Clinical efficacy and safety of imepitoin in comparison with phenobarbital for the control of idiopathic epilepsy in dogs.

The anticonvulsant activity and safety of imepitoin, a novel antiepileptic drug licensed in the European Union, were evaluated in a multicentre field efficacy study as well as in a safety study under laboratory conditions. Efficacy of imepitoin was compared with phenobarbital in 226 client-owned dogs in a blinded parallel group design. The administration of imepitoin twice daily in incremental doses of 10, 20 or 30 mg/kg demonstrated comparable efficacy to phenobarbital in controlling seizures in dogs. The frequency of adverse events including somnolence/sedation, polydipsia and increased appetite was significantly higher in the phenobarbital group. In phenobarbital-treated dogs, significantly increased levels of alkaline phosphatase, gamma-glutamyl-transferase and other liver enzymes occurred, while no such effect was observed in the imepitoin group. In a safety study under laboratory conditions, healthy beagle dogs were administered 0, 30, 90 or 150 mg/kg imepitoin twice daily for 26 weeks. A complete safety evaluation including histopathology was included in the study. A no-observed-adverse-event level of 90 mg/kg twice daily was determined. These results indicate that imepitoin is a potent and safe antiepileptic drug for dogs.

Bioequivalence in dogs of a meloxicam formulation administered as a transmucosal oral mist with an orally administered pioneer suspension product.

A mucosal mist formulation of meloxicam, administered as a spray into the mouth (test article), was compared for bioequivalence to a pioneer meloxicam suspension for oral administration (reference article). Pharmacokinetic profiles and average bioequivalence were investigated in 20 dogs. The study design comprised a two-period, two-sequence, two-treatment cross-over design, with maximum concentration (C(max)) and area under plasma concentration-time curve to last sampling time (AUC(last)) used as pivotal bioequivalence variables. Bioequivalence of the products was confirmed, based on relative ratios of geometric mean concentrations (and 90% confidence intervals within the range 0.80-1.25) for C(max) of 101.9 (97.99-106.0) and for AUC(last) of 97.24 (94.44-100.1). The initial absorption of meloxicam was more rapid for the test article, despite virtually identical C(max) values for the two products. Mean elimination half-lives were 29.6 h (test article) and 30.0 h (reference article). The meloxicam plasma concentration-time profiles were considered in relation to published data on the inhibition of the cyclooxygenase-1 (COX-1) and COX-2 isoenzymes by meloxicam.

Leptospirosis. Epidemiological features of a sporadic case.

Leptospirosis occurred in a 45-year-old man with presumed infection from an exposure to contaminated water at his source of employment. An intensive epidemiological investigation, including serological examination of all family members and pets and cultures on the patient and his family pets (cats and dogs), proved that the leptospiral organism was acquired by the patient's exposure to his dogs. The risk of acquiring infection from dogs that are asymptomatic and vaccinated is emphasized by this report.

Mortality in beagles irradiated during prenatal and postnatal development. II. Contribution of benign and malignant neoplasia.

To evaluate the lifetime carcinogenic hazards of exposure to ionizing radiation during development, 1,680 beagles received whole-body exposures to 60Co gamma rays or sham exposures. Eight groups of 120 dogs each received mean doses of 15.6-17.5 or 80.8-88.3 cGy in early, mid- or late gestation, at 8, 28 or 55 days postcoitus or at 2 days after birth. Another group of 120 dogs received a mean dose of 82.6 cGy as 70-day-old juveniles and one group of 240 dogs received a mean dose of 81.2 cGy as 365-day-old young adults. Sham irradiations were given to 360 controls. Sexes were equally represented. In 1,343 dogs allowed to live out their life span, neoplasia was a major disease, contributing to mortality in 40% of the dogs. There was a significant increase in benign and malignant neoplasms occurring in young dogs (<4 years old), including fatal malignancies, after irradiation in the perinatal (late fetal and neonatal) periods. The lifetime incidence of fatal neoplasms was also increased in dogs irradiated perinatally. Three malignancies-lymphomas, hemangiosarcomas and mammary carcinomas-accounted for 51% of all fatal tumors. There was an apparent lifetime increase and earlier onset of lymphomas in dogs exposed as fetuses. Fatal hemangiosarcomas were increased in dogs irradiated early and late in gestation. Fatal mammary carcinomas were not increased by irradiation, although non-fatal carcinomas were increased after perinatal exposure. Myeloproliferative disorders and central nervous system astrocytomas appeared to be increased in perinatally irradiated dogs. These data suggest that irradiation in both the fetal and neonatal periods is associated with increased early onset and lifetime cancer risk.

