Topic:Adverse Effects
Adverse effects in horses refer to unintended and potentially harmful outcomes that occur as a result of medical treatment, environmental exposure, or other interventions. These effects can impact various physiological systems and may manifest as behavioral changes, organ dysfunction, or other health-related issues. Monitoring and understanding adverse effects are important for ensuring the safety and well-being of horses, particularly in the context of veterinary medicine and equine management. This page gathers peer-reviewed research studies and scholarly articles that explore the causes, mechanisms, and implications of adverse effects in horses, offering insights into their identification, management, and prevention.
Pharmacokinetics of tilmicosin in equine tissues and plasma. The macrolide antibiotic tilmicosin has potential for treating bacterial respiratory tract infections in horses. A pharmacokinetic study evaluated the disposition of tilmicosin in the horse after oral (4 mg/kg) or subcutaneous (s.c.) (10 mg/kg) administration. Tilmicosin was not detected in equine plasma or tissues after oral administration at this dose. With s.c. injection, tilmicosin concentrations reached a maximum concentration of approximately 200 ng/mL in the plasma of the horses. Tilmicosin concentrations in plasma persisted with a mean residence time (MRT) of 19 h. Maximum tissue resid...
Comparison of efficacy and safety of paste formulations of firocoxib and phenylbutazone in horses with naturally occurring osteoarthritis. To compare efficacy and safety of paste formulations of firocoxib and phenylbutazone in horses with naturally occurring osteoarthritis. Methods: Randomized controlled clinical trial. Methods: 253 client-owned horses with naturally occurring osteoarthritis. Methods: Horses were treated with firocoxib (0.1 mg/kg [0.045 mg/lb], PO, q 24 h) or phenylbutazone (4.4 mg/kg [2 mg/lb], PO, q 24 h) for 14 days. Physical examinations and lameness evaluations were performed prior to treatment and after 7 and 14 days. Clinical improvement was defined as a reduction of at least 1 lameness grade or a combined...
Safety of an attenuated West Nile virus vaccine, live Flavivirus chimera in horses. West Nile virus (WNV) infection is endemic and able to cause disease in naive hosts. It is necessary therefore to evaluate the safety of new vaccines. Objective: To establish: 1) the safety of a modified live Flavivirus/West Nile virus (WN-FV) chimera by administration of an overdose and testing for shed of vaccine virus and spread to uninoculated sentinel horses; 2) that this vaccine did not become pathogenic once passaged in horses; and 3) vaccine safety under field conditions. Methods: There were 3 protocols: 1) In the overdose/shed and spread study, horses were vaccinated with a 100x immun...
Alternative vaccination against equine botulism (BoNT/C). In Europe the incidence of botulism in horses has increased in the last decade due to the growing popularity of haylage feeding. Recombinant vaccines are safer and less expensive to produce and are generally better tolerated than toxoids. Objective: To investigate whether the recombinant C-terminal half of the heavy chain of the botulinum neurotoxin C (Hc BoNT/C) in combination with an immunstimulatory adjuvant is an appropriate vaccine candidate for horses by testing its efficacy to induce neutralising antibodies and by comparing its immunogenic properties and adverse reactions to a commercia...
Phosphodiesterase isoenzymes in equine platelets and their influence on platelet adhesion. To determine the phosphodiesterase (PDE) isoenzymes in equine platelets and evaluate their influence on platelet adhesion. Methods: Platelets obtained from healthy New Forest Pony geldings that ranged from 12 to 20 years of age (mean +/- SEM, 17.3 +/- 1.1 years). Methods: PDE isoenzyme activity in equine platelets was determined by use of a 2-step radioactive assay. Functional importance of PDE isoenzymes was established by use of selective inhibitors in a colorimetric adhesion assay. Results: PDE1, PDE2, PDE3, and PDE5 and small amounts of PDE4 were found in equine platelets. Inhibition of PD...
Equine recurrent airway obstruction and insect bite hypersensitivity: understanding the diseases and uncovering possible new therapeutic approaches. Recurrent airway obstruction (RAO) and insect bite hypersensitivity (IBH) are allergic conditions that are commonly encountered in the horse. Whilst complete allergen avoidance is an effective management strategy for both diseases, this may not be achievable in all cases and treatment options are therefore required. The inflammatory response is the main therapeutic target for glucocorticoids given to horses with RAO and severe cases of IBH, whilst the bronchodilators used in RAO primarily target airway smooth muscle. Such drugs are effective in most but not all individuals and there may be unw...
