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.
The effects of equine skin preparation on transdermal drug penetration in vitro. An increasing number of formulations are applied to equine skin, yet variable penetration can affect efficacy, or the incidence of adverse effects, or both. To investigate the effects of common methods of skin preparation on transdermal drug penetration in vitro, we clipped, harvested, and froze skin samples from 5 Thoroughbred geldings. Thawed samples were prepared as follows: control (no preparation); cleaned with aqueous chlorhexidine (Aq-C, 0.1% w/v); cleaned with alcoholic chlorhexidine (Al-C, 0.5% w/v); shaved (Sh); or tape-stripped (Ta) with the use of adhesive tape. The samples were th...
Evaluation of tulathromycin in the treatment of pulmonary abscesses in foals. Tulathromycin is a new injectable macrolide antibiotic used for the treatment of pulmonary diseases of swine and cattle. In this study, 37 foals with sonographic evidence of lung abscesses were treated with tulathromycin (2.5mg/kg intramuscularly [IM] once weekly, group 1) and 33 foals (group 2) with a combination of azithromycin (10mg/kg per os [PO] once daily for the first seven days of therapy, thereafter every other day) and rifampin (10mg/kg PO twice daily). The bacterial aetiological agent was not determined. The foals were only mildly sick and the median number of pulmonary abscesses wa...
[Diagnosis and therapy of Rhodococcus equi infection in the horse]. Infection with Rhodococcus equi is an important cause of pneumonia in foals, but other organ systems may also be affected. The intracellular presence of R. equi and the formation of granulomatous and suppurative inflammatory tissue mean that prolonged treatment is needed. The pharmacological properties of the combination of erythromycin and rifampicin have improved the survival of foals infected with R. equi; however, erythromycin can cause adverse reactions in foals and mares, which has prompted the search for alternative therapies. The combination of azithromycin or clarithromycin with rifam...
Efficacy of imiquimod 5% cream in the treatment of equine sarcoids: a pilot study. Imiquimod is an immune response modifier with potent antiviral and antitumour activity. The objective of this pilot study was to evaluate the efficacy of an imiquimod 5% cream (Aldaratrade mark: 3M, Saint Paul, MN, USA) as a topical treatment for equine sarcoids. Fifteen horses with a total of 19 tumours were enrolled, including mixed (7), fibroblastic (5), flat (3), verrucous (2), and nodular (2) types. Baseline data included history, physical examination, tumour location, measurement and digital photography. Imiquimod was applied by the owners three times a week until complete resolution of ...
Adverse extrapyramidal effects in four horse given fluphenazine decanoate. 4 racehorses were examined because of markedly abnormal behavior following administration of fluphenazine decanoate. Results: Clinical signs included restlessness, agitation, profuse sweating, hypermetria, aimless circling, intense pawing and striking with the thoracic limbs, and rhythmic swinging of the head and neck alternating with episodes of severe stupor. Fluphenazine was detected in serum or plasma from all 4 horses. The dose of fluphenazine decanoate administered to 3 of the 4 horses was within the range (25 to 50 mg) routinely administered to adult humans. Results: In 2 horses, there ...
Evaluation of permissiveness and cytotoxic effects in equine chondrocytes, synovial cells, and stem cells in response to infection with adenovirus 5 vectors for gene delivery. To evaluate host cell permissiveness and cytotoxic effects of recombinant and modified adenoviral vectors in equine chondrocytes, synovial cells, and bone marrow-derived mesenchymal stem cells (BMD-MSCs). Methods: Articular cartilage, synovium, and bone marrow from 15 adult horses. Methods: Equine chondrocytes, synovial cells, and BMD-MSCs and human carcinoma (HeLa) cells were cultured and infected with an E-1-deficient adenovirus vector encoding the beta-galactosidase gene or the green fluorescent protein gene (Ad-GFP) and with a modified E-1-deficient vector with the arg-gly-asp capsid pepti...
Pharmacokinetics of the opioid antagonist N-methylnaltrexone and evaluation of its effects on gastrointestinal tract function in horses treated or not treated with morphine. To determine the pharmacokinetics and effects of the morphine antagonist N-methylnaltrexone (MNTX) on gastrointestinal tract function in horses when administered alone and in combination with morphine. Methods: 5 healthy adult horses. Methods: Horses were treated with MNTX (1 mg/kg, IV), and serial blood samples were collected for determination of drug pharmacokinetics. For evaluation of effects on the gastrointestinal tract when administered alone, MNTX was administered at a dosage of 0.75 mg/kg, IV, twice daily for 4 days. For evaluation of effects when administered concurrently with morphin...
