Diet and Renal Failure
JOSEF L. LEIBETSEDER2 ANDKLAUS W. NEÃœFELD Institute of Nutrition, University of Veterinary Medicine, Vienna, Austria In addition maintaining metabolic balance of cal cium, magnesium, sodium and potassium by manip ulation of dietary concentration, reduction of phos phorus intake to maintain normal serum phosphorus concentration is considered important to inhibit or re tard CRF progression (2, 3). The practice of reducing dietary protein is controversial. Experimental and clinical studies have revealed beneficial as well as ad verse effects of low protein diets (4-6). Most of the findings were obtained by experimentally induced CRF and may be criticized with regard to their applicability to spontaneous CRF. Therefore a clinical study was conducted to monitor effects of two medium protein diets with low phos phorus content.
ABSTRACT To study dietary management of chronic renal failure (CRF), 1600 dogs older than 5 y were screened for serum urea and serum creatinine concen tration. Three hundred fifty-eight dogs (22.4%) showed values above normal (6.67 mmol/L of serum urea, 88.4 ¿tmol/Lof serum creatinine). Sixty of these dogs with slight or moderate clinical signs of CRF, at least polyuria, were selected for the study. Thirty-two dogs were fed a commercial canned medium protein diet (MPD) [27% protein, 0.36% phosphorus in dry matter (DM)] and 28 dogs were fed a homemade diet (HMD; 21.5% protein, 0.38% phosphorus in DM). Dogs were reevaluated for clinical status, blood chemistry profile (urea, creatinine, total protein, calcium and phosphorus) and urinalysis at 9 intervals over 28 wk. In general, palatability of both diets was high and dogs maintained their body weight. Nevertheless eight dogs of the MPD and six dogs of the HMD group died or had to be killed during the study. In surviving dogs, serum urea, cre atinine, phosphorus and [P X Ca] were significantly re duced nearly to the normal range after 4 wk. A slight increase at the end of the study occurred because clients did not adhere strictly to dietary instruction after re covery of the dogs. These results suggest that elderly dogs frequently show a mild or moderate CRF, and dietary treatment with medium protein and low phos phorus diets is effective in improving blood chemistry data as well as physical condition of those dogs. J. Nutr. 121: S145-S149, 1991.
MATERIALS
In a clinical study 1600 dogs older than 5 y admitted to the Medical Clinic of the University of Veterinary Medicine Vienna for various reasons were screened >12 h postprandially for serum urea and creatinine concentrations. Dogs with >6.67 mmol/L of serum urea and 88.4 fimol/L of serum creatinine were con sidered to be suspicious of CRF (7). Three hundred fifty-eight dogs (22.4%) showed levels above these limits. Dogs were reevaluated 1 wk after the first ex amination to confirm elevated levels. After clinical in vestigation pre- and postrenal azotemic dogs were ex cluded, and those with slight or moderate clinical signs of CRF (i.e., polyuria, polydipsia, dehydration, dull hair coat, offensive breath, lethargy) whose owners
INDEXING KEY WORDS:
•symposium •dogs •protein •diet •chronic renal failure
AND METHODS
phosphorus
Although chronic renal failure (CRF) is frequently diagnosed in dogs, slight cases of CRF probably occur more often without being detected because clinical signs do not appear until a substantial proportion of nephrons is nonfunctional (1). It is generally believed that existing renal damage of CRF is irreversible and that CRF is a progressive disease. The goal of dietary management is to minimize adverse nutritional and metabolic effects, to retain renal function and to slow down the CRF progression (1).
1Presented as part of the Waltham International Symposium on Nutrition of Small Companion Animals, at University of California, Davis, CA 95616, on September 4-8, 1990. Guest editors for the symposium were James G. Morris, D'Ann C. Finley and Quinton R. Rogers. *To whom correspondence should he addressed: Institute of Nutrition, University of Veterinary Medicine, Linke Bahngasse 11, A-1030 Vienna, Austria.
0022-3166/91 S3.00 ©1991 American Institute of Nutrition.