Mortality in beagles irradiated during prenatal and postnatal development. I. Contribution of non-neoplastic diseases.

To evaluate the lifetime health effects of exposure to ionizing radiation during development, 1,680 beagles received whole-body exposures to 60Co gamma rays or sham exposures. Eight groups of 120 dogs each received mean doses of 15.6-17.5 or 80.8-88.3 cGy in early, mid- or late gestation, at 8, 28 or 55 days after breeding, or at 2 days after birth. Another group of 120 dogs received a mean dose of 82.6 cGy as 70-day-old juveniles and one group of 240 dogs received a mean dose of 81.2 cGy as 365-day-old young adults. Sham irradiations were given to 360 controls. Sexes were equally represented. There was no significant effect of irradiation on mean survival times in any groups. In 1,343 dogs allowed to live out their life span, chronic renal disease was a common cause of mortality, and irradiation in the late fetal or juvenile periods potentiated this disease, resulting in increased mortality due to renal failure. This was consistent with earlier findings of the high radiosensitivity of the kidney in the perinatal period. Hypothyroidism associated with atrophic thyroiditis was decreased by irradiation, a finding contrary to expectation and not easily explained. Diabetes mellitus was increased by irradiation in the mid- and late gestation and juvenile periods, a finding which is intriguing based on early reports of a similar finding in atomic bomb survivors. Though convulsive seizures were a common cause of mortality in the dogs, there was no evidence for increased risk associated with prenatal irradiation as has been reported in humans. Genetic analyses indicated that renal disease, hypothyroidism, diabetes mellitus and convulsive seizures all had a heritable component, but that this did not influence or bias the radiation responses evaluated.

Ecology of California encephalitis viruses on the Del Mar Va Peninsula. I. Virus isolations from mosquitoes.

The ecology of California encephalitis viruses was studied on the Del Mar Va Peninsula. Adult mosquitoes were collected weekly from May to October of 1971 and monthly from May to October of 1972, using CDC miniature light traps with Dry Ice. Floodwater mosquitoes were assayed for virus in suckling mice or cell cultures. In 1971 over 77,000 mosquitoes were processed, resulting in 33 virus isolations. In 1972, over 106,000 were processed and 63 virus strains were recovered. Of the 1971 strains, all but one were recovered from Aedes atlanticus mosquitoes, and of the 1972 strains all but two were recovered from A. atlanticus. All A. atlanticus strains were neutralized by Keystone virus mouse hyperimmune ascitic fluid (MHAF). All other strains were recovered from A. canadensis mosquitoes. The single 1971 strain, and one strain from 1972, were neutralized by Jamestown Canyon MHAF. The remaining strain was neutralized by Keystone MHAF. The rate of virus recovery from A. atlanticus remained approximately the same, both between years and during each year studied, even during periods when large numbers of adults were emerging, suggesting that these mosquitoes had emerged infected.

Nonadditive hepatic tumor promoting effects by a mixture of two structurally different polychlorinated biphenyls in female rat livers.

This study evaluates and quantifies the interactive hepatic tumor promoting effects of two PCBs, the Ah receptor agonist PCB 126 (3,3',4,4',5-pentachlorobiphenyl) and the constitutive androstane receptor (CAR) agonist PCB 153 (2,2',4,4',5,5'-hexachlorobiphenyl). Promotion of altered hepatic foci was evaluated utilizing a medium-term 8-week bioassay for promoters of hepatocarcinogenesis. The assay employs placental glutathione-S-transferase positive (GST-P+) liver cell foci as markers of preneoplasia in female Fischer 344 rats treated with the known initiator diethylnitrosamine followed by partial hepatectomy and by gavage exposure to test chemicals. GST-P+ foci were quantified by histomorphometry and were reported as areas and numbers of GST-P+ foci within the area of liver examined. For PCB 126, the doses were 0.1, 1.0, and 10 microg/kg body weight. For PCB 153, the doses were 10, 100, 1000, 5000, and 10,000 microg/kg body weight. Combined PCB 126 and 153 exposures were 0.1 + 10, 1 + 100, 10 + 1000, 10 + 5000, and 10 + 10,000 microg/kg, respectively. Individual PCB treatment resulted in dose dependent increases in liver and adipose concentrations. Hepatic PCB 153 levels were significantly increased (p < 0.01) after combined exposure. Treatment with PCB 126 or PCB 153 alone resulted in a significant (p < 0.01) dose dependent increase in GST-P+ foci area and number compared with controls. Treatment with the mixture of PCB 126 and 153 resulted in antagonistic GST-P+ focus formation (p < 0.001) for both foci area and number. The less than additive effect was present at all 5 PCB 126/PCB 153 dose combinations, including the low doses of PCB 126 and 153 that did not show significant promotional activity alone.