[Reported adverse reactions due to veterinary drugs in 2006]. We received 190 reports of suspected adverse events (SARs) following the use of veterinary drugs for the year 2006: 118 declarations for veterinary drugs and 72 declarations following the application of immunolgical medicinal products. Most of the 118 declarations relate to the use of antiparasitic drugs (48%) and every second declaration to drug use in dogs. Other drug classes concerned were, in decreasing order, antiinfectives (20%) and drugs used off-label (12%; other target species or other indication). For the vaccines, most of the reactions occurred in dogs (62%) followed by horses (11%)...
Evaluation of the safety, immunogenicity and pharmacokinetics of equine anti-SARS-CoV F(ab’)(2) in macaque. To warrant potential clinical testing, the equine anti-SARS-CoV F(ab')(2) requires evaluation in as many animal models as possible and a safety test in a primate model. In this study, we evaluated the pharmacokinetics, tolerance and immunity of this kind of antibody in macaques and rats. Results showed that the F(ab')(2) fragments had a normal metabolism in injected animals. The general physiological indexes did not differ between animals injected with anti-SARS-CoV F(ab')(2) or saline. However, a mild inflammatory response in local injection site and a moderate immune response against this an...
Glossitis and tongue trauma subsequent to administration of an oral medication, using an udder infusion cannula, in a horse. A 10-year-old gelding was presented with a tongue that had swelled immediately after oral administration of oxfendazole, using an udder infusion cannula. The tongue appeared to have been punctured inadvertently. The horse recovered after treatment with intravenous fluid, antibiotics, and anti-inflammatory drugs. Administering oral medication by this method should be discouraged. Un cheval hongre âgé de 10 ans a été présenté avec une langue devenue tuméfiée immédiatement après l’administration orale d’oxfendazole à l’aide d’une canule à infusion du pis. La langue semblait a...
Effects of an adapted intravenous amiodarone treatment protocol in horses with atrial fibrillation. Good results have been obtained with a human amiodarone (AD) i.v. protocol in horses with chronic atrial fibrillation (AF) and a pharmacokinetic study is required for a specific i.v. amiodarone treatment protocol for horses. Objective: To study the efficacy of this pharmacokinetic based i.v. AD protocol in horses with chronic AF. Methods: Six horses with chronic AF were treated with an adapted AD infusion protocol. The protocol consisted of 2 phases with a loading dose followed by a maintenance infusion. In the first phase, horses received an infusion of 6.52 mg AD/kg bwt/h for 1 h followed by...
Lack of systemic absorption of lidocaine from 5% patches placed on horses. To measure concentrations of lidocaine serum after application of two 5% patches on horses. Methods: Prospective experimental trial Methods: Six client-owned, systemically healthy horses. Methods: The hair was clipped on the medial aspect above the carpus of both fore limbs and 2 patches of 5% lidocaine were applied within 30 minutes of jugular catheter placement and the area was then bandaged. Venous blood was drawn from a jugular vein catheter that was inserted using lidocaine as a local block. Samples were drawn immediately before and at 2, 4, 6, 8, and 12 hours after patch application. The...
Some commonly fed herbs and other functional foods in equine nutrition: a review. Most herbs and functional foods have not been scientifically tested; this is especially true for the horse. This paper reviews some of the literature pertinent to herbal supplementation in horses and other species. Common supplements like Echinacea, garlic, ginger, ginseng, and yucca are not regulated, and few studies have investigated safe, efficacious doses. Ginseng has been found to exert an inhibitory effect on pro-inflammatory cytokines and cyclooxygenase-2 expression. Equine studies have tested the anti-inflammatory effects of a single dose of ginger, post-exercise. Echinacea has been re...
Effects of intra-articular botulinum toxin type A in an equine model of acute synovitis: a pilot study. To test the hypothesis that botulinum toxin type A (BoNT-A) can attenuate lameness associated with acute synovitis in an equine model. Methods: Four horses 2-6 yrs of age with clinically normal carpi were studied for 15 days. Kinematic gait analysis and clinical measures of lameness were conducted before and after experimental interventions. Horses were randomly assigned to either placebo (saline) or treatment (BoNT-A) groups. On day 0 of the intervention, 50 units of BoNT-A or an equivalent volume of saline (0.09%) was given into the middle carpal joints. On day 14, acute synovitis was induce...
