Effects of an extract of Serenoa repens on dogs with hyperplasia of the prostate gland

OBJECTIVE

To determine effects of an extract of Serenoa repens on dogs with prostatic hyperplasia.

ANIMALS

20 mature male dogs with benign prostatic hyperplasia.

PROCEDURE

Dogs were assigned to 3 comparable groups on the basis of prostatic volume per kg of body weight and degree of prostatic hyperplasia determined histologically. Dogs in 2 groups were treated for 91 days (8 received 500 mg, PO, q 8 h [1,500 mg/d], and 6 received 100 mg, PO, q 8 h [300 mg/d]). The control group of 6 dogs did not receive medication. Effects of treatment on prostatic volume, prostatic weight, prostatic histologic characteristics, radiographic and ultrasonographic assessment of prostatic size, results of CBC, serum biochemical analyses, and urinalysis, serum testosterone concentration, and semen characteristics were determined. At the termination of the study, all dogs were euthanatized, and necropsies were performed. Investigators conducting tests and interpreting results were not aware of treatment group of each dog.

RESULTS

Treatment did not affect prostatic weight, prostatic volume, or prostatic histologic scores, libido, semen characteristics, radiographs of the caudal portion of the abdomen, prostatic ultrasonographs, or serum testosterone concentrations. Results of CBC, serum biochemical analyses or urinalysis, and body weights did not change during treatment.

CONCLUSIONS AND CLINICAL RELEVANCE

Treatment with an extract of S repens for 91 days did not significantly affect the prostate gland of dogs. Adverse effects were not evident. Although products containing extracts of S repens are widely advertised for men with prostatic hyperplasia, beneficial or harmful effects of this plant extract were not found in dogs with prostatic hyperplasia.

Effects of dietary polyunsaturated fatty acid supplementation in early renal insufficiency in dogs

Dietary supplementation with polyunsaturated fatty acids (PUFAs) alters the course of experimental kidney disease in dogs. In particular, supplementation with omega-6 PUFAs hastens the decline of kidney function, and omega-3 PUFAs are renoprotective. We investigated the early stages of renal insufficiency to determine whether PUFA supplementation altered the magnitude of hypercholesterolemia or glomerular hemodynamics. Two months after 11/12 nephrectomy, dogs were randomly divided into three groups of 6 animals each. Each group of dogs was then fed a low-fat basal diet supplemented with one of three sources of lipid to achieve a final concentration of 15% added fat. Fat sources were rich in omega-3 PUFAs (menhaden fish oil, group FO), omega-6 PUFAs (safflower oil, group SO), or saturated fatty acids (beef tallow, group C). Early in renal insufficiency, before significant kidney damage, group FO had a lower (P<.05) serum cholesterol concentration and tended to have a lower urinary prostaglandin E2 (PGE2) and thromboxane A2 (TxA2) excretion than group C. In contrast, group SO had a higher mean glomerular capillary pressure (P<.05) and more glomerular enlargement (P<.05) and tended to have higher eicosanoid excretion rates than group C. These differences in lipid metabolism, glomerular hypertension and hypertrophy, and urinary eicosanoid metabolism could explain, in part, the beneficial effects of omega-3 PUFAs and the detrimental effects of omega-6 PUFAs when administered on a long-term basis in this model of renal insufficiency.

Progression of chronic renal disease in the dog

Progressive loss of nephron function may be caused by persistence of factors that initiated renal disease. However, newer studies suggest that nephron damage is self-perpetuating once renal mass is reduced to some critical level. Original theories on mechanisms of self-perpetuated nephron injury focused on intraglomerular hypertension and glomerular hypertrophy, but several other factors have now been incriminated, including tubulointerstitial responses, proteinuria, and oxidative stress. Studies of dogs with surgically reduced renal mass (remnant kidney model of chronic renal disease) have allowed investigation of the self-progression theory in this species. Use of this model eliminates pre-existing renal disease as a confounding factor. Data from these studies indicate that self-perpetuated renal injury is initiated when mild azotemia is induced (plasma creatinine concentration = 2 to 4 mg/dL). Thus, with naturally occurring renal disease(s), it is likely that self-perpetuated nephron damage is occurring before or at the time when most cases of chronic renal disease are diagnosed. In dogs with remnant kidneys, loss of renal function often occurs at a linear rate over time, but non-linear patterns are common as well. The reciprocal of plasma creatinine concentration, which has been used to monitor rate of progression, is only a fair marker of renal function when compared to GFR. Thus, clinical results from creatinine measurements on cases of naturally occurring disease should not be interpreted too stringently. In remnant kidney dogs, the magnitude of proteinuria (UPC ratio) was not predictive of the rate in decline of GFR, casting doubt on importance of proteinuria in causing progression of renal disease. However, progressive increases in UPC may be a marker of an accelerated rate of renal injury. Self-perpetuation of renal injury in dogs could be the sole mechanism by which naturally occurring renal diseases progress. When more information is available on the rate of progression of naturally occurring diseases, it may become apparent whether factors initially inciting renal damage have an additive effect on rate of progression.