Association of semen quality and occupational factors: comparison of case-control analysis and analysis of continuous variables.

OBJECTIVE: To compare two statistical approaches, case-control and analysis of continuous parameters of semen, in examining the relationship between occupational exposures and male reproductive function. DESIGN: Case-control study. SETTING: Males providing semen samples at a university infertility clinic. PATIENT(S): Nonvasectomized males who provided at least one semen sample at an infertility clinic. MAIN OUTCOME MEASURE(S): Standard clinical semen analysis. RESULT(S): Analyses using a dichotomous dependent variable did not uncover significant associations between any occupational factor and infertility case status. However, linear models incorporating continuous variables identified a number of occupational factors that were associated with specific parameters of semen. A reduction in percentage of progressive sperm and an increase in percentage of coiled tail sperm defects in welders, compared with unexposed subjects, were found. Significant dose-response relationships between level of perceived job stress and percentage of progressive sperm, total motile count, morphology, abnormal heads, and coiled tail defects were found. CONCLUSION(S): The findings suggest that subtle changes in semen variables, possibly associated with workplace exposure, may be detected only with parametric analyses of continuous variables of semen.

Electroless and chemical metal deposition on human tooth enamel.

The feasibility of depositing a thin metal film onto tooth enamel has been demonstrated. The process employs chemical solutions containing ions of the metal to be deposited and suitable reducing agent solutions. The deposits are quite adherent and exhibit the normal properties of the bulk metal.

Lack of promotional effects of groundwater contaminant mixtures on the induction of preneoplastic foci in rat liver.

F344 rats were exposed to drinking water mixtures of seven of the most common groundwater contaminants associated with hazardous waste sites [arsenic, benzene, chloroform, chromium, lead, phenol, and trichloroethylene (TCE)] as the full mixture or submixtures of the organic and/or inorganic chemicals. The lowest concentrations (1x) of the individual chemicals were environmentally realistic and below what would be expected to induce significant short-term toxicity. This study was intended to determine if previously reported increases in localized hepatocellular proliferation in response to these chemicals might be correlated with increased risk for hepatocarcinogenesis. Rats were exposed via a drinking water solution to the full seven- chemical mixture (at 1x and 10x concentrations), submixtures of the organic or inorganic chemicals (at 10x concentrations), a mixture of TCE, lead, and chloroform (TLC submixture at 10x and 100x concentrations), or deionized water as a control. The rats were evaluated for promotion of placental glutathione-S-transferase (GST-P) positive preneoplastic liver cell foci after diethylnitrosamine (DEN) initiation and partial hepatectomy. Focus formation, cell proliferation, and apoptosis were evaluated after exposure to DEN or saline controls, the chemical mixtures or deionized water controls, or combinations of these treatments. The total number and area of GST-P positive foci in DEN-treated rats exposed to the full seven-chemical mixture was increased as compared with the DEN-water controls, but this was statistically significant only for total focus area in the 1x dose group. In DEN-treated rats, the inorganic or TLC submixtures resulted in a significant reduction in number and area of GST-P positive foci. Focus area also was decreased in the organic submixture-treated group, but not significantly. Hepatocellular proliferation was not significantly changed in the chemical mixture saline groups as compared with the mixture water controls. After DEN treatment, however, cell proliferation was significantly decreased after the 10x seven-chemical and organic mixture treatments and the 100x TLC mixture treatment. Different groups showed either increased or decreased apoptotic rates which did not correlate well with proliferation rates or focus formation. Mixtures of these seven chemicals, therefore, did not appear to act as promoters of hepatic foci at environmentally relevant concentrations, and some mixture combinations appeared to decrease promotional activity.

Retroperitoneal abscess. A potentially fatal complication of closed fracture of the pelvis.

Two patients were seen in whom a retroperitoneal abscess developed following closed pelvic fracture. A retroperitoneal abscess is often unsuspected clinically, and presents a difficult diagnostic challenge. Prompt recognition and treatment are essential to patient survival.

Risk factors for exposure to arsenic at a hazardous waste site.

