Pharmacokinetics of cefpodoxime in plasma and subcutaneous fluid following oral administration of cefpodoxime proxetil in male beagle dogs

Kumar, V., Madabushi, R., Lucchesi, M. B. B., Derendorf, H. Pharmacokinetics of cefpodoxime in plasma and subcutaneous fluid following oral administration of cefpodoxime proxetil in male beagle dogs. J. vet. Pharmacol. Therap. 34 , 130–135. Pharmacokinetics of cefpodoxime in plasma (total concentration) and subcutaneous fluid (free concentration using microdialysis) was investigated in dogs following single oral administration of prodrug cefpodoxime proxetil (equivalent to 5 and 10 mg/kg of cefpodoxime). In a cross over study design, six dogs per dose were utilized after a 1 week washout period. Plasma, microdialysate, and urine samples were collected upto 24 h and analyzed using high performance liquid chromatography. The average maximum concentration (C_max) of cefpodoxime in plasma was 13.66 (±6.30) and 27.14 (±4.56) μg/mL with elimination half‐life (t_1/2) of 3.01 (±0.49) and 4.72 (±1.46) h following 5 and 10 mg/kg dose, respectively. The respective average area under the curve (AUC_0–∞) was 82.94 (±30.17) and 107.71 (±30.79) μg·h/mL. Cefpodoxime was readily distributed to skin and average free C_max in subcutaneous fluid was 1.70 (±0.55) and 3.06 (±0.93) μg/mL at the two doses. Urinary excretion (unchanged cefpodoxime) was the major elimination route. Comparison of subcutaneous fluid concentrations using pharmacokinetic/pharmacodynamic indices of fT_>MIC indicated that at 10 mg/kg dose; cefpodoxime would yield good therapeutic outcome in skin infections for bacteria with MIC₅₀ upto 0.5 μg/mL while higher doses (or more frequent dosing) may be needed for bacteria with higher MICs. High urine concentrations suggested cefpodoxime use for urinary infections in dogs.     

STATIC AND DYNAMIC 18FDG‐PET IN NORMAL HISPANIOLAN AMAZON PARROTS (AMAZONA VENTRALIS)

Positron emission tomography (PET) is often used to stage and monitor human cancer and has recently been used in a similar fashion in veterinary medicine. The most commonly used radiopharmaceutical is 2‐Deoxy‐2‐[¹⁸F]‐Fluoro‐d ‐glucose (¹⁸F‐FDG), which is concentrated and trapped within cells that use glucose as their energy substrate. We characterized the normal distribution of ¹⁸F‐FDG in 10 healthy Hispaniolan Amazon parrots (Amazona ventralis) by performing whole body PET scans at steady state, 60 min after injection. Significant variability was found in the intestinal activity. Avian species are known to reflux fluid and electrolytes from their cloaca into their colon. To evaluate reflux as the cause of variability in intestinal distribution of ¹⁸F‐FDG, dynamic PET scans were performed on the coelomic cavity of six Hispaniolan Amazon parrots from time 0 to 60 min postinjection of radiotracer. Reflux of radioactive material from the cloaca into the colon occurred in all birds to varying degrees and occurred before 60 min. To evaluate the intestinal tract of clinical avian patients, dynamic scans must be performed starting immediately after injection so that increased radioactivity due to metabolism or hypermetabolic lesions such as cancer can be differentiated from increased radioactivity due to reflux of fluid from the cloaca.     

Copper toxicosis in cattle fed chicken litter

Cattle from 2 herds developed copper toxicosis after the ingestion of chicken litter. The affected animals were adult Holstein cows and crossbred steers that ate 9 to 16 kg of litter/day. These cattle developed a sudden onset of weakness, depression, anorexia, icteric mucous membranes, and dark reddish brown urine. Liver copper concentrations in 2 cattle (1 from each herd) were 436 and 730 ppm. Results of copper analyses of chicken litter ranged from 620 to 920 ppm. Sodium molybdate and sodium thiosulfate were added to the ration of the dairy herd. Two cows with clinical signs of copper toxicosis recovered after being given additional sodium molybdate and thiosulfate supplements, orally.     

Cerebral phaeohyphomycosis in a dog

Cerebral phaeohyphomycosis was diagnosed in a 9-year-old spayed dog that had a series of epileptic convulsions a day before death. About 6 weeks before her death, she had been treated for severe demodectic mange. During this period, persistent leukopenia, lymphocytopenia, and thrombocytopenia were found by blood analyses. At necropsy, multiple large pyogranulomatous lesions were found in the cerebrum and meninges. Dematiaceous fungi with brown, branching, septate hyphae and budding yeasts were found within tissue cells and in the necrotic areas.     

Limiting amino acids in an 11% crude protein corn-soybean meal diet for growing pigs

Three experiments were conducted to test the hypothesis that methionine, isoleucine, valine or nitrogen either singly or in combination are limiting in an 11% crude protein, lysine-tryptophan-threonine-supplemented, corn-soybean meal diet for growing pigs. A 16% crude protein diet was used as a positive control in each experiment and all amino acid additions were made, at a minimum, to equal requirements. Average initial weights were 21.3 kg, 23.0 kg and 19.1 kg in Exp. 1, 2 and 3, respectively. The experiments averaged 4 wk in duration. In Exp. 1 and 2, neither the addition of glutamic acid as a source of nitrogen, nor methionine to the 11% diet resulted in any improvement (P greater than .20) in rate or efficiency of growth. Addition of the combination of isoleucine and valine to the 11% diet resulted in an increase (P less than .05) in both growth rate and feed efficiency to a level not different (P greater than .20) from that of the pigs consuming the positive control diet. The addition of valine to the 11% crude protein diet with supplemental lysine, tryptophan and threonine (Exp. 3) caused an improvement in daily gain (P less than .05) but not feed efficiency (P greater than .10). Isoleucine addition tended to reduce pig performance. The results of these experiments suggest that an 11% crude protein, corn-soybean meal diet fortified with lysine, tryptophan and threonine is not limiting in sulfur amino acids or nitrogen. Valine may be the only limiting amino acid.