The placebo effect in horses refers to the phenomenon where a horse experiences a perceived or actual improvement in condition following a treatment that has no therapeutic effect. This effect is often observed in clinical trials and studies where control groups receive a placebo treatment to assess the efficacy of a new drug or therapy. Understanding the placebo effect in horses is important for designing rigorous equine research studies, as it helps distinguish between the actual effects of a treatment and psychological or physiological responses that are not directly caused by the treatment itself. This page compiles peer-reviewed research studies and scholarly articles that explore the mechanisms, implications, and methodologies for accounting for the placebo effect in equine research.
Broeckx SY, Martens AM, Bertone AL, Van Brantegem L, Duchateau L, Van Hecke L, Dumoulin M, Oosterlinck M, Chiers K, Hussein H, Pille F, Spaas JH.There is a need to improve therapies for osteoarthritis in horses. Objective: To assess the efficacy of equine allogeneic chondrogenic-induced mesenchymal stem cells combined with equine allogeneic plasma as a novel therapy for osteoarthritis in horses. Methods: Randomised, double-blinded, placebo-controlled experiment. Methods: In 12 healthy horses, osteoarthritis was induced in the metacarpophalangeal joint using an osteochondral fragment-groove model. Five weeks after surgery, horses were randomly assigned to either an intra-articular injection with chondrogenic-induced mesenchymal stem cel...
Lavoie JP, Bullone M, Rodrigues N, Germim P, Albrecht B, von Salis-Soglio M.Inhaled corticosteroids are effective for the treatment of equine asthma but they induce cortisol suppression with potential side effects. Objective: To study the efficacy of ciclesonide, an inhaled corticosteroid with an improved safety profile, on lung function, clinical signs related to airway obstruction, and serum cortisol levels in asthmatic horses exposed to a mouldy hay challenge. Methods: Cross-over placebo controlled, blinded, randomised experiment. Methods: Sixteen horses were enrolled in three subsequent dose-titration studies (8 horses/study) to investigate the effects of inhaled ...
Urubschurov V, Stroebel C, Günther E, Romanowski K, Büsing K, Zeyner A.Effects of probiotics on the intestinal microbiota of foals are yet insufficiently studied. The aim of this study was to investigate whether supplementation of Lactobacillus rhamnosus (DSM 7133) and Enterococcus faecium (DSM 7134) influences the bacterial composition of the faecal microbiota of foals. A total of 34 newborn foals were randomly assigned to the placebo group (PG, n = 16) and the treatment group (TG, n = 18). From day 1 to day 14 of life, foals orally received 3 ml of either a probiotic preparation (1.05 × 10 CFU E. faecium and 4.50 × 10 CFU L. rhamnosus) or placebo (...
Donnelly CG, Sones JL, Dockweiler JC, Norberg LA, Norberg LE, Cheong SH, Gilbert RO.OBJECTIVE To evaluate use of flunixin meglumine as a treatment to postpone ovulation in mares, mare fertility after flunixin meglumine treatment during estrous cycles, and effects of flunixin meglumine on function of the corpus luteum after ovulation. ANIMALS 13 healthy mares. PROCEDURES A single-blinded, placebo-controlled, crossover study was conducted. Flunixin meglumine (1.1 mg/kg, IV, q 24 h) or lactated Ringer solution (placebo treatment) was administered for 2 days to mares with a dominant follicle (≥ 35 mm in diameter) and behavioral signs of estrus. Mares then were bred by artificia...
Morresey PR, White GW, Poole HM, Hu T, Yin M, Sundman EA.OBJECTIVE To evaluate the effectiveness and safety of dipyrone to control pyrexia in horses with naturally occurring disease under field conditions. ANIMALS 138 horses with pyrexia and various infections evaluated at 14 veterinary sites in 12 states. PROCEDURES In the first (effectiveness) phase of this 2-phase study, horses were randomly assigned 3:1 to receive 1 dose of dipyrone (30 mg/kg [13.6 mg/lb], IV) or an equivalent amount of placebo. Effectiveness was defined as a decrease in rectal temperature ≥ 1.1°C (2°F), compared with the pretreatment value, or a rectal temperature of ≤ 38...
Meier A, de Laat M, Reiche D, Fitzgerald D, Sillence M.A previous six-week (wk) study demonstrated the potential of the sodium-glucose linked transport inhibitor velagliflozin as a novel treatment for equine insulin dysregulation. The present study examined the safety and efficacy of velagliflozin over 16 wk. of treatment, and over 4 wk. of withdrawal. Twenty-four insulin dysregulated ponies were selected, based on their hyper-responsiveness to a diet challenge meal containing 3.8 g non-structural carbohydrates (NSC)/kg bodyweight (BW). Ponies with serum insulin > 90 μIU/mL either 2 or 4 h after feeding were enrolled, and randomly allocated...