S145
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Effects of Medium Protein Diets in Dogs with Chronic Renal Failure1
LEIBETSEDER AND NEUFELD
S146 TABLE 1 Main components of diets1 CMP
TABLE 3 Breeds of dogs
HMD Pasta
Breed
CMP
Mongrel German Shepherd Poodle
Rice Meat (chicken, beef) Butter Corn oil
Plus one patient each of Barsoi, Belgian Shepherd, Cairn Terrier, Dachshund, Doberman, Irish Setter, King Charles, Schnauzer, Shi-Tzu, Pomeranian, Welsh Terrier, Yorkshire Terrier
CaCo3
Total
1 CMP, Canine Medium Protein Diet (Waltham); HMD, home made diet.
were willing to cooperate were selected. Eighty-two dogs were available for the study and 60 dogs partic ipated. Twenty-two dogs did not participate because 13 owners subsequently decided not to participate, five dogs had to be euthanized immediately due to pro gression of CRF and four dogs had to be excluded be cause of additional hepatic pathology. Thirty-two dogs were fed three times a day ad li bitum a canned prescription canine medium protein diet [(CMP) Waltham, United Kingdom] and 28 dogs were fed a homemade diet (HMD) prepared by the owners following recipes of the Medical Clinic (Tables 1 and 2). For ethical reasons (Austrian law for preven tion of cruelty to animals) it was not possible to include an untreated control group in this study. Breed, gender, age and body weight of the dogs are listed in Tables 3 and 4, respectively. Table 5 gives the history of pre vious diet, which indicates dogs had a high protein and phosphorus intake before the beginning of the study. Dogs were reevaluated at 1,2 and 4 wk after starting the diets and every 4 wk for 28 wk. Initial and recheck
TABLE
2
Average content of nutrients and digestible energy (DE) in dry matter ¡DM) of diets1 Nutrient
CMP
Dry dietProtein, matter, g/kg g/kgEther g/kgFiber, extracts, g/kgN-free g/kgCalcium, extracts, g/kgPhosphorus, g/kgSodium, g/kgDE, Mi/kgDE,
32
HMDTotalMongrelGerman (Bracke),Collie, Hound ShepherdSpanielDachshundSchnauzerPomeranian76322228Boxer, Leonberger,Poodle, Rottweiler
1Abbreviations
as in Table 1.
examinations consisted of history, physical examina tion, findings, complete blood cell count, blood chem istry profile (urea, creatinine, total protein, calcium, phosphorus) and urinalysis. Statistical analysis was performed by Student's paired t test. At each interval the value for each in dividual dog was compared to the respective value at the beginning of the study.
RESULTS
Of the 60 dogs in the study 8 dogs of the CMP group and 6 dogs of the HMD group died or were euthanized at the owner's request. The cause of death or euthana sia was mainly the deterioration of CRF. Detailed in formation on these dogs is given in Table 6. Six dog owners of the CMP group and five owners of the HMD group terminated cooperation before the end of the study because of the improvement of the physical condition of their dogs and could not be per suaded to continue examinations.
HMD
TABLE 4 Gender, age and body weight of dogs1 CMP nMaleFemaleAge, Gender,
Meal/kgProtein/energy,
yBody 4.21(9.25)21.58 ± g/MJProtein/energy, g/Mcal289.7271.5338.28.0311.913.53.63.324.085.7511.2749.22300.0215.0216.315.0483.512.83.83.521.135.0510.1842.37 weight, kg2399.23 ±12.352089.11 Abbreviations
HMD
as in Table 1.
' Values are means ±SD; median in parentheses.
3.71(10.00)24.61 ± ±13.71
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Poultry trimmings Lung Pig stomach Rice Liver Chicken fat Minerals Vitamins
Group
MEDIUM PROTEIN DIETS IN CANINE RENAL FAILURE
S147
mmol / L
TABLE S Nutrition history of dogs1
1918CMP
HMD
6 9 8 4
6 11 4 3 2
4 — 1
17 16 14 12H 10 86420-
2
1Values are number of dogs fed each food before the study. Ab breviations
012
4
8
as in Table 1.