Morphine-associated pruritus after single extradural administration in a horse. Pruritus following a single administration of 100 microg kg(-1) of preservative-free morphine sulphate given via an extradural catheter was seen in a 580 kg horse. The catheter was placed in the first intercoccygeal space. Focal irritation, represented by both local alopecia over the left gluteal muscles and serum exudation, occurred 4-8 hours after injection. This was attributed to the extradural morphine administration.
Use of force plate analysis to assess the analgesic effects of etodolac in horses with navicular syndrome. To evaluate the musculoskeletal analgesic effect of etodolac administered PO every 12 or 24 hours in chronically lame horses by use of force plate analysis. Methods: 22 horses with navicular syndrome. Methods: Horses received etodolac (23 mg/kg, PO, q 12 h; n = 7), etodolac (23 mg/kg, PO, q 24 h; 8), or corn syrup (20 mL, PO, q 24 h; control treatment; 7) for 3 days. Combined forelimb peak vertical ground reaction force (PVF) was measured via force plate analysis before the first treatment (baseline) and at 6, 12, 24, and 36 hours after the last treatment. Differences in mean PVF (mPVF) betwee...
Target animal safety and tolerance study of pyrantel pamoate paste (19.13% w/w pyrantel base) administered orally to horses. Pyrantel pamoate paste (19.13% w/w pyrantel base) for the treatment of tapeworm, Anoplocephala spp was evaluated for target animal safety and tolerance in horses treated orally at 0, 1, 3, 5, and 10 times the clinical dose of 13.2 mg pyrantel base/kg body weight administered daily for six consecutive days. Parameters evaluated included clinical signs, food and water consumption, body weights, physical examinations, clinical pathology (hematology, coagulation, serum chemistry, urinalyses, and fecal examinations), complete necropsy, organ weights, and histopathology. No adverse events or test ar...
Dose-confirmation studies of the cestocidal activity of pyrantel pamoate paste in horses. Dose confirmation studies of the cestocidal activity of pyrantel pamoate paste were conducted at two sites in North America during 2001. Horses with naturally-acquired cestode infections were identified by detection of typical Anoplocephala spp. eggs in feces collected between 7 and 92 days prior to treatment. Twenty and 22 horses were enrolled at Site 1 (Urbana, IL) and Site 2 (Knoxville, TN), respectively. Candidate horses were acclimated to study conditions for 14 days, ranked by length of interval since coprologic confirmation, and allocated randomly to one of two treatment groups: (T1) py...
Effects of phenylbutazone alone or in combination with flunixin meglumine on blood protein concentrations in horses. To assess effects of treatment with phenylbutazone (PBZ) or a combination of PBZ and flunixin meglumine in horses. Methods: 24 adult horses. Methods: 13 horses received nonsteroidal antiinflammatory drugs (NSAIDs) in a crossover design. Eleven control horses were exposed to similar environmental conditions. Treated horses received PBZ (2.2 mg/kg, PO, q 12 h, for 5 days) and a combination of PBZ and flunixin meglumine (PBZ, 2.2 mg/kg, PO, q 12 h, for 5 days; flunixin meglumine, 1.1 mg/kg, IV, q 12 h, for 5 days). Serum samples were obtained on day 0 (first day of treatment) and day 5, and total...
Lack of clinical efficacy of a phosphodiesterase-4 inhibitor for treatment of heaves in horses. Phosphodiesterase-4 (PDE 4) enzyme inhibitors have been shown to have anti-inflammatory properties in various animal disease processes and therefore could be effective drugs for the treatment of equine airway diseases. The purpose of this study was to evaluate the efficacy and adverse effects of the PDE 4 inhibitor L-826,141 in horses with heaves. In a blinded parallel design, horses with heaves exposed daily to moldy hay were given a placebo for 14 days and then administered either L-826,141 (n = 6; loading dose of 1 mg/kg IV followed by 0.5 mg/kg IV q48h) or dexamethasone (n = 6; 0.04 mg/kg ...