Beneficial effects of chronic administration of dietary omega-3 polyunsaturated fatty acids in dogs with renal insufficiency

Dietary supplementation with polyunsaturated fatty acids (PUFA) alters the course of experimental renal disease in rats. However, chronic renal disease in other laboratory animals and in human beings frequently responds differently to experimental manipulations. We investigated the effects of variations in dietary PUFA composition on the chronic course of induced renal disease in dogs. Two months after 15/16 nephrectomy, dogs were randomly divided into three groups of seven animals each. For the next 20 months, each group of dogs was fed a low-fat basal diet supplemented with one of three sources of lipid to achieve a final concentration of 15% added fat. Fat sources provided omega-3 PUFA (menhaden fish oil, group FO), omega-6 PUFA (safflower oil, group SO), or saturated fatty acids (beef tallow, group BT). Throughout the dietary trial, the magnitude of proteinuria and the plasma concentrations of creatinine, cholesterol, and triglyceride were lower in group FO. The mean overall glomerular filtration rate was 0.89+/-0.18 ml/min per kilogram of body weight in group SO, a value that was significantly less (p < 0.05) than the corresponding values for groups BT and FO (1.21+/-0.18 and 1.43+/-0.20 ml/min/kg, respectively). Renal interstitial fibrosis also was significantly elevated in group SO. The extents of mesangial matrix expansion, glomerulosclerosis, and renal interstitial cellular infiltrate were similar in groups BT and SO, but lower (p < 0.05) in group FO. We conclude that supplementation with omega-6 PUFA enhanced renal injury; supplementation with omega-3 PUFA was renoprotective.

Protein and calorie effects on progression of induced chronic renal failure in cats

OBJECTIVE

To determine effects of dietary protein and calories on progression of induced chronic renal failure in cats.

ANIMALS

28 young adult female cats.

PROCEDURE

Renal mass was reduced surgically, and glomerular filtration rate (GFR) was determined. Cats were alloted to 4 groups of 7 with similar mean GFR (1.52 to 1.55 ml/min/kg of body weight). Diets were formulated to provide: low protein and calorie (diet A), low protein and high calorie (diet B), high protein and low calorie (diet C), and high protein and calorie (diet D) intakes. Cats were fed their prescribed diet for 12 months, then blood and urine biochemical variables were measured, after which kidney specimens were examined microscopically.

RESULTS

Protein intake by cats of groups C and D (9.0 g/d/kg) was substantially greater than that by cats of groups A and B (5.3 and 5.2 g/d/kg, respectively). Caloric intake by cats of groups B and D (73 and 71 calories/d/kg, respectively) was greater than that by cats of groups A and C (58 and 55 calories/d/kg, respectively). Renal glomerular lesions were mild and not affected by protein, calories or their interactions. Nonglomerular lesions, though mild, were significantly influenced by calorie intake, but not by protein or calorie-protein interactions. The GFR did not decrease in any group. Urine protein-to-creatinine ratio increased significantly in all groups after reduction of renal mass, but values from all groups remained within the reference range (0 to 0.3).

CONCLUSIONS AND CLINICAL RELEVANCE

Diets replete in protein were not associated with increased severity of glomerular or nonglomerular renal lesions, increased proteinuria, or decreased GFR. Diets replete in calories were not associated with increased severity of glomerular lesions, but were associated with mild increase of nonglomerular lesions. Factors other than protein and calorie intake must be considered potential causes of progression of renal failure in cats. Results raise questions about the practice of restricting quantity of protein in the diet of cats with chronic renal failure, with the intention of ameliorating development of further renal damage.

Use of partial prostatectomy for treatment of prostatic abscesses and cysts in dogs

OBJECTIVE

To determine whether dogs had prostatic disease, urinary incontinence, or urinary tract infection 1 year after partial prostatectomy to treat prostatic abscesses and cysts.

DESIGN

Prospective study.

ANIMALS

20 male dogs with prostatic abscesses or cysts. Fifteen dogs had evidence of urinary tract infection. Only 8 dogs urinated normally; the remainder dribbled, had obstructions, or required medical treatment.

PROCEDURE

Partial prostatectomy was performed on each dog. Sexually intact dogs (n = 12) also were castrated.

RESULTS

None of the dogs had return of prostatic cystic enlargement or clinical signs of prostatic disease during the first year after surgery. Two dogs were euthanatized within 1 year after surgery, with 1 dog having prostatic enlargement and adenocarcinoma and 1 dog having unrelated lymphosarcoma. Fifteen dogs were continent. The remaining 5 dogs urinated normally but had intermittent and minor incontinence. Eleven dogs had no signs of infection 1 year after surgery, 5 had pyuria or positive urine bacteriologic culture results, 2 did not have urinalysis performed, and 2 were euthanatized.

CLINICAL IMPLICATIONS

Dogs with severe prostatic abscesses or cysts and infections can be successfully treated by partial prostatectomy with an ultrasonic surgical aspirator and castration, resulting in long-term disease resolution. Although most dogs with severe prostatic disease do not urinate normally before surgery, nearly all dogs resume normal micturition after partial prostatectomy. Postoperative results of partial prostatectomy appear to be better than those of previous drainage techniques for treatment of prostatic cavitary disease.

