Omneity® Pellets
All-In-One Vitamin & Mineral Pellet
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.
Peritonitis in adult horses: a review of 21 cases. The clinical signs in 21 adult horses affected by peritonitis (unassociated with gastrointestinal rupture or surgical interference of the abdomen) included colic (18 cases), pyrexia (15 cases), weight loss (six cases) and diarrhoea (five cases). The diagnosis was based on a nucleated cell count in peritoneal fluid greater than 10(10)/litre. Haematological abnormalities (either neutropenia or neutrophilia) were present in 17 animals, and hyperfibrinogenaemia was identified in 14. Twelve of the 21 horses survived after intensive antibiotic therapy; the other nine were destroyed either at explora...
The effect of phenylbutazone on the plasma disposition of penicillin G in the horse. A pilot study in two ponies showed that the plasma concentrations of intramuscularly administered procaine penicillin were higher if phenylbutazone was administered concurrently. In two other trials, each involving five horses, intravenous sodium penicillin was administered with and without concurrent intravenously injected phenylbutazone, and procaine penicillin was injected intramuscularly with and without oral phenylbutazone. In both cases the plasma concentrations of penicillin were higher when phenylbutazone was given. The pharmacokinetic parameters indicated that the effect was probably ...
In vitro antimicrobial activity of defensins against ocular pathogens. New approaches to antimicrobial therapy for ocular pathogens must overcome organisms that are resistant to current therapeutic modalities. This investigation examined the antimicrobial activity of novel antimicrobial neutrophil peptides (defensins NP-1 and NP-5) against isolates from clinical ocular microbial infections in humans and horses. The test panel of human clinical isolates included Candida albicans, an alpha-hemolytic Streptococcus, Streptococcus pneumoniae, Pseudomonas aeruginosa, and Morganella morganii. The test panel of equine pathogens included three clinical isolates of P aerug...
Ulcerative duodenitis with luminal constriction in two horses. Proximal enteritis was diagnosed on the basis of clinical signs of disease in 2 Standard-bred yearlings from the same farm. Large volumes of fluid were repeatedly obtained during gastric decompression. The horses did not respond to treatment with IV administered fluids, antimicrobial agents, cimetidine, and metoclopramide. Postmortem findings confirmed severe focal chronic active duodenitis with stricture formation. An etiologic agent was not identified.
Surgical repair of ruptured trachea in a horse. An Arabian mare was referred with traumatically induced complete transection of the trachea. A temporary airway was established through the open wound at the site of the rupture. Resection of devitalized tissue including 3 tracheal ring segments, and anastomosis of the tracheal ends was subsequently performed under general anesthesia. Wound healing was complicated by a peritracheal abscess, which responded successfully to drainage and antibiotic administration.
Plasma disposition and tolerance of aditoprim in horses after single intravenous injection. Aditoprim, a broad spectrum antimicrobial agent acting as a reversible dihydrofolate reductase inhibitor, was intravenously injected into four 12 to 24-year old horses at a dosage of 5 mg/kg b. w. Blood samples were collected over a 48-hour period after drug injection, and the separated plasma samples were assayed for aditoprim by high performance liquid chromatography. The body temperature, heart rate, respiration rate, and behaviour were recorded during the experiment. The bilirubin and urea concentrations were also determined in several plasma samples, and liver function tests were carried ...
Concentrations of trimethoprim and sulfamethoxazole in cerebrospinal fluid and serum in mares with and without a dimethyl sulfoxide pretreatment. Each of seven mares was given an intravenous (IV) injection of 40% dimethyl sulfoxide (DMSO) at a dosage of 1 g/kg, over 35 min, immediately followed by a single IV injection of a trimethoprim (TMP) and sulfamethoxazole (SMZ) combination (SMZ 83%, TMP 17%) at a combined dosage of 44 mg/kg (7.48 mg/kg TMP; 36.52 mg/kg SMZ). Each horse served as its own control and was alternately treated with an identical dose of TMP-SMZ treatment alone at least seven days following or preceding the DMSO and TMP-SMZ treatment. Serum and cerebrospinal fluid (CSF) concentrations of TMP and SMZ were measured over ...
