首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 31 毫秒
1.
Eighteen male cats were fed either a canned complete diet or a commercially available dry pelleted diet or the same dry diet containing 1.6 per cent ammonium chloride. The daily food and water intake of four of these cats was measured. Urine samples were taken at random and the pH and the presence of struvite crystals in their sediment estimated. In some samples in which the pH was less than 7.0, and struvite crystals were absent, the pH was increased to 7.0 and any sediment was examined for struvite. No spontaneous struvite was seen in urine samples (pH 5.8) from cats fed the canned complete diet but when its pH was raised to 7.0, 46 per cent of these samples showed struvite. Cats fed the dry pelleted diet had urine of higher pH (7.55) and 78 per cent of the samples contained struvite crystals. Cats fed this diet supplemented with ammonium chloride had a urine pH of 5.97 and only 9 per cent contained struvite crystals but when the pH was adjusted to 7.0 all the samples showed struvite crystals. Energy intake was similar on all three diets but the intake of dry matter was greater on the dry diets. Liquid water intake was greater on the dry diets but total water intake was greatest on the canned complete diet. The intake of magnesium, calcium and phosphate was greater on the dry diets. It is concluded that urine pH is a more important controller of struvite precipitation than mineral intake.  相似文献   

2.
In three separate experiments nine male cats were fed either a canned complete diet or a commercially available dry pelleted diet or the same dry diet containing 1.6 per cent ammonium chloride for seven days and then fasted for 20 hours. Then ad libitum feeding was continued and urine samples were taken at four-hour intervals for 12 hours and a final sample 12 hours later. Urine pH and the presence of struvite crystals in urine sediment were evaluated. The food and water intake of four of the nine cats was measured at the time of urine collection. After the fast, urine pH was raised, even after feeding the dry diet supplemented with ammonium chloride. A post prandial rise in urine pH was also seen on all three diets. After feeding the dry diet the postprandial peak pH was 7.97 and struvite occurred spontaneously. Urine pH after feeding the dry diet supplemented with ammonium chloride peaked at 7.75 then fell to 6.1 12 hours after the start of feeding. Struvite occurred spontaneously at all times until the pH reached 6.1 but when the pH of urine was raised to 7.0 the struvite crystallised. Urine pH on the canned complete diet peaked at 6.8 then fell to 5.8; struvite did not occur spontaneously but when urine pH was raised to 7.0 struvite crystallised except at the eighth and 12th hour sampling. These data show that fasting initiates a post prandial rise in urine pH and struvite crystalluria even when a normally effective urinary acidifier is used.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

3.
To learn more about the biomineralization process of struvite in ruminants, a seldom noticeable crystal, struvite-K, was investigated in six goats in which urolithiasis was induced by feeding a cottonseed meal and rice straw diet supplemented with MgO. The compositions of crystals and calculi were studied by chemical qualitative analysis and X-ray energy dispersive spectrometry (EDS). The activity product (AP) and relative supersaturation (RSS) of magnesium ammonium phosphate (MAP) and potassium magnesium phosphate (MKP) were calculated to compare the difference of crystals formed in this process. The results showed that calculi consisted of MAP with a little MKP. Crystals in the urine consisted of MAP and MKP before stone formation, but crystals in urine after stone formation mainly consisted of MKP. The AP and RSS of MAP and MKP significantly decreased after stone formation. It was concluded that MAP and MKP may coexist in the crystals of urine before struvite calculi formation but MKP did not precipitate to struvite calculi and was separated out as crystal sedimentation of urine. The changes of crystallization of MAP and MKP contributed partially to the supersaturation status of MAP and MKP during struvite stone formation.  相似文献   

4.
The efficacy of a diet designed to facilitate dissolution of feline magnesium ammonium phosphate (struvite) uroliths was evaluated in 30 cases of urolithiasis, sterile struvite uroliths dissolved in a mean of 36 days after initiation of dietary treatment. In 5 cases of urolithiasis, struvite urocystoliths associated with urease-negative bacterial urinary tract infection dissolved in a mean of 23 days after initiation of dietary and antimicrobial treatment. In 3 cases of urolithiasis, struvite urocystoliths associated with urease-positive staphylococcal urinary tract infection dissolved in a mean of 79 days after initiation of dietary and antimicrobial treatment. Dissolution of uroliths in cats fed the treatment diet was associated with concomitant remission of dysuria, hematuria, and pyuria, and reduction in urine pH and struvite crystalluria. In one case, a urocystolith composed of 100% ammonium urate, and in another case, a urolith composed of 60% calcium phosphate, 20% calcium oxalate, and 20% magnesium ammonium phosphate did not dissolve.  相似文献   