Communities surrounding the Rocky Mountain Arsenal (RMA), a Superfund site in Colorado, were studied in order to determine whether exposures to arsenic were greater among persons who resided there than among residents of a comparison area. A census was conducted in areas adjacent to the RMA and in a comparison area 12-15 miles distant. From a stratified random sample, 469 persons were interviewed and urine samples obtained. Arsenic was detected in urine from 43 (9.2%) of the 469 persons sampled at a detection limit of 10 ppb. Trace levels of arsenic (detectable, but non-quantifiable) were found in 184 (39.2%) of those persons sampled. Neither the frequency of detection, the arithmetic mean nor the geometric mean values for urine arsenic was found to be statistically different when persons living near the site were compared to persons from the more distant comparison area. Therefore, the data were pooled across the study areas to evaluate risk factors for exposure to arsenic in this population-based sample. Multivariate logistic regression analyses were conducted to evaluate the risk of arsenic exposure associated with variables included in the interviews while controlling for confounding. Pathways for exposure to arsenic were evaluated through analysis of residence history, occupation, hobbies, dietary habits, water supply, housing and activity patterns. Children of Hispanic origin or non-white race, children who drank less than three glasses of water daily, and children who spent more time outdoors had an increased risk of having > or = 10 ppb of arsenic in their urine. Among adults, younger persons, especially those less than 40 years of age, persons of Hispanic origin or nonwhite race, and those employed in occupations where arsenic is likely to be found had an increased risk of having > or = 10 ppb of urine arsenic. Consumption of red wine or fish during the week prior to sampling was associated with trace levels of arsenic in urine.

Nocturnal excretion of a urinary melatonin metabolite among electric utility workers.

OBJECTIVES: The effects of 60-Hz magnetic field and ambient light exposures on the pineal hormone melatonin were studied among electric utility workers. METHODS: Personal exposure was measured at 15-second intervals over 3 consecutive 24-hour periods. Exposure metrics based on magnetic field intensity, intermittence, or temporal stability were calculated for periods of work, home, and sleep. A rate-of-change metric (RCM) was used to estimate intermittence, and the standardized RCM (RCMS = RCM/standard deviation) was used to evaluate temporal stability. The effects of magnetic field exposure on total overnight 6-hydroxymelatonin sulfate (6-OHMS) excretion and creatinine-adjusted nocturnal 6-OHMS (6-OHMS/cr) concentration were analyzed with adjustment for age, month, and light exposure. RESULTS: Magnetic field intensity, intermittence, or cumulative exposure had little influence on nocturnal 6-OHMS excretion. Residential RCMS magnetic field exposures were associated with lower nocturnal 6-OHMS/cr concentrations. In multivariate statistical analyses, the interaction term for geometric mean and RCMS magnetic field exposures at home was associated with lower nocturnal 6-OHMS/cr and overnight 6-OHMS levels. Modest reductions in the mean 6-OHMS levels occurred after RCMS exposures during work. The greatest reductions occurred when RCMS exposures both at work and at home were combined; therefore the effects of temporally stable magnetic fields may be integrated over a large portion of the day. CONCLUSIONS: Results from this study provide evidence that temporally stable magnetic field exposures are associated with reduced nocturnal 6-OHMS excretion in humans.

Comparison of two commercially available single radial immunodiffusion kits for quantitation of llama immunoglobulin G.

Immunoglobin G (IgG) quantitation was performed by a commercially available single radial immunodiffusion kit on 528 plasma samples obtained from llamas. Fifty samples encompassing the range of values obtained were selected for further evaluation. The IgG concentration of these samples was measured by a second commercially available single radial immunodiffusion kit and a sodium sulfite precipitation kit. gamma-Globulins also were measured. IgG values predicted by the single radial immunodiffusion kits were not in agreement. Failure to appreciate this lack of agreement could result in misinterpretation of a llama's IgG level derived from one kit when clinical guidelines established using the other kit are followed.

Effects of malathion on survival, growth, development, and equilibrium posture of bullfrog tadpoles (Rana catesbeiana).

