for assessing equine health. It provides insight into the respiratory function and can indicate changes in a horse's health status. The normal respiratory rate for a resting adult horse typically ranges from 8 to 16 breaths per minute, though it can vary based on factors such as activity level, environmental conditions, and individual variability. Deviations from the normal range can suggest respiratory or systemic issues, prompting further veterinary evaluation. This page compiles peer-reviewed research studies and scholarly articles that explore the measurement, variability, and clinical implications of respiratory rate in horses.
Freitas GC, Carregaro AB, Gehrcke MI, De La Côrte FD, Lara VM, Pozzobon R, Brass KE.This study evaluated the analgesia effects of the epidural administration of 0.1 mg/kg bodyweight (BW) of morphine or 5 μg/kg BW of buprenorphine in ponies with radiocarpal joint synovitis. Six ponies were submitted to 3 epidural treatments: the control group (C) received 0.15 mL/kg BW of a 0.9% sodium chloride (NaCl) solution; group M was administered 0.1 mg/kg BW of morphine; and group B was administered 5 μg/kg BW of buprenorphine, both diluted in 0.9% NaCl to a total volume of 0.15 mL/kg BW administered epidurally at 10 s/mL. The synovitis model was induced by injecting 0.5 ng of lipopol...
Muñoz A, Riber C, Trigo P, Castejón FM, Lucas RG, Palacio J.This study investigated the effect of hypertonic dehydration on exercise in horses. Valencian draft horses (n=43) with hypertonic dehydration following water and food deprivation and competing in pulling events (COM), were compared to euhydrated horses (n=11) during a pulling exercise test (PET). Both groups were divided into bodyweight (BW) categories A (≤350 kg), B (351-450 kg), and C (≥451 kg), and pulled 2, 2.25, and 2.5 times BW, respectively. Exercise duration (ED) was 1.3±0.8 min. Heart rate, respiratory rate, rectal temperature and blood samples were taken at rest, after exercise,...
Huff NK, Thompson DL, Mitcham PB, Storer WA.Mares and geldings in good body condition selected for hyperleptinemia vs. normal leptin concentrations were studied to determine whether the hyperleptinemic condition affected various characteristics of the hematologic and hormonal systems after a challenge with lipopolysaccharide endotoxin. Four mares and 4 geldings that were determined to be hyperleptinemic (mean plasma leptin concentrations of 10.0 to 15.5 ng/mL) and 4 mares and 4 geldings with mean plasma leptin concentrations between 2.4 and 5.5 ng/mL were administered Escherichia coli O55:B5 endotoxin (35 ng/kg of BW in 500 mL of saline...
Leclere M, Magdesian KG, Kass PH, Pusterla N, Rhodes DM.The purpose of this study was to compare the clinical, microbiological, radiological, haematological and cytological features of foals with pneumonia caused by Rhodococcus equi infection and with other bacteria, in order to provide markers for early diagnosis and treatment. A retrospective study of 113 cases of bacterial pneumonia was undertaken. Although there was considerable overlap in the affected populations, foals with R. equi pneumonia were significantly younger and had higher respiratory rates. Radiological evidence of thoracic abscessation had a sensitivity of 71% and a specificity of...
Schauvliege S, Van den Eede A, Duchateau L, Gasthuys F.To evaluate the combined effects of enoximone and dobutamine on the cardiovascular system and respiratory gas exchange in isoflurane-anaesthetized ponies. Methods: Prospective, randomized, experimental study. Methods: Six ponies (286 +/- 52 kg), aged 5.0 +/- 1.6 years. Methods: After sedation (romifidine 80 microg kg(-1)), anaesthesia was induced with midazolam (0.06 mg kg(-1)) and ketamine (2.2 mg kg(-1)) and maintained with isoflurane in oxygen. The ponies were ventilated to maintain eucapnia. After 90 minutes (=T0), enoximone alone (0.5 mg kg(-1)) (E) or enoximone, followed by a constant ra...
Solano AM, Valverde A, Desrochers A, Nykamp S, Boure LP.Standing surgical procedures are performed commonly in horses under sedation. This approach minimises the morbidity/mortality risks associated with general anaesthesia. The use of a medetomidine and morphine combination has not been investigated in horses despite the usefulness of each drug individually. Objective: To determine the efficacy of a medetomidine and morphine combination to produce standing sedation with minimal cardiorespiratory changes and adequate analgesia for exploratory laparascopy in mature horses. Objective: The combination of medetomidine and morphine will induce reliable ...
Breuhaus BA.This study was performed to determine whether anhidrotic horses have altered thyroid function compared with horses that sweat normally. Objective: Anhidrotic horses have normal thyroid function. Methods: Ten client-owned horses with clinical signs of anhidrosis were paired with 10 horses living in the same environment that had normal sweat production. Methods: Horses were diagnosed as having normal sweat production or being anhidrotic based on responses to intradermal injections of terbutaline and physiologic responses to lunging exercise. Control horses were selected from the same environment...