Changes in the concentrations of various serum constituents are shown in Figures 1-6. Serum urea (Fig. 1), serum creatinine (Fig. 2) and serum phospho rus (Fig. 4) concentrations were significantly decreased 4 wk after the beginning of the study and remained significantly decreased over the course of the study in the CMP group, whereas in the HMD group significant differences occurred only at 4, 8 and 28 wk for serum urea and at 4 wk for serum creatinine. This difference as well as the slight increase of serum values in general towards the end of the study might be due to decreased client compliance in feeding the dog only the pre-
12 , 16 weeks
20
24
28
FIGURE 1 Mean (and standard deviation) serum urea concentration of dogs fed CMP diet (•) or HMD (O). Each mean is compared with that at week 0 for the respective diet ('P < 0.05, **P < 0.01, ***P< 0.001). At week 0 there were 32 dogs in group CMP and 28 in group HMD. As explained in the text and Table 6, at week 28 there were 18 dogs in group CMP and 17 in group HMD.
scribed diet. Although clients had to record daily the type and amount of diet fed, some did not adhere strictly to dietary instructions, especially in the HMD group. This was obviously prevalent after recovery of the dogs. The increase of serum values was not accom-
TABLEÕ Data of dogs that died or were euthanized during the study findings2Cause
DogGroup BreedSex
of AgeLaboratorydeath1
Last check before death
BU
SC
SGClinical
signs3
mmol/L CMP
MongrelMongrelMongrelMongrelMongrelBelgian
anorexiaPolyuria, vomitingNonePolyuria, polydipsia,anorexiaPolyuria, deteriorationof rapid conditionPolyuria, physical anorexiaNocturia, physicalconditionVomiting, poor
ShepherdPoodleShi-TzuHMD
diarrheaPolyuria, SpanielMongrelBoxerSchnauzerSpanielMongrelMMMFMMMFFMMMMM151514.51413139.57.510.588141211CRFEE£EEECRFEpilepsyAcute anorexiaPolyuria polydipsia, othersignsSlight improved, no
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Meat Meat and supplements (pasta, cereals) Meat and dry dog food (flakes, extruded food) Meat, supplements, and commercial food Complete food (flakes, extruded food) Canned food Canned food and supplements Others (human food)
20-
ofappetite, polyuria, lack congestiveheart signsNocturia,no other failureEEE6011400212421135298475179482771946939020618422523811777443532415530224310686691.0151 deteriorationVomiting, rapid anorexiaPoor condition,anorexia physical 1E, euthanasia at owner's request; CRF, chronic renal failure. JAt last check; BU, blood urea concentration; tration; SG, specific gravity of urine. 3At last check; other abbreviations as in Table 1.
SC, serum creatinine concen
LEIBETSEDER AND NEUFELD
S148
mmol / L 3**
**
1** 012
12 16 weeks
4
20
24
28
O0124
12 16 weeks
20
24
28
FIGURE 2 Mean (and standard deviation) serum creatinine concentration of dogs fed CMP diet (•), or HMD (O). Each mean is compared with that at week 0 for the respective diet (*P < 0.05, **P < 0.01, ***P < 0.001). At week 0 there were 32 dogs in group CMP and 28 in group HMD. As ex plained in the text and Table 6, at week 28 there were 18 dogs in group CMP and 17 in group HMD.
panied by impairment of the physical condition and behavior of the dogs, except in the dogs that died. In concert with the changes in the laboratory data the physical condition of surviving dogs was not im paired or it was somewhat improved, which was in accordance with the subjective opinion of the owners about the recovery of their dogs. The palatability of both diets was satisfactory (Ta ble 7). Consequently surviving dogs were able to maintain their body weight. DISCUSSION As in other long-term clinical studies (8), it was dif ficult to convince clients to feed exclusively the premmol / L
FIGURE 4 Mean (and standard deviation) serum phos phorus concentration of dogs fed CMP diet (•) or HMD (O). Each mean is compared with that at week 0 for the respective diet (*P < 0.05, **P < 0.01, ***P< 0.001). At week 0 there were 32 dogs in group CMP and 28 in group HMD. As ex plained in the text and Table 6, at week 28 there were 18 dogs in group CMP and 17 in group HMD.
