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Topic:Gentamicin

Gentamicin is an aminoglycoside antibiotic commonly used in equine medicine to treat bacterial infections. It is effective against a broad spectrum of Gram-negative bacteria and some Gram-positive bacteria. In horses, gentamicin is frequently administered for conditions such as respiratory infections, uterine infections, and septicemia. The drug is typically delivered via intravenous or intramuscular injection, and its use requires careful dosage management due to potential nephrotoxic effects. Monitoring serum levels and renal function is important during treatment to minimize the risk of toxicity. This page compiles peer-reviewed research studies and scholarly articles that explore the pharmacokinetics, therapeutic applications, and safety considerations of gentamicin in equine medicine.
Association of Stenotrophomonas maltophilia infection with lower airway disease in the horse: a retrospective case series.
Veterinary journal (London, England : 1997)    September 15, 2009   Volume 186, Issue 3 358-363 doi: 10.1016/j.tvjl.2009.08.026
Winther L, Andersen RM, Baptiste KE, Aalbæk B, Guardabassi L.Stenotrophomonas maltophilia is being reported with increasing frequency as a human nosocomial pathogen, especially among immuno-compromised patients. To the authors' knowledge, this pathogen has not previously been associated with lower airway disease in the horse. In this paper the clinical findings, laboratory diagnosis and response to treatment of seven cases of respiratory infection with S. maltophilia in horses, presented at three equine referral hospitals in Denmark in 2007, are described. In all cases there was a clinical history of chronic coughing and abundant mucopurulent exudate wa...
Retrospective multicentre study of methicillin-resistant Staphylococcus aureus infections in 115 horses.
Equine veterinary journal    July 1, 2009   Volume 41, Issue 4 401-405 doi: 10.2746/042516408x345134
Anderson ME, Lefebvre SL, Rankin SC, Aceto H, Morley PS, Caron JP, Welsh RD, Holbrook TC, Moore B, Taylor DR, Weese JS.Methicillin-resistant Staphylococcus aureus (MRSA) is an emerging veterinary and zoonotic pathogen, associated with increasing reports of disease in horses. Objective: To provide an overview of the characteristics of clinical MRSA infections in horses. Methods: A retrospective case study was performed on 115 horses admitted to 6 participating veterinary teaching hospitals in Canada and the United States between 2000 and 2006, and diagnosed with clinical MRSA infection. Descriptive statistics, univariate and multivariable analyses for community- (CA) vs. hospital-associated (HA) MRSA infections...
Development of intraosseous infusion of the distal phalanx to access the foot lamellar circulation in the standing, conscious horse.
Veterinary journal (London, England : 1997)    June 21, 2009   Volume 183, Issue 3 273-277 doi: 10.1016/j.tvjl.2009.05.008
Nourian AR, Mills PC, Pollitt CC.Intraosseous (i.o.) infusion of the distal phalanx (IOIDP) as a delivery route targeting hoof lamellar tissue of standing, conscious horses was evaluated. Following sedation and regional nerve blockade in six Standardbred horses, a microdialysis (MD) probe was implanted into the hoof lamellar tissue of one forelimb. A purpose designed cannulated bone screw was introduced into the body of the distal phalanx, approximately 6 cm from the MD probe. Gentamicin solution (25 mg/mL) was infused at 20 microL/min through the bone screw for 2 h without the application of a tourniquet. MD and blood sample...
Development of an intra-lamellar microdialysis method for laminitis investigations in horses.
Veterinary journal (London, England : 1997)    February 14, 2009   Volume 183, Issue 1 22-26 doi: 10.1016/j.tvjl.2009.01.003
Nourian AR, Mills PC, Pollitt CC.Microdialysis (MD) was used for continuous monitoring of the lamellar extracellular fluid (ECF) in six mature healthy Standardbred horses. MD probes were introduced into the lamellar tissue under local anaesthesia. Following intravenous injection of gentamicin (5mg/kg), MD and serum samples were collected for 24h and analysed using a sensitive ELISA test for gentamicin and fluorescence polarization immunoassay for urea concentrations. Calibration of probes was performed through in vivo urea recovery and in vitro gentamicin and urea recovery. Data obtained from different body compartments were ...
Effects of oxygen exposure and gentamicin on stallion semen stored at 5 and 15 degrees C.