Pathophysiology and management of progressive renal disease

Recently, the hypothesis that all renal diseases are inherently progressive and self-perpetuating has focused attention on adaptive changes in renal structure and function that occur whenever renal function is reduced. These glomerular adaptations to renal disease include increases in filtration rate, capillary pressure and size, and are referred to as glomerular hyperfiltration, glomerular hypertension and glomerular hypertrophy, respectively. Extrarenal changes, such as dietary phosphate excess, systemic hypertension, hyperlipidaemia, acidosis and hyperparathyroidism occur in animals with renal disease and may be contributors to progression of renal disease. Emphasis in the management of companion animals with renal disease has shifted to identifying, understanding and controlling those processes that play a role in the progression from early to end-stage renal failure. Advances made by veterinary nephrologists in the past 15 years permit resolution of old controversies, formulation of new hypotheses and discussion of unresolved issues about the nature of progressive renal disease in dogs and cats.

Effects of parathyroidectomy on induced renal failure in dogs

OBJECTIVE

To determine the effects of parathyroid hormone (PTH) depletion on dogs with induced chronic renal failure.

ANIMALS

2 groups of 26 mixed-breed dogs of both sexes (13 were parathyroidectomized [PTX] and 13 had sham surgery).

PROCEDURE

After surgical reduction of renal mass and PTX, dogs were selected for a 24-month period of study and monitored for clinical, hematologic, blood biochemical, and organ function status. On development of uremia or after 24 months, dogs were euthanatized, and tissues were examined.

RESULTS

Higher survival rate and smaller decrement in renal function (glomerular filtration rate) were observed in PTX dogs, compared with those that had sham surgery, but values did not reach statistical significance. The PTX dogs remained hypocalcemic during the study and had lower serum Ca2+ X P product values. Regardless of parathyroid state, survivors and fatalities could be separated on the basis of serum Ca2+ X P product values. Parathyroidectomy did not prevent renal deposition of calcium, and renal lesions were poorly correlated with renal cortical calcium concentration. Abnormalities reported in dogs with renal failure, which were attributed to PTH (glucose intolerance, pulmonary hypertension), were not observed in PTX dogs or those that had sham surgery.

CONCLUSIONS AND CLINICAL RELEVANCE

PTX had beneficial effects, but these were mediated via changes in mineral homeostasis rather than via direct effects of PTH. Results attributable to PTX were similar to those previously obtained by dietary restriction of phosphate intake.

Does modifying dietary lipids influence the progression of renal failure?

Recent studies have identified important effects of dietary fatty acid composition in animals with chronic renal disease, particularly in dogs. The theoretic basis for these effects provides a rationale for the use of diets enriched with omega-3 (but not omega-6) polyunsaturated fatty acids. A therapeutic trial with a diet enriched with omega-3 polyunsaturated fatty acids should be considered as a maneuver designed to slow the rate of progression of chronic renal disease in dogs.

A retrospective study of multicentric bovine renal cell tumors

Tissues from twenty mature cows with primary renal cell tumors were submitted over an 11-year period because of gross lesions detected during routine slaughter and inspection. Tumors visualized grossly were multiple and bilateral in seven cattle, multiple within one kidney in four cattle, and solitary in nine cattle. The tumors were primarily cortical, yellow-orange to tan, proliferative, well circumscribed, and extended above the capsular surface of the kidney. Tumors were microscopically multiple even when grossly described as solitary lesions, except in one cow. Twelve tumors (60%) were microscopically multiple in one kidney, seven tumors (35%) were multiple and bilateral, and only one cow (5%) exhibited extrarenal metastasis. Tumors from nineteen cows were composed of eosinophilic granular epithelial cells; tumors from one cow were clear cell type. Each tumor contained several histologic patterns. Corpora amylacea, proteinaceous secretions, and hemosiderin were characteristic findings in bovine renal cell carcinoma. All 20 cows with renal cell tumors exhibited positive immunoreactivity to uromodulin (Tamm-Horsfall protein).

Effects of aging and dietary protein intake on uninephrectomized geriatric dogs

Thirty-one clinically normal Cocker Spaniels, Miniature Schnauzers, and Doberman Pinschers (28 female, 3 male) 7 to 8 years old were uninephrectomized (month -2) to increase the risk of renal damage associated with reduction of renal mass. Two diets, differing principally in protein concentration, were used to test the hypothesis that high dietary protein intake causes renal damage in aging dogs. For 2 months after uninephrectomy, all dogs were fed diet A (18% protein). After glomerular filtration rate (GFR) was measured (month 0), 16 dogs were assigned to group A and were fed diet A for an additional 48 months. The other 15 dogs were assigned to group B, and were fed diet B (34% protein) for the subsequent 48 months. At 6-month intervals, GFR and urine protein-to-creatinine ratio (UP/C) were determined. At 48 months, terminal studies were done, survivors were euthanatized, and tissues were examined. Of 16 dogs in group A, 10 survived, compared with 13 of 15 in group B. Among survivors, a significant difference in GFR was not found between groups A and B, and decrease in GFR was not evident with time in either group. At 48 months, oral administration of casein caused minor acute effects on GFR and renal plasma flow in dogs of groups A and B. The UP/C values increased significantly (P = 0.001) from baseline values, but the increase was not progressive. The UP/C values were not affected by diet. Some dogs in both groups developed UP/C > 1.0.(ABSTRACT TRUNCATED AT 250 WORDS)

Ultrastructural examination and cell count determinations of avian glomeruli from grossly normal and grossly swollen kidneys of broilers at slaughter