5.
Ninety adult cats were fed an experimental canned meat-based cat food at levels necessary to maintain weight for 11 days. On the 12th day the cats were split into six groups of 15 cats each and fed 0, 20, 40, 60, 80 or 100 per cent of their previous food allotment. Four hours after the food was offered a urine sample was obtained via cysto-centesis. The pH of the urine sample was determined and the sample microscopically evaluated for the presence of struvite crystals. Post prandial urine pH was found to be a linear function of the amount of food consumed: (urine pH = 6–15 + [food intake (g) × 0–015]; P = 0-000). The presence of struvite crystals was dependent on urine pH while amorphous crystals were not. These data suggest that ad libitum feeding (nibble eating) may be beneficial in the management of feline struvite urolithiasis by reducing the magnitude of the post prandial alkaline tide. It also supports the suggestion that struvite crystal formation is largely a function of urinary pH.  相似文献   

6.
Eight cats were fed a dry commercial cat food and after six months developed urinary struvite crystalluria with alkaline urine. The animals were subsequently divided into two groups and fed either a dry or a canned struvite calculolytic diet. The crystalluria was reduced after five to six weeks with both treatment diets. Decreased crystalluria coincided with a reduction in urinary pH and an increased titratable acidity. The highest food acid load, determined by the lowest undetermined anion, was found with the dry diet and resulted in the highest renal hydrogen excretion, measured as net acid excretion.  相似文献   

7.
Etiopathogenesis of canine struvite urolithiasis   总被引：1，自引：0，他引：1  
Urine must be oversaturated with magnesium ammonium phosphate for struvite uroliths to form. Oversaturation of urine with magnesium ammonium phosphate may be associated with several factors, including urinary tract infections with urease-producing microbes, alkaline urine, diet, and genetic predisposition. Of the urease-producing microbes, staphylococci are most struvitogenic in dogs. The precise mechanisms resulting in formation of sterile struvite uroliths in dogs have not been determined.  相似文献   

8.
OBJECTIVE: To evaluate the effects of a high-protein diet versus dietary supplementation with ammonium chloride (NH4Cl) on struvite crystal formation in the urine of clinically normal cats by measuring the urine concentration of hydrochloric acid (HCl)-insoluble sediment, urine pH, struvite activity product (SAP), number of struvite crystals in urine, and urine volume. ANIMALS: 23 healthy adult cats. PROCEDURE: Urine was fractionated by centrifugation with subsequent extraction of the sediment with 1 N HCl (study 1). Diets containing either 29% crude protein or 55% crude protein were fed to cats in a crossover trial of 3 weeks/period (study 2). Diets supplemented with either sodium chloride (NaCl) or NH4Cl were fed, by use of a 3 x 3 Latin-square design with 3 wk/period (study 3). In studies 2 and 3, urine samples were collected for the last 7 days of each period. RESULTS: The HCl-insoluble sediment contained Tamm-Horsfall glycoprotein (THP; study 1). The high-protein diet (study 2) and dietary supplementation with NH4Cl (study 3) resulted in a decrease in urine pH, SAP, and the number of struvite crystals in urine. However, the high-protein diet decreased urine concentrations of HCl-insoluble sediment containing THP (study 2), in contrast to the NH4Cl supplementation that increased urine volume without a significant effect on the urine concentration of the HCl-insoluble sediment (study 3). CONCLUSIONS AND CLINICAL RELEVANCE: Our results indicate that compared with dietary supplementation with NH4Cl, the high-protein diet is preferable as a urine acidifier for the prevention of struvite crystal formation in clinically normal cats.  相似文献   

9.
OBJECTIVE: To evaluate effects of dietary carbohydrate on urine volume; struvite crystal formation; and calcium, phosphorus, and magnesium balance in clinically normal cats. ANIMALS: 21 healthy adult cats (15 sexually intact males and 6 sexually intact females). PROCEDURE: Diets containing no carbohydrate source (control diet), control plus starch, or control plus fiber were given in a 3 X 3 Latin-square design. The diets were available ad libitum in study 1 (n = 12) and given under restrictions in study 2 (9) to equalize daily intakes of crude protein among the 3 groups. Formation of struvite crystals and balance of calcium, phosphorus, and magnesium were measured. RESULTS: Urine volume was lower in the starch group and fiber group in study 1, whereas no differences were detected among the groups in study 2. Urinary pH and struvite activity product were higher in the starch group in both studies, and the fiber group also had higher struvite activity product in study 2. In both studies, urinary concentrations of HCl-insoluble sediment were higher in the starch group and fiber group. In the fiber group, a net loss of body calcium, phosphorus, and magnesium was detected in study 2. CONCLUSIONS AND CLINICAL RELEVANCE: Starch and fiber in diets potentially stimulate formation of struvite crystals. Hence, reducing dietary carbohydrate is desirable to prevent struvite urolith formation. In addition, a net loss of body calcium, phosphorus, and magnesium during feeding of the fiber diet suggests that dietary inclusion of insoluble fiber could increase macromineral requirements of cats.  相似文献   

