Control of bovine respiratory disease, with and without co-morbidity by otitis media, in dairy heifers comparing gamithromycin, tulathromycin, or no medication at a commercial development facility.

The objective of this study was to evaluate one strategy for control (metaphylaxis) of bovine respiratory disease, with and without co-morbidity with otitis media, in dairy heifers at a commercial development facility. Individual heifers were the experimental unit. At weaning, 1 of 3 experimental treatments (gamithromycin, tulathromycin, or no medication) was randomly assigned to 1,567 heifers from 11 different dairies.

Will antimicrobial resistance of BRD pathogens impact BRD management in the future?

Resistance is a qualitative interpretation of antimicrobial activity in vitro. Critical to management of bovine respiratory disease (BRD) is the clinical response in vivo. Attempts to connect activity in vitro to response in vivo have been complicated by the complexity of BRD, interpretation of antimicrobial activity in vitro, and inconsistent measures of clinical success or failure.

Serologic response to Mannheimia haemolytica in calves concurrently inoculated with inactivated or modified-live preparations of M. haemolytica and viral combination vaccines containing modified-live bovine herpesvirus type 1.

Objective: To assess the serologic response of calves to inactivated and modified-live (ML) Mannheimia haemolytica (MH) preparations given alone and concurrently with combination viral vaccines containing ML bovine herpesvirus type 1 (BHV-1).

Animals: 642 calves seronegative for BHV-1.

Procedures: In experiment 1, 192 calves received 1 of 3 MH preparations alone or concurrently received 1 of 3 MH preparations and 1 of 4 combination viral vaccines.

In vitro activities of tulathromycin and ceftiofur combined with other antimicrobial agents using bovine Pasteurella multocida and Mannheimia haemolytica isolates.

The purpose of this study was to determine the activities of two antibacterial agents used in the treatment of bovine respiratory infections-tulathromycin, a macrolide, and ceftiofur, a third-generation cephalosporin-alone, in combination with each other, and in combination with each of seven additional antibiotics (tilmicosin, florfenicol, enrofloxacin, danofloxacin, ampicillin, tetracycline, and penicillin G) against bovine Pasteurella multocida (n = 60) and Mannheimia haemolytica (n = 10) isolates for determination of synergy, antagonism, or indifference. Of 458 organism-drug combinations, 160 combinations of tulathromycin and 209 combinations of ceftiofur with eight antimicrobial drugs were indifferent. One combination was antagonistic (ceftiofur + florfenicol against one isolate of P.

Melengestrol acetate as a tool for inducing early ovulation in transitional mares.

The efficacy of melengestrol acetate (MGA) to shorten the vernal transition of mares by synchronising and accelerating the first ovulation of the year after 60 days of phototherapy was determined by ultrasonographic monitoring. Sixteen mares in late transition were fed two doses of MGA (150 mg/mare/day and 100 mg/mare/day, respectively) for 10 days. A luteolytic dose of prostaglandin was administered to each mare one day after the end of MGA treatment.

Pharmacokinetics and clinical effects of a subanesthetic continuous rate infusion of ketamine in awake horses.

Objective: To determine the pharmacokinetics and clinical effects of a subanesthetic, continuous rate infusion of ketamine administered to healthy awake horses.

Animals: 8 adult horses.

Procedures: Ketamine hydrochloride was administered to 2 horses, in a pilot study, at rates ranging from 0.

Effect of tilmicosin on chemotactic, phagocytic, and bactericidal activities of bovine and porcine alveolar macrophages.

Objective: To evaluate chemotactic, phagocytic, and bactericidal activities of bovine and porcine alveolar macrophages (AM) exposed to tilmicosin.

Animals: 12 healthy calves and 12 healthy pigs.

Procedures: Lungs were obtained immediately after euthanasia; AM were collected by means of bronchoalveolar lavage and density gradient centrifugation.

Use of antimicrobials in wound management.

Antimicrobial medication should be considered an adjunct to the general care of wounds rather than a substitute for lavage, drainage, or other physical care intended to promote healing. Judicious use is based on results of diagnostic procedures and the professional judgment of the attending veterinarian. Organisms that contaminate or infect wounds of horses are similar to those that can affect human patients, such that personal hygiene and protection are important when caring for these equine patients, because attendants can easily be exposed to them.

Susceptibility of Mycobacterium avium sbsp paratuberculosis to monensin sodium or tilmicosin phosphate in vitro and resulting infectivity in a murine model.

This study was designed to determine the susceptibility in vitro and infectivity of 1 field isolate of Mycobacterium avium sbsp paratuberculosis after exposure to monensin sodium and tilmicosin phosphate. Minimum inhibitory concentrations (0.39 microg monensin sodium/mL; 1.

How to respond to adverse drug reactions.

Adverse drug reactions (ADRs) are part of the risks, professional responsibilities, and liabilities inherent to veterinary medicine. The incidence of proven ADRs is not known, but veterinarians should anticipate, plan, and practice a response for patients that experience adverse reactions. The attending veterinarian should work closely with professional services personnel at pharmaceutical manufacturers to provide care for those patients, to investigate causes of ADRs, and to factually improve reports of ADRs that can be of considerable medicolegal benefit to the client and the profession.

Neonatal adjustments.