Bullfrog (Rana catesbeiana) tadpoles were exposed to malathion in water in a 28-d static renewal test. The effects of malathion on survival, growth, development, and loss of equilibrium posture were determined. Survival was significantly decreased at malathion concentrations of 2,500 micrograms/L and higher. Development of tadpoles was delayed significantly by malathion exposure as indicated by a dose-related decrease in developmental stage over time. Development of tadpoles in the 1,000-microgram/L and higher treatment groups was significantly delayed from that observed in the control. The effects of malathion on developmental stage suggest that malathion may decrease thyroid function in tadpoles, as it does in other species. Maintenance of equilibrium posture following agitation of the test containers was significantly impaired in tadpoles in all the malathion treatment groups (500 to 3,000 micrograms/L) relative to the control. Maintenance of equilibrium posture was thus the most sensitive end point measured in this study. Loss of equilibrium posture could increase predation losses and decrease feeding in populations of bullfrog tadpoles in the field. However, concentrations of malathion that produced adverse effects in our study are higher than published, measured concentrations found in wetlands or streams.

Ticarcillin administration to the equine: Intrauterine and intramuscular.

Serum levels of ticarcillin disodium, a semi-synthetic penicillin (Beecham Laboratories, Bristol, Tennessee, 37620), were measured at various time intervals up to and including 24 h after intrauterine and intramuscular administration in adult female horses. Three separate studies were conducted in Part I: in the first and second studies, serum levels were measured after intrauterine administration of 1 and 3 g of ticarcillin, respectively, and in the third study, levels were measured after intramuscular administration of 6 g of ticarcillin. In Part II, serum levels of ticarcillin were measured after intramuscular administration of ticarcillin at dosages based on body weight: 10 mg/lb (22 mg/kg) of body weight, 15 mg/lb (33 mg/kg) of body weight and 20 mg/lb (44 mg/kg) of body weight. Results showed little if any absorption of the antibiotics into the systemic circulation after intrauterine administration. All serum levels measured after administration of both intrauterine dosages of 1 and 3 g were less than 4.0 ug/ml. Peak serum concentrations, after intramuscular administration of 6 g of ticarcillin, occurred between 20 and 45 min after administration and averaged 15.97 +/- 5.0 ug/ml. Average peak serum concentrations, after intramuscular administration of 10 mg/lb (22 mg/kg) of body weight, 15 mg/lb (33 mg/kg) of body weight, 15 mg/lb (33 mg/kg) and 20 mg/lb (44 mg/kg) of body weight, were 16.12 ug/ml, 25.75 ug/ml and 50.25 ug/ml, respectively. After intramuscular administration of 6 g of ticaracilin, average serum half-life was determined to be 2.9 h.

Effect of dose of GnRH analog on ovulation in mares.

Proper timing of insemination for optimal conception is accomplished by frequent palpations per rectum, by ultrasonography of the preovulatory follicle and/or by treatment with hCG or GnRH. Sustained release of GnRH from implants has been shown to hasten ovulation. Therefore, 2 studies were conducted to evaluate the efficacy of a GnRH analog, deslorelin, for hastening ovulation in nonlactating cyclic mares. The GnRH implant was 2.3x3.7 mm and released deslorelin for 2 to 3 days. In Experiment 1, 60 nonlactating, cycling mares were assigned to 1 of 5 doses: 0, 1.2, 1.7, 2.2 and 2.7 mg per implant. Mares were assigned sequentially on the first day of estrus (Day 1). Ovaries were examined per rectum and with ultrasonography every 12 h until ovulation. Once the mares obtained a follicle>30 mm, they were injected subcutaneously with a GnRH implant. The mares were inseminated every other day during estrus with semen from 1 of 3 stallions. Pregnancy was determined with ultrasonography. Experiment 2, 40 nonlactating, cyclic mares were assigned to 1 of 5 treatments (same treatments as in Experiment 1). Data were obtained on interval to ovulation, duration of estrus and pregnancy rates at 12, 18 and 35 d after ovulation. Time to ovulation was shorter (P<0.05) in GnRH-treated mares than in control mares in the Experiment 1. Mean time to ovulation was 68, 49, 48, 47, 44 h in Experiment 1, and 91, 66, 58, 46, 58 h in Experiment 2 for mares given 0, 1.2, 1.7, 2.2 and 2.7 mg/mare in the 2 trials. Averaged for both experiments, the proportion of mares ovulating within 48 h of treatment was 40, 75, 85, 90 and 90% for 0, 1.2, 1.7, 2.2 and 2.7 mg/mare. For both experiments, there was no effect of GnRH on pregnancy rate. In summary, a subcutaneous implant containing GnRH analog induced ovulation in most mares by 48 h of injection, and there was no advantage of doses higher than 2.2 mg/mare.

Amoxycillin and clavulanic acid combination in the treatment of experimentally induced bacterial cystitis in cats.