10.
A diet providing less than 20 mg of magnesium per 100 kcal that maintains urine pH near 6.0 3 to 5 hours after eating, or a diet providing this amount fo magnesium (see Table 2) with 1 gm of ammonium chloride or 1.5 gm of dl-methionine added daily, should be fed for 1 to 3 months to dissolve struvite uroliths (see Fig. 1). The low-magnesium diet should be fed indefinitely to prevent recurrence, because struvite urolithiasis and all of its effects (hematuria, pollakiuria, and/or complete to partial obstruction to urinary excretion) recurs repeatedly in cats that have previously experienced the condition if they are returned to regular cat food. In contrast, if a diet low in magnesium is fed, recurrence is uncommon. For cats that have never been affected, feeding a low-magnesium ration is unnecessary. For all cats, the following measures are recommended: encourage exercise, allow frequent urination, prevent obesity, decrease confinement, keep the litter box clean, and always have palatable water readily available.  相似文献   

11.
A large radiodense calculus in the left renal pelvis of a 22-month-old, male Great Dane disappeared one month following surgical removal of two struvite (magnesium ammonium phosphate) calculi from the right renal pelvis. The dog's urine likely became undersaturated with struvite for a sufficient period to permit dissolution of the renal calculus. Several factors may have contributed to the decrease in urine struvite concentration, including eradication of a urease-producing Proteus sp from the urinary tract and induction of polydipsia and compensatory polyuria by oral administration of sodium chloride.  相似文献   

12.
OBJECTIVE: To compare the nutritional value of corn gluten meal (CGM) and meat meal (MM) as a dietary source of protein in dry food formulated for adult cats. ANIMALS: 8 healthy adult cats (4 males and 4 females). PROCEDURE: Diets containing CGM or MM as the main protein source were each fed for a 3-week period in a crossover study. Digestibility and nutritional balance experiments were conducted during the last 7 days of each period. Furthermore, freshly voided urine was obtained to measure urinary pH, struvite crystals, and sediment concentrations. RESULTS: Daily food intake and dry-matter digestibility were significantly higher for the MM diet. Fecal moisture content also was higher for the MM diet. Apparent nitrogen (N) absorption and N retention were higher for the MM diet, even when values were expressed as a percentage to account for differences in N intake. Urinary pH, struvite activity product, number of struvite crystals in urine, and urinary sediment concentrations were not different between diets. Retention of calcium, phosphorus, and magnesium was lower for the CGM diet, and cats lost body calcium and magnesium when fed the CGM diet. CONCLUSIONS AND CLINICAL RELEVANCE: Meat meal was superior to CGM as a protein source in dry foods formulated for cats, because dry-matter digestibility and N utilization were higher for the MM diet. In addition, net loss of body calcium and magnesium for the CGM diet suggests that mineral requirements increase when CGM is used as a protein source.  相似文献   

13.
OBJECTIVE: To assess the effect of dietary potassium citrate supplementation on the urinary pH, relative supersaturation of calcium oxalate and struvite (defined as the activity product/solubility product of the substance), and concentrations of magnesium, ammonium, phosphate, citrate, calcium, and oxalate in dogs. ANIMALS: 12 healthy adult dogs. PROCEDURE: Canned dog food was fed to dogs for 37 days. Dogs were randomly allocated to 3 groups and fed test diets for a period of 8 days. Study periods were separated by 6-day intervals. During each study period the dogs were fed either standard diet solus (control) or standard diet plus 1 of 2 types of potassium citrate supplements (150 mg potassium citrate/kg of body weight/d) twice daily. Urinary pH, volume and specific gravity, relative supersaturation of calcium oxalate and struvite, and concentrations of magnesium, ammonium, phosphate, calcium, oxalate, and citrate were assessed for each treatment. RESULTS: Mean urine pH was not significantly affected by dietary potassium citrate supplementation, although urine pH did increase by 0.2 pH units with supplementation. Diets containing potassium citrate maintained a higher urine pH for a longer part of the day than control diet. Three Miniature Schnauzers had a significantly lower urinary relative calcium oxalate supersaturation when fed a diet supplemented with potassium citrate, compared with control diet. CONCLUSIONS AND CLINICAL RELEVANCE: Dietary potassium citrate supplementation has limited effects on urinary variables in most healthy dogs, although supplementation results in maintenance of a higher urine pH later in the day. Consequently, if supplementation is introduced, dogs should be fed twice daily and potassium citrate should be given with both meals or with the evening meal only.  相似文献   