Schoonover MJ, Whitfield CT, Young JM, Sippel KM, Payton ME.OBJECTIVE To determine effects for 2 IV regional limb perfusion (IVRLP) protocols involving tiludronate on lameness of horses with navicular syndrome. ANIMALS 15 horses with bilateral forelimb navicular syndrome. PROCEDURES Shoeing and anti-inflammatory injection into the distal interphalangeal joint (DIPJ) of both forelimbs (day 0) were performed on all horses. On day 14, horses received 1 of 3 IVRLPs consisting of 0.1 mg of tiludronate/kg (low-dose tiludronate [LDT]; n = 5), 0.2 mg of tiludronate/kg (high-dose tiludronate [HDT]; 5), or saline (0.9% NaCl) solution (placebo; 5); treatments wer...
Richardson LM, Whitfield-Cargile CM, Cohen ND, Chamoun-Emanuelli AM, Dockery HJ.To determine whether a cyclooxygenase (COX)-2 selective nonsteroidal anti-inflammatory drug (NSAID) would reduce gastric ulceration and gastrointestinal (GI) inflammation compared with a non-COX selective NSAID. Methods: Randomized block design. Methods: Twenty-five healthy adult horses. Methods: Horses were randomly assigned to receive placebo (n = 5), phenylbutazone (n = 10), or firocoxib (n = 10) administered daily for 10 days. Gastroscopy was performed on days 0 and 10, and both squamous and glandular ulcers were scored according to established scoring criteria. Fecal samples w...
Bannai H, Nemoto M, Tsujimura K, Yamanaka T, Kokado H, Kondo T, Matsumura T.Immune responses were compared after intranasal (IN) and intramuscular (IM) vaccination of horses with a modified live equine herpesvirus type-1 (EHV-1) vaccine, and the protective effect after EHV-1 challenge was evaluated. IN- and IM-vaccinated groups (n = 5 each) showed significant rises in serum virus-neutralizing titers with increased levels of IgGa and IgGb antibodies after the first vaccination (P < 0.05). In nasal secretions, the IN group had significantly increased levels of IgA antibodies after vaccination (P < 0.05), whereas the response of the IM group was dominat...
Niemelä TM, Tulamo RM, Aaltonen K, Sankari SM, Hielm-Björkman AK.Inflammatory and degenerative activity inside the joint can be studied in vivo via analysis of synovial fluid (SF) biomarkers, which are molecular markers of inflammatory processes and tissue turnover. The aim of this study was to investigate the response of selected biomarkers in the SF after an intra-articular (IA) high-molecular-weight non-animal stabilized hyaluronic acid (NASHA) treatment. Our hypothesis was that prostaglandin E (PGE), substance P, aggrecan chondroitin sulfate 846 epitope (CS846), and carboxypeptide of type II collagen (CPII) concentrations in SF would decrease more in th...
Ströbel C, Günther E, Romanowski K, Büsing K, Urubschurov V, Zeyner A.Foal first diarrhoea is one of the most prominent problems in the early life of horses. Probiotics might have the potency to prevent or at least diminish neonatal diarrhoea. We hypothesised that the treatment of foals with probiotic strains of Lactobacillus rhamnosus and Enterococcus faecium starting early after birth and then daily over 2 weeks would prevent or mitigate foal heat diarrhoea. The influence of this probiotic treatment on diarrhoea incidence and growth and health performance of young foals was investigated. Thirty-four foals were randomly allocated to two groups. From day 1 to 1...
Tosi I, Bureau F, Farnir F, Denoix JM, Lekeux P, Art T.Cytosine-phosphate-guanosine (CpG-ODN) has been described as a potent immunostimulatory agent in different species. No study reported the effect of a P-class CpG when administered systemically in healthy horses. The aim of this study was to evaluate the tolerance and the effect of an intramuscularly administered P-class CpG-ODN on hematology and on plasma cytokines (IFN-α, IL-10, TNF-α, IFN-γ) in 8 healthy horses. Intra-muscular CpG-ODN or placebo (PBS) was administered twice at a 7 days-interval. Groups were inversed after 2 months of washout period. A physical examination, complete bloo...
Fettelschoss-Gabriel A, Fettelschoss V, Thoms F, Giese C, Daniel M, Olomski F, Kamarachev J, Birkmann K, Bühler M, Kummer M, Zeltins A, Marti E....Insect-bite hypersensitivity is the most common allergic dermatitis in horses. Excoriated skin lesions are typical symptoms of this seasonal and refractory chronic disease. On a cellular level, the skin lesions are characterized by massive eosinophil infiltration caused by an underlying allergic response. To target these cells and treat disease, we developed a therapeutic vaccine against equine IL-5 (eIL-5), the master regulator of eosinophils. The vaccine consisted of eIL-5 covalently linked to a virus-like particle derived from cucumber mosaic virus containing the tetanus toxoid universal T-...