Reproduction in domestic animals = Zuchthygiene    November 27, 2007   Volume 43, Issue 3 261-266 doi: 10.1111/j.1439-0531.2007.00888.x
Price S, Aurich J, Davies-Morel M, Aurich C.This study was undertaken to investigate the effects of storage of stallion semen in a defined milk protein extender at 5 and 15 degrees C under either anaerobic or aerobic conditions, with or without addition of the antibiotic gentamicin. Semen samples were collected from eight fertile stallions and stored for 96 h (day 0-4) and assessed daily for motility, velocity and membrane integrity (viability) using a CASA system. Samples for bacteriology assessment were taken on day 2 of storage. No significant (p > 0.05) differences in motility, velocity or viability were observed between treatmen...
Antimicrobial susceptibility of streptococci from various indications of swine, horses, dogs and cats as determined in the BfT-GermVet monitoring program 2004-2006.
Berliner und Munchener tierarztliche Wochenschrift    October 18, 2007   Volume 120, Issue 9-10 380-390 
Schwarz S, Alesík E, Grobbel M, Lübke-Becker A, Werckenthin C, Wieler LH, Wallmann J.A total of 500 streptococci from two indications of swine (beta-haemolytic streptococci from infections of the urinary/genital tract including strains from the mastitis metritis agalactia syndrome as well as S. suis from infections of the central nervous system and the musculoskeletal system), two indications of horses (S. equi from respiratory tract infections and beta-haemolytic streptococci from infections of the genital tract), as well as three indications of dogs and cats (beta-haemolytic streptococci from infections of the respiratory tract, the urinary/genital tract, and skin/ear/mouth)...
Evaluation of the in vivo behaviour of gentamicin sulphate ocular mini-tablets in ponies.
Journal of veterinary pharmacology and therapeutics    September 7, 2007   Volume 30, Issue 5 470-476 doi: 10.1111/j.1365-2885.2007.00890.x
Gasthuys F, Pockelé K, Vervaet C, Weyenberg W, De Prijck K, Pille F, Vlaminck L, Nelis H, Remon JP.The in vivo behaviour of 5% gentamicin sulphate ocular mini-tablets (2-mm diameter, 6.525 mg weight) was compared with gentamicin eye drops in six ponies. Two mini-tablets were inserted on the bulbar conjunctiva of the right eye while a similar dose of gentamicin was administered via eye drops in the left eye. Irritation induced by the mini-tablets and the eye drops was evaluated using a visual analogue scale (0-10). Tears were sampled with ophthalmologic absorption triangles for 1 min for the determination of the concentration of gentamicin sulphate using a microbiological plate diffusion met...
In vitro evaluation of three bacterial culture systems for the recovery of Escherichia coli from equine blood.
American journal of veterinary research    December 6, 2006   Volume 67, Issue 12 2025-2029 doi: 10.2460/ajvr.67.12.2025
Lorenzo-Figueras M, Pusterla N, Byrne BA, Samitz EM.To evaluate the effectiveness of a commercial conventional blood culture system (BCS), a commercial resin-containing BCS, and a commercial lysis-centrifugation-based BCS for the recovery of Escherichia coli from equine blood samples inoculated with that organism. Methods: Samples of blood obtained from a clinically normal horse that were inoculated with E coli. Methods: Blood samples were aseptically collected and inoculated with an E coli specimen (50 CFUs/mL) that had been previously isolated from a foal with sepsis. Subsequently, samples were spiked with gentamicin at a concentration of 30 ...
Influence of bacteria and gentamicin on cooled-stored stallion spermatozoa.
Theriogenology    December 1, 2006   Volume 67, Issue 5 912-918 doi: 10.1016/j.theriogenology.2006.11.004
Aurich C, Spergser J.This study investigated effects of bacteria from the genital tract of horses and the effect of gentamicin in semen extender on spermatozoal function in cooled-stored stallion semen. Semen was collected from healthy stallions and processed with a milk-based extender with or without gentamicin (1g/l). Pseudomonas (Ps.) aeruginosa, Staphylococcus (St.) aureus, Streptococcus (Sc.) equi subsp. equi (Sc. equi), Sc. equi subsp. zooepidemicus (Sc. zooepidemicus), Sc. dysgalactiae subsp. equisimilis (Sc. equisimilis) or culture medium alone (control) were added. Immediately after addition of bacteria a...