Kidneys from broiler chickens at slaughter (6 to 7 weeks of age and mixed sex) were collected by U.S. Department of Agriculture personnel. Forty kidneys were collected from grossly normal birds with grossly normal kidneys (Group D). Grossly swollen kidneys were collected from birds that were otherwise grossly normal (Group A), that had gross lesions of Marek's disease (Group B), or that had gross lesions of squamous cell carcinoma (Group C). These kidneys were fixed in Carson's 10% buffered formalin, embedded in plastic, sectioned at 2 microns, and then stained with periodic acid-Schiff-hematoxylin for glomerular cell counting. Tissue was also processed for electron microscopy from six Group D birds and from six birds total from Groups A, B, and C that had the most severe histologic glomerular lesions. Glomerular tuft cell counts and visceral epithelial cell counts were performed by light microscopy at a magnification of 100x (oil immersion). Total tuft cell counts of all abnormal groups (A, B, and C) were significantly higher (P < 0.05) than those of Group D. Reptilian glomerular tuft cell counts for all abnormal groups were significantly higher (P < 0.05) than the reptilian glomerular tuft counts for Group D. Mammalian glomerular tuft cell counts for Groups A and B were significantly higher than those of the control group (Group D). Electron microscopic examination of the glomeruli from selected birds revealed no dense deposits in the basement membrane and no effacement of epithelial podocyte foot processes. No essential ultrastructural differences were noted between the control group and the abnormal groups.

Effects of parathyroid hormone depletion in dogs with induced renal failure

Six parathyroidectomized (PTX) and 6 control dogs had renal mass reduced by 15/16, and were studied for effects of parathyroid hormone depletion on progression of renal failure. All PTX dogs and 4 of 6 control dogs survived until necropsy after 32 weeks. Plasma parathyroid hormone concentration was undetectable in PTX dogs throughout the study, but was greater than normal in control dogs. Serum inorganic phosphate (P) concentration was increased in PTX dogs (6.8 +/- 0.1 mg/dl) and in control dogs (7.5 +/- 0.2), but did not differ significantly (P = 0.254) between groups. Ionized blood calcium values (Ca2+) were significantly (P = 0.014) lower in PTX dogs (1.31 +/- 0.01 mmol/L) than in control dogs (1.36 +/- 0.00 mmol/L), but were more variable in PTX dogs. Values in PTX dogs were not significantly different from those in control dogs for glomerular filtration rate (P = 0.914), plasma creatinine concentration (P = 0.903), and urine protein to creatinine ratio (P = 0.756) determined at intervals during the study. Terminal glucose tolerance and plasma insulin concentrations, P tolerance, and renal P excretion did not differ between groups. Histologic comparison of kidneys removed during reduction of renal mass with kidneys removed at necropsy revealed development of lesions in both groups of dogs, and no protective effect from parathyroidectomy. Mineral analysis of aorta, brain, heart, lungs, and skeletal muscle obtained at necropsy revealed no significant difference between PTX and control groups. Renal cortical calcium concentration was significantly (P < 0.05) greater in kidneys obtained at necropsy then in kidneys obtained during nephrectomy, but PTX did not protect renal cortex from calcium deposition.

Intracapsular subtotal prostatectomy in normal dogs: use of an ultrasonic surgical aspirator

In an attempt to reduce postoperative incontinence associated with excisional prostatectomy and the recurrence of prostatic disease after less radical surgeries, a new technique for subtotal prostatectomy was developed using an ultrasonic surgical aspirator. During laparotomy, a longitudinal incision was made in the ventral surface of each lobe of the prostate gland. Biopsies for histology and culture were taken. Through the ventral incisions, the ultrasonic surgical aspirator was used to resect approximately 85% of the glandular tissue from inside the capsule. The ultrasonic surgical aspirator allowed resection of the glandular tissue without damaging the vessels, nerves, and connective tissue stroma. The ventral portion of the capsule was excised. The dorsal portions of the capsule were apposed on the ventral midline by suturing their ventral margins to form a periurethral cuff. As preclinical research, seven intact male dogs were evaluated by physical examination, complete blood cell count, serum urea nitrogen, urinalyses, and urethral pressure profile (UPP) with urethral electromyograms (EMGs). The dogs underwent subtotal prostatectomy and castration. All dogs were continent after surgery. UPPs and EMGs at 1 and 2 months after surgery were no different than before surgery. This contrasts to our previous studies in which excisional prostatectomy reduced maximal urethral closure pressure (MUCP) in dogs without prostatic disease. The use of the ultrasonic surgical aspirator for intracapsular subtotal prostatectomy facilitated removal of glandular tissue with decreased hemorrhage and provided preservation of the prostatic urethra, nerves, and vessels involved in maintaining urinary continence.

Selective parathyroidectomy of the dog

Selective parathyroidectomy (PTX) is preferred to thyroparathyroidectomy (TPTX) when specific effects of parathyroid hormone depletion are being studied. However, because of the anatomic proximity of thyroid and parathyroid glands, TPTX often is performed, leaving animals depleted of thyroxine (T4) and calcitonin as well as parathyroid hormone (PTH). In the present study, six normal dogs had parathyroid tissue and about seven-eighths of thyroid tissue removed. This quantity of thyroid tissue was inadequate to maintain normal serum T4 concentrations, despite allowance of 168 days for thyroid recovery. Five of six dogs with reduced renal mass had successful selective PTX and normal serum T4 concentrations at 28 days, when one-half or more of thyroid tissue was spared. We conclude that with attention to the surgical technique, selective PTX can be achieved in a high percentage of dogs and sufficient thyroid tissue spared to maintain euthyroidism.

