Biomedical subjects

L A Koehler

Publications and source records attributed to L A Koehler.

27 records · Page 2Linked to original sources

PubMed1996

Influence of four diets on uric acid metabolism and endogenous acid production in healthy beagles.

OBJECTIVE: To evaluate the influence of 3 diets used to dissolve or prevent ammonium urate uroliths in dogs, and a diet formulated for growth, on 24-hour excretions of uric acid, ammonia, net acid, titratable acid, bicarbonate, and creatinine; 24-hour urine volumes; pH values of 24-hour urine samples; plasma uric acid concentration; serum creatinine concentration; and endogenous creatinine clearance values. DESIGN: Randomized block. ANIMALS: Six reproductively intact female Beagles, 3.9 to 4.2 years old, weighing 8.5 to 11.1 kg. PROCEDURES: Four diets were evaluated for their ability to dissolve magnesium ammonium phosphate hexahydrate (struvite) uroliths (diet S); to minimize uric acid excretion (diet U); to minimize clinical signs associated with renal failure (diet K); and to promote growth in pups (diet P). Each diet was fed for 14 days; then 24-hour urine samples were collected. An adult maintenance diet was fed during a 7-day washout period. RESULTS: Consumption of diet U was associated with lowest plasma uric acid concentration, lowest 24-hour urinary uric acid, ammonia, titratable acid, and net acid excretions, lowest endogenous creatinine clearance values, highest 24-hour urinary bicarbonate excretion and urine pH values, and highest 24-hour urine volumes. Consumption of diet P was associated with opposite results; results of consumption of diets S and K were intermediate between those for diets U and P. CONCLUSION: Consumption of diet U by healthy Beagles is associated with reduced magnitude of urinary excretion of uric acid and ammonia, with alkaluria, and with polyuria, which may be beneficial in the management of ammonium urate uroliths in dogs. CLINICAL RELEVANCE: Results support use of diet U for management of ammonium urate urolithiasis in dogs.

Ammonia↗

PubMed1996

Feline urolithiasis. Etiology and pathophysiology.

A variety of different types of uroliths occur in cats, of which calcium oxalate and magnesium ammonium phosphate are the most common. Treatment and prevention are most likely to be successful if associated risk factors are identified and eliminated or controlled.

Animals↗

PubMed1996

Feline urethral plugs. Etiology and pathophysiology.

Feline urethral plugs commonly are composed of large quantities of matrix mixed with minerals (especially struvite). However, some urethral plugs are composed primarily of matrix, some consist of sloughed tissue, blood, and/or inflammatory reactants, and a few are composed primarily of aggregates of crystalline minerals. The formation of matrix-crystalline urethral plugs may be analogous to the preparation of fruit jello.

Animals↗

PubMed1995

Influence of four diets containing approximately 11% protein (dry weight) on uric acid, sodium urate, and ammonium urate urine activity product ratios of healthy beagles.

Urine activity product ratios of uric acid (APRua), sodium urate (APRna), and ammonium urate (APRau), and urinary excretion of 10 metabolites were determined in 24-hour urine samples produced by 6 healthy Beagles during periods of consumption of 4 diets containing approximately 11% protein (dry weight) and various protein sources: a 72% moisture, casein-based diet; a 10% moisture, egg-based diet; a 72% moisture, chicken-based diet; and a 71% moisture, chicken-based, liver-flavored diet. Significantly (P < 0.05) higher APRua, APRna, and APRau were observed when dogs consumed the egg-based diet, compared with the other 3 diets; there were no differences in these ratios among the other 3 diets. Twenty-four-hour urinary excretions of chloride, potassium, phosphorus, and oxalic acid were significantly (P < 0.05) higher when dogs consumed the egg-based diet. Twenty-four-hour urinary excretions of sodium were significantly (P < 0.05) higher when dogs consumed the egg-based diet, compared with the casein-based diet and the chicken-based, liver-flavored diet, but were not significantly different between the egg-based diet and chicken-based diet. Twenty-four-hour urine volume was similar when dogs consumed the 4 diets. Twenty-four-hour endogenous creatinine clearance was significantly (P < 0.05) lower when dogs consumed the casein-based diet; there were no differences among the other 3 diets. Although consumption of all diets was associated with production of alkaline urine, the 24-hour urine pH was significantly (P < 0.05) higher when dogs consumed the egg-based diet.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗

PubMed1995

Diet effect on activity product ratios of uric acid, sodium urate, and ammonium urate in urine formed by healthy beagles.

Urine activity product ratios of uric acid, sodium urate, and ammonium urate and urinary excretion of metabolites were determined in 24-hour samples produced by 6 healthy Beagles during periods of consumption of a low-protein, casein-based diet (diet A) and a high-protein, meat-based diet (diet B). Comparison of effects of diet A with those of diet B revealed: significantly lower activity product ratios of uric acid (P = 0.025), sodium urate (P = 0.045), and ammonium urate (P = 0.0045); significantly lower 24-hour urinary excretion of uric acid (P = 0.002), ammonia (P = 0.0002), sodium (P = 0.01), calcium (P = 0.005), phosphorus (P = 0.0003), magnesium (P = 0.01), and oxalic acid (P = 0.004); significantly (P = 0.0001) higher 24-hour urine pH; and significantly (P = 0.01) lower endogenous creatinine clearance. These results suggest that consumption of diet A minimizes changes in urine that predispose dogs to uric acid, sodium urate, and ammonium urate urolithiasis.

Animals↗

PubMed1994

Prevalence of cystine and urate uroliths in bulldogs and urate uroliths in dalmatians.