Braun C, Trim CM, Eggleston RB.To investigate the impact of a change in body position on blood gases and arterial blood pressures in foals anesthetized with guaifenesin, ketamine, and xylazine. Methods: Prospective, randomized experimental study. Methods: Twelve Quarter Horse foals, age of 5.4 +/-0.9 months and weighing 222 +/- 48 kg. Methods: Foals were anesthetized with guaifenesin, ketamine, and xylazine for 40 minutes in lateral recumbency and then assigned to a change in lateral recumbency after hoisting (Group 1, n = 6), or no change (Group 2, n = 6). Oxygen 15 L minute(-1) was insufflated into the endotracheal tube t...
Granot N, Milgram J, Bdolah-Abram T, Shemesh I, Steinman A.A retrospective review of the medical records of 41 horses requiring abdominal surgery for sand colic. Results: The diagnosis of sand colic was made when sand was found to be the cause of impaction of the gastrointestinal tract during surgical exploration. The most common clinical signs at presentation were abdominal pain, abdominal distension and diarrhoea. A statistically significant association was found between the respiratory rate on arrival and short-term survival. Sand impaction at multiple locations was detected in one-third of the horses. Concurrent pathology was detected in half of t...
Peterbauer C, Larenza PM, Knobloch M, Theurillat R, Thormann W, Mevissen M, Spadavecchia C.To investigate the effect of plasma concentrations obtained by a low dose constant rate infusion (CRI) of racemic ketamine or S-ketamine on the nociceptive withdrawal reflex (NWR) in standing ponies. Methods: Prospective, blinded, cross-over study. Methods: Six healthy 5-year-old Shetland ponies. Methods: Ponies received either 0.6 mg kg(-1) racemic ketamine (group RS) or 0.3 mg kg(-1) S-ketamine (group S) intravenously (IV), followed by a CRI of 20 microg kg(-1)minute(-1) racemic ketamine (group RS) or 10 microg kg(-1)minute(-1) S-ketamine (group S) for 59 minutes. The NWR was evoked by trans...
Sanchez LC, Elfenbein JR, Robertson SA.To evaluate effects of butorphanol, acepromazine, and N-butylscopolammonium bromide (NBB) on visceral and somatic nociception and duodenal motility in conscious, healthy horses. Methods: 6 adult horses. Methods: Visceral nociception was evaluated by use of colorectal distention (CRD) and duodenal distention (DD) threshold. Somatic nociception was evaluated via thermal threshold (TT). Nose-to-ground height, heart rate, and respiratory rate were also measured. Each horse received each treatment in randomized order; investigators were not aware of treatments. Butorphanol was administered IV as a ...
Dória RG, Valadão CA, Duque JC, Farias A, Almeida RM, Netto AC.To evaluate the cardiorespiratory and behavioural effects of epidural xylazine (XYL) or clonidine (CLO) in horses. Methods: Blinded, randomized experimental study. Methods: Twelve healthy Arabian yearling horses weighing 117-204 kg were randomly allocated into two groups: XYL (n = 6) and CLO (n = 6). Methods: An epidural catheter was inserted and a facial arterial catheter was placed and the next day the horses were restrained in stocks. Baseline values for heart (HR) and respiratory (RR) rates, arterial pressure and behavioural responses were evaluated before (T0) and 10, 20, 30, 45, 60, 90 a...
Wagner AE, Mama KR, Steffey EP, Hellyer PW.To determine whether infusion of xylazine (XYL) and ketamine (KET) for 30 minutes after isoflurane administration in horses would result in improved quality of recovery from anesthesia, without detrimental cardiopulmonary changes. Methods: Randomized, blinded experimental trial. Methods: Seven healthy adult horses aged 6.4 +/- 1.9 years and weighing 506 +/- 30 kg. Methods: Horses were anesthetized twice, at least 1 week apart. On both occasions, anesthesia was induced by the administration of XYL, diazepam, and KET, and maintained with isoflurane for approximately 90 minutes, the last 60 minut...
Seddighi MR, Mohri M.To evaluate some of the clinical and laboratory parameters following diazepam-acepromazine, thiopental, and halothane anesthesia in Caspian ponies. Methods: Prospective experimental trial. Methods: Six healthy Caspian ponies of both sexes, aged 11 +/- 3 years and weighing 318 +/- 71 kg. Methods: The ponies were pre-medicated with diazepam (0.2 mg kg(-1)) and acepromazine (0.05 mg kg(-1)) IV. Sodium thiopental 5% was administered IV, 10 minutes later and anesthesia was maintained with halothane in oxygen for 1 hour. Heart and respiratory rates, mean arterial blood pressure, cardiac rhythm, and ...