Trimetoquinol: bronchodilator effects in horses with heaves following aerosolised and oral administration. The bronchodilator effects of trimetoquinol (TMQ) have been studied when administered i.v. or intratracheally, but not in an aerosolised form. Objective: To define the relationship between the therapeutic and adverse responses (therapeutic index) of TMQ when administered as an aerosol or by the oral route. Methods: Increasing doses of TMQ were administered to horses with heaves as an aerosol and by the oral route. Dose ranged 100-1000 microg/horse for aerosolised TMQ and from 6-60 microg/kg bwt for the oral route. Airway and cardiac effects were assessed by measurement of maximal change in ple...
Effects of oral tetrachlorvinphos fly control (Equitrol) administration in horses: physiological and behavioural findings. Highly reactive horses may pose risks to humans involved in equestrian activities. Among the factors that may affect horses' reactivity to external stimuli are pesticides used for fly control in equine facilities. The organophosphorus (OP) insecticide tetrachlorvinphos (TCVP) is used as a feed-through larvicide to prevent completion of the fly larval life cycle in horse manure. TCVP exerts its effect by inhibiting the enzyme cholinesterase (ChE) leading to the accumulation of the neurotransmitter acetylcholine (AChE) in synapses of the central and peripheral nervous systems. The aim of the pre...
Clinical signs and etiology of adverse reactions to procaine benzylpenicillin and sodium/potassium benzylpenicillin in horses. Case reports of 59 horses reacting adversely to procaine benzylpenicillin or to sodium or potassium benzylpenicillin in Sweden in 2003-2005 were obtained through contacts with horse-owners. For the assessment of the reports, various parameters were evaluated, such as the times to the reactions, information on previous penicillin treatment, the clinical signs and the actions taken in the reacting horses. Among the reports, two horses had received sodium or potassium benzylpenicillin intravenously, whereas the remaining 57 horses had been treated with procaine benzylpenicillin intramuscularly. A...
Safety of elevated dosages of a 0.24% diflubenzuron pellet administered orally to horses. The safety of a feed-thru pellet formulation containing the insect growth regulator diflubenzuron (0.24%) for control of manure-breeding flies (Musca domestica L. and Stomoxys calcitrans L.) in horses was evaluated. Pellets were administered orally at 0, 1, 3, and 5 times the clinical dosage (0.12 to 0.20 mg/kg) on a daily basis for 31 consecutive days. Variables examined included daily clinical observations, hematology, coagulation, serum chemistry, acetylcholinesterase inhibition, body weights, and physical examinations. Horses remained healthy throughout the study, and no adverse reactions ...
Defocused CO2 laser on equine skin: a histological examination. No studies have been published on effects of treatment with a defocused beam carbon dioxide (CO2) laser on equine skin histology. A better understanding of this will help to define how lasers should be used, in order to reduce potential side effects. Objective: To describe the acute effects of different doses of defocused CO2 laser, ranging from therapeutic to surgical levels, on equine skin. Methods: Defocused CO2 laser was administered to the skin in the hamstrings (91 J/cm2), fetlock (137 J/cm2) and loin (450 J/cm2) areas of 13 Standardbred horses. The acute effects on skin histology were e...
Oral and intravenous administration of nimesulide in the horse: rational dosage regimen from pharmacokinetic and pharmacodynamic data. The selective COX-2-inhibitor nimesulide is used extra-label in equine veterinary practice as an anti-inflammatory agent. However, there are no data on which to base the rational use of the drug in this species. Objective: To determine the effective COX selectivity of nimesulide in the horse, and suggest a suitable dosing schedule. Methods: The pharmacokinetics of nimesulide in the horse after oral administration (1 mg/kg bwt), and oral and i.v. administration (1.5 mg/kg bwt) were investigated, effects of feeding status on bioavailability determined, and plasma protein binding of the drug and ...
Effects of continuous oral administration of phenylbutazone on biomarkers of cartilage and bone metabolism in horses. To evaluate the effects of continuous oral administration of phenylbutazone on serum and synovial fluid biomarkers of skeletal matrix metabolism in horses. Methods: 11 adult female horses without clinical or radiographic evidence of joint disease. Methods: Horses were randomly assigned to control or treatment groups. Phenylbutazone was administered orally twice daily at a dose of 4.4 mg/kg for 3 days to the treatment group and subsequently at a dose of 2.2 mg/kg for 7 days. Serum and radiocarpal synovial fluid samples were obtained at baseline and thereafter at regular intervals for 4 weeks. B...