scribed diet. Changes of the blood chemistry findings indicate that some of the dog owners did not follow strictly the directions. The food used before the study could not be ana lyzed, but estimating the nutrient content gave high protein and phosphorus values of ~40% and 0.8% in dry matter, respectively. The decrease in serum urea concentration may have been caused, at least to some extent, by reduced protein intake. The moderate pro tein restriction in dogs fed either diet is adequate to meet the minimum requirement of 2.0-2.5 g/kg BW075 of good quality digestible protein (9). The maintenance of body weight and total serum protein are consistent with a sufficient protein supply. mmol / L 10 987-
3-
**
6-
**
52-
**
43-
**
2-
1-
***
1012 0124
12
16
20
24
28
4
***
***
**
12 16 weeks
**
**
20
24
***
28
weeks
FIGURE 3 Mean (and standard deviation) serum calcium concentration of dogs fed CMP diet (•) or HMD (O). Each mean is compared with that at week 0 for the respective diet (*P < 0.05, **P < 0.01, **«P < 0.001). At week 0 there were 32 dogs in group CMP and 28 in group HMD. As explained in the text and Table 6, at week 28 there were 18 dogs in group CMP and 17 in group HMD.
FIGURE 5 Mean (and standard deviation) product of serum calcium X phosphorus concentrations of dogs fed CMP diet (•) or HMD (O).Each mean is compared with that at week 0 for the respective diet (*P< 0.05, **P < 0.01, ***P < 0.001). At week 0 there were 32 dogs in group CMP and 28 in group HMD. As explained in the text and Table 6, at week 28 there were 18 dogs in group CMP and 17 in group HMD.
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2-
MEDIUM PROTEIN DIETS IN CANINE RENAL FAILURE
i80g
^^rT T J 60-40-20-LSJï
T 1 —
ï i i iiii
TABLE 7 Palatability
of diets1
Palatability
CMP
HMD
Poor Medium Good
3 5 24
1 2 25
Values are no. of dogs; abbreviations
LITERATURE
as in Table 1.
CITED
1. POLZIN, D. J. & OSBORNE,C. A. (1986) Dietary management of canine renal failure. In: Nephrology and Urology. (Breitschwerdt, E. B., éd.), pp. 152-153, Livingstone, New York, NY. 2. IBELS,L. S., ALFREY,A. C., HAUT, L. &. HOFFER,W. E. (1978) Preservation of function in experimental renal disease by dietary restriction of phosphate. N. EngJ. /. Med, 298: 122-126. 3. Ross, L. A., FINCO, D. R. &. CROWELL,W. A. (1982) Effect of dietary phosphorus restriction on the kidneys of cats with re duced renal mass. Am. /. Vet. Res. 43: 1023-1026. 4. POLZIN, D. J., LEININGER, J. L. & OSBORNE, C. A. (1988) Chronic, progressive renal failure: can progression be modified? In: Renal Disease in Dogs and Cats. Comparative and Clinical Aspects. (Micheli, A. R., éd.),pp. 129-144, Blackwell Scientific Publications, Oxford, United Kingdom. 5. KRONFELD,D. S. (1983) Geriatric diets for dogs. Comp. Coni. Ed. Pract. Vet. 5: 136-142. 6. BOVÉE, K. C. & KRONFELD,D. S. (1981) Reduction of renal hemodynamics in uremie dogs fed reduced protein diets. /. Am. Vet. Med. Assoc. 17: 277-285. 7. LEWIS,L. D., MORRIS, M. L., JR. &. HAND, M. S. (1987) Small Animal Clinical Nutrition, 3rd éd.pp. 8/18-19, Mark Morris Assoc., Topeka, KS. 8. BARSANTI,J. A. & FINCO, D. R. (1985) Dietary management of chronic renal failure in dogs. /. Am. Anim. Hosp. Assoc. 21: 371-376.
012
4
12 16 weeks
20
24
28
FIGURE 6 Mean (and standard deviation) serum protein concentration of dogs fed CMP diet (•) or HMD (O). Each mean is compared with that at week 0 for the respective diet (*P < 0.05, "P < 0.01, *"P < 0.001). At week 0 there were 32 dogs in group CMP and 28 in group HMD. As explained in the text and Table 6, at week 28 there were 18 dogs in group CMP and 17 in group HMD.
9. AUSSCHUßFÜRBEDARFSNORMENDERGESELLSCHAFT FÜRERNÄH RUNGSPHYSIOLOGIE (1989) Energie- und Nährstoffbedarf/En ergy and nutrient requirements, Nr. 5, Hunde/dogs. pp. 43-55, DLG Verlag, Frankfurt (Main), Germany. 10. POLZIN, D. J., OSBORNE, C. A., STEVENS,J. B. & HAYDEN, D.W. (1982) Influence of modified protein diets on electrolyte, acid base, and divalent ion balance in dogs with experimentally induced chronic renal failure. Am. J. Vet. Res. 43: 1978-1986. 11. MASSRY,S. G. (1980) Requirements of vitamin D metabolites in patients with renal disease. Am. /. Clin. Nutr. 33: 1530-1535.