Rossetti RB, Gaido Cortopassi SR, Intelizano T, de Lima Machado TS, Ferreira da Cruz RS.To compare the quality of induction and recovery, degree of muscle relaxation, clinically apparent potency and cardiopulmonary effects of racemic ketamine or S(+)-ketamine when used for total intravenous anesthesia in horses. Methods: Prospective randomized clinical trial Methods: Sixteen healthy stallions (323 +/- 99 kg), with a mean age of 6.2 years, undergoing castration. Methods: Horses were pre-medicated with romifidine IV, 15 minutes before induction of anesthesia. Each animal was then randomly allocated to receive either diazepam and ketamine (DK) or diazepam and S(+)-ketamine (DKS) at ...
Connysson M, Muhonen S, Lindberg JE, Essén-Gustavsson B, Nyman G, Nostell K, Jansson A.High-energy forage might be an alternative to concentrates for performance horses and such forage can be produced by an early cut. However, early cut forage is high in crude protein (CP), which may result in an excessive CP intake. Objective: To investigate how CP intake affects nitrogen (N), fluid and acid-base balance, and exercise response in horses fed high-energy forage diets. The hypothesis was that high CP intake causes acidosis, and alters fluid balance and response to intensive exercise. Methods: Two forage-only diets based on high-energy grass forage were fed for 23 days in a crossov...
Fielding CL, Brumbaugh GW, Matthews NS, Peck KE, Roussel AJ.To determine the pharmacokinetics and clinical effects of a subanesthetic, continuous rate infusion of ketamine administered to healthy awake horses. Methods: 8 adult horses. Methods: Ketamine hydrochloride was administered to 2 horses, in a pilot study, at rates ranging from 0.4 to 1.6 mg/kg/h for 6 hours to determine an appropriate dose that did not cause adverse effects. Ketamine was then administered to 6 horses for a total of 12 hours (3 horses at 0.4 mg/kg/h for 6 hours followed by 0.8 mg/kg/h for 6 hours and 3 horses at 0.8 mg/kg/h for 6 hours followed by 0.4 mg/kg/h for 6 hours). Conce...
Borer KE, Clarke KW.To determine whether hyoscine has a sparing effect on the volume of dobutamine required to maintain mean arterial pressure (MAP) at 70 mmHg in horses anaesthetized with halothane. Methods: Prospective, randomized, controlled clinical trial. Methods: Twenty adult horses weighing 507 +/- 97 kg (mean +/- SD), aged 10 +/- 5 years. Methods: Pre-anaesthetic medication in all horses was intramuscular (IM) acepromazine (40 mug kg(-1)) and intravenous (IV) detomidine (0.02 mg kg(-1)). Anaesthesia was induced with ketamine (2.2 mg kg(-1) IV) and diazepam (0.02 mg kg(-1) IV), and maintained with halothan...
Garcia Lascurain AA, Sumano Lopez H, Steffey EP, Santillán Doherty P, Hernandez EN.To characterize behavioral and physiological responses to short-term, unsupplemented intravenous (IV) anesthesia in healthy horses at high altitude (2240 m), and to test the hypothesis that the dose of butorphanol modifies the response of the horse to propofol anesthesia following xylazine pre-medication. Methods: Randomized prospective butorphanol dose cross-over experimental design. Animals Eight healthy horses, 13 +/- 6 (mean +/- SD) years of age, and weighing 523 +/- 26 kg. Methods: Each horse was anesthetized three times with at least 3 weeks between each anesthesia. After collecting pre-...
Derossi R, Miguel GL, Frazílio FO, Nunes DB, Kassab TA.Bupivacaine is available as a racemic mixture of its enantiomers, d-bupivacaine and l-bupivacaine (LB). The aim of this randomized, double-blind study was to investigate the clinical efficacy and safety of S(-)-bupivacaine compared with standard racemic bupivacaine (RB) in horses under caudal epidural analgesia. Two treatments were administered to each horse, with a 2-week interval between subsequent treatments. Treatment 1 consisted of 0.5% LB at a dose of 0.06 mg/kg of body weight, and treatment 2 consisted of 0.5% RB at a dose of 0.06 mg/kg of body weight. Epidural injections were given in ...
Corletto F, Raisis AA, Brearley JC.The aim of this study was to compare two different alpha2 agonist-opioid combinations in ponies undergoing field castration. Methods: Prospective double-blind randomized clinical trial. Methods: Fifty-four ponies undergoing field castration. Methods: The ponies were randomly allocated to receive one of three different pre-anaesthetic medications [intravenous (IV) romifidine 100 microg kg(-1) and butorphanol 50 micro kg(-1); romifidine 100 microg kg(-1) and morphine 0.1 mg kg(-1) IV, or romifidine 100 microg kg(-1) and saline IV] before induction of anaesthesia with ketamine 2.2 mg kg(-1) IV. F...