Pharmacokinetics and tissue distribution of doxycycline after oral administration of single and multiple doses in horses. To determine pharmacokinetics, safety, and penetration into interstitial fluid (ISF), polymorphonuclear leukocytes (PMNLs), and aqueous humor of doxycycline after oral administration of single and multiple doses in horses. Methods: 6 adult horses. Methods: The effect of feeding on drug absorption was determined. Plasma samples were obtained after administration of single or multiple doses of doxycycline (20 mg/kg) via nasogastric tube. Additionally, ISF, PMNLs, and aqueous humor samples were obtained after the final administration. Horses were monitored for adverse reactions. Results: Feeding ...
A multicenter evaluation of the effectiveness of Quest Gel (2% moxidectin) against parasites infecting equids. Controlled trials with a common protocol were conducted in Idaho, Illinois and Tennessee to evaluate anthelmintic effectiveness of Quest Gel (QG; 2% moxidectin) against lumenal parasites in horses. Candidate horses were required to have naturally acquired nematode infections, as confirmed by presence of strongylid eggs in feces. At each site, 24 equids were blocked on the basis of pretreatment strongyle fecal egg counts (EPG) and randomly assigned to treatments within blocks. Within each block of two animals, one received QG on Day 0 at a dosage of 0.4 mg moxidectin/kg b.w. and one was an untr...
Effect of repeated oral administration of hypertonic electrolyte solution on equine gastric mucosa. Electrolyte supplementation is common in horses during endurance competitions, but the effect on the gastric mucosa is unknown. Objective: Repeated oral administration of hypertonic electrolyte solution is associated with exacerbation of gastric ulcers in mature horses. Methods: The study design was a randomised, blinded, crossover trial. Fourteen horses were divided randomly into equal groups and administered either 60 ml water (placebo) or 56.7 g commercial electrolyte supplement mixed with 60 ml water by dose syringe orally once an hour for 8 h. The minimum concentration of individual const...
Pharmacokinetics of azathioprine following single-dose intravenous and oral administration and effects of azathioprine following chronic oral administration in horses. To determine pharmacokinetics of azathioprine (AZA) and clinical, hematologic, and serologic effects of i.v. and oral administration of AZA in horses. Methods: 6 horses. Methods: In study phase 1, a single dose of AZA was administered i.v. (1.5 mg/kg) or orally (3.0 mg/kg) to 6 horses, with at least 1 week between treatments. Blood samples were collected for AZA and 6-mercaptopurine (6-MP) analysis 1 hour before and at predetermined time points up to 4 hours after AZA administration. In study phase 2, AZA was administered orally (3 mg/kg) every 24 hours for 30 days and then every 48 hours for ...
Factors associated with adverse reactions induced by caprylic acid-fractionated whole IgG preparations: comparison between horse, sheep and camel IgGs. Caprylic acid purification of IgG, currently used in the manufacture of horse-derived antivenoms, was successfully adapted for the preparation of sheep and camel IgG. Sheep IgG had a molecular mass of approximately 150 kDa, whereas camel IgG presented two bands of molecular masses of approximately 160 and 100 kDa, the latter corresponding to heavy-chain IgG, which is devoid of light chains. Horse, sheep and camel IgGs were compared by several parameters aiming at predicting their potential for induction of early and late adverse reactions. Horse and sheep IgGs showed a higher anticomplementary...
Pharmacokinetics of imipenem-cilastatin following intravenous administration in healthy adult horses. In two studies, six healthy adult horses were given imipenem-cilastatin by slow intravenous (i.v.) infusion at an imipenem dosage of 10 mg/kg (study 1) and 20 mg/kg (study 2). The same horses were used in each dosage schedule, with a 2-week washout period between studies. In each dosage group, serial blood and synovial fluid samples were collected for 6 h after completion of the infusion. HPLC was used to determine the imipenem concentration in all samples. Imipenem was well tolerated by all horses at both dosages; no adverse effects were noted during the study period or during the 24-hour pos...
[Suspected adverse drug reactions in 2004]. We received 62 reports of suspected adverse events (SARs) for the year 2004. Their number and repartition according to affected animals and active substances were comparable with the previous year. The distributors or manufacturers submitted most of the declarations, but the proportion submitted by practicing veterinarians is slowly growing. 72% of the declarations dealt with adverse reactions in small animals (cats and dogs), followed by cattle and horses. Antiparasitics, anti-inflammatory drugs and immunologicals were the most frequently mentioned therapeutic classes, which are listed here a...
