Effects of dietary phosphorus and protein in dogs with chronic renal failure

Four diets were formulated to contain: 16% protein and 0.4% phosphorus--diet 1; 16% protein and 1.4% phosphorus--diet 2; 32% protein and 0.4% phosphorus--diet 3; and 32% protein and 1.4% phosphorus--diet 4. Forty-eight dogs were fed diet 1 for 3 months after surgical reduction of renal mass, then were allotted to 4 groups of 12 dogs each, with equal mean values for glomerular filtration rate (GFR). Dog of groups 1-4 were fed diets 1-4, respectively, for 24 months. Data collected from the dogs during and at termination of the study were analyzed statistically for effects of dietary protein, phosphorus (P), time, and interactions between these factors. During the 24 months of study, 24 dogs developed uremia and were euthanatized for necropsy. Necropsy also was performed on the remaining 24 dogs after they were euthanatized at the end of the study. Dog survival was significantly enhanced by 0.4% P diets (vs 1.4% P diets), but survival was not significantly influenced by amount of dietary protein. The 0.4% P diets (vs 1.4% P diets) significantly increased the period that GFR remained stable before it decreased, but dietary protein did not have significant effect. Significant blood biochemical changes attributed to P, protein, and time were identified during the study. Terminally, plasma parathyroid hormone concentration was significantly increased from prediet values in all groups of dogs. Urine protein excretion was not significantly affected by dietary amount of either protein or P, when measured by either timed urine collection or urine protein-to-creatinine ratio.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of therapy on susceptibility to urinary tract infection in male cats with indwelling urethral catheters

Indwelling urinary catheters with a closed urine collection system were maintained in 30 male cats for 3 days after induction of irritant cystitis. All cats received subcutaneous fluids during the 3 days the catheters were in place. The effects of four different treatment regimens on urinary tract infection rates, incidence of urethral obstruction, and development of urinary tract lesions over a 10-day period were compared with results in a nontreated group. Treatments were 1) amoxicillin for 5 days PO; 2) prednisolone for 5 days PO; 3) both amoxicillin and prednisolone for 5 days PO; and 4) dimethylsulfoxide (DMSO) for 3 days intravesicularly. Euthanasia was done before the end of the 10-day experimental period if the cats had two bouts of urethral obstruction or if the cats became uremic for causes unrelated to urethral obstruction. Seven cats were euthanatized before the conclusion of the experiment. These cats had been treated with prednisolone, prednisolone and amoxicillin, or DMSO. All cats that received amoxicillin alone or no therapy survived the 10-day period. Mortality was due to repeated urethral obstruction or to uremia associated with pyelonephritis or papillitis. Urinary tract infection rate was similar in all groups. The group treated with prednisolone alone had the highest incidence of renal infection. Inflammatory lesions in the lower urinary tract were similar in all groups. In conclusion, persistent urinary tract infection often develops in cats with cystitis after indwelling urethral catheterization even when closed systems of urine drainage are used.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of phosphorus/calcium-restricted and phosphorus/calcium-replete 32% protein diets in dogs with chronic renal failure

Twenty-four dogs with induced, severe chronic renal failure were allotted to 2 groups of 12 each. Group-A dogs were fed a 0.4% phosphorus (P)/0.6% calcium, 32% protein diet, and group-B dogs were fed a 1.4% P/1.9% calcium, 32% protein diet. Dogs were studied over 24 months to determine clinical status, survival, blood biochemical alterations, glomerular filtration rate (GFR), urinary excretion of P and protein, renal morphologic changes, and renal tissue concentrations of calcium, P, and magnesium. Group-A dogs developed statistically significant differences from group-B dogs in several blood biochemical values (PCV and total solids, calcium, P, potassium, sodium, chloride, total CO2 (TCO2), anion gap, and parathyroid hormone concentrations) and in urinary P excretion. Mean (+/- SEM) GFR values in group-A and group-B dogs were nearly identical when diets were initiated (group A = 0.73 +/- 0.05 ml/min/kg of body weight; group B = 0.72 +/- 0.08 ml/min/kg), but significantly (P = 0.0346) lower GFR developed in group-B than in group-A dogs over time. At 24 months, GFR in survivors was 0.83 +/- 0.08 and 0.63 +/- 0.15 ml/min/kg for dogs of groups A and B, respectively. Other measurements favored the hypothesis that P/calcium restriction was beneficial, but values failed to reach statistical significance. Survival was greater at 24 months in group-A than in group-B (7 vs 5) dogs, and renal tissue concentrations of calcium and P were higher in group-B than in group-A dogs. Differences were not detected between groups in urinary excretion of protein and in the type or severity of renal lesions.(ABSTRACT TRUNCATED AT 250 WORDS)