Clark L, Clutton RE, Blissitt KJ, Chase-Topping ME.To study the effects of morphine on haemodynamic variables, blood gas values and the requirement for additional anaesthetic drugs in horses undergoing surgery. Methods: Prospective randomized study. Methods: Thirty-eight client-owned horses, ASA(American Society of Anesthesiologists) category I or II, undergoing elective surgical procedures, were studied. Horses were divided between two groups, and were paired according to operation, anaesthetist, body position during surgery, mass and breed. Group M+ received morphine by intravenous (IV) injection (0.15 mg kg(-1)) before induction of anaesthe...
Lin HC, Johnson CR, Duran SH, Waldridge BM.To evaluate the cardiopulmonary and clinicopathologic effects of rapid IV administration of dimethyl sulfoxide (DMSO) in awake and halothane-anesthetized horses. Methods: Prospective study. Methods: 6 adult horses. Methods: Horses received IV infusion of 5 L of a balanced electrolyte solution with and without 1 g/kg (0.45 g/lb) of 10% DMSO solution when they were awake and anesthetized with halothane (4 treatments/horse). Arterial and venous blood samples were collected immediately before and at intervals during or after fluid administration and analyzed for blood gases and hematologic and ser...
Natalini CC, Robinson EP.Heart rate, arterial blood pressures, respiratory rate, body temperature, and central nervous system excitement were compared before and after epidural administration of morphine (0.1 mg/kg), butorphanol (0.08 mg/kg), alfentanil (0.02 mg/kg), tramadol (1.0 mg/kg), the k-opioid agonist U50488H (0.08 mg/kg), or sterile water using an incomplete Latin square crossover design in five conscious adult horses. Treatments were administered into the first intercoccygeal epidural space. Significant (P <.05) reductions in respiratory rate were detected after epidural administration of morphine, alfent...
Natalini CC, Alves SD, Guedes AG, Polydoro AS, Brondani JT, Bopp S.To evaluate the analgesic, physiologic, and behavioral effects of the epidural administration of tiletamine/zolazepam in horses. Methods: Prospective, double-blind, randomized experimental study. Methods: Five adult, healthy horses aged 10-16 years and weighing (mean +/- SD) 400 +/- 98 kg. Methods: The horses were sedated with 1.0 mg kg(-1) intravenous (IV) xylazine, and an epidural catheter was placed into the first intercoccygeal intervertebral space. After a 48-hour resting period, epidural tiletamine/zolazepam, 0.5 mg kg(-1) (treatment I) or 1.0 mg kg(-1) (treatment II), diluted up to 5 mL...
DeRossi R, Sampaio BF, Varela JV, Junqueira AL.Epidural administration of bupivacaine and meperidine produces analgesia in several animal species and in humans. A prospective randomized study was conducted in 18 healthy horses to compare the effect of these 2 drugs administered by the epidural route. Animals were divided into 3 treatment groups of 6 animals each. All drugs were injected by the epidural route in all animals between the 1st and 2nd coccygeal vertebrae. Treatment 1 (BUP)--0.06 mg/kg of body weight of 0.5% hyperbaric bupivacaine; treatment 2 (MEP)--0.6 mg/kg of body weight of 5% meperidine; treatment 3 (SS)--0.9% saline soluti...
Morgan K, Funkquist P, Nyman G.The aim of this study was to study the physiological, especially thermoregulatory, responses during intense exercise in the clipped horse compared to the horse with winter coat. Six Standardbred trotters were studied before and after clipping. They performed an inclined incremental high intensity treadmill exercise test and were monitored during recovery. The clipped horse differed significantly (ANOVA) during exercise as compare to coated: less increase in central venous blood temperature, higher skin surface temperature, greater difference skin to ambient temperature and higher rate of nonev...
Merritt AM, Xie H, Lester GD, Burrow JA, Lorenzo-Figueras M, Mahfoud Z.To evaluate the reliability of a method for inducing colic via small intestinal distention in horses and to examine the analgesic potential of bilateral electroacupuncture (EAP) at the Guan-yuan-shu (similar to BL21) acupoint. Methods: 5 healthy adult horses, each with a gastric cannula. Methods: A polyester balloon connected to an electronic barostat was introduced into the duodenum via the gastric cannula. At 2 specified intervals (before and after commencement of EAP), the balloon was inflated to a barostat-controlled pressure that induced signs of moderate colic. Each inflation was maintai...