Evaluation of Lactobacillus pentosus WE7 for prevention of diarrhea in neonatal foals. To evaluate the efficacy of Lactobacillus pentosus WE7, an equine-origin organism with potentially beneficial in vitro properties, as a probiotic for prevention of neonatal diarrhea in foals. Methods: Randomized controlled clinical trial. Methods: 153 foals. Methods: Foals were enrolled at 24 to 48 hours of age and randomly assigned to treatment or control groups. The treatment group received approximately 2 x 10(11) CFU of freeze-dried L. pentosus WE7 orally once daily for 7 days, whereas the control group received a placebo. Clinical monitoring was performed for 14 days. Results: Probiotic a...
Intravenous amiodarone treatment in horses with chronic atrial fibrillation. Six horses without underlying cardiac disease were presented because of atrial fibrillation of between 5 and 12 months duration. These horses received an intravenous amiodarone treatment of 5mg/kg/h for 1 h followed by 0.83mg/kg/h for 23h and subsequently 1.9mg/kg/h for 30h. During treatment, clinical signs were monitored and a surface ECG and an intra-atrial electrogram were recorded. Infusion was discontinued when sinus rhythm or side effects occurred. Four horses successfully cardioverted, of which one showed symptoms of hind limb weakness and weight shifting. Two horses did not cardiovert ...
Clinical and clinicopathological changes in 6 healthy ponies following intramuscular administration of multiple doses of imidocarb dipropionate. Haematological variables and selected serum indices, particularly those affected by changes in renal and hepatic function, were examined in 6 healthy ponies following 4 intramuscular doses of 4 mg/kg imidocarb dipropionate administered every 72 hours. This treatment regime has been reported to sterilise experimental Babesia equi infections in horses and may have value in preventing the spread of this disease during exportation of possible carrier horses to non-endemic countries. Serum bile acids and serum gamma glutamyltransferase activity were measured to evaluate the effect of this treatment...
Effect of systemic lidocaine on visceral and somatic nociception in conscious horses. Commonly used analgesics (nonsteroidal anti-inflammatory agents, opioids and alpha2-agonists) have unwanted side effects. An effective alternative with minimal adverse effects would benefit clinical equine pain management. Objective: To compare the effect of lidocaine or saline on duodenal and rectal distension threshold pressure and somatic thermal threshold in conscious mature horses. Objective: Systemically administered lidocaine would increase somatic and visceral nociceptive thresholds. Methods: Lidocaine (2 mg/kg bwt bolus followed by 50 microg/kg bwt/min for 2 h) or saline was administe...
Effects of GnRH immunization in sexually mature pony stallions. Immunization against gonadotrophin releasing hormone (GnRH) was studied as an alternative for the commonly used surgical castration in stallions. Two GnRH vaccines comprising non-mineral oil adjuvants were evaluated for their potential to induce high antibody titers directed against GnRH and subsequent effects on reproductive characteristics. Twelve sexually mature male hemicastrated Shetland ponies were assigned to three groups. Group 1 and 2 were injected with 1mg peptide equivalent of G6k-GnRH-tandem-dimer conjugated to ovalbumin (OVA) in CoVaccine HT adjuvant (GnRH/CoVaccine) and in Carbop...
Gentamicin nephrotoxicity–a comparison of in vitro findings with in vivo experiments in equines. The aminoglycoside gentamicin is often used in equine practice. Despite its clinical use, concerns remain regarding the potential toxic side-effects, such as nephrotoxicity, in equine patients, particularly after repeated dosing. The aim of the study was to investigate first in vitro the mechanisms contributing to the renal toxicity of gentamicin and to identify sensitive biomarkers indicating proximal tubule damage. To this end, the kidney-derived cell lines LLC-PKI and MDCK were treated with gentamicin at different concentrations. Toxicity was assessed by measuring the release of gamma-gluta...
Use of intravenous flecainide in horses with naturally-occurring atrial fibrillation. It has been reported that i.v. flecainide has a high efficacy for the treatment of experimentally-induced acute atrial fibrillation (AF) in horses and that its use is associated with minimal toxic side effects. Objective: The objectives were to study the efficacy of i.v. flecainide as a treatment for atrial fibrillation in horses with naturally-occurring AF. Methods: Ten horses with naturally-occurring AF were treated with 2 mg/kg bwt flecainide i.v. at a rate of 0.2 mg/kg bwt/min. In 3 horses, the infusion was continued at 0.05-0.10 mg/kg bwt/min until a total dose of 3.0 mg/kg bwt had been a...