Christen G, Gerber V, van der Kolk JH, Frey CF, Fouché N.Pituitary pars intermedia dysfunction (PPID) has been associated with diminished immune response in aged horses. This prospective study hypothesised that this may result in increased strongyle egg shedding in affected animals and that horses treated with pergolide would have reduced fecal egg counts (eggs per gram, EPG) compared to placebo-treated animals. Adrenocorticotropic hormone (ACTH) concentrations and EPG were tested in 48 horses. There were no significant differences in baseline EPG between horses with pre-clinical PPID and healthy controls. There was no significant difference in EPG ...
Jacquet-Guibon S, Dupays AG, Coudry V, Crevier-Denoix N, Leroy S, Siñeriz F, Chiappini F, Barritault D, Denoix JM.A randomized controlled trial was performed on racing horses, to evaluate the efficacy of a new class of therapeutic agents in regenerative medicine-ReGeneraTing Agents® (RGTA®), to treat tendinopathies. Preliminary uncontrolled studies on tendon healing in racing horses with RGTA® (OTR4131)-Equitend® showed encouraging results, justifying performing a randomized, controlled, multicenter study with a two-year racing performance follow up. The objective of this study was to evaluate the effect of Equitend® versus placebo on acute superficial digital flexor tendonitis in racing French Stand...
Pedersen SK, Cribb AE, Read EK, French D, Banse HE.In equids, phenylbutazone at high doses induces gastric disease, primarily in the glandular portion of the stomach. However, the mechanism of nonsteroidal anti-inflammatory drug (NSAID)-induced gastric disease in horses has yet to be determined. While phenylbutazone-associated ulceration is often attributed to a decrease in basal gastric prostaglandins, this has not been demonstrated in the horse. Twelve horses were randomly assigned to treatment (n = 6; 4.4 mg/kg phenylbutazone PO in 20 ml molasses q 12 hr for 7 days) or placebo (n = 6; 20 ml molasses PO q 12 hr for 7 days) groups....
Haspeslagh M, Jordana Garcia M, Vlaminck LEM, Martens AM.Previous studies mention the use of topical acyclovir for the treatment of equine sarcoids. Success rates vary and since the bovine papillomavirus (BPV) lacks the presence of a kinase necessary to activate acyclovir, there is no proof of its activity against equine sarcoids. Results: Twenty-four equine sarcoids were topically treated with acyclovir cream and 25 with a placebo. Both creams were applied twice daily during 6 months. Before the start of the treatment and further on a monthly basis, photographs and swabs were obtained. On the photographs, sarcoid diameter and surface area were meas...
Allison A, Robinson R, Jolliffe C, Taylor PM.There are limited investigations comparing ketamine to a ketamine-midazolam co-induction. Objective: To compare quality and safety of general anaesthesia induced using ketamine alone with anaesthesia co-induced using ketamine and midazolam. Methods: Randomised, double blinded, placebo controlled trial. Methods: After i.v. detomidine (20 μg/kg) thirty-eight ponies undergoing field castration received either 0.06 mg/kg (0.6 mL/50 kg) midazolam (group M) or 0.6 mL/50 kg placebo (group P) with 2.2 mg/kg ketamine i.v. for anaesthetic induction. Quality of anaesthetic induction, endotracheal intuba...
Saville WJA, Dubey JP, Marsh AE, Reed SM, Keene RO, Howe DK, Morrow J, Workman JD.Equine protozoal myeloencephalitis (EPM) is an important equine neurologic disorder, and treatments for the disease are often unrewarding. Prevention of the disease is the most important aspect for EPM, and a killed vaccine was previously developed for just that purpose. Evaluation of the vaccine had been hampered by lack of post vaccination challenge. The purpose of this study was to determine if the vaccine could prevent development of clinical signs after challenge with Sarcocystis neurona sporocysts in an equine challenge model. Seventy horses that were negative for antibodies to S. neuron...
Huxford KE, Dart AJ, Perkins NR, Bell R, Jeffcott LB.AIMS To compare the efficacy of an enteric coated esomeprazole paste with an enteric coated omeprazole paste to increase gastric pH after oral administration in horses. METHODS Nine adult Standardbred horses were randomly assigned to three groups, each containing three horses, for a study comprising three phases of 10 days, with an 18-day washout period between each phase. In each phase, three horses received either 0.5 mg/kg esomeprazole, 1 mg/kg omeprazole or a placebo, as an oral paste, once daily for 10 days (Days 0-9). Over the course of study all horses received all three treatments....
Watts AE, Millar NL, Platt J, Kitson SM, Akbar M, Rech R, Griffin J, Pool R, Hughes T, McInnes IB, Gilchrist DS.Tendon injuries (tendinopathies) are common in human and equine athletes and characterized by dysregulated collagen matrix, resulting in tendon damage. We have previously demonstrated a functional role for microRNA29a (miR29a) as a post-transcriptional regulator of collagen 3 expression in murine and human tendon injury. Given the translational potential, we designed a randomized, blinded trial to evaluate the potential of a miR29a replacement therapy as a therapeutic option to treat tendinopathy in an equine model that closely mimics human disease. Tendon injury was induced in the superficial...