Meyer GA, Lin HC, Hanson RR, Hayes TL.This study aimed to identify blood serum lidocaine concentrations in the horse which resulted in clinical signs of intoxication, and to document the effects of toxic levels on the cardiovascular and cardiopulmonary systems. Nineteen clinically normal mature horses of mixed breed, age and sex were observed. Lidocaine administration was initiated in each subject with an i.v. loading dose of 1.5 mg/kg bwt and followed by continuous infusion of 0.3 mg/kg bwt/min until clinical signs of intoxication were observed. Intoxication was defined as the development of skeletal muscle tremors. Prior to admi...
Marlin DJ, Schroter RC, White SL, Maykuth P, Matthesen G, Mills PC, Waran N, Harris P.The aims of the present field-based study were to investigate changes in fit horses undergoing acclimatisation to a hot humid environment and to provide data on which to base recommendations for safe transport and acclimatisation. Six horses (age 7-12 years) were flown from Europe to Atlanta and underwent a 16 day period of acclimatisation. Exercise conditions during acclimatisation (wet bulb globe temperature index 27.6+/-0.0 [mean +/- s.e.]) were more thermally stressful compared with the European climate from which the horses had come (22.0+/-1.8, P<0.001). Following the flight, weight l...
Matthews NS, Taylor TS, Skrobarcek CL, Williams JD.Three combinations of injectable anaesthetic agents were compared in nine adult mules. The combinations were xylazine/ketamine (X/K), xylazine/butorphanol/ketamine (X/B/K), and xylazine/tiletamine-zolazepam (X/T). Measured variables were heart rate, respiratory rate, systolic blood pressure, arterial blood pH, PCO2 and PO2, recumbency time and number of attempts to stand. Quality of induction and recovery, muscle relaxation and response to stimulus were evaluated subjectively. Recumbency time was significantly (P < 0.05) longer with X/B/K and X/T than with X/K. Mules required significantly mor...
Taylor PM, Bennett RC, Brearley JC, Luna SP, Johnson CB.To compare detomidine hydrochloride and romifidine as premedicants in horses undergoing elective surgery. Methods: 100 client-owned horses. Methods: After administration of acepromazine (0.03 mg/kg, IV), 50 horses received detomidine hydrochloride (0.02 mg/kg of body weight, IV) and 50 received romifidine (0.1 mg/kg, IV) before induction and maintenance of anesthesia with ketamine hydrochloride (2 mg/kg) and halothane, respectively. Arterial blood pressure and blood gases, ECG, and heart and respiratory rates were recorded. Induction and recovery were timed and graded. Results: Mean (+/- SD) d...
Stefánsdóttir GJ, Ragnarsson S, Gunnarsson V, Roepstorff L, Jansson A.This study compared the effect of ridden tölt and trot at 3 speeds on physiological responses in trained adult (15.3 ± 1.6 yr) Icelandic horses. The experiment had a crossover design with 8 horses, 2 treatments (incremental exercise test in tölt and trot), and 2 riders. Each horse performed 2 tests per day (1 gait with 2 riders, minimum 4.5 h between) on 2 separate days, with 1 d of rest in between. The exercise test consisted of three 642-m phases at 3.0 m/s (Speed), 4.0 m/s (Speed), and 5.0 m/s (Speed) and was performed outdoors on a 300-m oval gravel riding track in northern Iceland in M...
Stopyra A, Sobiech P, Waclawska-Matyjasik A.The acid-base equilibrium is closely linked to gas exchange in the lungs, and respiratory exchange ratios are used to evaluate respiratory effectiveness and tissue oxygen levels. Acid-base indicators are determined in both arterial and venous blood samples. This study compares the usefulness of acid-base indicators of venous and arterial blood in monitoring the condition of horses with recurrent airway obstruction. Prior to treatment involving bronchodilating glucocorticoids, expectorant and mucolytic drugs, more pronounced changes were observed in venous blood (pH 7.283, pCO2 61.92 mmHg, pO2 ...
Muir WW, Skarda RT, Sheehan WC.The cardiopulmonary effects of two xylazine-morphine sulfate drug combinations (mixtures) given IV were evaluated in horses. In horses given xylazine (0.66 mg/kg of body weight) and morphine sulfate (0.12 mg/kv) IV (experiment 1), there were significant (P less than 0.05) decreases in heart rate, cardiac output, and respiratory rate. Central venous pressure was significantly (P less than 0.05) increased. Arterial and pulmonary arterial blood pressures increased significantly (P less than 0.05) but transiently. Arterial blood gas tensions (PaCO2 and PaO2) and pH remained unchanged. In the horse...
Van Dijk P, Lankveld D, Rijkenhuizen A, Jonker FH.To assess the hormonal, metabolic and physiological effects of laparascopic surgery performed under a sedative analgesic combination of detomidine and buprenorphine in standing horses. Methods: Prospective study. Methods: Eight healthy adult Dutch Warmblood horses and five healthy adult ponies undergoing laparoscopy were studied. Five healthy adult horses not undergoing laparoscopy were used as a control group. Methods: The sedative effect of an initial detomidine and buprenorphine injection was maintained using a continuous infusion of detomidine alone. The heart and respiratory rate, arteria...