14.
Effect of diet on struvite activity product in feline urine   总被引：2，自引：0，他引：2  
Groups of male specific-pathogen-free cats were fed a basal, purified diet (A), with or without 0.45% added magnesium (MgCl2, diet B; MgO, diet C) or 1 of 2 commercial diets (D,E). Urine samples collected for 48 hours after 2 weeks of feeding were analyzed for calcium, magnesium, sodium, potassium, ammonium, sulfate, phosphate, oxalate, and citrate content. Concentrations were used to calculate the negative logarithm of the struvite activity product (pSAP), using a microcomputer-based program for calculation of supersaturation of the urine with crystal solutes. The pSAP value for all samples also was hand-calculated by use of an equation. Consumption of diet B caused a significant (P less than 0.05) increase in urine calcium concentration. Total urine phosphate concentration was lower in urine from cats fed diets A, B, or C than in urine from cats fed diets D or E. For the various diets, urine PO4(-3) was: 5.3 microM for diet A; 6.3 microM for diet C; 0.9 microM for diet E; 36 nM for diet D, and 0.5 nM for diet B. Consumption of diets B and C caused significant increases in urine magnesium concentration (53.1 nM and 49.1 mM, respectively). Ammonium ion concentration was highest in urine from cats fed diets B and D, 116.2 mM and 100.3 mM, respectively. When the pSAP, hand-calculated assuming ionic strength u = 0.2, was regressed on that calculated by use of the microcomputer program, the coefficient of determination was 0.96 (P less than or equal to 0.01).  相似文献   

15.
Thirteen adult cats were each fed consecutively five test diets: firstly a complete canned diet, and then four commercially available dry cat diets (New Formula Biscats, Cat Chow, Go-Cat and Whiskettes) for 7,13, 5, 4 and 4 weeks respectively. Urine samples were tested for pH and presence of struvite crystals. Body weight was recorded weekly. Urine pH was ranked from acid to alkaline as follows: Whiskettes (pH 5.8), canned diet (pH 5.9), Biscats (pH 6.1), Cat Chow (pH 6.45) and Go-Cat (pH 6.5). The pH of urine when cats were fed Whiskettes, Biscats and canned diet was not significantly different. Biscats produced a urine pH significantly higher than Whiskettes but, in each case, these three diets produced a significantly lower urine pH than Cat Chow and Go-Cat. Struvite crystals occurred spontaneously in 9% of urine samples from cats when fed Whiskettes and Biscats, 71% when fed Cat Chow and 38% when fed Go-Cat: spontaneous struvite was not seen in any cat fed CX9. Haematuria was seen in 2.9% (2/69) urine samples from cats fed Cat Chow. One tom cat had a blocked urethra after 24 days on Go-Cat. No abnormalities were observed in any cat when fed canned diet, Biscats or Whiskettes. It was concluded that of the four dry cat diets tested only Biscats and Whiskettes produce urine with an acceptably low rate of spontaneous struvite crystalluria.  相似文献   

16.
Thirteen adult cats were each fed consecutively five test diets: firstly a complete canned diet, and then four commercially available dry cat diets (New Formula Biscats, Cat Chow, Go-Cat and Whiskettes) for 7,13, 5, 4 and 4 weeks respectively. Urine samples were tested for pH and presence of struvite crystals. Body weight was recorded weekly.

Urine pH was ranked from acid to alkaline as follows: Whiskettes (pH 5.8), canned diet (pH 5.9), Biscats (pH 6.1), Cat Chow (pH 6.45) and Go-Cat (pH 6.5). The pH of urine when cats were fed Whiskettes, Biscats and canned diet was not significantly different. Biscats produced a urine pH significantly higher than Whiskettes but, in each case, these three diets produced a significantly lower urine pH than Cat Chow and Go-Cat. Struvite crystals occurred spontaneously in 9% of urine samples from cats when fed Whiskettes and Biscats, 71% when fed Cat Chow and 38% when fed Go-Cat: spontaneous struvite was not seen in any cat fed CX9. Haematuria was seen in 2.9% (2/69) urine samples from cats fed Cat Chow. One tom cat had a blocked urethra after 24 days on Go-Cat. No abnormalities were observed in any cat when fed canned diet, Biscats or Whiskettes.