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In contrast to others (8) a significant reduction of serum phosphorus concentration was observed in this study. A dietary effect on serum phosphorus concen tration has also been demonstrated in dogs with ex perimentally induced CRF (10). Serum calcium con centration was always in the normal range. Due to the decrease of serum phosphorus concentration, serum [Ca x P] was reduced below the solubility product (11), which is important to avoid nephrocalcinosis. The concomitant decrease in serum creatinine con centration was unexpected. A possible explanation of this improvement of renal function might be the early stage of CRF with only mild renal dysfunction in most of the dogs whose kidneys were still capable of com pensatory processes. In conclusion, the results of the present study sug gest that elderly dogs show a mild or moderate CRF more frequently than is clinically diagnosed. In these dogs, blood chemistry parameters relevant to CRF and urinalysis should be determined to detect renal failure at an early stage. In mild and moderate cases of CRF, dietary treatment with medium protein and low phos phorus diets was effective in improving laboratory data as well as the clinical consequences of CRF, allowed a good quality of life and can be recommended for those dogs.
S149
JOSEF L. LEIBETSEDER2 ANDKLAUS W. NEÃœFELD Institute of Nutrition, University of Veterinary Medicine, Vienna, Austria In addition maintaining metabolic balance of cal cium, magnesium, sodium and potassium by manip ulation of dietary concentration, reduction of phos phorus intake to maintain normal serum phosphorus concentration is considered important to inhibit or re tard CRF progression (2, 3). The practice of reducing dietary protein is controversial. Experimental and clinical studies have revealed beneficial as well as ad verse effects of low protein diets (4-6). Most of the findings were obtained by experimentally induced CRF and may be criticized with regard to their applicability to spontaneous CRF. Therefore a clinical study was conducted to monitor effects of two medium protein diets with low phos phorus content.
ABSTRACT To study dietary management of chronic renal failure (CRF), 1600 dogs older than 5 y were screened for serum urea and serum creatinine concen tration. Three hundred fifty-eight dogs (22.4%) showed values above normal (6.67 mmol/L of serum urea, 88.4 ¿tmol/Lof serum creatinine). Sixty of these dogs with slight or moderate clinical signs of CRF, at least polyuria, were selected for the study. Thirty-two dogs were fed a commercial canned medium protein diet (MPD) [27% protein, 0.36% phosphorus in dry matter (DM)] and 28 dogs were fed a homemade diet (HMD; 21.5% protein, 0.38% phosphorus in DM). Dogs were reevaluated for clinical status, blood chemistry profile (urea, creatinine, total protein, calcium and phosphorus) and urinalysis at 9 intervals over 28 wk. In general, palatability of both diets was high and dogs maintained their body weight. Nevertheless eight dogs of the MPD and six dogs of the HMD group died or had to be killed during the study. In surviving dogs, serum urea, cre atinine, phosphorus and [P X Ca] were significantly re duced nearly to the normal range after 4 wk. A slight increase at the end of the study occurred because clients did not adhere strictly to dietary instruction after re covery of the dogs. These results suggest that elderly dogs frequently show a mild or moderate CRF, and dietary treatment with medium protein and low phos phorus diets is effective in improving blood chemistry data as well as physical condition of those dogs. J. Nutr. 121: S145-S149, 1991.
MATERIALS
In a clinical study 1600 dogs older than 5 y admitted to the Medical Clinic of the University of Veterinary Medicine Vienna for various reasons were screened >12 h postprandially for serum urea and creatinine concentrations. Dogs with >6.67 mmol/L of serum urea and 88.4 fimol/L of serum creatinine were con sidered to be suspicious of CRF (7). Three hundred fifty-eight dogs (22.4%) showed levels above these limits. Dogs were reevaluated 1 wk after the first ex amination to confirm elevated levels. After clinical in vestigation pre- and postrenal azotemic dogs were ex cluded, and those with slight or moderate clinical signs of CRF (i.e., polyuria, polydipsia, dehydration, dull hair coat, offensive breath, lethargy) whose owners
INDEXING KEY WORDS:
•symposium •dogs •protein •diet •chronic renal failure
AND METHODS
phosphorus
Although chronic renal failure (CRF) is frequently diagnosed in dogs, slight cases of CRF probably occur more often without being detected because clinical signs do not appear until a substantial proportion of nephrons is nonfunctional (1). It is generally believed that existing renal damage of CRF is irreversible and that CRF is a progressive disease. The goal of dietary management is to minimize adverse nutritional and metabolic effects, to retain renal function and to slow down the CRF progression (1).