Fielding CL, Brumbaugh GW, Matthews NS, Peck KE, Roussel AJ.To determine the pharmacokinetics and clinical effects of a subanesthetic, continuous rate infusion of ketamine administered to healthy awake horses. Methods: 8 adult horses. Methods: Ketamine hydrochloride was administered to 2 horses, in a pilot study, at rates ranging from 0.4 to 1.6 mg/kg/h for 6 hours to determine an appropriate dose that did not cause adverse effects. Ketamine was then administered to 6 horses for a total of 12 hours (3 horses at 0.4 mg/kg/h for 6 hours followed by 0.8 mg/kg/h for 6 hours and 3 horses at 0.8 mg/kg/h for 6 hours followed by 0.4 mg/kg/h for 6 hours). Conce...
Guedes AG, Matthews NS, Hood DM.To investigate the effects of ketamine hydrochloride on the analgesic effects of tramadol hydrochloride in horses with signs of pain associated with naturally occurring chronic laminitis. Methods: 15 client-owned adult horses with chronic laminitis. Methods: Each horse received tramadol alone or tramadol and ketamine in a randomized, crossover study (≥ 2 months between treatments). Tramadol (5 mg/kg) was administered orally every 12 hours for 1 week. When appropriate, ketamine (0.6 mg/kg/h) was administered IV for 6 hours on each of the first 3 days of tramadol administration. Noninvasive sy...
Van Dijk P, Lankveld D, Rijkenhuizen A, Jonker FH.To assess the hormonal, metabolic and physiological effects of laparascopic surgery performed under a sedative analgesic combination of detomidine and buprenorphine in standing horses. Methods: Prospective study. Methods: Eight healthy adult Dutch Warmblood horses and five healthy adult ponies undergoing laparoscopy were studied. Five healthy adult horses not undergoing laparoscopy were used as a control group. Methods: The sedative effect of an initial detomidine and buprenorphine injection was maintained using a continuous infusion of detomidine alone. The heart and respiratory rate, arteria...
Muñoz A, Riber C, Trigo P, Castejón FM, Lucas RG, Palacio J.This study investigated the effect of hypertonic dehydration on exercise in horses. Valencian draft horses (n=43) with hypertonic dehydration following water and food deprivation and competing in pulling events (COM), were compared to euhydrated horses (n=11) during a pulling exercise test (PET). Both groups were divided into bodyweight (BW) categories A (≤350 kg), B (351-450 kg), and C (≥451 kg), and pulled 2, 2.25, and 2.5 times BW, respectively. Exercise duration (ED) was 1.3±0.8 min. Heart rate, respiratory rate, rectal temperature and blood samples were taken at rest, after exercise,...
Muir WW, Gadawski JE, Grosenbaugh DA.To determine cardiorespiratory effects of a tiletamine/zolazepam-ketamine-detomidine (TZKD) combination in horses. Methods: 8 healthy adult horses. Methods: Horses were instrumented for measurement of cardiorespiratory, acid-base, and electrolyte values. Each horse was given xylazine (0.44 mg/kg of body weight, IV) 10 to 15 minutes prior to induction of recumbency by administration of the TZKD combination. Cardiorespiratory, acid-base, and electrolyte values were measured at 5-minute intervals for > or =30 minutes. Results: All horses became recumbent within 1 minute after IV administration of...
Bossut DF, Leshin LS, Stromberg MW, Malven PV.Electro-acupuncture (EA) treatment of horses to induce cutaneous analgesia also increased plasma concentrations of beta-endorphin (beta-EP) and cortisol. The magnitude of these increases did not relate consistently to the degree of EA-induced analgesia. Respiration and heart rates were also markedly increased during EA treatment. Intact female horses had higher packed cell volume and plasma beta-EP as well as lower plasma total protein than castrated male horses. Plasma cortisol, heart rate, and respiration rate did not differ significantly between sexes. None of the parameters measured before...
Quattrini C, Bozorgmanesh R, Egli P, Magdesian KG.Fecal microbiota transplant (FMT) is increasingly administered as part of the treatment of colitis in horses, yet there is little data as to its effectiveness. Retrospective evaluation of the effects of FMT on discharge status, fecal consistency, length of hospitalization, and improvement in clinical signs in horses hospitalized for diarrhea. Retrospective case-control study. Medical records of adult horses (>1 year old) that received at least one transfaunation treatment (2013-2018) in two referral hospitals were identified through a medical records database search. Medical records of contemp...