Ness SL, Frye AH, Divers TJ, Rishniw M, Erb HN, Brooks MB.OBJECTIVE To determine effects of oral administration of Yunnan Baiyao on platelet activation, coagulation, and fibrinolysis in healthy horses. ANIMALS 12 healthy adult horses. PROCEDURES In a randomized blinded crossover study that included a 4-week washout period between treatments, horses were orally administered a paste containing Yunnan Baiyao (15 mg/kg) or placebo at 12-hour intervals for 3 days. Blood samples were collected before start of treatment (time 0) and at 24 and 72 hours for a CBC, measurement of fibrinogen concentration, coagulation screening tests, and a panel of assays to a...
Gozalo-Marcilla M, Luna SP, Crosignani N, Filho JNP, Possebon FS, Pelligand L, Taylor PM.To evaluate intravenous (IV) detomidine with methadone in horses to identify a combination which provides sedation and antinociception without adverse effects. Methods: Randomized, placebo-controlled, blinded, crossover. Methods: A group of eight adult healthy horses aged (mean ± standard deviation) 7 ± 2 years and 372 ± 27 kg. Methods: A total of six treatments were administered IV: saline (SAL); detomidine (5 μg kg; DET); methadone (0.2 mg kg; MET) alone or combined with detomidine [2.5 (MLD), 5 (MMD) or 10 (MHD) μg kg]. Thermal, mechanical and electrical nociceptive thresholds were mea...
Serrano-Rodríguez JM, Gómez-Díez M, Esgueva M, Castejón-Riber C, Mena-Bravo A, Priego-Capote F, Ayala N, Caballero JMS, Muñoz A.Pharmacokinetic and pharmacodynamic (PK/PD) properties of the angiotensin-converting enzyme inhibitor (ACEI) benazeprilat have not been evaluated in horses. This study was designed to establish PK profiles for benazepril and benazeprilat after intravenous (IV) and oral (PO) administration of benazepril using a PK/PD model. This study also aims to determine the effects of benazeprilat on serum angiotensin converting enzyme (ACE), selecting the most appropriate dose that suppresses ACE activity. Six healthy horses in a crossover design received IV benazepril at 0.50mg/kg and PO at doses 0 (place...
Giguère S.Pneumonia caused by Rhodococcus equi remains an important cause of disease and death in foals. The combination of a macrolide (erythromycin, azithromycin, or clarithromycin) with rifampin remains the recommended therapy for foals with clinical signs of infection caused by R equi. Most foals with small, subclinical ultrasonographic pulmonary lesions associated with R equi recover without therapy, and administration of antimicrobial agents to these subclinically affected foals does not hasten lesion resolution relative to administration of a placebo. Resistance to macrolides and rifampin in isol...
Watts AE, Dabareiner R, Marsh C, Carter GK, Cummings KJ.OBJECTIVE To determine the effect of resveratrol administration in performance horses with lameness localized to the distal tarsal joints. DESIGN Randomized, blinded, placebo-controlled clinical trial. ANIMALS 45 client-owned horses with lameness localized to the distal tarsal joints. PROCEDURES All horses received injections of triamcinolone acetonide in the centrodistal and tarsometatarsal joints of both hind limbs. A placebo or a supplement containing resveratrol was fed twice daily by owners for 4 months. Primary outcomes were horse performance as determined by rider opinion (better, worse...
Silk LN, Greene DA, Baker MK, Jander CB.Engagement in high volumes of physical activity coupled with energy restriction during periods of musculoskeletal development may compromise bone health. Jockeys limit caloric intakes on a weekly basis often from their mid-to-late teens. The aim of this study was to establish whether calcium and vitamin D supplementation would improve bone turnover markers (BTM) and non-weight bearing bone properties of young male jockeys. Methods: A six-month randomised, double-blinded, placebo-controlled trial with two groups of apprentice male jockeys was conducted. Methods: Participants (age 20.18±3.23yea...
Wilson CS, Brookes VJ, Hughes KJ, Trope GD, Ip H, Gunn AJ.In human subjects, arytenoid chondritis can be caused by chemical trauma of mucosa attributable to gastro-oesophageal reflux. Although a similar process may be involved in the aetiopathogenesis of arytenoid chondritis in horses, the oesophageal lumen pH in this species is poorly understood. Objective: To determine if gastro-oesophageal reflux occurs in horses by characterising oesophageal lumen pH. Methods: Blinded, randomised, placebo-controlled, crossover, experimental study. Methods: Luminal oesophageal pH in six yearling horses was recorded over four 24 h periods using an ambulatory pH rec...