1Presented as part of the Waltham International Symposium on Nutrition of Small Companion Animals, at University of California, Davis, CA 95616, on September 4-8, 1990. Guest editors for the symposium were James G. Morris, D'Ann C. Finley and Quinton R. Rogers. *To whom correspondence should he addressed: Institute of Nutrition, University of Veterinary Medicine, Linke Bahngasse 11, A-1030 Vienna, Austria.
0022-3166/91 S3.00 ©1991 American Institute of Nutrition.
S145
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Effects of Medium Protein Diets in Dogs with Chronic Renal Failure1
LEIBETSEDER AND NEUFELD
S146 TABLE 1 Main components of diets1 CMP
TABLE 3 Breeds of dogs
HMD Pasta
Breed
CMP
Mongrel German Shepherd Poodle
Rice Meat (chicken, beef) Butter Corn oil
Plus one patient each of Barsoi, Belgian Shepherd, Cairn Terrier, Dachshund, Doberman, Irish Setter, King Charles, Schnauzer, Shi-Tzu, Pomeranian, Welsh Terrier, Yorkshire Terrier
CaCo3
Total
1 CMP, Canine Medium Protein Diet (Waltham); HMD, home made diet.
were willing to cooperate were selected. Eighty-two dogs were available for the study and 60 dogs partic ipated. Twenty-two dogs did not participate because 13 owners subsequently decided not to participate, five dogs had to be euthanized immediately due to pro gression of CRF and four dogs had to be excluded be cause of additional hepatic pathology. Thirty-two dogs were fed three times a day ad li bitum a canned prescription canine medium protein diet [(CMP) Waltham, United Kingdom] and 28 dogs were fed a homemade diet (HMD) prepared by the owners following recipes of the Medical Clinic (Tables 1 and 2). For ethical reasons (Austrian law for preven tion of cruelty to animals) it was not possible to include an untreated control group in this study. Breed, gender, age and body weight of the dogs are listed in Tables 3 and 4, respectively. Table 5 gives the history of pre vious diet, which indicates dogs had a high protein and phosphorus intake before the beginning of the study. Dogs were reevaluated at 1,2 and 4 wk after starting the diets and every 4 wk for 28 wk. Initial and recheck
TABLE
2
Average content of nutrients and digestible energy (DE) in dry matter ¡DM) of diets1 Nutrient
CMP
Dry dietProtein, matter, g/kg g/kgEther g/kgFiber, extracts, g/kgN-free g/kgCalcium, extracts, g/kgPhosphorus, g/kgSodium, g/kgDE, Mi/kgDE,
32
HMDTotalMongrelGerman (Bracke),Collie, Hound ShepherdSpanielDachshundSchnauzerPomeranian76322228Boxer, Leonberger,Poodle, Rottweiler
1Abbreviations
as in Table 1.
examinations consisted of history, physical examina tion, findings, complete blood cell count, blood chem istry profile (urea, creatinine, total protein, calcium, phosphorus) and urinalysis. Statistical analysis was performed by Student's paired t test. At each interval the value for each in dividual dog was compared to the respective value at the beginning of the study.
RESULTS
Of the 60 dogs in the study 8 dogs of the CMP group and 6 dogs of the HMD group died or were euthanized at the owner's request. The cause of death or euthana sia was mainly the deterioration of CRF. Detailed in formation on these dogs is given in Table 6. Six dog owners of the CMP group and five owners of the HMD group terminated cooperation before the end of the study because of the improvement of the physical condition of their dogs and could not be per suaded to continue examinations.
HMD
TABLE 4 Gender, age and body weight of dogs1 CMP nMaleFemaleAge, Gender,
Meal/kgProtein/energy,
yBody 4.21(9.25)21.58 ± g/MJProtein/energy, g/Mcal289.7271.5338.28.0311.913.53.63.324.085.7511.2749.22300.0215.0216.315.0483.512.83.83.521.135.0510.1842.37 weight, kg2399.23 ±12.352089.11 Abbreviations
HMD
as in Table 1.