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)

Effects of bacterial infection and castration on prostatic tissue zinc concentration in dogs

An Escherichia coli bacterial prostatitis was experimentally induced to determine the effect of bacterial infection on prostatic tissue zinc concentrations in castrated and gonadally intact male dogs. Five of the 22 mixed-breed dogs (group 1) had no culture evidence of infection 2 weeks after the instillation of bacteria into the prostate gland. The remaining 17 infected dogs were allotted to 2 groups; 1 group of dogs was subjected to castration (group CA, 7 dogs), and the other group of dogs was subjected to sham operation (group SO, 10 days). The groups were divided into groups of dogs with prostatic infection at necropsy (groups CA-I and SO-I), and those dogs without prostatic infection at necropsy (groups CA-N and SO-N). Urine, prostatic fluid, and prostatic tissue (week 0, 7, +/- 12) specimens were obtained for bacteriologic culturing to determine whether prostatic infection was present. Prostatic tissue was obtained at necropsy (week less than 6, 7, or 12) for analysis of zinc concentration by atomic absorption spectrophotometry. The logarithmic mean prostatic tissue zinc concentrations were compared between groups. Group CA had a significantly lower prostatic zinc concentration than all other groups. Zinc concentrations were not statistically different between any of the other groups. Castration did decrease the prostatic tissue concentration of zinc, a known natural antibacterial factor. However, resistance to infection and resolution of infection were not correlated with prostatic tissue zinc concentrations in this experimental model.

Exogenous creatinine clearance as a measure of glomerular filtration rate in dogs with reduced renal mass

Renal mass was surgically reduced in 78 dogs by uninephrectomy or by combined renal infarction and uninephrectomy. Renal clearance of inulin and renal clearance of exogenous creatinine were determined simultaneously, and the creatinine to inulin clearance (C/I) ratio was calculated. Clearance procedures were performed 2 to 3 months after reduction of renal mass, and were repeated at intervals thereafter. Overall, the C/I ratio was 1.008 +/- 0.007 for 192 determinations, with a highly significant correlation (R2 = 0.994, P less than 0.0001) between creatinine clearance and inulin clearance. There was no significant effect of gender of dogs, time after partial renal ablation, or dietary protein intake on C/I ratios. Degree of renal ablation did not affect C/I ratios. The results indicated that exogenous creatinine clearance is a valid measure of glomerular filtration rate in both male and female dogs with reduced renal mass.

Beneficial effects of dietary mineral restriction in dogs with marked reduction of functional renal mass

Although studies in partially nephrectomized rats have identified a progressive nephropathy that is altered by dietary restriction of phosphorus intake, the response of dogs to similar perturbations has not been established. Functional renal mass was reduced by 15/16 in dogs to determine its long-term effects on renal function and to evaluate the effects of two levels of dietary mineral (calcium and phosphorus) intake (0.44% phosphorus/0.57% calcium versus 1.50% phosphorus/1.91% calcium). Following a 3-month stabilization period, dogs were fed either the lower mineral diet (group 1, N = 12) or the higher mineral diet (group 2, N = 12) for 24 months. Loss of renal function with the passage of time was observed in 10 of 12 dogs maintained on the higher mineral diet, with an average decrease in exogenous creatinine clearance of 11.1 +/- 6.3%/month, leading to a survival rate of 33% in this group. Restriction of dietary mineral intake slowed (P less than 0.05) the rate of decline of exogenous creatinine clearance in group 1 to 2.6 +/- 1.1%/month and improved 24-month survival to 75% (P less than 0.01). Deterioration of renal function was associated with renal calcium accumulation and histologic evidence of nephrocalcinosis, tubular atrophy and dilatation, and interstitial fibrosis. These events were more readily apparent in female than in male dogs. A role for glomerulosclerosis was not apparent, and neither glomerular pathology nor glomerular volume was related to the observed decrements in renal function.