Histologic and morphometric examination of avian glomeruli from normal and swollen kidneys of broilers at slaughter

Normal and abnormal kidneys collected from broiler chickens at slaughter (6 to 7 weeks of age and of mixed sex) were evaluated to establish histopathologic and morphometric parameters for broilers. Normal kidneys (group D) had an overall mean glomerular diameter of 67.4 +/- 27.8 microns. Abnormal groups (Groups A, B, and C) had an average glomerular diameter of 75.2 +/- 32.1 microns, which was significantly different (P < 0.01) from that of Group D. All glomerular diameters in Group A (otherwise normal birds with swollen kidneys) were significantly different (P < 0.01) from corresponding diameters in Group D. In Group B (birds condemned for Marek's disease virus), only the mammalian glomeruli were significantly different from Group D mammalian glomeruli (P < 0.01). A significant increase in glomerular density was observed for all abnormal groups and glomerular types. The data indicate that glomerular diameter and cellularity might be practical and sensitive indicators of early glomerular changes that can occur in grossly swollen kidneys. Increased glomerular density indicates tubular loss or increase in glomerular numbers.

Early renal disease in BHE/cdb rats is less in rats fed beef tallow than in rats fed menhaden oil

The effects of feeding a 1% corn oil-9% menhaden oil or beef tallow diet on the early phase of diabetic nephropathy in BHE/cdb rats was studied. The diet groups were subdivided into rats with or without impaired glucose tolerance. Those fed menhaden oil had renal hypertrophy, mild albuminuria, decreased creatinine clearance, increased urea clearance, and more severe lesion scores than rats fed beef tallow. No differences in glomerular filtration rate, Na+, K+-ATPase activity, sorbitol dehydrogenase, or inositol 1, 4, 5-phosphate were observed. Beef tallow-fed rats had higher serum triglyceride levels and renal cholesterol levels. Renal and hepatic fatty acid profiles reflected the fatty acid profile of the dietary fat. These results suggest that beef tallow conferred a protective effect on the renal tissues of these diabetes-prone rats.

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)

Invasion of enterocytes in cultured porcine small intestinal mucosal explants by Salmonella choleraesuis

Porcine small intestinal explants maintained in vitro were inoculated with Salmonella choleraesuis to study the characteristics of its invasion of enterocytes. The explants were fixed at selected intervals for up to 12 hours after inoculation and examined by conventional light microscopy, immunoperoxidase staining, and transmission electron microscopy. Although there was diffuse loss of villous enterocytes during the first hour of incubation, the villi were reepithelialized by the end of 2 hours of culture, and the mucosal epithelium remained intact and appeared to be viable through 12 hours of culture. Intraepithelial S choleraesuis were not detected before 6 hours after inoculation, but after 12 hours of incubation, bacteria were numerous within enterocytes. Ultrastructurally, penetration of the brush border by S choleraesuis resulted in focal loss of microvilli. Bacteria were endocytosed into membrane-bound vacuoles where most remained, but a few were free within the cytoplasm of enterocytes. Invasion of the explants closely resembled that described for live animal and cell culture models of Salmonella spp invasion.

Cephaloridine nephrotoxicity is potentiated by selenium deficiency but not copper deficiency in rats

Lipid peroxidation may contribute to the nephrotoxicity of cephaloridine, a beta-lactam antibiotic. Copper and Se may protect against free radical damage, and dietary Se deficiency potentiates cephaloridine nephrotoxicity. The objectives of this study were to further investigate potentiation of cephaloridine toxicity by Se deficiency and to determine whether Cu deficiency increases cephaloridine-induced injury. Weanling male Sprague-Dawley rats were fed adequate, Cu-deficient, Se-deficient, and Se and Cu-deficient diets for 4 wk and subsequently injected i.p. with cephaloridine (1200 mg/kg body wt) or saline. Nephrotoxic response to cephaloridine occurred, with increased plasma urea, kidney weight, excretion of urinary enzymes, and kidney lesions. Cephaloridine also increased plasma sorbitol dehydrogenase activity. Selenium deficiency depressed kidney glutathione peroxidase activity (78%) and potentiated cephaloridine nephrotoxicity. Copper deficiency did not increase cephaloridine nephrotoxicity; the small depression (13%) in kidney Cu,Zn-superoxide dismutase activity may not have been sufficient to impair antioxidant status. However, the marked depression in kidney glutathione peroxidase activity during Se deficiency may have impaired antioxidant status and enhanced cephaloridine-induced injury. In contrast to results in the kidney, neither Se deficiency nor Cu deficiency potentiated cephaloridine hepatotoxicity, as assessed by plasma SDH activity.

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)

Iron supplementation increases gentamicin nephrotoxicity in rats

Gentamicin (GM), an aminoglycoside antibiotic, can cause acute renal failure in humans and experimental animals. It has been proposed that lipid peroxidation may play a role in GM nephrotoxicity. Nutrients such as copper, selenium or iron that influence lipid peroxidation may also be a factor in toxicity. This study investigated the effect of supplemental dietary iron on the nephrotoxicity of GM. Weanling male Sprague-Dawley rats were fed control [0.75 mmol (42 mg) iron/kg] or iron-supplemented [4.32 mmol (242 mg) iron/kg] diets for 3 wk. Rats were subsequently injected intraperitoneally with GM (50 or 100 mg.kg body wt-1.d-1) or saline for 8 d. High dietary iron resulted in greater sensitivity to GM (100 mg/kg body wt) toxicity in terms of elevated urinary excretion of n-acetyl-beta-glucosaminidase (NAG) and increased mineralization, casts and megalocytes in renal tubules. After GM treatment was terminated, NAG excretion decreased with both dietary treatments. However, renal tubular cell damage, due to GM, remained higher than in saline-treated controls in rats fed 4.32 mmol iron/kg diet.