Clavulanic acid (CA) competitively inhibits beta-lactamase hydrolysis of penicillins in vitro. Treatment with amoxycillin combined with clavulanic acid (A-CA) was compared with placebo in a blind study in cats with experimental cystitis caused by Escherichia coli demonstrating in vitro resistance to amoxycillin. Bacterial cystitis was induced in 20 cats by bladder infusion of 5 ml of 0.05 per cent alcoholic salicylic acid followed after 24 hours by a brain-heart infusion broth of E coli (10(8) colony forming units ml-1) previously found to be resistant to amoxycillin in vitro (minimum inhibitory concentration over 512 micrograms ml-1). Four days after infection, cats were randomly divided into two groups of 10 and treated with amoxycillin combined with clavulanic acid or placebo for 10 days. When compared to the placebo-treated group, the A-CA treated group showed: reduced quantitative bacterial counts in urine on days 7 (P less than 0.001) and 14 (P less than 0.02); reduced culture positive urine on days 7 (P less than 0.001) and 14 (P less than 0.001); and less severe inflammation on histological examination of the bladder and urethra (P less than 0.01). It was concluded that A-CA was effective in reducing the bacterial count and reducing the histopathological changes in the bladder and urethra in an experimental model of acute bacterial cystitis in cats infected with an E coli demonstrating in vitro resistance to amoxycillin.

Dose titration and confirmation tests for determination of cesticidal efficacy of epsiprantel in dogs.

Fifty-five dogs, naturally infected with Taenia sp or Dipylidium caninum or both, were assigned to the following treatment groups for dose titration studies with epsiprantel: nonmedicated control dogs (n = 14), medicated dogs given a dosage of 2.75 mg/kg of body weight (n = 15), medicated dogs given a dosage of 5.5 mg/kg (n = 16), and medicated dogs given a dosage of 8.25 mg/kg (n = 10). Medication was given orally in a tablet formulation. Feces were examined for cestodes passed and the gastrointestinal tract was examined at necropsy for retained cestodes. Efficacy of epsiprantel was 92.9% against Taenia and 44.8% against Dipylidium for a dosage of 2.75 mg/kg, 100% against Taenia and 99.8% against Dipylidium for a dosage of 5.5 mg/kg, and 94.6% against Taenia and 100% against Dipylidium for a dosage of 8.25 mg/kg. For dose confirmation, 36 dogs naturally infected with Taenia sp or D caninum or both were allotted to 2 treatment groups: nonmedicated control dogs (n = 16) and dogs medicated with epsiprantel at a dosage of 5.5 mg/kg (n = 20). Efficacy was 100% for both Taenia sp and D caninum.

Kinetic gait analysis assessment of meloxicam efficacy in a sodium urate-induced synovitis model in dogs.

OBJECTIVE: To examine the ability of meloxicam, a cyclooxygenase inhibitor, to mediate the effects of sodium urate-induced acute stifle synovitis in dogs. ANIMALS: 12 clinically normal adult hound-type dogs. PROCEDURE: A blinded, randomized, controlled single crossover design study was performed to determine the efficacy of meloxicam, using 2 dosage groups. In 2 experimental phases, dogs, according to group, received meloxicam (0.1 or 0.5 mg/kg of body weight) or matched volume of meloxicam vehicle, with a washout period of 21 to 28 days between phases. Blood samples for hematologic and biochemical analysis, as well as synovial fluid or cytologic analysis, were collected immediately before and approximately 24 hours after articular challenge of dogs under propofol anesthesia. Ground reaction forces (GRF) and subjective clinical scores were determined before and at 4, 8, 12, and 24 hours after articular challenge. Vertical force data included peak force, impulse, limb loading, and unloading rates. Craniocaudal data were divided into braking and propulsion phases and consisted of peak force and associated impulses. RESULTS: Except for propulsion impulse at 24 hours, all GRF variables were significantly greater at all post-synovitis induction times in the group receiving the high meloxicam dose. Significant differences in all GRF variables were seen at various times between the low-dose meloxicam group and the corresponding control group, and between the low- and high-dose meloxicam groups. Similar significance was seen in the subjective clinical evaluations. Strong correlations existed between the subjective and objective data. CONCLUSIONS: Meloxicam was effective in attenuating the effects of sodium urate-induced acute synovitis in dogs. Kinetic gait data provided an objective measurement of lameness in an experimentally induced arthritis model and quantified lameness improvements in response to medication with a nonsteroidal anti-inflammatory drug.