Noble GK, Li X, Zhang D, Sillence MN.Tryptophan (TRP) is marketed as a calmative for horses despite reservations about its efficacy. The aim of this study was to measure the effect of oral TRP administration on the reaction speed of horses. Sixty mature horses were used in a two stage randomised, blind, cross-over study, receiving a placebo and an oral dose of TRP (30, 60 or 120 mg/kg body weight), before undergoing a reaction speed test. Blood samples were taken up to 96 h after TRP administration, to identify signs of acute haemolytic anaemia. Plasma TRP concentrations were increased (P <0.001) by the administration of...
Niemelä TM, Tulamo RM, Hielm-Björkman AK.Intra-articular inflammation resulting in lameness is a common health problem in horses. Exogenous intra-articular hyaluronic acid has been shown to provide an analgesic effect and reduce pain in equine and human osteoarthritis. High molecular weight non-animal stabilized hyaluronic acid (NASHA) has gained popularity in the treatment of human arthritic conditions due to its long-acting pain-relieving effects. The aim of this study was to compare the response to treatment of lameness localized in the equine metacarpophalangeal joint injected with non-animal stabilized hyaluronic acid (NASHA) an...
Foekel C, Schubert R, Kaatz M, Schmidt I, Bauer A, Hipler UC, Vogelsang H, Rabe K, Jahreis G.In a double-blind, placebo-controlled crossover trial, 23 patients consumed 250 ml mare's milk or placebo for 16 weeks. The aim was to examine the effects of mare's milk on the characteristics of atopic dermatitis (AD), on faecal microbiota and on clinical and immunological parameters. The intensity of AD was examined using the Severity Scoring of Atopic Dermatitis (SCORAD) index. During the mare's milk period, the mean SCORAD value of patients (n=23; 17 females, 6 males) decreased from 30.1 to 25.3 after 12 weeks (P<0.05) and to 26.7 after 16 weeks (P<0.1). In a subgroup (n=7) the SCORA...
Gaustad G, Larsen S.A randomised double blind and placebo controlled clinical study was carried out. Standardbred trotters (n=77), age 3-4 years) with moderate to severe lameness were grouped according to number of affected joints and, within each group, were randomised for treatment with polysulphated glycosaminoglycan (PSGAG), sodium hyaluronate (SH) or placebo for 3 weeks. The horses were inspected weekly with a final examination 2-4 weeks after the end of treatment. Mean initial lameness score was significantly reduced during treatment and at the last examination in all 3 groups (P<0.01). Additionally, the...
O'Neill W, McKee S, Clarke AF.The purpose of this study was to quantify the effect of flaxseed (Linum usitatissimum) supplementation on the skin test response of atopic horses. Six horses that displayed a positive skin test for allergy to extract from Culicoides sp. participated in the 42-day, placebo-controlled, double-blind, cross-over trial. Results showed that supplementation with flaxseed for 42 days in our experimental horses reduced the mean skin test response to Culicoides sp. This observation was concurrent with a significant decrease in the long-chain saturated fatty acids; behenic acid (22:0) and lignoceric acid...
Read JR, Boston RC, Abraham G, Bauquier SH, Soma LR, Nolen-Walston RD.To determine whether prolonged administration of clenbuterol results in tachyphylaxis, specifically regarding its bronchoprotective properties and effect on sweating in horses. Methods: 8 Thoroughbreds with inflammatory airway disease. Methods: In a crossover design, horses received clenbuterol (0.8 μg/kg, p.o., q 12 h) or placebo for 21 days, with a washout period of ≥ 30 days between the 2 treatments. Airway reactivity was evaluated by use of flowmetric plethysmography and histamine broncho-provocation before (day 0; baseline) and every 7 days after the start of treatment. Sweat function ...
Edner A, Lindberg LG, Broström H, Bergh A.Static magnetic blankets are often claimed to induce increases in blood flow, reduce muscle tension and tenderness, and be beneficial in both prevention and treatment of musculoskeletal injuries in horses. However, there are no studies that confirm alleged beneficial effects of magnets on muscles of the back in healthy horses. Objective: To investigate whether static magnets sewn into a blanket affect back muscle blood flow, skin temperature, mechanical nociceptive threshold (MNT) and behaviour in healthy horses. Methods: Prospective, randomised, blinded, placebo-controlled crossover study. Me...
Perez-Moreno CI, Couëtil LL, Pratt SM, Ochoa-Acuña HG, Raskin RE, Russell MA.The objective was to quantify the effect of furosemide and carbazochrome on exercise-induced pulmonary hemorrhage (EIPH) in Standardbred horses using red blood cell count and hemoglobin concentration in bronchoalveolar lavage (BAL) fluid. Six healthy Standardbred horses with prior evidence of EIPH performed a standardized treadmill test 4 h after administration of placebo, furosemide, or furosemide-carbazochrome combination. Red blood cell (RBC) counts and hemoglobin concentrations were determined on the BAL fluid. The RBC count in BAL ranges were (2903-26,025 cells/microL), (45-24,060 cells/m...
