Florfenicol urinary excretion and its potential for treating canine urinary tract infections.

The canine urinary excretion of florfenicol was evaluated to explore its potential for treating urinary tract infections. Nine healthy male intact purpose-bred Beagles and four healthy client-owned dogs each received a single oral dose of florfenicol 20 mg/kg (300 mg/mL parenteral solution) with food. All voluntary urinations were collected for 12 h. Although florfenicol is reportedly bitter tasting, 7/9 Beagles and 4/4 client-owned dogs completely ingested the florfenicol and were enrolled; salivation (n = 1) and headshaking (n = 3) were observed. The last measured urine florfenicol concentrations were variable: Beagles (0.23-3.19 mcg/mL), Pug (3.01 mcg/mL) English Setter (21.29 mcg/mL), Greyhound (32.68 mcg/mL), and Standard Poodle (13.00 mcg/mL). Urine half-life was similar for the Beagles and the Pug, 0.75-1.39 h, whereas the half-life was 1.70-1.82 h for the English Setter, Greyhound, and Standard Poodle. Larger breed dogs exceeded 8 mcg/mL florfenicol (wild-type cutoff) in their urine at 12 h, whereas the Beagles and Pug had <8 mcg/mL; it is unclear if this is an individual, breed, or size difference. These data suggest oral florfenicol may need to be administered q6-12h for canine urinary tract infections, but further data are needed (more enrolled dogs, multiple-dose regimens) before considering clinical trials or breed-specific differences.

Correlation of opioid antinociception and hypothermia in dogs-An animal welfare refinement.

The purpose of this study was to assess antinociception and correlation of antinociception and hypothermic effects after intravenous opioids in dogs. Nine healthy male Beagles were enrolled in the study. They were acclimated to a thermal nociceptive device, then received three IV treatments (saline, butorphanol 0.4 mg/kg and methadone 0.5 mg/kg) in a randomized complete block design. Rectal temperature and thermal withdrawals were assessed prior to and 0.5-6 h after drug administration. One dog was excluded due to lack of withdrawal to thermal stimuli. Rectal temperatures were not significantly different between treatments at time 0, but significantly decreased from 0.5 to 5 h for both opioids compared to saline. Withdrawals were significantly decreased, compared to saline, from 0.5 to 4 h for butorphanol and 0.5-5 h for methadone. A significant (p = .0005) and moderate (R2 = .43) correlation between antinociception and hypothermia occurred. Based on these data, intravenous butorphanol (0.4 mg/kg) and methadone (0.5 mg/kg) provided 4 and 5 h of antinociception, respectively. Opioid hypothermia can serve as an easy, noninvasive and humane manner for preclinical assessment of opioid antinociception in dogs prior to evaluation in clinical trials. This is a major refinement in animal welfare for assessing novel opioids, opioid doses and dose intervals in dogs.