Topic:Antibiotics
Antibiotics are medications used to treat bacterial infections in horses. They work by either killing bacteria or inhibiting their growth, aiding the horse's immune system in overcoming the infection. Commonly used antibiotics in equine medicine include penicillin, trimethoprim-sulfamethoxazole, and gentamicin. The selection of an antibiotic depends on factors such as the type of bacteria, the site of infection, and the horse's health status. Responsible use of antibiotics is essential to minimize the risk of resistance. This page compiles peer-reviewed research studies and scholarly articles that explore the efficacy, administration, and impact of antibiotics on equine health.
Rattlesnake venom poisoning in horses: 32 cases (1973-1993). To determine the clinical manifestations, morbidity, mortality, and treatment methods for rattlesnake venom poisoning in horses. Methods: Retrospective analysis of medical records. Methods: 27 horses with acute venom poisoning attributable to prairie rattlesnakes, and 5 with chronic problems subsequent to a rattlesnake bite. Results: Most horses were bitten on or near the muzzle while on pasture, resulting in head swelling, dyspnea, and epistaxis. Additional manifestations of acute poisoning included fever, tachycardia, tachypnea, cardiac arrhythmia, hemolytic anemia, thrombocytopenia, hemorrh...
Treatment of intrasynovial infection with gentamicin-impregnated polymethylmethacrylate beads. Gentamicin-impregnated polymethylmethacrylate beads were used in the treatment of infective synovitis in 12 horses and 10 cattle. They had either proved refractory to standard treatments (lavage, debridement, joint drainage and systemic antibiotics) or had evidence of osteomyelitis adjacent to a synovial cavity. All the animals were severely lame. All the cattle and six of the horses had radiological evidence of osteomyelitis in communication with a synovial cavity. The beads were placed intrasynovially under general anaesthesia and left in place for 14 days. One horse and one calf were euthan...
Pharmacokinetics and tolerance of florfenicol in Equidae. Florfenicol was administered to horses and ponies at a dose rate of 22 mg/kg bwt by i.v., i.m. and oral routes. Following i.v. administration it had an elimination half-life of 1.8 ± 0.9 h, a body clearance of 0.4 ± 0.11/h.kg and a volume of distribution at steady-state of 0.7 ± 0.2 1/kg. It was highly bioavailable following i.m. (81%) and oral (83%) administration. Less than 15% of the administered dose was excreted unchanged in the urine during the 30 h following administration. Animals treated with florfenicol had elevated bilirubin concentrations. Florfenicol was well tolerated by anima...
Infection of the intertubercular bursa in horses: four cases (1978-1991). To determine the clinical outcome of horses treated for infection of the intertubuercular bursa (infectious bicipital bursitis). Methods: Retrospective analysis of case records. Methods: Four horses referred for treatment of infectious bicipital bursitis. Methods: Medical records of horses that were severely lame on admission were reviewed. Results: In 3 horses, palpation over the bicipital bursa as well as flexion and extension of the scapulohumeral joint were resented. Ultrasonography performed in 1 horse revealed that the bicipital bursa was large and that excessive amounts of fluid contain...
Effects of potentiated chlorhexidine on bacteria and tarsocrural joints in ponies. To evaluate the bactericidal properties of chlorhexidine diacetate (CHD) after potentiation with EDTA and Tris buffer (EDTA-Tris), and to find a potentiated CHD concentration that would achieve 90 to 100% killing for all bacteria tested. Methods: 6 adult ponies. Methods: Serial dilutions of CHD, CHD in EDTA-Tris and EDTA-Tris alone were evaluated for bactericidal activity against Staphylococcus aureus, Escherichia coli, and Streptococcus zooepidemicus. The tarsocrural joints of 6 ponies were lavaged with either 1 L phosphate-buffered saline solution (control) or 1 L of 0.0005% CHD in EDTA-Tris...
Assessment of the effect of three treatments to remove intrauterine fluid on pregnancy rate in the mare. The effects on pregnancy rate of three different treatments to remove intrauterine fluid were assessed in 1267 mares. The mares were mated and allocated, in strict rotation, to four treatment groups: 1) untreated controls, 2) intrauterine infusion of broad spectrum antibiotics, 3) intravenous injection of oxytocin, 4) intravenous injection of oxytocin followed by intrauterine antibiotics. The pregnancy status of the mares was determined 13 to 15 days and 27 to 30 days after ovulation by transrectal ultrasonography. The pregnancy rate of group 4 (72 per cent) was higher than that of group 2 (64...