Pharmacodynamic responses by neonates are the same as those for adults, but physiologic differences and pathophysiologic changes can affect pharmacokinetic values sufficiently to require adjustments in dosage regimens used for calves. Adjunctive care may be necessary for some patients to correct or maintain perfusion and temperature of tissues so that absorption and distribution may be adequate. Intravenous administration may be the only route appropriate for some critically ill patients.

Effectiveness of a unique dihydropyridine (BAYTG 1000) for prevention of laminitis in horses.

Objective: To determine whether a unique dihydropyridine (BAYTG 1000) would be beneficial in preventing laminitis in horses.

Animals: 16 clinically normal adult horses.

Procedure: 8 pairs of horses were used in a controlled double-blind study, using sex- and age-matched horses randomly assigned to treatment or control groups.

Adverse drug reactions and interactions in the horse.

Drugs undergo extensive evaluation before they are marketed. The occurrence of adverse reactions, however, may be so rare that thousands of patients must receive the drug before reliable data are available. It is necessary that veterinarians be informed about the drugs they use, be able to recognize drug-associated complications, know how to evaluate the patient for evidence of drug-associated toxicity, report adverse effects of drugs to the respective manufacturers, and be prepared to provide medical support and antidotal treatment (if it exists) for a patient if toxicosis occurs.

Voluntary limb-load distribution in horses with acute and chronic laminitis.

Objectives: To compare limb-load distribution between horses with and without acute or chronic laminitis.

Animals: 10 horses with carbohydrate-induced acute laminitis, 20 horses with naturally occurring chronic laminitis, and 20 horses without foot abnormalities (controls).

Procedures: Limb-load distribution was determined, using a custom-designed system that allowed simultaneous quantification of the mean percentage of body weight voluntarily placed on each limb (ie, mean limb load) and the SD of the mean load over a 5-minute period (ie, load distribution profile [LDP]).

Evaluation of hoof wall surface temperature as an index of digital vascular perfusion during the prodromal and acute phases of carbohydrate-induced laminitis in horses.

Objective: To evaluate the use of hoof wall surface temperature (HWST) as an indirect indicator of digital perfusion and to describe HWST patterns during the prodromal and acute phases of carbohydrate-induced laminitis in horses.

Animals: 30 adult horses without foot abnormalities.

Procedures: Three experiments were performed.

Effect of monensin sodium on histological lesions of naturally occurring bovine paratuberculosis.

Of 19 adult cows naturally infected with paratuberculosis, 13 were treated with monensin sodium and six remained untreated. At the beginning of the study, the severity of the histological lesions was assessed from biopsy samples of ileum, liver, mesenteric lymph node and rectal mucosa. From the data acquired it was possible to assign the animals so that the lesions in the two groups were similar (P=0.

Bacteriology of preserved stallion semen and antibiotics in semen extenders.

Three experiments were conducted to evaluate the effects of different antibiotics in a milk-glucose semen extender on motility of equine sperm and elimination of bacteria following storage of extended semen in vitro. In Experiment 1, 7 antibiotics were compared: amikacin, gentamicin, streptomycin, potassium penicillin, sodium penicillin, ticarcillin, and polymixin B. In Experiment 2, 3 antibiotic treatments were compared: potassium penicillin G, amikacin, or a combination of potassium penicillin G and amikacin.

Pharmacologic and alternative therapies for the horse with chronic laminitis.

This article deals with treatment of the chronically foundered horse. The first section of this article is focused on aspects of the traditional pharmacologic approaches to management of digital pain and sepsis, dietary management, and thyroid supplementation. A second section introduces the concepts, principles, and agents that are used in homeopathic treatments for laminitis.

The pharmacologic basis for the treatment of developmental and acute laminitis.

Each horse with laminitis is presented to the veterinarian at a different stage in progression of the condition and with varying severity. The pathogenic timing is often unknown and is difficult to determine. Because timing and severity are related to both the lesion's severity and responsiveness to treatment, these factors are critical to treatment selection and success.

Pharmacokinetics of a high dose of gentamicin administered intravenously or intramuscularly to horses.

Objective: To evaluate pharmacokinetics of a high dose of gentamicin administered i.v. or i.

Effectiveness of two fluoroquinolones for the treatment of chronic respiratory disease outbreak in broilers.

1. Chronic respiratory disease (CRD) caused by Mycoplasma synoviae in association with Escherichia coli is the disease most frequently encountered in poultry in Mexico. 2.

Plasma pharmacokinetics of ranitidine HCl in foals.

Plasma pharmacokinetics of ranitidine HCl were investigated after intravenous (i.v.) and oral (p.

Effects of postoperative peritoneal lavage on pharmacokinetics of gentamicin in horses after celiotomy.

Objective: To evaluate the effect of peritoneal lavage on pharmacokinetics of gentamicin sulfate in healthy horses after experimental celiotomy.

Animals: 13 clinically normal horses.

Procedure: Horses were randomly assigned to control or experimental groups.

Plasma pharmacokinetics of ranitidine HCl in adult horses.

Plasma pharmacokinetics of ranitidine HCl were investigated after intravenous (i.v.) and oral (p.

Amikacin pharmacokinetics and the effects of ambient temperature on the dosage regimen in ball pythons (Python regius).

The serum concentration of amikacin following intracardiac and i.m. administration of amikacin (3.