Nagae M, Nishio T, Ohnuki K, Shimizu K.Placenta extract is used as an ingredient in ointments for treating dermatological diseases, skin dryness, and for skin beautification. However, the clinical effects of the equine placenta on humans and the underlying mechanism of action are unclear. This randomized, controlled, double-blind study aimed to clinically evaluate the effect of oral intake of equine placental extract on human skin quality. Methods: Healthy women volunteers between the ages of 30 and 59 years (n = 29) were randomly assigned to receive 220 mg of equine placental extract-placebo orally, once daily for 4 weeks....
Schatzman U, Armbruster S, Stucki F, Busato A, Kohler I.The analgesic potency of butorphanol 25 microg/kg bodyweight (BW) and levomethadone 100 microg/kg BW, administered together with detomidine 10 microg/kg BW, was measured in twelve Warmblood horses in a randomized, blinded cross-over study. Detomidine with saline 10 ml 0.9% was used as placebo. The nociceptive threshold was determined using a constant current and a pneumatic pressure model for somatic pair Detomidine alone and in combination with butorphanol or levomethadone caused a significant temporary increase (P < 0.05) of the nociceptive threshold with a maximum effect within 15 min and a...
Weber LA, Puff C, Kalbitz J, Kietzmann M, Feige K, Bosse K, Rohn K, Cavalleri JV.The naturally occurring betulinic acid (BA) and its derivative NVX-207 show anticancer effects against equine malignant melanoma (EMM) cells and a potent permeation in isolated equine skin in vitro. The aim of the study was to determine the in vivo concentration profiles of BA and NVX-207 in equine skin and assess the compounds' local and systemic tolerability with the intent of developing a topical therapy against EMM. Eight horses were treated percutaneously in a crossover design with 1% BA, 1% NVX-207 or a placebo in a respective vehicle twice a day for seven consecutive days with a seven-d...
Weber LA, Delarocque J, Feige K, Kietzmann M, Kalbitz J, Meißner J, Paschke R, Cavalleri JV.The naturally occurring betulinic acid (BA) and its derivative NVX-207 induce apoptosis in equine melanoma cells in vitro. After topical application, high concentrations of the substances can be reached in healthy equine skin. With the aim to investigate the effect and safety of topically applied BA and NVX-207 in horses with melanocytic tumors, the longitudinal, prospective, randomized, double-blind, placebo-controlled study protocol included eighteen Lipizzaner mares with early-stage cutaneous melanoma assigned to three groups. Melanocytic lesions were topically treated either with a placebo...
Ness SL, Frye AH, Divers TJ, Rishniw M, Erb HN, Brooks MB.OBJECTIVE To determine effects of oral administration of Yunnan Baiyao on platelet activation, coagulation, and fibrinolysis in healthy horses. ANIMALS 12 healthy adult horses. PROCEDURES In a randomized blinded crossover study that included a 4-week washout period between treatments, horses were orally administered a paste containing Yunnan Baiyao (15 mg/kg) or placebo at 12-hour intervals for 3 days. Blood samples were collected before start of treatment (time 0) and at 24 and 72 hours for a CBC, measurement of fibrinogen concentration, coagulation screening tests, and a panel of assays to a...
Walliser U, Fenner A, Mohren N, Keefe T, deVries F, Rundfeldt C.The benefit of pre and post-operative administration of non-steroidal anti-inflammatory drugs for the relief of post-operative pain and control of inflammation in horses following orthopaedic surgery has not been previously investigated in controlled clinical field trials, and the utility of such treatment is a matter of ongoing dispute. Recently the utility of post-operative pain management was emphasized. It was therefore our aim to determine the efficacy of meloxicam in horses following partial resection of fractured splint bones. This condition was selected since the limited extent of the ...
Allison A, Robinson R, Jolliffe C, Taylor PM.There are limited investigations comparing ketamine to a ketamine-midazolam co-induction. Objective: To compare quality and safety of general anaesthesia induced using ketamine alone with anaesthesia co-induced using ketamine and midazolam. Methods: Randomised, double blinded, placebo controlled trial. Methods: After i.v. detomidine (20 μg/kg) thirty-eight ponies undergoing field castration received either 0.06 mg/kg (0.6 mL/50 kg) midazolam (group M) or 0.6 mL/50 kg placebo (group P) with 2.2 mg/kg ketamine i.v. for anaesthetic induction. Quality of anaesthetic induction, endotracheal intuba...
Marshall K, Marsella R.Increased antimicrobial resistance highlights the need for alternatives to antibiotics. Bacteriophages, which are benign viruses that kill bacteria, are promising. We studied the efficacy of topical bacteriophages for treating equine staphylococcal superficial pyodermas. Eight isolates were tested against a bacteriophage bank, and a cocktail consisting of two bacteriophages was prepared. Twenty horses with clinical and cytological evidence of superficial pyoderma and confirmed infection based on swabbed culture were enrolled in the study. Each horse received both the bacteriophage cocktail a...