Adverse drug reactions: report of the Australian Veterinary Association Adverse Drug Reaction Subcommittee, 1994. Seventy-seven reports of suspected adverse drug reactions (ADRs) were received by the Adverse Drug Reaction Subcommittee (ADRSc) of the Australian Veterinary Association from April 1993 to December 1994 inclusive. The number of reports received/number of animals involved per species were: dogs (32/44), cats (18/31), horses (17/48), and cattle (10/21). Of these, 49 (64%) were classified as definite ADRs and 9 (12%) as probable ADRs. In 11 (14%) reports an ADR could not be substantiated or there was insufficient information available to make a decision. Eight reports were not classified because ...
Side effects of oral antimicrobial agents in the horse: a comparison of pivampicillin and trimethoprim/sulphadiazine. To evaluate the side effects of oral pivampicillin and trimethoprim/ sulphadiazine, 200 horses receiving these antimicrobial agents were studied. The horses received either trimethoprim/ sulphadiazine (30 mg/kg twice daily) or pivampicillin (25 mg/kg twice daily) for three or more days. No adverse effects other than loose faeces and diarrhoea were detected. The risk of diarrhoea was significantly less after the oral administration of pivampicillin (3 per cent) than after trimethoprim/ sulphadiazine (7 per cent). Horses whose appetite was reduced appeared to be predisposed to develop diarrhoea ...
Bacterial pneumonia associated with corticosteroid therapy in three horses. Three horses developed severe pulmonary infections while being treated with systemic corticosteroids for other diseases. Two of them had an immune-mediated skin disease, compatible with a diagnosis of pemphigus foliaceus, and one had severe chronic obstructive pulmonary disease. Case 1 developed diffuse pneumonia from which Streptococcus zooepidemicus and Bacteroides melaninogenicus were isolated, and it responded to antibiotic therapy. Case 2 developed septicaemia, pulmonary thrombosis and pneumonia associated with Escherichia coli, and died during a peracute illness with signs of disseminate...
Tissue and serum concentrations of amikacin after intramuscular and intrauterine administration to mares in estrus. Concentrations of amikacin in endometrial tissue and plasma were studied in mares in estrus after intrauterine infusion of 1.0 or 2.0 g once a day for 3 consecutive d, and after 9.7 or 14.5 mg/kg body weight (BW) had been injected intramuscularly once a day for 3 consecutive d to determine concentrations of amikacin sulfate in plasma and endometrial tissues, and whether parenteral administration provides any advantages over intramuscular infusion. No amikacin was detected in serum at the 1.0 g dose. At the infusion dose of 2.0 g once a day, very low levels of serum amikacin were detected at 1 ...
Pharmacokinetics of cefoperazone in horses. The pharmacokinetics and bioavailability of cefoperazone (CPZ) were studied following intravenous (IV) and intramuscular (IM) administration of single doses (30 mg/kg) to horses. Concentrations in serum, urine and synovial fluid samples were measured following IV administration. CPZ concentrations in serum, synovial fluid and spongy bone samples were measured following IM administration. After IV administration a rapid distribution phase (t1/2 (alpha): 4.22 +/- 2.73 min) was followed by a slower elimination phase (t1/2(beta) 0.77 +/- 0.19 h). The apparent volume of distribution was 0.68 +/- 0....
Characterization of Escherichia coli isolated from foals. Serotype, biotype, antibiogram, hemolysin production, fimbrial hemagglutinins, select toxin genes (STb, STaP, LT, slt1 and slt2) and the attaching effacing (eae) gene were determined for 99 foal strains of E. coli. E. coli from diarrheic and normal foals could not be distinguished by serotype, biotype, or antibiogram. Differences (P < or = 0.05) were observed in hemolysin production (11.5% vs 0%) and the expression of mannose-resistant hemagglutinins (23% vs 13%) among E. coli from diarrheic and healthy foals, respectively. Three of the E. coli strains from diarrheic foals were positive wit...
Actinobacillus suis septicaemia in two foals. A 24-hour-old Hackney ony filly developed signs of weakness, depression and a poor suck reflex, with harsh lung sounds over both fields, and a 48-hour-old Arabian colt from a normal birth which had sucked vigorously developed loose stools and became depressed, weak and anorectic. Both foals had serum IgG concentrations greater than 800 mg/dl, but each had a severe neutropenia with a left shift, and blood cultures from both of them yielded Actinobacillus suis. The A suis isolates had different antimicrobial susceptibility patterns and, in the case of the Arabian, the isolate was resistant to co...