Dietary protein intake and the glomerular adaptations to partial nephrectomy in dogs

After partial nephrectomy (Nx) in rats, a temporal pattern of progressively declining renal function often develops. This pattern has been attributed to the development of glomerular hyperfiltration, hypertension and hypertrophy in remnant nephrons. In rats, dietary protein restriction prevents these adaptive changes in remnant nephrons, thereby preserving renal structure and function. However, long-term studies of the temporal pattern of renal function have failed to identify a consistently progressive deterioration of renal function in partially Nx dogs, and a protective effect of protein restriction has not been apparent in this species. To address these issues in dogs, we evaluated the single nephron adaptations to partial Nx in dogs and the effect of dietary protein restriction on these adaptations. Results of our micropuncture studies in partially Nx dogs indicate that remnant nephrons of dogs exhibit glomerular hyperfiltration (single nephron glomerular filtration rate of 144 +/- 8 vs. 71 +/- 4 nL/min in controls, P less than 0.05), hypertension (glomerular capillary pressure of 75.1 +/- 1.6 vs. 63.2 +/- 1.9 mmHg in controls) and hypertrophy (glomerular volume of 3.54 +/- 0.24 x 10(6) vs. 2.04 +/- 0.05 x 10(6) microns3 in controls, P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of dietary protein on functional, morphologic, and histologic changes of the kidney during compensatory renal growth in dogs

Two diets similar in caloric density and mineral content, but markedly different in protein content, were used to study the effects of dietary protein on renal function and morphologic and histopathologic changes in dogs that had functional renal tissue reduced by seven-eights nephrectomy. The effects of moderate protein intake (MPrI = 15% protein; dry-matter basis) and high-protein intake (HPrI = 31% protein; dry-matter basis) were studied for the initial 7 months (period 1 [P1]) after renal mass reduction. Diets were then switched between groups during the following 7 months (period 2 [P2]) to evaluate the effects of increased or decreased protein intake. The HPrI caused significantly (P less than 0.05) greater glomerular filtration rate (GFR) and renal growth than did MPrI during P1. Dogs that maintained HPrI during P1 and MPrI during P2 (group 1) had significant (P less than 0.05) reduction in GFR during P2. Dogs that maintained MPrI during P1 and HPrI during P2 (group 2) had significant (P less than 0.05) improvement in GFR and renal growth during P2. At the end of the study, renal reserve was evaluated in both groups of dogs before and after group 1 was returned to HPrI for 2 weeks. During this 2-week feeding trial, group-1 dogs had marked improvement in renal reserve, relative to group 2, and GFR increased to the terminal P1 values. Results indicate a possible residual benefit from HPrI during the early phase of compensatory renal growth in the form of functional compensatory memory to HPrI. The severity of renal lesions was indistinguishable between dogs of dietary groups during both study phases.(ABSTRACT TRUNCATED AT 250 WORDS)

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.

Culture and morphologic features of small intestinal mucosal explants from weaned pigs

Small intestinal explants from weaned pigs were cultured under a variety of conditions. Explants maintained villus-to-crypt ratio between 1:1 and 1.5:1 for 48 hours. The mucosal epithelium remained well preserved and retained good cellular morphologic features, as determined by light and electron microscopy. Between 48 and 72 hours, considerable mucosal degeneration was evident. Best results were obtained when the explants were cultured on a rocking platform placed in an atmosphere of 95% O2 and 5% CO2, using supplemented RPMI 1640 cell culture medium.

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.

Ventral approach to the pelvic canal in the female dog

A ventral approach to the pelvic canal by bilateral pubic and ischial osteotomy was performed in five female dogs. The entire urogenital tract could be exposed and easily manipulated through this approach. All animals were ambulatory within 24 hours. Clinical union had formed in three of the four osteotomies by the time of euthanasia (months 2-4) in all animals. Incomplete union in some osteotomies indicated that exercise should be restricted for at least 4 months after the procedure. The procedure was determined to be clinically useful when wide exposure of the entire female urogenital tract is desired.

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.

Single-nephron adaptations to partial renal ablation in the dog

Micropuncture and histological studies were performed in dogs to characterize single-nephron adaptations to partial renal ablation. Dogs underwent sham surgery (group 1, n = 6), three-fourths nephrectomy (group 2, n = 10), or seven-eighths nephrectomy (group 3, n = 6). Single-nephron glomerular filtration rate (SNGFR) was 71.0 +/- 4.2 nl/min in group 1, 132.5 +/- 9.6 nl/min in group 2, and 161.8 +/- 12.4 nl/min in group 3 (P less than 0.05). There were parallel increases in single-nephron glomerular plasma flow rate (GPF), with a mean value of 235.3 +/- 20.1 nl/min in group 1, 442.4 +/- 34.4 nl/min in group 2, and 569.6 +/- 73.7 nl/min in group 3 (P less than 0.05, group 1 vs. groups 2 and 3). Glomerular capillary pressure, estimated from the sum of proximal tubule stop-flow pressure and arterial oncotic pressure, was 63.2 +/- 1.9 mmHg in group 1, 73.5 +/- 2.0 mmHg in group 2, and 77.9 +/- 2.2 mmHg in group 3 (P less than 0.05, group 1 vs. groups 2 and 3). The mean glomerular transcapillary hydraulic pressure gradient (delta P) in group 2 was not different from group 1 (46.8 +/- 1.3 vs. 43.9 +/- 1.8 mmHg, NS); however, it was significantly increased in group 3 (50.0 +/- 1.4 mmHg; P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Pathologic changes and tissue gentamicin concentrations after intravenous gentamicin administration in clinically normal and endotoxemic cats