Data were evaluated from all dogs admitted to the University of Minnesota Veterinary Teaching Hospital (UMVTH) between June 1, 1981 and Dec 31, 1991. During this period, uroliths were retrieved and analyzed from 452 of 37,574 dogs admitted. The odds that uroliths from Bulldogs were composed of cystine were 32.3 times greater than for other breeds evaluated. The odds that a Bulldog admitted was affected with cystine uroliths were 154.1 times greater than for other breeds. Cystine uroliths were retrieved only from male Bulldogs. The odds that uroliths from Bulldogs were composed of urate were 7.9 times greater than for other breeds. The odds that a Bulldog admitted was affected with urate uroliths were 43.0 times greater than for other breeds. Male Bulldogs were 14.3 times more likely to be affected with urate uroliths than were females. The odds that uroliths from Dalmatians were composed of urate were 228.9 times greater than for other breeds. The odds that a Dalmation admitted was affected with urate uroliths were 122.4 times greater than for other breeds. Male Dalmatians were 16.4 times more likely to be affected with urate uroliths than were females. Data also were evaluated from files of canine uroliths submitted to the Minnesota Urolith Center for quantitative mineral analysis between June 1, 1981 and Dec 31, 1991. During this period, 94 of 11,188 uroliths analyzed were obtained from Bulldogs and 387 were obtained from Dalmatians. The odds that uroliths retrieved from Bulldogs were composed of cystine were 40.7 times greater than for other breeds. Cystine uroliths were retrieved only from male Bulldogs.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Distribution↗

PubMed1994

Reliability of single urine and serum samples for estimation of 24-hour urinary uric acid excretion in six healthy beagles.

Urine uric acid-to-urine creatinine ratios (UUA:UC), urine uric acid concentrations, urine uric acid concentrations corrected for glomerular filtration rate, and urinary uric acid fractional excretions were compared with 24-hour urinary uric acid excretions measured in 6 healthy adult female Beagles. Comparisons, using correlation analysis, were made when dogs consumed a 10.4% protein (dry weight), casein-based diet and a 31.4% protein (dry weight), meat-based diet. The UUA:UC, urine uric acid concentrations corrected for glomerular filtration rate, and urinary uric acid fractional excretions were not reliable estimates of 24-hour urinary uric acid excretions during consumption of either diet. Urine uric acid concentrations in samples collected 2, 4, 6, and 24 hours after initiation of collection correlated with 24-hour urinary uric acid excretions when dogs consumed the casein-based diet; correlation was not found at any time interval when dogs consumed the meat-based diet. Therefore, determination of 24-hour urinary uric acid excretion is recommended because UUA:UC are unreliable.

Animals↗

PubMed1993

Nonsurgical removal of urocystoliths in dogs and cats by voiding urohydropropulsion.

A technique called voiding urohydropropulsion has been developed that facilitates nonsurgical removal of urocystoliths. Voiding urohydropropulsion was performed in 11 dogs and 10 cats with urocystoliths. Urocystoliths were completely removed from 15 of 21 animals (5 female dogs, 3 male dogs, 5 female cats, and 1 male cat). The number of uroliths removed from any animal varied between 1 and 983. The mean time required to complete voiding urohydropropulsion in the 15 animals from which all uroliths were completely removed was 22 minutes. In 6 animals (2 female dogs, 3 female cats, and 1 male cat), not all urocystoliths were removed. Visible hematuria was induced in all animals as a consequence of voiding urohydropropulsion. In dogs, visible hematuria resolved within 4 hours. Dysuria was not induced by this technique in dogs. In many cats, visible hematuria and dysuria persisted for 1 to 2 days. One male cat developed urethral obstruction after we failed to remove a urolith from the bladder. The urolith was returned to the urinary bladder, and subsequently removed by cystotomy. Voiding urohydropropulsion is a simple and effective method that should be considered for removal of small urocystoliths from dogs and cats before cystotomy is performed.

Animals↗

PubMedDate not supplied

Evaluation of urinary carnitine and taurine excretion in 5 cystinuric dogs with carnitine and taurine deficiency.

Five client owned dogs with cystinuria were diagnosed with carnitine and taurine deficiency while participating in a clinical trial that used dietary management of their urolithiasis. Stored 24-hour urine samples collected from the cystinuric dogs before enrollment in the clinical diet trial were quantitatively evaluated for carnitine and taurine. These results were compared to those obtained from 18 healthy Beagles. Both groups of dogs were fed the same maintenance diet for a minimum of 2 weeks before 24-hour urine collection. The protocol used for 24-hour urine collections was the same for cystinuric dogs and healthy Beagles except that cystinuric dogs were catheterized at baseline, 8 hours, 12 hours, and at the end of the collection, whereas Beagles were catheterized at baseline, 8 hours, and at the end of the collection. Three of 5 dogs with cystinuria had increased renal excretion of carnitine. None of the cystinuric dogs had increased renal excretion of taurine, but cystinuric dogs excreted significantly less (P < .05) taurine in their urine than the healthy Beagles. Carnitinuria has not been recognized previously in either humans or dogs with cystinuria, and it may be 1 risk factor for developing carnitine deficiency. Cystinuric dogs in this study were not taurinuric; however, cystine is a precursor amino acid for taurine synthesis. Therefore, cystinuria may be 1 risk factor for developing taurine deficiency in dogs. We suggest that dogs with cystinuria be monitored for carnitine and taurine deficiency or supplemented with carnitine and taurine.

Animals↗