Determination of highest no effect dose (HNED) for local anaesthetic responses to procaine, cocaine, bupivacaine and benzocaine. The highest no effect doses (HNEDs) for the local anaesthetic (LA) effects of procaine, cocaine, bupivacaine and benzocaine were determined using the heat lamp/hoof withdrawal model of Kamerling et al. (1985b) and the abaxial sesamoid block model of local anaesthesia. The heat lamp rapidly (4 or 5 s) increased the temperature of the superficial skin layers of the pastern to about 90 degrees C, at which point the animal sharply withdrew its hoof. Effective LA blockade precluded this response and superficial skin temperatures exceeded 120 degrees C. Thermal stimulus experiments were routinely te...
A comparison of N-butylscopolammonium bromide and butorphanol tartrate for analgesia using a balloon model of abdominal pain in ponies. The analgesic effect of N-butylscopolammonium bromide (0.3 mg/kg) using a balloon-induced model of colic in ponies was evaluated and compared with butorphanol tartrate (0.1 mg/kg). Eight adult ponies were used and each received both treatments during the two different trials. The order in which the treatment was received was randomly assigned. At the start of each trial, moderate abdominal pain was induced by inflation of a balloon placed in the lumen of the caecum. The ponies were evaluated every 5 minutes, and a cumulative pain score (CPS) was assigned. Two baseline measurements were recorde...
Attempts to find phenotypic markers of the virulence plasmid of Rhodococcus equi. Four isolates of Rhodococcus equi, from pneumonic foals, and containing the 85 kb virulence plasmid, a porcine isolate containing an 80 kb plasmid, and their plasmid cured derivatives, were examined for 239 phenotypic properties in an attempt to find characters other than the virulence-associated protein (VapA) which might be encoded by the virulence plasmid in organisms grown at 37 degrees C. Tests chosen included those which have previously given variable results for R. equi isolates, since such variability might be attributed to plasmid curing, and characteristics which have been described ...
Use of antibiotic-impregnated polymethyl methacrylate for treatment of an open radial fracture in a horse. An open, contaminated, comminuted fracture of the radius of a 500-kg adult horse was diagnosed. Antibiotic-impregnated polymethyl methacrylate implants were placed into the fracture site to help eliminate infection from the limb. Later in the course of treatment, lag screws were placed across the fracture to generate compression and healing. The fracture healed, and the horse was released to its owners. The implants were not removed, and only a mild lameness existed 90 days later.
Pharmacokinetics and therapeutic potential for repeated oral doses of trimethoprim/sulphachlorpyridazine in horses. The pharmacokinetic parameters of a powder formulation of trimethoprim/sulphachlorpyridazine were studied in eight healthy horses which received 5 mg/kg trimethoprim and 25 mg/kg sulphachlorpyridazine 12-hourly with concentrate for five days. The intake of the medicated concentrate by the horses was variable during the first two days, but after they became accustomed to the taste the intake by all the horses during the last three days was good. Faecal samples taken before and on the last day of the drug administrations were negative when cultured for salmonella. Compared with the results of a ...
Pharmacokinetics of bacampicillin in equids. Bacampicillin hydrochloride is an ester prodrug that is hydrolyzed to ampicillin after its absorption from the gastrointestinal tract. It was administered intragastrically at a dose rate of 13.5 mg/kg of body weight to ponies and horses, and was highly bioavailable (F = 41.0%), compared with other penicillins in adult horses. The high peak ampicillin plasma concentration of 6.1 +/- 0.5 micrograms/ml achieved and persistence of the antibiotic at concentration of 0.3 +/- 0.1 microgram/ml 6 hours after its intragastric administration, suggest that bacampicillin hydrochloride may reach suitable ba...
Corneal stromal abscesses in the horse: a review of 24 cases. The medical records of 24 horses with corneal stromal abscesses were reviewed. Twenty of the horses initially presented with a corneal ulcer, corneal opacity, or evidence of ocular pain. All of the horses were treated with topical antibiotics prior to referral. Most had also been treated with topical atropine sulphate and systemic flunixin meglumine. Ophthalmic examinations revealed focal, yellow-white corneal opacities, corneal vascularisation and evidence of iridocyclitis. Nine of the horses were treated primarily medically as the initial response to topical and systemic medication was rapid...