Continuous monitoring of penicillin G and gentamicin in allantoic fluid of pregnant pony mares by in vivo microdialysis.
Equine veterinary journal    November 28, 2006   Volume 38, Issue 6 520-525 doi: 10.2746/042516406x156136
Murchie TA, Macpherson ML, LeBlanc MM, Luznar S, Vickroy TW.Most current treatments for placentitis in mares are empirical with few control studies to evaluate their effectiveness. Objective: To monitor drug concentrations in allantoic fluid of pregnant pony mares using in vivo microdialysis and establish if this method would be useful for determining allantoic concentrations of drugs in normal mares and those with placentitis. Methods: Five late gestational pony mares had microdialysis probes inserted into the allantoic fluid using transabdominal ultrasound-guided allantocentesis. Single injections of penicillin G (22,000 u/kg), gentamicin (6.6 mg/kg ...
Gentamicin concentrations in synovial fluid obtained from the tarsocrural joints of horses after implantation of gentamicin-impregnated collagen sponges.
American journal of veterinary research    September 5, 2006   Volume 67, Issue 9 1519-1526 doi: 10.2460/ajvr.67.9.1519
Ivester KM, Adams SB, Moore GE, Van Sickle DC, Lescun TB.To determine synovial fluid gentamicin concentrations and evaluate adverse effects on the synovial membrane and articular cartilage of tarsocrural joints after implantation of a gentamicin-impregnated collagen sponge. Methods: 6 healthy adult mares. Methods: A purified bovine type I collagen sponge impregnated with 130 mg of gentamicin was implanted in the plantarolateral pouch of 1 tarsocrural joint of each horse, with the contralateral joint used as a sham-operated control joint. Gentamicin concentrations in synovial fluid and serum were determined for 120 hours after implantation by use of ...
Isolation and identification of Taylorella asinigenitalis from the genital tract of a stallion, first case of a natural infection.
Veterinary microbiology    May 7, 2006   Volume 116, Issue 4 294-300 doi: 10.1016/j.vetmic.2006.04.027
Båverud V, Nyström C, Johansson KE.Contagious equine metritis (CEM), caused by Taylorella equigenitalis, is a widely known highly contagious genital equine disease that is transmitted venereally. A new bacterium, Taylorella asinigenitalis resembling T. equigenitalis was recently isolated from three American donkey jacks, at routine testing for CEM. The purpose of this study was to identify and characterize a strain of Taylorella sp. from the genital tract of a stallion. Swab samples for culture of T. equigenitalis were taken from urethral fossa, urethra and penile sheath of a 3-year-old stallion of the Ardennes breed when it wa...
Arthroscopically assisted arthrodesis of the distal interphalangeal joint with transarticular screws inserted through a dorsal hoof wall approach in a horse.
Journal of the American Veterinary Medical Association    March 16, 2006   Volume 228, Issue 6 909-913 doi: 10.2460/javma.228.6.909
Busschers E, Richardson DW.A 16-year-old Thoroughbred gelding was examined because of chronic right forelimb lameness. Results: On radiographs of the right front foot, the distal interphalangeal (DIP) joint space was narrow, and osteophytes and periarticular bony proliferation indicative of severe osteoarthritis were seen. Arthrodesis of the right DIP joint was recommended to improve the horse's comfort on the limb. Results: The horse was anesthetized, and palmar and dorsal arthroscopic approaches were used to remove as much of the articular cartilage as was accessible. Holes were then drilled through the dorsal aspect ...
Gentamicin concentrations in synovial fluid and joint tissues during intravenous administration or continuous intra-articular infusion of the tarsocrural joint of clinically normal horses.
American journal of veterinary research    March 2, 2006   Volume 67, Issue 3 409-416 doi: 10.2460/ajvr.67.3.409
Lescun TB, Ward MP, Adams SB.To compare gentamicin concentrations achieved in synovial fluid and joint tissues during IV administration and continuous intra-articular (IA) infusion of the tarsocrural joint in horses. Methods: 18 horses with clinically normal tarsocrural joints. Methods: Horses were assigned to 3 groups (6 horses/group) and administered gentamicin (6.6 mg/kg, IV, q 24 h for 4 days; group 1), a continuous IA infusion of gentamicin into the tarsocrural joint (50 mg/h for 73 hours; group 2), or both treatments (group 3). Serum, synovial fluid, and joint tissue samples were collected for measurement of gentami...