Anaerobic bacterial pneumonia with septicemia in two racehorses. Anaerobic bacterial pneumonia with septicemia was diagnosed in 2 Thoroughbred racehorses referred with respiratory tract disease that had failed to respond to initial treatment with various antibiotics including penicillin and trimethoprim-sulfamethoxazole. Multiple anaerobic organisms, including Bacteroides spp and Fusobacterium spp, were isolated from blood and transtracheal aspirates obtained from both horses and from aspirates of cutaneous nodules obtained from 1 horse. The latter horse responded to metronidazole treatment followed by procaine penicillin G administration and regained its h...
Pharmacokinetics of tinidazole in the horse. Serum tinidazole concentrations were monitored in five clinically healthy adult horses after intravenous (i.v.) and oral administration of the drug (15 mg/kg and 25 mg/kg, respectively). After i.v. administration, the mean residence time was 7.0 h, the elimination half-life 5.2 h and the body clearance rate 1.6 ml/min/kg. The distribution volume was found to be 660 ml/kg. After oral administration, the mean residence time was 8.5 h, the absorption half-life 1.1 h and the bioavailability essentially 100%. In view of the in-vitro sensitivities of various anaerobic bacteria, a dosage of 10-15 mg/...
Pericarditis in horses: six cases (1982-1986). Records of 6 horses with pericarditis were reviewed. Septic pericarditis was suspected in all horses, based on historic and clinical findings. In horses 1, 2, and 4, cytologic examination of the pericardial effusion revealed acute inflammation with severe neutrophil degeneration. In horses 3 and 5, cytologic examination of pericardial fluid revealed subacute inflammation with degenerated neutrophils, and in horse 6, chronic active inflammation, with well preserved neutrophils. In horses 1 and 3, bacteria were identified on cytologic examination of pericardial fluid. Results of microbiologic cu...
Endometrial concentrations of ampicillin in mares after intrauterine infusion of the drug. Serum concentration of ampicillin, a semisynthetic penicillin, was measured in mares at various time intervals up to 24 hours after intrauterine infusion of 3 g of ampicillin. Blood samples were drawn immediately before infusion and at 1-, 4-, 10- and 24-hour intervals after infusion. At postinfusion hour 24, two endometrial biopsy specimens were obtained to measure endometrial concentrations of ampicillin. Blood was drawn twice as part of the 24-hour postinfusion sample collection, once before removal of the biopsy specimens and again 5 minutes after removal of the biopsy specimens. After dru...
Debridement of septic physeal lesions in 3 foals. Radiographically, osteolysis of the physis consistent with a septic physitis was observed in 3 foals. The foals were treated with surgical debridement and antimicrobials. Two of the horses were sound for use as adults; the third was euthanatized due to concurrent infectious arthritis and septicemia.
Antimicrobial susceptibilities of Staphylococcus aureus isolated from animal and human sources in Brazil. The susceptibilities of 760 Staphylococcus aureus strains isolated from animal infections (400), human infections (300) and healthy human carriers (60) to seven antibiotics were determined by an agar dilution technique. The isolates from human infections were more resistant to a wider spectrum of antibiotics than were the strains from animal infections and healthy human carriers. Amikacin and gentamicin were the most active drugs against all groups of strains.
Pharmacokinetics of trimethoprim-sulphamethoxazole in two-day-old foals after a single intravenous injection. Six healthy two-day-old foals (3 pony foals and 3 horse foals) were given a single intravenous (iv) injection of trimethoprim (TMP)--sulphamethoxazole (SMZ) at a dosage of 2.5 mg of TMP/kg bodyweight (bwt) and 12.5 mg of SMZ/kg bwt. Serum TMP and SMZ concentrations were measured serially during a 24 hour period. The overall elimination rate constant (K) for TMP in the pony and horse foals was 0.45/h, whereas the K values for SMZ for the pony and horse foals were 0.12/h and 0.07/h, respectively (no significant difference; P greater than 0.05). Based on published minimum inhibitory concentration...