Suspected familial renal disease in chow chows

Renal disease was diagnosed in 6 young Chow Chows. Clinical abnormalities included vomiting, polyuria, polydipsia, and weight loss. Common abnormal laboratory findings were azotemia, hyperphosphatemia, hypocalcemia, nonregenerative anemia, and low urine specific gravity. All 6 dogs had similar microscopic renal lesions. characterized by interstitial fibrosis, a population of small glomeruli, and lack of inflammatory cells. A familial basis for the renal disease is suggested because of its development in 4 closely related dogs.

Determination of excretion of inulin, creatinine, sodium sulfanilate, and phenolsulfonphthalein to assess renal function in goats

Excretion of creatinine, sodium sulfanilate (SS), and phenolsulfonphthalein (PSP) was studied in healthy goats. In conscious goats, mean (+/- SEM) inulin clearance was 2.26 +/- 0.08 ml/min/kg of body weight. Endogenous creatinine clearance, 1.97 +/- 0.09 ml/min/kg, underestimated inulin clearance (P less than 0.01), probably because of the presence of noncreatinine chromogens in caprine plasma. The estimated renal clearance of PSP was 6.88 +/- 0.39 ml/min/kg, whereas the estimated renal clearance of SS was 3.71 +/- 0.39 ml/min/kg. Both exceeded inulin clearance (P less than 0.01), confirming renal tubular secretion of both compounds. In 6 anesthetized goats, exogenous creatinine clearance and SS clearance exceeded inulin clearance (P less than 0.05). Results of stop-flow experiments documented secretion of creatinine and SS by the proximal portion of the caprine nephron. Plasma half-life of PSP in uninephrectomized goats exceeded that in intact goats (20.2 +/- 1.5 min vs 11.9 +/- 0.7 min; P less than 0.01). Similarly, plasma half-life of SS was greater in goats after uninephrectomy (58.2 +/- 6.2 min vs 30.4 +/- 1.2 min; P less than 0.01).

Glucose conservation by the kidney and effect of systemic glucose infusion on inulin clearance in female goats

In 6 female goats, the mean threshold for glucosuria was 159.5 +/- 4.3 mg/dl. During increasing filtered loads of glucose, renal reabsorption of glucose reached maximal capacity, which was not exceeded when plasma glucose concentration was increased further. Measured in 10 female goats, the transport maximum for glucose was 119.1 +/- 9.1 mg of glucose reabsorbed/min. During infusion of glucose, there was a significant (P less than 0.05) time-dependent reduction in inulin clearance indicating that IV glucose administration may be inappropriate in goats with compromised renal function.

Influence of dietary source of phosphorus on fecal and urinary excretion of phosphorus and other minerals by male cats

Twelve male cats were fed 2 diets that differed in the source of P. In diet 1 (1.4% P), 62.7% of P originated from poultry, meat, and fish meal, and the remainder from other organic ingredients of food. In diet 2 (1.6% P), 63.5% of P was derived from neutral monobasic/dibasic salts, and the remainder from other organic ingredients of the food. The P intake was nearly the same with both diets, but there was a significant (P less than 0.05) difference between diets in the percentage of ingested P that was excreted in the urine (14.7 +/- 5.3% for diet 1; 34.9 +/- 8.4% for diet 2), and in 6-day urinary P excretion (774 +/- 290 mg for diet 1; 2,004 +/- 556 mg for diet 2). The P concentrations in urine samples obtained by cystocentesis after cats ate were significantly (P less than 0.05) higher when cats were fed diet 2 than when those same cats were fed diet 1. Plasma P concentrations increased after ingestion of diet 2, but were unchanged after ingestion of diet 1. Seemingly, urinary excretion of P was markedly influenced by dietary composition. Diets with the same P content have potential for different biologic effects because of differences in availability of P.

Quantitative buffy coat analysis for hematologic measurements of canine, feline, and equine blood samples and for detection of microfilaremia in dogs

A quantitative buffy coat (QBC) analysis was evaluated for 175 canine, 125 feline, and 125 equine blood samples. The method used centrifuged whole blood and yielded rapid results expressed as respective band lengths for RBC, granulocytes, nongranulocytes, and platelets. Simple regression analysis of band lengths and reference laboratory methods yielded correlation coefficients (r) ranging from 0.72 to 0.99. The PCV, granulocyte count, and total WBC count, as determined by the 2 methods, correlated well (r greater than or equal to 0.93 in all cases). Platelet and nongranulocyte counts were less well correlated. The QBC system provided a means of performing rapid hematologic screening. The principal problem encountered was poor separation of the RBC-granulocyte interface in 17% of canine samples, which interfered with measurement of band lengths. Evaluation of the QBC tube for detection of Dirofilaria immitis microfilaremia revealed 100% sensitivity to counts as low as 160 microfilariae/ml of whole blood.