Class 1 integrons in Enterobacteriaceae isolated from clinical infections of horses and dogs in the Netherlands.
Microbial drug resistance (Larchmont, N.Y.)    December 20, 2005   Volume 11, Issue 4 383-386 doi: 10.1089/mdr.2005.11.383
Duijkeren EV, Box AT, Schellen P, Houwers DJ, Fluit AC.Integrons in gentamicin- and cotrimoxazole-resistant Enterobacteriaceae from dogs and horses with clinical infections were analyzed by conserved segment PCR-RFLP. Five distinct integron types were found, most of which have previously been reported in Enterobacteriaceae isolated from humans and farm animals, indicating that resistance genes are exchanged between the reservoirs in humans, farm animals, and companion animals.
Gentamicin nephrotoxicity–a comparison of in vitro findings with in vivo experiments in equines.
Veterinary research communications    March 2, 2005   Volume 29, Issue 3 247-261 doi: 10.1023/b:verc.0000047492.05882.bb
van der Harst MR, Bull S, Laffont CM, Klein WR.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...
Influence of fluid therapy on gentamicin pharmacokinetics in colic horses.
Veterinary research communications    February 26, 2005   Volume 29, Issue 2 141-147 doi: 10.1023/b:verc.0000047493.50112.97
van der Harst MR, Bull S, Laffont CM, Klein WR.The aminoglycoside antibiotic gentamicin is commonly used in equine medicine for the prevention and treatment of Gram-negative and staphylococcal bacteria in surgically treated colic patients. The pharmacokinetics of gentamicin in these patients might be altered by the disease status, and/or under the influence of fluid therapy. The purpose of this study was to investigate the effect of intravenous fluid treatment on gentamicin kinetics in colic patients. Colic patients subjected to laparotomy were given fluid infusions according to clinical status. Following gentamicin administration, blood s...
Scanning electron microscopy of the endometrium of mares infused with gentamicin. Al-Bagdadi FK, Eilts BE, Richardson GF.Scanning electron microscopy (SEM) was used to study the endometrium of nine 1-year-old thoroughbred mares after twice intrauterine infusions of gentamicin, on 2 consecutive days. Five mares were infused on 2 consecutive days with 40 ml gentamicin (50 mg/ml) mixed with 80 ml of normal saline. Four mares served as controls and were infused with 120 ml of saline on 2 consecutive days. Endometrial biopsies were obtained from all mares 3 days after the second intrauterine infusion. Each biopsy was processed for SEM by standard methods. The endometrial epithelium of the gentamicin-infused mares had...
Prevention of ischaemia-induced small intestinal adhesions in foals.
Equine veterinary journal    July 16, 2004   Volume 36, Issue 5 370-375 doi: 10.2746/0425164044868431
Sullins KE, White NA, Lundin CS, Dabareiner R, Gaulin G.Treatments addressing variously theorised pathophysiological mechanisms of small intestinal adhesions have been reported. This study applied those classes of treatments to the most clinically relevant aetiology of post operative adhesions. Objective: Treatments addressing the pathophysiology of ischaemia-reperfusion induced adhesions would accordingly reduce the incidence of adhesions from this model. Methods: Four classes of treatments were administered for 72 h to 16 foals subjected to complete ischaemia followed by reperfusion to create peritoneal adhesions. These groups were: 1) FPG group-...
Intraosseous gentamicin perfusion of the distal metacarpus in standing horses.
Veterinary surgery : VS    March 19, 2004   Volume 33, Issue 2 180-186 doi: 10.1111/j.1532-950x.2004.04026.x
Mattson S, Bouré L, Pearce S, Hurtig M, Burger J, Black W.To report tissue gentamicin concentrations after intraosseous (IO) perfusion in standing horses. Methods: In vivo study. Methods: Twelve horses. Methods: Sedated horses had a cannulated cortical bone screw inserted into the dorsolateral aspect of the treated metacarpus and a tourniquet applied proximally. Gentamicin (2.2 mg/kg) diluted in sterile saline solution (0.1 mL/kg) was infused through the screw. Two horses were euthanatized at each time interval: 0, 2, 6, 12, 24, and 36 hours. Synovial fluid and bone samples were collected distal to the screw from both forelimbs. Gentamicin concentrat...