Pharmacokinetics of amikacin in critically ill neonatal foals treated for presumed or confirmed sepsis. Fourteen foals less than four days of age were treated with the aminoglycoside, amikacin sulphate, and either penicillin or ampicillin for septicaemia, pneumonia, and/or failure of passive immunoglobulin transfer. Serum amikacin concentrations were determined at three times during an 8 or 12 h dosing interval. A 7.0 mg/kg bodyweight dose of amikacin every 8 h was appropriate. Prematurity did not influence mortality. All seven premature foals survived, whereas four of the seven full term foals died. Uraemia in three foals was caused by urinary bladder rupture; amikacin-induced nephrotoxicity wa...
Further investigations into the potentiation of infection by intra-articular injection of polysulfated glycosaminoglycan and the effect of filtration and intra-articular injection of amikacin. Polysulfated glycosaminoglycan (PSGAG) recently have been reported to potentiate the infectivity of Staphylococcus aureus in horses with experimentally induced septic arthritis. Four groups of 8 horses each had 1 midcarpal joint injected with approximately 33 viable colony-forming units (CFU) of S aureus plus either 1 ml of saline solution (group 1), 250 mg of PSGAG (group 2), 250 mg of PSGAG passed through a 0.6-microns filter (group 3), or 250 mg of PSGAG plus 125 mg of amikacin (group 4). Horses that developed clinical signs consistent with sepsis were euthanatized, and samples were collect...
Absorption of two trimethoprim/sulphonamide combinations from the uterus of pony mares. Plasma drug concentrations were measured after two commercially available potentiated sulphonamides, trimethoprim and sulfadoxine and trimethoprim and sulphadiazine, were infused daily for 2 and 3 days, respectively, into the uteri of pony mares which had been mated before ovulation. Intravenous administration of trimethoprim and sulfadoxine allowed uterine absorption of trimethoprim (23-43%) and sulfadoxine (29-34%) to be calculated. After intra-uterine administration trimethoprim and sulphadiazine were detected in the milk of a lactating mare. In order to maintain plasma concentrations likel...
The management of open joint injuries. The prognosis for returning horses with open joint injuries to athletic function is most closely related to the duration of the injury prior to treatment. Prompt diagnosis and appropriate therapy should yield a favorable result. Delayed diagnosis or inappropriate therapy that allow the wound to progress to an infected state makes the likelihood of return to athletic function poor. Refractory joint infection can occur despite early diagnosis and prompt appropriate therapy. The development of these infections is undoubtedly increased by tissue loss and gross contamination. Appropriate antibiotic...
Phenolsulfonphthalein pharmacokinetics and renal morphologic changes in adult pony mares with gentamicin-induced nephrotoxicosis. Changes in renal function, determined by pharmacokinetics of phenolsulfonphthalein (PSP), and renal morphologic features were examined in adult pony mares given 20 mg of gentamicin sulfate/kg of body weight, IV, q 8 h (group A) n = 7 or isotonic saline solution, IV, q 8 h, n = 5 (group B) for 14 days. Susceptibility of ponies to gentamicin-induced nephrotoxicosis was varied. Two group-A ponies developed acute renal failure and were euthanatized before treatment day 14, whereas 5 group-A A ponies did not develop physical or behavioral abnormalities after 14 days of gentamicin administration. Al...
Surgical treatment of septic pedal osteitis in horses: nine cases (1980-1987). Over an 8-year period, 9 horses with septic pedal osteitis were admitted to the New York State College of Veterinary Medicine. Septic pedal osteitis was defined by the presence of purulent exudate combined with radiographic evidence of lysis of the distal phalanx. The condition described involved only the distal phalanx, the laminae and hoofwall, and the soft tissues of the sole. Treatment included curettage and removal of the affected portion of the distal phalanx through a ventral approach to the foot, combined with systemic administration of antibodies. Of the 9 horses, 7 returned to soundn...
Effects of polymyxin B on selected features of equine carbohydrate overload. Gram negative endotoxins play a contributory role in the syndrome which results from over consumption of carbohydrates by horses and ponies. Since the antibiotic polymyxin B exerts a direct anti-endotoxin effect by chemically modifying the active lipid A moiety of endotoxin, it might be expected to protect horses after carbohydrate overload and provide a new therapeutic and experimental tool for this condition. The present study was undertaken to evaluate the effect of polymyxin B on hemostatic, hemodynamic, acid-base, and clinical aspects of the syndrome resulting from carbohydrate overload. ...