' Values are means ±SD; median in parentheses.
3.71(10.00)24.61 ± ±13.71
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Poultry trimmings Lung Pig stomach Rice Liver Chicken fat Minerals Vitamins
Group
MEDIUM PROTEIN DIETS IN CANINE RENAL FAILURE
S147
mmol / L
TABLE S Nutrition history of dogs1
1918CMP
HMD
6 9 8 4
6 11 4 3 2
4 — 1
17 16 14 12H 10 86420-
2
1Values are number of dogs fed each food before the study. Ab breviations
012
4
8
as in Table 1.
Changes in the concentrations of various serum constituents are shown in Figures 1-6. Serum urea (Fig. 1), serum creatinine (Fig. 2) and serum phospho rus (Fig. 4) concentrations were significantly decreased 4 wk after the beginning of the study and remained significantly decreased over the course of the study in the CMP group, whereas in the HMD group significant differences occurred only at 4, 8 and 28 wk for serum urea and at 4 wk for serum creatinine. This difference as well as the slight increase of serum values in general towards the end of the study might be due to decreased client compliance in feeding the dog only the pre-
12 , 16 weeks
20
24
28
FIGURE 1 Mean (and standard deviation) serum urea concentration of dogs fed CMP diet (•) or HMD (O). Each mean is compared with that at week 0 for the respective diet ('P < 0.05, **P < 0.01, ***P< 0.001). At week 0 there were 32 dogs in group CMP and 28 in group HMD. As explained in the text and Table 6, at week 28 there were 18 dogs in group CMP and 17 in group HMD.
scribed diet. Although clients had to record daily the type and amount of diet fed, some did not adhere strictly to dietary instructions, especially in the HMD group. This was obviously prevalent after recovery of the dogs. The increase of serum values was not accom-
TABLEÕ Data of dogs that died or were euthanized during the study findings2Cause
DogGroup BreedSex
of AgeLaboratorydeath1
Last check before death
BU
SC
SGClinical
signs3
mmol/L CMP
MongrelMongrelMongrelMongrelMongrelBelgian
anorexiaPolyuria, vomitingNonePolyuria, polydipsia,anorexiaPolyuria, deteriorationof rapid conditionPolyuria, physical anorexiaNocturia, physicalconditionVomiting, poor
ShepherdPoodleShi-TzuHMD
diarrheaPolyuria, SpanielMongrelBoxerSchnauzerSpanielMongrelMMMFMMMFFMMMMM151514.51413139.57.510.588141211CRFEE£EEECRFEpilepsyAcute anorexiaPolyuria polydipsia, othersignsSlight improved, no
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Meat Meat and supplements (pasta, cereals) Meat and dry dog food (flakes, extruded food) Meat, supplements, and commercial food Complete food (flakes, extruded food) Canned food Canned food and supplements Others (human food)
20-
ofappetite, polyuria, lack congestiveheart signsNocturia,no other failureEEE6011400212421135298475179482771946939020618422523811777443532415530224310686691.0151 deteriorationVomiting, rapid anorexiaPoor condition,anorexia physical 1E, euthanasia at owner's request; CRF, chronic renal failure. JAt last check; BU, blood urea concentration; tration; SG, specific gravity of urine. 3At last check; other abbreviations as in Table 1.
SC, serum creatinine concen
LEIBETSEDER AND NEUFELD
S148
mmol / L 3**
**
1** 012
12 16 weeks
4
20
24
28
O0124
12 16 weeks
20
24
28
FIGURE 2 Mean (and standard deviation) serum creatinine concentration of dogs fed CMP diet (•), or HMD (O). Each mean is compared with that at week 0 for the respective diet (*P < 0.05, **P < 0.01, ***P < 0.001). At week 0 there were 32 dogs in group CMP and 28 in group HMD. As ex plained in the text and Table 6, at week 28 there were 18 dogs in group CMP and 17 in group HMD.