Concentrations of gentamicin in serum and bronchial lavage fluid after once-daily aerosol administration to horses for seven days.
American journal of veterinary research    February 21, 2004   Volume 65, Issue 2 173-178 doi: 10.2460/ajvr.2004.65.173
McKenzie HC, Murray MJ.To assess gentamicin concentrations in serum and bronchial lavage fluid (BLF) of horses during a 24-hour period after once-daily aerosol administration of gentamicin (GAER) for 7 days and the pattern and degree of bronchial tree inflammation associated with repeated GAER. Methods: 13 healthy adult horses (9 geldings and 4 mares). Methods: The treatment group comprised 8 horses, and 5 horses were untreated control animals. Gentamicin (20 mL of gentamicin [50 mg/mL]) was administered via aerosol once daily for 7 days. Samples of serum and BLF were obtained from all horses before GAER and 0.5, 4,...
Bone gentamicin concentration after intra-articular injection or regional intravenous perfusion in the horse.
Veterinary surgery : VS    December 3, 2003   Volume 32, Issue 6 559-565 doi: 10.1111/j.1532-950x.2003.00559.x
Werner LA, Hardy J, Bertone AL.To compare intra-articular (IA) and bone gentamicin concentrations achieved after intra-articular administration or regional intravenous perfusion (RIP). Methods: Experimental study. Methods: Twelve healthy adult horses. Methods: Horses were assigned to 2 treatment groups (n = 6/group): Group 1, 1 g gentamicin administered simultaneously in both left and right metacarpophalangeal joints and group 2, 1 g gentamicin administered simultaneously in both left and right lateral palmar veins. Serum, synovial fluid, and bone biopsy specimens were collected. Gentamicin concentrations were determined by...
Characterization of antimicrobial aerosols for administration to horses.
Veterinary therapeutics : research in applied veterinary medicine    September 25, 2003   Volume 4, Issue 2 110-119 
McKenzie HC.A study was conducted to characterize the aerosols produced by a medical ultrasonic nebulizer using solutions containing antimicrobials appropriate for therapy of equine lower respiratory bacterial infections (gentamicin sulfate and ceftiofur sodium). Test aerosols were generated using an ultrasonic nebulizer and were analyzed using a laser diffraction aerosol particle analyzer. The aerosol was described in terms of the particle size distribution (volume median diameter), span (sample dispersion), and aerosol density (% volume). The particle size distribution and aerosol density of gentamicin ...
Comparative disposition kinetics and plasma protein binding of gentamicin sulphate in three juvenile animal species.
Journal of veterinary medicine. A, Physiology, pathology, clinical medicine    September 2, 2003   Volume 50, Issue 4 196-200 doi: 10.1046/j.1439-0442.2003.00530.x
Abo El Sooud K.The pharmacokinetics of gentamicin was studied in lambs, calves and foals, respectively after single intravenous (i.v.) injections of 5 mg kg(-1) body weight. The plasma concentration-time curves of gentamicin sulphate were best fitted to follow a two-compartment open model in calves and foals and a three-compartment open model in lambs. Gentamicin showed high plasma level at 5 min post-injection. Then its concentration decreased gradually until its minimum detectable level at 10 and 12 h post-injection in foals and calves, respectively, was reached. In contrast, the plasma concentrations were...
In vitro susceptibilities of Rhodococcus equi and other common equine pathogens to azithromycin, clarithromycin, and 20 other antimicrobials.
Antimicrobial agents and chemotherapy    April 24, 2003   Volume 47, Issue 5 1742-1745 doi: 10.1128/AAC.47.5.1742-1745.2003
Jacks SS, Giguère S, Nguyen A.The objective of this study was to determine in vitro activities of azithromycin (AZM), clarithromycin (CLR), and 20 other antimicrobial agents against Rhodococcus equi and other common equine bacterial pathogens. A total of 201 bacterial isolates from various equine clinical samples were examined. CLR was more active than AZM against R. equi, with MICs at which 90% of the isolates were inhibited of 0.12 and 1.0 micro g/ml, respectively. Other antimicrobial agents highly active against at least 90% of R. equi isolates in vitro included rifampin, gentamicin, and imipenem. Both AZM and CLR showe...