Effect of probenecid administration on cephapirin pharmacokinetics and concentrations in mares. Cephapirin (20 mg/kg of body weight, IV) was administered before and after 3 doses of probenecid (25, 50, or 75 mg/kg, intragastrically, at 12-hour intervals) to 2 mares. Clearance and apparent volume of distribution, based on area under the curve, were negatively correlated with probenecid dose. Clearance of cephapirin was decreased by approximately 50% by administration of 50 mg of probenecid/kg. Serum, synovial fluid, peritoneal fluid, CSF, urinary, and endometrial concentrations of cephapirin were determined after 5 doses of cephapirin (20 mg/kg, IM, at 12-hour intervals) without and with ...
Equine mastitis–a review of 28 cases. Mastitis was diagnosed in 28 mares. Cytological evaluation of milk samples showed large numbers of neutrophils in 72 per cent and bacteria in 33 per cent. Aerobic bacteria were cultured from 71 per cent of samples. Streptococcus zooepidemicus was the most common isolate (37 per cent). Gram-negative species accounted for 42 per cent. Determination of the probability for antimicrobial susceptibility of bacterial isolates from mares with mastitis indicated that a trimethoprim-sulphonamide combination would be active against more than 75 per cent of isolates while penicillin would be active agains...
Pseudallescheria boydii keratomycosis in a horse. The fungal organism Pseudallescheria boydii was isolated from the cornea of a Quarter Horse with ulcerative keratitis. Despite aggressive hourly medication through a subpalpebral lavage system, with drugs including miconazole and natamycin, the cornea developed a stromal abscess. Orbital exenteration was performed after 3 weeks. The fungal isolate was later determined to be resistant to all 8 antifungal drugs tested. Microscopic examination of the cornea revealed fungal hyphae throughout the corneal stroma and penetrating the Descemet membrane. Pseudallescheria boydii has not been implicated p...
Serratia marcescens septicemia associated with infusion of an amino acid solution in two horses. Clinical septicemia developed in 2 clinically normal horses after both were administered a portion of an amino acid solution IV. Serratia marcescens was subsequently isolated from blood of both horses. The isolates were shown to be identical on the basis of antibiograms and plasmid biochemistry, incriminating the infusate as the source of bacterial infection. The horses recovered after supportive and antimicrobial treatment.
Perioperative medical care for equine abdominal surgery. Rational perioperative management improves the success rate of abdominal surgery. Important aspects of management are discussed, including principles of fluid therapy, nutrition, intravenous catheterization, antimicrobial prophylaxis, and the use of nonsteroidal anti-inflammatory medication. Current advances in the area of immunotherapy are mentioned.
[Bilateral pleuritis following esophageal fistula in a horse as a complication of a Gasterophilus infection]. A six-year-old pregnant Haflinger mare of 510 kilograms died from bilateral pleurisy following a hospitalisation period of ten days, during which she was treated with various antibiotics. At necropsy a bilateral fibrinopurulent pleurisy accompanied by an ulceration of the cardia of the stomach measuring once cm2 was found. In the wall of the oesophagus, close to the cardia, there was a fistula harbouring a 3rd stage Gasterophilus larva. The epithelial layer at this site was unimpaired and no gross connection between the fistula and the ulceration of the cardia was observed. The fistula was in ...
Clinical, ultrasonographic, and surgical findings in foals with umbilical remnant infections. Infection of umbilical arteries, umbilical vein, and/or urachus was diagnosed ultrasonographically in 33 foals 1 to 90 days old (mean, 17.7 +/- 17.3 days). In these foals, the most common initial problems were umbilical abnormalities, septic arthritis, and/or neonatal septicemia. In 16 foals, abnormalities of the external umbilical stalk were noticed on admission. Abnormalities of the internal umbilical structures were identified when enlargement and echogenic material (fluid and/or gas) were imaged ultrasonographically within these structures. Multiple structures were affected in 23 foals, wi...