Treatment and outcome of chronic tenosynovitis in three horses. Three horses were presented for treatment of chronic infections of the digital flexor tendon sheath. Clinical signs included severe lameness, and heat, pain and swelling of the digital flexor tendon sheath. The horses were treated with surgical lavage of the tendon sheath, systemic and local antibiotics, and analgesics. In each case, resolution of the lameness occurred over weeks to months. Only one horse returned to athletic activity, while the other two became comfortable at pasture. Response to treatment in cases of chronic tenosynovitis may not be as rapid or complete as that reported for ...
Antibacterial susceptibility patterns for microbial isolates associated with infectious keratitis in horses: 63 cases (1986-1994). Seventy-three aerobic bacterial isolates were cultured from 64 eyes of 63 horses with infectious keratitis. Forty-two (58%) of the organisms isolated initially were gram-positive (g+, 10 genera) and 31 (42%) were gram-negative (g-, 5 genera). After local antimicrobial treatment, repeat cultures from samples obtained from 15 eyes of hospitalized horses yielded 21 secondary bacterial isolates. Staphylococci spp and Streptococci spp were the most common g(+) isolates and accounted for 79% of g(+) organisms isolated initially. Antibiograms revealed ticarcillin to be the most efficacious antibiotic...
Single and multiple dose pharmacokinetics of gentamicin administered intravenously and intramuscularly in adult conditioned thoroughbred mares. The pharmacokinetics of gentamicin following single and multiple intravenous and intramuscular doses were compared in a two phase, randomised cross-over study in horses. Gentamicin was administered to 6 healthy, conditioned Thoroughbred mares at a dosage of 3.3 mg/kg body weight every 12 hours for 5 intravenous or intramuscular consecutive treatments. Equal numbers of horses were treated by either route during each phase. There was a wash-out period of 5 days between phases. During each phase serial blood samples were collected from each mare immediately before treatment and at 16 intervals fo...
Pseudomonas spp. associated vegetative endocarditis in two horses. This paper describes the case histories of two Thoroughbred horses, a 2-year-old colt in training and a 7-year-old broodmare, that were presented with histories of weight loss, exercise intolerance, intermittent fever, limb oedema and anaemia. Vegetative endocarditis of the mitral and tricuspid valves was diagnosed in the colt by means of echocardiography. Pseudomonas sp. endocarditis of the mitral valve was diagnosed in the mare using echocardiography and bacterial culture. The colt had secondary congestive heart failure and was euthanased on humane grounds. Pseudomonas cepacia was isolated f...
Effects of high doses of oxytetracycline on metacarpophalangeal joint kinematics in neonatal foals. Thirteen clinically normal Belgian-type foals were used to study the effects of high doses of oxytetracycline on metacarpophalangeal joint kinematics. Seven foals (treatment group) received 2 doses of oxytetracycline (3 g, IV). The first dose was given when foals were 4 days old; the second dose was given 24 hours later. Six foals (control group) received 2 doses of saline (0.9% NaCl) solution (15 ml, IV) at equivalent time periods. All foals were videotaped at a walk twice: immediately prior to the first treatment and 24 hours after the second treatment. The tapes were digitized, and metacarp...
Disposition of penicillin G sodium following intravenous and oral administration to Equidae. The present study was designed to determine and compare the plasma disposition and pharmacokinetics of penicillin G sodium following intravenous (i.v.) administration to horses, ponies and donkeys. The plasma disposition and pharmacokinetics of penicillin G was similar in horses, ponies and donkeys (elimination half-lives--39.0, 27.3 and 31.5 min, respectively) and a dosage interval of 6-8 h would be suitable to treat infections caused by susceptible bacteria. Although penicillin G was absorbed rapidly following nasogastric administration, the systemic availability was low (0.12-0.34%), theref...
[Off-label use of lincomycin hydrochloride in 2 horses. Dysbacteriosis and fatal complications due to inadequate symptomatic therapy]. A lawyer inquired about the possible harmful effects of 'off-label use' of lincomycin in two trotting horses. From information in the relevant dossier it could be concluded that there was no direct indication to use antibiotics. In addition, mistakes were made in the medicinal treatment of horses, namely, the off-label use of lincomycin without prior consultation with the manufacturer, fluid and electrolyte replacement therapy not continued for long enough, and incorrect use of antipyretic analgesics. The intravenous administration of gentamicin to dehydrated patients is permissible only in co...