Urayama S, Tanaka A, Kusano K, Sato H, Muranaka M, Mita H, Nagashima T, Matsuda H.Flunixin meglumine (FM), a nonselective cyclooxygenase (COX) inhibitor, is most frequently selected for the treatment of equine systemic inflammatory response syndrome (SIRS)/endotoxemia. However, FM has considerable adverse effects on gastrointestinal function. The aims of this study were to compare the effect of meloxicam (MX), a COX-2 selective inhibitor commonly used in equine clinical practice, with FM, and to investigate the potential for clinical application in horses with SIRS/endotoxemia. Fifteen horses were divided into three groups of five and orally administered MX (0.6 mg/kg), FM ...
Levine DG, Epstein KL, Neelis DA, Ross MW.To determine whether topical application of 1% diclofenac sodium cream would decrease inflammation at sites of IV regional limb perfusion (IVRLP) in healthy horses. Methods: 6 healthy adult horses (12 forelimbs). Methods: Bilateral IVRLP with 2.5 g of amikacin sulfate was performed twice in each horse, with 24 hours between each session. Horses were treated with topical 1% diclofenac liposomal cream (treated limbs) or a placebo cream (control limbs). All injection sites were evaluated before the first IVRLP session and 24 hours after the second session by means of ultrasonographic examination ...
Lizarraga I, Castillo-Alcala F.Combinations of α2 -adrenoceptor and opioid agonists are commonly used in equids, but little scientific information is available on donkeys. Objective: To compare the sedative and hypoalgesic effects of xylazine alone or in combination with different dosages of butorphanol in donkeys. Methods: Placebo-controlled, operator-blinded, randomised, crossover, Latin square study. Methods: Six donkeys received intravenous normal saline and normal saline (NS-NS); xylazine (0.5 mg/kg bwt) and normal saline (X-NS); xylazine and 10 μg/kg bwt butorphanol (X-B10); xylazine and 20 μg/kg bwt butorpha...
Niemelä TM, Tulamo RM, Hielm-Björkman AK.Intra-articular inflammation resulting in lameness is a common health problem in horses. Exogenous intra-articular hyaluronic acid has been shown to provide an analgesic effect and reduce pain in equine and human osteoarthritis. High molecular weight non-animal stabilized hyaluronic acid (NASHA) has gained popularity in the treatment of human arthritic conditions due to its long-acting pain-relieving effects. The aim of this study was to compare the response to treatment of lameness localized in the equine metacarpophalangeal joint injected with non-animal stabilized hyaluronic acid (NASHA) an...
Ishizaka S, Matsuda A, Amagai Y, Oida K, Jang H, Ueda Y, Takai M, Tanaka A, Matsuda H.The effects of probiotics on horses are still controversial. The present study was a randomized, double-blinded, placebo-controlled crossover study designed to evaluate the ability of probiotics to improve intestinal conditions in adult horses. Fermented probiotics were administered to 10 healthy adult geldings for 28 days. The clinical condition of the horses was monitored daily, and the blood and feces were biochemically analyzed every 14 days. In the probiotic-treated group, the concentration of carboxylic acids in the feces was increased at days 14 and 28. In contrast to the fecal pH in th...
Zoller D, Lüttgenau J, Steffen S, Bollwein H.Poor uterine perfusion has been proposed as a cause of infertility in mares. The objective of this study was to investigate the effect of isosorbide dinitrate (ISDN), a nitric oxide donor, on uterine and ovarian blood flow resistance during diestrus and early pregnancy in mares. Six Trotter mares, aged 7 to 14 years, were examined daily during the first 11 days of three diestrous periods, and five of those mares were also examined during the first 11 days of two pregnancies. Six mares randomly received a placebo, a low dose (30 mg, ISDN30), or a high dose of ISDN (60 mg, ISDN60) through t...
Haspeslagh M, Jordana Garcia M, Vlaminck LEM, Martens AM.Previous studies mention the use of topical acyclovir for the treatment of equine sarcoids. Success rates vary and since the bovine papillomavirus (BPV) lacks the presence of a kinase necessary to activate acyclovir, there is no proof of its activity against equine sarcoids. Results: Twenty-four equine sarcoids were topically treated with acyclovir cream and 25 with a placebo. Both creams were applied twice daily during 6 months. Before the start of the treatment and further on a monthly basis, photographs and swabs were obtained. On the photographs, sarcoid diameter and surface area were meas...
Bannai H, Nemoto M, Tsujimura K, Yamanaka T, Kokado H, Kondo T, Matsumura T.Immune responses were compared after intranasal (IN) and intramuscular (IM) vaccination of horses with a modified live equine herpesvirus type-1 (EHV-1) vaccine, and the protective effect after EHV-1 challenge was evaluated. IN- and IM-vaccinated groups (n = 5 each) showed significant rises in serum virus-neutralizing titers with increased levels of IgGa and IgGb antibodies after the first vaccination (P < 0.05). In nasal secretions, the IN group had significantly increased levels of IgA antibodies after vaccination (P < 0.05), whereas the response of the IM group was dominat...