Effect of atropine on cystometry and urethral pressure profilometry in the dog

Effects of atropine on cystometry and urethral pressure profilometry were examined in 12 healthy young adult dogs by comparing recordings obtained after xylazine alone with those obtained after administration of xylazine and atropine. Significant differences (P greater than 0.05) were not found, indicating that atropine, when administered SC with xylazine, did not markedly affect cystometrographic results and urethral pressure profiles.

Recovery from severe hydroureter and hydronephrosis after ureteral anastomosis in a dog

Progressive hydroureter and hydronephrosis were diagnosed in a dog after anastomosis of a crushed ureter. Nephrectomy was averted when partial resolution was noticed one month after the ureteral repair. The appearance of the kidney and ureter was nearly normal several months later. Conservative management should be considered in cases of partial unilateral ureteral obstruction.

Urinary incontinence secondary to idiopathic detrusor instability: cystometrographic diagnosis and pharmacologic management in two dogs and a cat

Idiopathic detrusor instability was diagnosed as the cause of urinary incontinence in 2 dogs and a cat. The diagnosis was based on abnormal cystometrographic findings and by exclusion of other causes of detrusor hyperactivity. Anticholinergic or combined anticholinergic, antispasmodic, and local anesthetic treatment resolved the clinical signs in all 3 animals. Increased threshold volumes after treatment were documented by cystometrography in one dog and in the cat.

Urodynamic alterations after prostatectomy in dogs without clinical prostatic disease

Prostatectomy in dogs with clinical prostatic disease has been associated with a high incidence of urinary incontinence. In this study, urodynamic alterations after prostatectomy in 10 dogs without clinical prostatic disease were evaluated. Measurements of residual urine volume, simultaneous urethral pressure profilometry and electromyography, and carbon dioxide cystometry were made before and 14 and 20 weeks after prostatectomy. Voiding was observed daily for 20 weeks after prostatectomy. All dogs remained continent for 20 weeks after prostatectomy, and only minor urodynamic abnormalities were noted. Castration had no effect on urodynamic changes associated with prostatectomy. Prostatectomy produced minimal functional changes in dogs without clinical prostatic disease.

Efficacy of azathioprine versus cyclosporine on kidney graft survival in transfused and nontransfused unmatched mongrel dogs

Sixteen mongrel dogs had bilateral nephrectomy and received a renal allograft from an unmatched mongrel. One group of eight dogs was treated orally with azathioprine and prednisone; another group of eight dogs was treated orally with cyclosporine and prednisone. Four dogs of each group received four blood transfusions each prior to surgery. Mean survival time was nearly the same in the azathioprine-treated and the cyclosporine-treated dogs. Transfusions prolonged survival in the azathioprine-treated group but not in the cyclosporine-treated group. Retrospective measurement of whole blood trough cyclosporine concentrations indicated marked variation between dogs and in the same dog at different times. This variation may have influenced graft survival. Only one dog survived the 9-month period of observation, indicating that refinements of the techniques used in this study will be required for long-term survival of renal allografts in unrelated mongrel dogs.

Lesions in dogs following renal transplantation and immunosuppression

Renal allografts were transplanted into 20 dogs (12 beagles, eight mongrels) following a prescribed protocol for pre-transplantation blood transfusions and kidney exchange. Immunosuppressive therapy (azathioprine and prednisone) was modified as needed for each dog. Seven of the beagle dogs survived for 1 year and were then euthanized; all other dogs died or were euthanized prior to 1 year post-transplantation. Graft rejection and renal failure were the greatest causes of mortality. Renal lesions which contributed to the death of some animals included renal vein thrombosis, nephrosis, and pyelonephritis. Inflammation of the lower respiratory tract (bronchitis, pneumonia, and pleuritis) was a contributory cause of death in some dogs. Cystitis and ureteritis occurred in almost half of the dogs. Prostatitis was seen in six of the 16 male dogs. Adrenal cortical atrophy, parathyroid gland hyperplasia, and bone marrow hypocellularity were seen in a majority of the dogs which survived 1 year.