Vaccination of horses against strangles using recombinant antigens from Streptococcus equi. Strangles is an upper respiratory tract infection in horses, which is highly contagious and one of the more costly diseases of the horse. Three recombinant antigens were used to vaccinate horses, which were then experimentally challenged with Streptococcus equi, the causative agent for strangles. The vaccinated horses showed significantly reduced bacterial growth (p=0.02) and nasal discharge (p=0.0004), a typical symptom of strangles. Other clinical signs of strangles were also reduced and at post mortem examination, lower rate of empyaema or scarring of the guttural pouches was found in the v...
[Doping in sports]. Drugs used by athletes for the improvement of results are described and classified with respect to chemical structure and pharmacological action. The main groups of drugs treated as doping are considered and the WADA requirements to prohibited preparations are formulated. The main effects produced by drugs on the athletes and animals (race horses, fight dogs, etc ) are described and the measures of therapy against side effects are outlined.
Severe acute inflammatory reaction (SAIR) of the fetlock joint after intraarticular hyaluronate injection in a horse. Hyaluronate (HA) was administered by intra-articular injection to a 13-year-old Haflinger mare for treatment of metacarpophalangeal osteoarthritis. Ten hours after the injection, a severe inflammatory reaction developed in the treated joint. While awaiting results of synovial fluid analysis, treatment for iatrogenic infectious arthritis was initiated, but the analysis did not confirm sepsis. Clinical signs improved significantly following systemic non-steroidal anti-inflammatory medication and the horse was discharged three days later. Following an intravenous hyaluronate injection, four days ...
Intravenous and intratracheal administration of trimetoquinol, a fast-acting short-lived bronchodilator in horses with ‘heaves’. Trimetoquinol (TMQ) is a potent beta-adrenoceptor agonist bronchodilator used in human medicine but has not been evaluated for potential use as a therapeutic agent for horses with 'heaves'. Objective: To assess the pharmacodynamics of TMQ in horses with 'heaves' to determine potential therapeutic effects. Methods: Increasing doses of TMQ were administered to horses with 'heaves' by i.v. and intratracheal (i.t.) routes. Doses ranged 0.001-0.2 microg/kg bwt i.v. and 0.01-2 microg/kg bwt i.t. Cardiac and airways effects were assessed by measurement of heart rate (HR) and maximal change in pleural...
Use of cisplatin-containing biodegradable beads for treatment of cutaneous neoplasia in equidae: 59 cases (2000-2004). To determine outcome for equids with cutaneous neoplasms treated with cisplatin-containing biodegradable beads, alone or in conjunction with debulking. Methods: Retrospective case series. Methods: 56 horses, 1 zebra, 1 donkey, and 1 mule. Methods: Medical records were reviewed. Follow-up information was obtained through telephone conversations with owners and trainers of the animals. Results: 22 tumors were sarcoids, 6 were fibrosarcomas, 1 was a fibroma, 2 were peripheral nerve sheath tumors, 11 were squamous cell carcinomas, 14 were melanomas (13 gray horses and 1 bay horse), 1 was a lymphos...
Clinical trials of efficacy of praziquantel horse paste 9% against tapeworms and its safety in horses. The aim of this study with horses and a few ponies naturally infected with tapeworms was to confirm in clinical trials the efficacy and safety of a praziquantel horse paste 9%. The field trials were conducted in 1997 and 1998 in Canada, France, Germany and New Zealand. A secondary aim of the study in Canada was to determine if a 24h post-treatment fecal sample provides the best estimate of the prevalence of tapeworms in horses when using a fecal examination technique. Fecal samples were taken from each of 1062 animals at least three times pre-treatment (PRT). In Canada, fecal samples were exam...
Pharmacokinetics of fentanyl delivered transdermally in healthy adult horses–variability among horses and its clinical implications. The safety and pharmacokinetics of fentanyl, delivered transdermally at a dosage of 60-67 microg/kg, were investigated in six healthy adult horses. Three transdermal fentanyl patches (Duragesic), each containing 10 mg of fentanyl citrate, were applied to the mid-dorsal thorax of each horse and left in place for 72 h. Plasma fentanyl concentrations were periodically measured throughout this period and for 12 h after patch removal. After an initial delay of approximately 2 h, the plasma fentanyl concentration rose rapidly in a fairly linear fashion, reaching a peak at around 12 h; thereafter, it...