Neomycin toxicosis in calves

Calves (n = 4) were given neomycin (2.25 or 4.5 mg/kg) twice daily IM and were compared with 2 calves given penicillin IM. The 2 hallmarks of aminoglycoside toxicosis, nephrotoxicosis and ototoxicosis, were seen with both dosages of parenterally administered neomycin. Nephrotoxicosis was confirmed by abnormal findings in urinalysis (granular casts, proteinuria, low specific gravity), renal biopsy results (tubular degeneration and necrosis), and increased 24-hour amounts of urinary enzymes (alanine aminopeptidase and gamma-glutamyltranspeptidase). Azotemia, decreased creatinine clearance, polyuria, and polydipsia also were documented in calves given neomycin. Clinically, deafness was suspected in 2 calves and was documented by electrical auditory-evoked response tests. Abnormalities in partial thromboplastin times and renal residues of neomycin were seen in all 4 calves that were given neomycin, but not in calves that were given penicillin.     

Effects of castration on chronic bacterial prostatitis in dogs

An Escherichia coli bacterial prostatitis was experimentally induced in dogs to determine the effect of castration on chronic bacterial prostatitis. Two weeks after instillation of bacteria directly into the prostate gland, 17 of 22 adult mixed-breed male dogs had positive urine or prostatic fluid cultures or both. Seven of the 17 dogs were randomly chosen to be castrated, and 10 of the 17 served as sham-operated controls. At weekly intervals, urine was obtained from 17 dogs for aerobic microbiologic culturing. At each week, dogs with no bacterial growth in the cultured urine had prostatic fluid collected for aerobic microbiologic culture. Dogs with negative urine, prostatic fluid, and prostatic tissue needle biopsy culture results at week 7 were euthanatized. For remaining dogs, weekly cultures were continued until the dogs were euthanatized at week 12. None of the 7 castrated dogs and 6 of the 10 dogs subject to sham operation had prostatic infection at the time of necropsy. The castrated dogs had a mean infection duration of 4.2 weeks, which was statistically shorter than the 9.5-week mean duration of infection in the sham-operated controls. Cultures of prostatic tissue obtained immediately after euthanasia correlated 100% with urine and prostatic fluid cultures taken before euthanasia. All of the 6 dogs with positive prostatic cultures at termination had moderate to marked lymphoplasmacytic chronic prostatitis. The 11 dogs that were not infected at the end of the study had normal to moderate lymphoplasmacytic chronic prostatitis on histologic examination.(ABSTRACT TRUNCATED AT 250 WORDS)     

Pelvic bladder in dogs without urinary incontinence

Double-contrast cystography was performed simultaneously with cystometrography in 6 male and 6 female dogs. All dogs were continent, and results of urinalyses were normal. Initial radiographs were made following intravesical infusion of 0.88 ml of positive contrast medium/kg of body weight. Additional radiographs were made during infusion of CO2. The last radiographs were made at the time of detrusor reflex (11 dogs) or when intravesical pressure reached 50 cm H2O (1 female). An average of 34% (range, 11% to 67%) of bladder length was within the pelvic canal when only the positive contrast medium was infused into the bladders. By the end of CO2 infusion, the bladder neck was more cranially located in 5 of 6 males and in 5 of 6 females. On the last radiographs made, an average of 19% (range, 10% to 35%) of bladder length was within the pelvic canal in 3 of 6 males and in 4 of 6 females. The bladder neck was rounded in 10 of 12 dogs. Thus, it was concluded that previous reports associating pelvic urinary bladder with urinary incontinence and other urologic abnormalities are questionable.     

Pharmacokinetic and pathological evaluation of gentamicin in cats given a small intravenous dose repeatedly for five days.

Gentamicin was administered to six cats at a dosage of 3 mg/kg of body weight intravenously every 8 h for five days. Peak and trough serum gentamicin concentrations were measured after each injection. Gentamicin elimination rate and serum half-life were calculated. Serum urea nitrogen, creatinine, biochemistry profile, electrolyte, glucose, total protein, and albumin concentrations were measured daily. Urinalyses were performed before and after the five-day experimental period. The mean +/- SD peak serum gentamicin concentration was 7.19 +/- 1.10 micrograms/mL, and the trough concentration was 0.59 +/- 0.09 microgram/mL. These concentrations are known to be effective against most gentamicin-sensitive bacteria. The mean +/- SD gentamicin elimination rate was 0.0065 +/- 0.0004 min-1. The harmonic mean +/- pseudo standard deviation serum half-life of gentamicin was 107.21 +/- 12.79 min. There were no significant increases (P greater than 0.05) in clinicopathological variables. Microscopic examination of renal sections did not disclose pathological lesions. Signs of vestibular impairment were not observed. A dosage of 3 mg gentamicin/kg given intravenously every 8 h for five days was determined to be safe and to produce therapeutic blood levels in cats.