Leblanc PH, Eberhart SW.This study was designed to determine whether the epidural administration of an alpha2 agonist, xylazine, would produce measurable changes in arterial blood pressure, electrocardiographic (ECG) activity and arterial blood gas values in horses. Six horses were given each of four treatments: epidural xylazine, intravenous xylazine, epidural lidocaine and epidural saline. A carotid artery catheter was used to measure arterial blood pressure and to collect samples for blood gas analysis before treatment and at intervals post treatment. Heart rate, arterial pressures, ECG activity and respiratory ra...
Nilsfors L, Kvart C, Kallings P, Carlsten J, Bondesson U.Cardiorespiratory and sedative effects of a combination of acepromazine, xylazine and methadone were studied in the horse. Acepromazine and xylazine produced cardiovascular effects whereas methadone mainly affected respiratory rate. Decreases in heart rate, arterial blood pressure and respiratory rate were seen. Sedation was superior to that of acepromazine, xylazine or a combination of these. No serious side effects were seen.
Luna SP, Beale NJ, Taylor PM.Atipamezole antagonism of xylazine sedation was evaluated in six ponies. Atipamezole (0.15 mg/kg) or saline was injected intravenously 15 minutes after the ponies had been sedated with xylazine (1.0 mg/kg). Arterial blood pressure and gases, pulse and respiratory rates, the electrocardiogram, nose-to-ground distance and a subjective sedation score were recorded. The pretreatment nose-to-ground distance and PaO2 returned to normal sooner after atipamezole than after saline and the ponies' appetite and normal locomotion also recovered sooner. No significant differences were observed between the ...
Nyman G, Grubb TL, Heinonen E, Frendin J, Edner A, Malavasi LM, Frostell C, Högman M.The study aimed to investigate the effect of varying pulse lengths of inhaled nitric oxide (iNO), and 2.5 hours of continuous pulse-delivered iNO on pulmonary gas exchange in anaesthetized horses. Methods: Experimental study. Methods: Six Standardbred horses. Methods: Horses received acepromazine, detomidine, guaifenesin, thiopentone and isoflurane in oxygen, were positioned in dorsal recumbency and were breathing spontaneously. iNO was on average pulsed during the first 20, 30, 43 or 73% of the inspiration in 15 minute steps. The pulse length that corresponded to the highest (peak) partial pr...
Muir WW, Mason DE.The cardiorespiratory effects of thiamylal (10 mg/kg of body weight, IV) and the effects of preanesthetic medication with diazepam, acepromazine, detomidine, or xylazine administered prior to a thiamylal dosage of 6 mg/kg, IV, were evaluated in 6 adult horses. The quality of recovery from thiamylal anesthesia also was evaluated. Intravenous administration of thiamylal at a dosage of 10 mg/kg increased heart rate, systemic arterial, pulmonary artery, and central venous blood pressures, as well as cardiac output and arterial partial pressure of CO2 (PaCO2). The maximal rate of right ventricular ...
Dória RG, Valadão CA, Duque JC, Farias A, Almeida RM, Netto AC.To evaluate the cardiorespiratory and behavioural effects of epidural xylazine (XYL) or clonidine (CLO) in horses. Methods: Blinded, randomized experimental study. Methods: Twelve healthy Arabian yearling horses weighing 117-204 kg were randomly allocated into two groups: XYL (n = 6) and CLO (n = 6). Methods: An epidural catheter was inserted and a facial arterial catheter was placed and the next day the horses were restrained in stocks. Baseline values for heart (HR) and respiratory (RR) rates, arterial pressure and behavioural responses were evaluated before (T0) and 10, 20, 30, 45, 60, 90 a...
Rossetti RB, Gaido Cortopassi SR, Intelizano T, de Lima Machado TS, Ferreira da Cruz RS.To compare the quality of induction and recovery, degree of muscle relaxation, clinically apparent potency and cardiopulmonary effects of racemic ketamine or S(+)-ketamine when used for total intravenous anesthesia in horses. Methods: Prospective randomized clinical trial Methods: Sixteen healthy stallions (323 +/- 99 kg), with a mean age of 6.2 years, undergoing castration. Methods: Horses were pre-medicated with romifidine IV, 15 minutes before induction of anesthesia. Each animal was then randomly allocated to receive either diazepam and ketamine (DK) or diazepam and S(+)-ketamine (DKS) at ...
Carter SW, Robertson SA, Steel CJ, Jourdenais DA.Six healthy foals underwent instrumentation for measurement of the cardiopulmonary effects of sedation with 1.1 mg/kg bodyweight xylazine hydrochloride given intravenously. Responses to xylazine in foals at 10 and 28 days of age were not significantly different. Foals became sedate and markedly ataxic, and four of the six foals became recumbent. Heart rate decreased significantly but no arrhythmias were detected. Arterial blood pressure increased initially and then fell significantly below pre-injection values. Changes in respiratory airflow, upper airway obstruction and respiratory noise were...