Edwards JG, Newtont JR, Ramzan PH, Pilsworth RC, Shepherd MC.Dantrolene sodium (Dantrium) has been used extensively for the treatment of myopathies in man and anecdotal evidence suggests it is of clinical benefit in the control of exercise-induced rhabdomyolysis (ER) in racehorses, although data to support this are currently lacking. Objective: To investigate the efficacy of oral dantrolene sodium in controlling ER in a randomised, double-blind, placebo-controlled crossover trial involving 77 Thoroughbred racehorses in Newmarket, UK. Methods: Horses were treated on 2 occasions 1 week apart, with treatment days coinciding with a return to exercise follow...
Pascoe JR, McCabe AE, Franti CE, Arthur RM.The repeatability of endoscopic observations of exercise-induced pulmonary hemorrhage (EIPH) and the efficacy of furosemide as a prophylactic treatment of horses with EIPH were studied in Thoroughbred race horses after consecutive breezes (at or near maximum speed, approx 16 m/s). Of 56 horses examined greater than or equal to 2 times, 21 (38%) had identical EIPH scores, whereas 26 (46%) and 9 (16%) had scores that differed by greater than or equal to 1 grade. In 56 nontreated horses, there was good agreement between 2 consecutive observations (K = 0.59, Z = 4.54, P less than 0.001). Similar c...
Notin C, Vallon L, Desbordes F, Leleu C.Intense physical exercise produces an excess of reactive oxygen species which can disturb the antioxidant/oxidant balance of the horse in training. Several classes of antioxidant dietary compounds have been suggested to provide health benefits and there is evidence that consumption of these products leads to a reduction in the expression of various pro-inflammatory and/or oxidative stress biomarkers. The recent development of a new galenic system allows the oral delivery of the antioxidant enzyme: superoxide dismutase (SOD). This has been developed from a specific melon variety with a particul...
Martin LM, Johnson PJ, Amorim JR, DeClue AE.Resveratrol, a phytophenol, is a commonly used equine nutraceutical supplement touted to exert anti-inflammatory effects. The effect of orally administered resveratrol on tumor necrosis factor (TNF), interleukin-1β (IL-1β), leukocyte phagocytic activity or oxidative burst function have not been reported in horses. The objective of this study was to determine the effects of a commercially available, orally administered resveratrol product on innate immune functions in healthy adult horses. Whole blood was collected from 12 horses prior to and following 3 weeks of treatment with either the man...
Banse HE, Whitehead AE, McFarlane D, Chelikani PK.Pituitary pars intermedia dysfunction (PPID) is a common endocrine disorder of aged horses, with muscle atrophy as one of the clinical signs. We sought to compare muscle mass and regulation of skeletal muscle proteolysis between horses with PPID and muscle atrophy to older horses without PPID, and to assess the impact of treatment with pergolide (dopaminergic agonist) on PPID horses. We hypothesized that PPID-associated muscle atrophy is a result of increased proteolysis, and that markers of muscle atrophy and proteolysis would improve over time with pergolide treatment. Markers of muscle atro...
Higler MH, Brommer H, L'Ami JJ, de Grauw JC, Nielen M, van Weeren PR, Laverty S, Barneveld A, Back W.Multiple in vitro studies assessing articular tissues have indicated that glucosamine and chondroitin sulphate may possess anti-inflammatory effects, but little is known of their clinical effects in vivo. Many old horses have stiff joints, which is likely to be attributable to inflammation and therapy with these nutraceutical compounds could improve joint function. Objective: To assess the clinical effects of a mixed supplement on the improvement of stiff gait in aged horses. Methods: Randomised, blinded, placebo-controlled study. Methods: A group of 24 geriatric equids (age 29 ± 4 years; mea...
Bairden K, Brown SR, McGoldrick J, Parker LD, Talty PJ.The efficacy of moxidectin 2 per cent equine gel against naturally acquired strongyle infections was assessed in 18 ponies which had grazed on contaminated pasture before being housed for eight weeks. Twenty-four hours before the treatment, two randomly selected ponies were euthanased and their worm burdens were determined. Eight of the remaining 16 ponies were treated with moxidectin 2 per cent gel while the other eight were given a placebo gel. Eight weeks later the 16 animals were necropsied and their worm burdens established. A 100 per cent efficacy was recorded against adult and lumenal L...
Fjordbakk CT, Haga HA.To assess the efficacy of a commercially available topical vapocoolant spray in reducing responses to arthrocentesis of the middle carpal (MC) and metacarpophalangeal (MCP) joints and jugular vein catheterization in unsedated horses. Methods: 8 healthy research horses. Methods: Arthrocentesis of both MC and MCP joints and bilateral jugular vein catheterization were performed in each horse. Immediately prior to skin penetration, 1 randomly selected MC joint, MCP joint, and jugular vein were sprayed with a vapocoolant liquid (intervention product), and the contralateral MC joint, MCP joint, and ...