Ibuprofen toxicosis in a dog

Acute renal failure, vomiting, and melena developed in a 10-month-old dog after ingestion of ten 600-mg tablets of ibuprofen. After 5 days of IV fluid therapy, clinical signs resolved and azotemia decreased. With increased availability of nonsteroidal anti-inflammatory drugs, similar complications may become more common in veterinary practice. If acute renal failure should develop, the prognosis for recovery is good, with rapid institution of appropriate therapy. However, renal dysfunction may not be completely reversed.

Food and water intake and urine composition in cats: influence of continuous versus periodic feeding

Twenty healthy, noncastrated, adult male cats had periodic (11 am to 12 am) or continuous (24 hours daily) access to food. With periodic feeding, cats ate less food, drank less water, and produced less urine than when food was available continuously. The composition of urine obtained by cystocentesis at 7:30 am, 3:30 pm, and 10 pm was influenced somewhat by feeding pattern. With periodic feeding, urine pH was lower at 7:30 am and higher at 3:30 pm than it was with continuous feeding. Most mineral concentrations and urine osmolality-specific gravity did not differ with the different feeding schedules. However, when periodic feeding was used, concentrations of magnesium and phosphorus in urine were as high or higher preprandially (7:30 am) than postprandially (3:30 pm). Frequency of urination per 24 hours was not influenced by the feeding schedule, but the time that urination occurred during the 24-hour period was somewhat different. An experimental, high magnesium diet fed to the cats for 200 days caused urethral obstruction in 7 of 10 cats fed periodically and in 7 of 10 cats fed continuously. Cats with obstruction had urinary mineral concentrations similar to concentrations in cats without obstruction, indicating that urinary mineral concentration may not be the only factor relevant to the process of obstruction. Necropsy findings and histologic evaluation of tissues from the cats indicated incidental lesions or abnormalities caused by urethral obstruction, but did not indicate anatomic abnormalities that would have predisposed the cats to obstruction.(ABSTRACT TRUNCATED AT 250 WORDS)

Canine prostatic diseases

Prostatic diseases such as benign hyperplasia, prostatic cysts, acute bacterial prostatitis, chronic bacterial prostatitis, prostatic abscessation, and prostatic neoplasia are discussed. Also discussed are diagnostic techniques such as prostatic palpation and massage, evaluation of semen and urethral discharge, and radiography.

Effect of induced prostatic infection on semen quality in the dog

Chronic Escherichia coli prostatitis was induced in 6 dogs, with 5 sham-operated dogs serving as controls. Semen volume and sperm motility, concentration, and appearance were measured 3 times (every other day) before surgery and 3 times during the 3rd and 5th week after surgery. When values for these collections were compared, using a 2-factor analysis of variance, no significant differences (P greater than 0.05) were found. However, the percentage of normal sperm decreased markedly (from 92% to 61% to 64%) in 2 infected dogs because of an increase in primary (from 6% to 32%) or secondary (from 2% to 28%) sperm abnormalities. Testes from both of these dogs were histologically normal.

Kidney graft survival in transfused and nontransfused sibling beagle dogs

In 6 pairs of sibling Beagle dogs, 1 kidney was exchanged between pairs, and contralateral nephrectomy was done. Previously, one dog of each pair was given blood transfusions from the donor of its allograft. All dogs were given azathioprine and prednisone postoperatively for immunosuppression. Four of 6 dogs given pretransplantation transfusions were healthy 1 year after surgical manipulation was done, and 2 died for reasons other than graft rejection. Of the 6 dogs that were not given pretransplantation transfusions, 3 were healthy after 1 years, but 2 were euthanatized because of graft rejection, and the last was euthanatized because of both graft rejection and intussusception. Other complications in these dogs were leukopenia (7 dogs), interdigital abscesses (2 dogs), urinary infection (3 dogs), and renal vein thrombosis (1 dog). Considering the lack of alternative methods for effective therapy for chronic renal failure in dogs, results of this study seem encouraging for selective use of renal transplantation, clinically. This study supports previous reports which indicated that pretransplantation transfusion enhanced graft survival in dogs.