It was concluded that of the four dry cat diets tested only Biscats and Whiskettes produce urine with an acceptably low rate of spontaneous struvite crystalluria.  相似文献   

17.
The effect of high intake of Mg on urolithiasis was compared with high intake of P and K in goats being fed with a cottonseed meal and rice straw diet. Eighteen wether goats were randomly allocated into group A, B and C evenly and fed with cottonseed meal and rice straw diet for three months. From day 60 onwards, KH2PO4 and K2HPO4 were provided via drinking water to goats in group B to increase the intake of P, K, and MgO to goats in group C to increase the intake of Mg. Blood and urine samples were collected to analyze the concentration of P, K, Mg and Ca, and the activity product (AP) of potassium magnesium phosphate (MKP) in urine was also calculated. The composition of calculi and urinary sedimentary crystals were examined by chemical qualitative analysis, X-ray diffraction, X-ray energy dispersive spectrometry and Fourier transform infrared spectroscopy. The results showed that the incidence of urolithiasis in group C (6/6) was higher than that in group A (1/6) and B (1/6) (P < 0.05). The calculi were mainly composed of magnesium ammonium phosphate (MAP) and partly composed of MKP. MKP presented in crystals of different phases in this experiment. The high intake of Mg contributed to a significant increase of plasma Mg, but additional P, K did not cause a further increase of plasma P, K. Urine P, K, Mg and Ca and AP of MKP in group C decreased significantly after the onset of urolithiasis. In conclusion, high intake of Mg was more important in inducing struvite calculi compared with high intake of K and P in goats under these feeding conditions. Cottonseed meal and rice straw with additional Mg is a good dietary model for inducing struvite calculi in castrated goats.  相似文献   

18.
The incidence of urolithiasis in cats is 0.6 per cent. A total of 41 calculi were subjected to epidemiological and analytical investigation. Calculus formation is most frequent in male castrates and occurs exclusively in the bladder and urethra. Eighty per cent of the animals under investigation were overweight and the same percentage required surgical or instrumental treatment. Thirty-seven per cent of the calculi were recurrent, but only 22 per cent were accompanied by an infection. A predisposition due to diet (dry food/tinned food) was not established. Over 75 per cent of the calculi which were analysed consisted of struvite, the formation of which is promoted by an increased pH-value, as well as by a high level of magnesium and phosphate in the urine. The crystalline structure of the calculi indicates a slow growth rate not influenced by an acute infection. The genesis of struvite urolithiasis in cats, as well as measures to prevent its recurrence, are explained.  相似文献   

19.
The nutritional value of meat meal (MM), chicken meal (CM), and corn gluten meal (CGM) as dietary sources of protein in dry food formulated for adult cats was evaluated. Twelve healthy adult cats (11 males and 1 female) were used. Dry diets containing MM, CM, or CGM as the main protein source were given for a 3-week period in a 3 x 3 Latin-square design. Digestion and balance experiments were conducted during the last 7 d of each period. In addition, freshly voided urine was taken to determine urinary pH and number of struvite crystals. As compared with the CM diet, dry-matter digestibility was higher and lower for the MM and CGM groups, respectively. Percentages of nitrogen (N) absorption and N retention to N intake were higher in the MM group, and N utilization was not different between the CM group and the CGM group. All cats excreted alkaline urine (pH > 7). Urinary pH, struvite activity product, and number of struvite crystals in urine were lower for the CGM group. There was no difference in retention of calcium and magnesium among the groups. From the point of view of digestibility and N utilization, MM is superior to CGM, and CM is better than or equivalent to CGM as a protein source of dry foods for adult cats. However, when CM is used as a dietary protein source, some manipulation of dietary base excess may be needed to control urinary acid-base balance, because CM contains higher calcium and phosphorus.  相似文献   

20.
Feline idiopathic cystitis (FIC) is the most common cause of feline lower urinary tract disease (FLUTD). This retrospective, case-controlled study evaluated possible risk factors associated with FIC and compared different clinical presentations in 64 cats with FIC. Several risk factors known to be involved in FLUTD were identified as playing a role in FIC. Of the stressful situations considered, most did not occur with increased frequency in cats with FIC compared to controls, except for a house move. The presence of pyuria, haematuria and an increased urine protein:creatinine ratio were significantly higher in obstructed males compared with non-obstructed males. An obstruction was significantly more likely in cats with struvite crystalluria compared with cats without struvite crystalluria. These findings suggest that urethral plugs might be an important cause or contributing factor of obstruction in FIC. Episodes of FIC seem to occur mainly in susceptible cats in combination with a deficient environment.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号