Postoperative infection with Actinobacillus spp in horses: 10 cases (1995-2000).
Journal of the American Veterinary Medical Association    November 7, 2002   Volume 221, Issue 9 1306-1310 doi: 10.2460/javma.2002.221.1306
Smith MA, Ross MW.To determine features of postoperative wound infection caused by Actinobacillus spp in horses undergoing clean, elective surgery and to evaluate bacterial susceptibility profiles of bacteria isolated. Methods: Retrospective study. Methods: 10 horses. Methods: Data were retrieved from medical records and the microbiology laboratory database. Results: 1,604 horses underwent clean, elective surgical procedures during the study period. Of these, 23 (1.43%) had postoperative wound infections, and Actinobacillus spp was isolated from 10 of these 23 (43%). Surgical procedures in these 10 horses inclu...
Pharmacokinetics of gentamicin C1, C1a and C2 in horses after single intravenous dose.
Equine veterinary journal    October 3, 2002   Volume 34, Issue 6 615-618 doi: 10.2746/042516402776180160
Steinman A, Isoherranen N, Ashoach O, Soback S.Gentamicin pharmacokinetics has not been studied in horses. Pharmacokinetics of gentamicin C1, C1a and C2 components following i.v. administration of total gentamicin at 6.6 mg/kg bwt to 6 healthy mature horses was determined. Significant differences in clearance, half-life (t 1/2), and mean residence time (MRT) between the gentamicin Cia and the 2 other components were found. The total body clearance (CL) of gentamicin C1a was 1.62 +/- 0.50 ml/min x kg and similar to the glomerular filtration rate (GFR) reported for horses. The CL of gentamicin C1 and C2 were 1.03 +/- 0.08 ml/min x kg and 1.1...
[Glanders–a potential disease for biological warfare in humans and animals].
Harefuah    August 13, 2002   Volume 141 Spec No 88-119 
Lehavi O, Aizenstien O, Katz LH, Hourvitz A.Infection with Burkholderia mallei (formerly Pseudomonas mallei) can cause a subcutaneous infection known as "farcy" or can disseminate to condition known as Glanders. It is primarily a disease affecting horses, donkeys and mules. In humans, Glanders can produce four types of disease: localized form, pulmonary form, septicemia, and chronic form. Necrosis of the tracheobronchial tree and pustular skin lesions characterize acute infection with B. mallei. Other symptoms include febrile pneumonia, if the organism was inhaled, or signs of sepsis and multiple abscesses, if the skin was the port of e...
Effects of continuous intra-articular infusion of gentamicin on synovial membrane and articular cartilage in the tarsocrural joint of horses.
American journal of veterinary research    May 16, 2002   Volume 63, Issue 5 683-687 doi: 10.2460/ajvr.2002.63.683
Lescun TB, Adams SB, Wu CC, Bill RP, Van Sickle DC.To determine the effects of a continuous intra-articular infusion of gentamicin on the synovial membrane and articular cartilage in the tarsocrural joint of horses. Methods: 6 healthy adult horses. Methods: A balloon infusion system attached to a catheter placed in the plantarolateral pouch of both tarsocrural joints in each horse was used for continuous gentamicin solution (GM) or balanced electrolyte solution (BES) delivery for 5 days. Cartilage and synovial membrane specimens were collected on day 5 from 3 horses and on day 14 from the remaining 3 horses. Both infused joints from each horse...
Peritonitis associated with Actinobacillus equuli in horses: 51 cases.
Australian veterinary journal    October 16, 2001   Volume 79, Issue 8 536-539 doi: 10.1111/j.1751-0813.2001.tb10741.x
Matthews S, Dart AJ, Dowling BA, Hodgson JL, Hodgson DR.To review the clinical findings, diagnosis and treatment of 51 horses with peritonitis attributed to Actinobacillus equuli. Methods: Retrospective study of clinical cases. Methods: Breed, age and gender of horse, history, physical examination findings, treatment and outcome were determined from the hospital records of 51 horses in which a diagnosis of peritonitis attributed to A. equuli was made between January 1993 and June 1999. Results of abdominal fluid cytology and bacteriology, antimicrobial sensitivity patterns, haematology and faecal egg counts, when performed, were also retrieved. Res...