Hematologic and serum biochemical values, tissue gentamicin concentrations, and renal pathologic changes were determined in clinically normal and endotoxemic cats given 3 mg of gentamicin/kg of body weight, IV. Endotoxemia was induced by IV administration of 0.5 microgram of Escherichia coli endotoxin/kg of body weight. In experiment 1, 6 cats were given endotoxin. After rectal temperature increased at least 1 degree C, cats were given gentamicin. Blood samples were collected before and at 1 and 3 hours after administration of gentamicin. With the exception of severe leukopenia, other hematologic changes or changes in serum biochemical values were not observed. In experiment 2, 24 cats were allotted to 4 groups and were given gentamicin, endotoxin, gentamicin plus endotoxin, or neither substance. Three hours later, cats were euthanatized, and tissue and body fluid specimens were obtained and were assayed for gentamicin concentration. Kidney specimens were examined microscopically. Endotoxemic cats had more gentamicin in the renal medulla than did control cats, but none of the cats had detectable renal lesions. The possible nephrotoxic synergism between gentamicin and severe endotoxemia and the lack of major differences in gentamicin concentration in extrarenal tissues indicated that the dosage of gentamicin in endotoxemic cats does not have to exceed the dosage recommended for clinically normal cats. A single dose of gentamicin administered IV did not cause renal damage in mildly endotoxemic cats, but nephrotoxicity ascribed to multiple doses of gentamicin in more severely endotoxemic cats needs to be evaluated.

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.

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.

Acute renal failure in six horses resulting from haemodynamic causes

Six horses had been admitted to the hospital because of illness other than renal failure; diarrhoea, myositis, abdominal pain and/or suspected bacterial sepsis. Hypotension and disseminated intravascular coagulopathy were frequent findings in the horses. Abnormally high serum creatinine concentration and urine specific gravity of less than 1.022 were found in the horses with acute renal failure. Hyponatraemia and hypochloraemia were the most common abnormal electrolyte findings. Pronounced hyperkalaemia was not found. Variable degrees of tubular necrosis were seen in three of the four horses that had kidney sections submitted for microscopic examination. Renal cortical necrosis occurred in one horse. Intravenous fluid and electrolyte replacement was the most important therapy in those cases that were non-oliguric. Furosemide, mannitol and dopamine were used in horses with oliguria. The prognosis was generally good if the predisposing cause could be corrected and the acute renal failure was not oliguric.

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.

Distal renal tubular acidosis and hepatic lipidosis in a cat

Clinical and laboratory evidence of hepatic failure was found in a chronically anorectic cat. Simultaneous blood and urine pH determinations established a diagnosis of distal renal tubular acidosis. The cat did not respond to treatment. Necropsy revealed distal tubular nephrosis and hepatic lipidosis. The finding of distal renal tubular acidosis in a cat with hepatic lipidosis emphasizes the importance of complete evaluation of acid-base disorders in patients.

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)

A nephrotic-like syndrome with an associated mesangio-proliferative glomerulopathy in a cow

A 3-year-old Limousin cow was admitted to the University of Georgia Teaching Hospital with a history of chronic weight loss and diarrhea of more than 1 year's duration. Clinical laboratory findings included proteinuria and hypoproteinemia and were suggestive of a nephrotic-like syndrome. Necropsy findings included generalized edema of the visceral organs and diffuse red glistening foci on the capsular and cut surfaces of the cortex of both kidneys. Microscopically, the kidney had hypercellular and hypersegmented glomeruli, focal glomerulosclerosis, periglomerular fibrosis, and tubular nephrosis. The glomerular hypercellularity was confirmed by electron microscopy to be due to increased mesangial cells.

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.

Morphometric studies of the bovine uterus: microscopic lesions and retrospective reproductive history

A survey of reproductive tracts from nonpregnant cows at an abattoir was conducted. Reproductive tracts from 98 cows were studied microscopically and evaluated with a grading system to determine the severity of pathologic changes. Inflammatory reaction (type and distribution), fibrosis, gland morphology, and appearance were measured, quantified, and scored (1 to 4). Category 1 endometrium (normal) was found in 18 cows, category 2 in 23, category 3 in 34, and category 4 in 23. The category of endometrium was then compared with the retrospective reproductive status, and it was found that reproductive problems had occurred in 6 cows (33.3%) in category 1, in 13 cows (56.5%) in category 2, in 25 cows (73.5%) in category 3, and in 21 cows (91.3%) in category 4. Cervicitis was found in 43 (43.8%) genital tracts; 16 cows (16.3%) had salpingitis. Ovarian lesions were not observed. Serum samples were tested for certain antibodies. Only 1 was seropositive for brucellosis, but 61 of 81 sera had leptospira titers greater than 1:100 and 1:50 (hardjo). The serovar hardjo was the most prevalent. All sera had neutralizing titers against parainfluenza type 3 virus; 74.2% and 56.7% of the sera had neutralizing antibodies against bovine viral diarrhea virus and infectious bovine rhinotracheitis virus, respectively.