Raidal SL, Catanchin M, Sacks M, Carstens A, Quinn C, Mosing M.Continuous positive airway pressure (CPAP) and pressure support ventilation (PSV) can improve respiratory mechanics and gas exchange, but different airway pressures have not been compared in foals. Objective: Assess the effect of different airway pressures during CPAP and PSV have on respiratory function in healthy foals with pharmacologically induced respiratory insufficiency. We hypothesized that increased airway pressures would improve respiratory mechanics and increased positive end-expiratory pressure (PEEP) would be associated with hypercapnia. Methods: Six healthy foals from a universit...
Aarnes TK, Lerche P, Bednarski RM, Hubbell JAE.This study evaluated use of midazolam, ketamine, and xylazine (MKX) for total intravenous (IV) anesthesia (TIVA) in horses. Medical records of 46 horses undergoing a clinical procedure using MKX for TIVA were reviewed. Age, breed, procedure, heart rate (HR), respiratory rate (RR), pre-anesthetic drugs, induction drugs, and total volume of MKX were recorded. Duration of anesthesia, time to standing, number of attempts to stand, and recovery score were also recorded. All horses were premedicated with an alpha-2 adrenoceptor agonist and anesthesia was induced with ketamine and midazolam. Duration...
Janczarek I, Wilk I, Zalewska E, Bocian K.The aim of this paper was to select atmospheric factors and their values, which may disrupt the correct behavior and physiological condition of recreational horses. The studies were carried out from 1 July until 1 September on 16 Anglo-Arabian geldings. Each day, from 09.00 to 10.00 hours, the horses worked under saddle. The riders and the authors gave a qualitative behavioral assessment for each horse. Mood and willingness to work were evaluated. The quantitative assessment was called 'incorrect behavior of the horse while riding' (IBHR). The percentage time of duration and the number of occu...
Roşu O, Melega I, Evans AL, Arnemo JM, Küker S.Feral horses are immobilized for a variety of reasons including population control via contraceptives. Although opioid combinations have been successfully used for immobilization of feral horses, there is a need for combinations using drugs that are more readily available and present less of a human health hazard. We evaluated the chemical immobilization with physiological measurements and blood gas analyses of 91 free-ranging feral horses () remotely immobilized with a combination of 30 mg medetomidine and 775 mg ketamine in a single disposable 6 ml dart. During immobilization, heart rate, re...
Hubbell JA, Muir WW, Sams RA.We determined the cardiopulmonary changes in horses given guaifenesin alone and in the same horses given xylazine (IV) immediately before administration of guaifenesin. In addition, plasma guaifenesin concentrations were determined in horses and 2 pregnant mares and compared with previously published values in ponies. The dose of guaifenesin necessary to produce lateral recumbency in adult horses was 134 +/- 34 mg/kg (mean +/- SD). The administration of guaifenesin caused insignificant (P less than 0.05) changes in heart rate, respiratory rate, right atrial pressure, pulmonary arterial pressur...
Hashem A, Keller H.The pharmacokinetics and pharmacological efficacy of orally (p.o.) administered acepromazine were studied and compared with the intravenous (i.v.) route of administration in a cross-over study using six horses. The oral kinetics of acepromazine can be described by a two-compartment open model with first-order absorption. The drug was rapidly absorbed after p.o. administration with a half-life of 0.84 h, tmax of 0.4 h and Cmax of 59 ng/ml. The elimination was slower after p.o. administration (half-life 6.04 h) than after i.v. injection (half-life 2.6 h). The bioavailability of the orally admini...
Nolan AM, Hall LW.The effects of four intravenous combinations, xylazine (0.7 mg/kg)/methadone (0.1 mg/kg), xylazine (0.7 mg/kg)/buprenorphine (0.004 and 0.006 mg/kg) and acepromazine (0.05 mg/kg)/buprenorphine (0.006 mg/kg) on arterial blood pressure, central venous pressure, heart rate, respiratory rate and blood gases were studied in four experimental ponies. With xylazine/buprenorphine and xylazine/methadone onset of sedation was rapid and obvious and although no surgical or diagnostic procedures were carried out, sedation was judged to be satisfactory for the next 30 to 40 minutes. Onset of sedation after ...
Uhlinger C.Black walnut toxicosis was diagnosed in 10 horses at one stable. The time from exposure to shavings to development of clinical signs was 8 to 12 hours. Most common clinical signs were moderate to severe laminitis (Obel grade 2 or 3), pitting edema of the distal portion of the limbs, and rapid respiratory rate. Two horses had clinical signs of colic and 2 other horses had anorexia and lethargy. All 10 horses recovered without complications.