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.

Gentamicin-associated acute renal failure in the dog

Gentamicin-associated acute renal failure was diagnosed in 10 dogs. The disease was characterized by a poor prognosis and lengthy hospitalization. Hypoalbuminemia, disorders of potassium homeostasis, proteinuria, hematuria, and cylindruria were common during therapy for renal failure. Fever and dehydration were the most commonly identified potential predisposing factors.

Effects of three diets on dogs with induced chronic renal failure

Healthy mixed-bred dogs of both sexes had renal mass surgically reduced and were allowed 2 to 3 months for hypertrophy of the remnant kidney. They were then allotted into 3 groups with equal renal function and were fed 1 of 3 diets that differed in composition. Group 1 dogs (n = 6) were fed moist food that contained 50% protein, 2.34% Ca, and 1.64% P with a P-binding agent (basic aluminum carbonate gel) added. Group 2 dogs (n = 6) were fed a dry diet that contained 24.5% protein, 1.26% Ca, 1.21% P, and the same P-binding agent as used for group 1. Group 3 dogs (n = 7) were fed a moist diet that contained 16.1% protein, 0.38% Ca, and 0.3% P without a P-binding agent. Each group was fed its diet for 92 days and monitored for responses. Mortality associated with uremia occurred in 2 of 6 group 1 dogs, 0 of 6 group 2 dogs, and in 2 of 7 group 3 dogs. Among survivors, clinical signs were seen in the more azotemic dogs of group 1, but not in dogs of groups 2 and 3. The blood urea nitrogen, plasma P concentrations, and PCV values were most favorable in group 3 and least favorable in group 1. Marked differences between groups were not seen in plasma concentrations of protein, albumin, or Ca or in plasma alkaline phosphatase activity. Values for glomerular filtration rate did not change in any group during the experiment.(ABSTRACT TRUNCATED AT 250 WORDS)

Characterization of magnesium-induced urinary disease in the cat and comparison with feline urologic syndrome

Aggregates of struvite crystals caused urethral obstruction in a high percentage of cats fed moist and dry diets supplemented with Mg oxide. Some of the diets were associated with cystolith formation as well. The percentage of Mg in the experimental diets was a misleading indicator of Mg intake because of differences between moist and dry diets in their caloric density. Magnesium homeostasis was maintained in cats ingesting large quantities of Mg. Tissue (kidney, muscle, and rib) concentrations of Mg were the same in cats fed high Mg and control diets. Plasma Mg concentration was increased only in cats ingesting the largest amount of Mg. Magnesium homeostasis was maintained by a marked increase in urine Mg excretion. However, urine Mg concentration was not directly related to Mg intake, apparently because of differences between diets in intestinal absorption of Mg. Urethral obstruction of experimental cats was not associated with a transient increase in Mg intake, nor did obstructing cats have higher urine Mg concentrations than did nonobstructing cats fed the same diet. This observation indicates that factor(s) other than urine Mg concentration are important in urethral obstruction. Cats with urethral obstruction due to naturally occurring disease, feline urological syndrome (FUS), had markedly lower urine Mg concentrations than cats fed high Mg diets. This finding refutes the theory that cats develop FUS because of primary Mg hyperabsorptive phenomena or because of a primary urinary leak of Mg. It also indicates that factors other than urine Mg concentration are involved in the genesis of naturally occurring urethral obstruction. Another difference between the natural and the induced disease was related to the character of the urinary precipitates. Experimental diets higher in Mg concentration caused urolith formation, which is uncommon with FUS. Lower Mg diets caused obstruction with aggregates of crystals, but mucus was not observed. However, in the experimental disease induced in the present study, urinary precipitates were predominantly or exclusively struvite, as has been reported in the natural disease. Many similarities were seen between the diet-induced disease and FUS, but factors in addition to Mg intake are involved in the natural disease. The importance of Mg, compared with the undefined factors, remains to be established.

Cystometry in dogs under oxymorphone and acepromazine restraint

Cystometry was performed in 12 dogs under oxymorphone and acepromazine restraint. A detrusor reflex occurred in 10 of 12 dogs (83%). Mean threshold pressure and volume were 31 cm H2O and 22 ml/kg, respectively. Tonus limb II varied inversely with threshold volume. Threshold volume varied directly with body weight; threshold pressure was independent of body weight.

Clinical aspects of experimentally induced chloride deficiency in Holstein calves

A severe total body chloride deficit was induced in Holstein calves by feeding a low-chloride ration (0.063% Cl) and removing digesta daily from the abomasum through a surgically implanted cannula. Clinical signs of the deficit observed included polydipsia, polyuria, dehydration, anorexia, scleral injection, decreased respiratory rate, and blood and mucus in the feces. Necropsy findings included dehydration, blood in the lumen of the small intestine, and renal lesions. The most extensive histopathologic changes occurred in the renal tubular epithelium of the outer medulla where mineralization of the tubular epithelium and basement membranes was frequently seen.