panied by impairment of the physical condition and behavior of the dogs, except in the dogs that died. In concert with the changes in the laboratory data the physical condition of surviving dogs was not im paired or it was somewhat improved, which was in accordance with the subjective opinion of the owners about the recovery of their dogs. The palatability of both diets was satisfactory (Ta ble 7). Consequently surviving dogs were able to maintain their body weight. DISCUSSION As in other long-term clinical studies (8), it was dif ficult to convince clients to feed exclusively the premmol / L
FIGURE 4 Mean (and standard deviation) serum phos phorus concentration of dogs fed CMP diet (•) or HMD (O). Each mean is compared with that at week 0 for the respective diet (*P < 0.05, **P < 0.01, ***P< 0.001). At week 0 there were 32 dogs in group CMP and 28 in group HMD. As ex plained in the text and Table 6, at week 28 there were 18 dogs in group CMP and 17 in group HMD.
scribed diet. Changes of the blood chemistry findings indicate that some of the dog owners did not follow strictly the directions. The food used before the study could not be ana lyzed, but estimating the nutrient content gave high protein and phosphorus values of ~40% and 0.8% in dry matter, respectively. The decrease in serum urea concentration may have been caused, at least to some extent, by reduced protein intake. The moderate pro tein restriction in dogs fed either diet is adequate to meet the minimum requirement of 2.0-2.5 g/kg BW075 of good quality digestible protein (9). The maintenance of body weight and total serum protein are consistent with a sufficient protein supply. mmol / L 10 987-
3-
**
6-
**
52-
**
43-
**
2-
1-
***
1012 0124
12
16
20
24
28
4
***
***
**
12 16 weeks
**
**
20
24
***
28
weeks
FIGURE 3 Mean (and standard deviation) serum calcium concentration of dogs fed CMP diet (•) or HMD (O). Each mean is compared with that at week 0 for the respective diet (*P < 0.05, **P < 0.01, **«P < 0.001). At week 0 there were 32 dogs in group CMP and 28 in group HMD. As explained in the text and Table 6, at week 28 there were 18 dogs in group CMP and 17 in group HMD.
FIGURE 5 Mean (and standard deviation) product of serum calcium X phosphorus concentrations of dogs fed CMP diet (•) or HMD (O).Each mean is compared with that at week 0 for the respective diet (*P< 0.05, **P < 0.01, ***P < 0.001). At week 0 there were 32 dogs in group CMP and 28 in group HMD. As explained in the text and Table 6, at week 28 there were 18 dogs in group CMP and 17 in group HMD.
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2-
MEDIUM PROTEIN DIETS IN CANINE RENAL FAILURE
i80g
^^rT T J 60-40-20-LSJï
T 1 —
ï i i iiii
TABLE 7 Palatability
of diets1
Palatability
CMP
HMD
Poor Medium Good
3 5 24
1 2 25
Values are no. of dogs; abbreviations
LITERATURE
as in Table 1.
CITED
1. POLZIN, D. J. & OSBORNE,C. A. (1986) Dietary management of canine renal failure. In: Nephrology and Urology. (Breitschwerdt, E. B., éd.), pp. 152-153, Livingstone, New York, NY. 2. IBELS,L. S., ALFREY,A. C., HAUT, L. &. HOFFER,W. E. (1978) Preservation of function in experimental renal disease by dietary restriction of phosphate. N. EngJ. /. Med, 298: 122-126. 3. Ross, L. A., FINCO, D. R. &. CROWELL,W. A. (1982) Effect of dietary phosphorus restriction on the kidneys of cats with re duced renal mass. Am. /. Vet. Res. 43: 1023-1026. 4. POLZIN, D. J., LEININGER, J. L. & OSBORNE, C. A. (1988) Chronic, progressive renal failure: can progression be modified? In: Renal Disease in Dogs and Cats. Comparative and Clinical Aspects. (Micheli, A. R., éd.),pp. 129-144, Blackwell Scientific Publications, Oxford, United Kingdom. 5. KRONFELD,D. S. (1983) Geriatric diets for dogs. Comp. Coni. Ed. Pract. Vet. 5: 136-142. 6. BOVÉE, K. C. & KRONFELD,D. S. (1981) Reduction of renal hemodynamics in uremie dogs fed reduced protein diets. /. Am. Vet. Med. Assoc. 17: 277-285. 7. LEWIS,L. D., MORRIS, M. L., JR. &. HAND, M. S. (1987) Small Animal Clinical Nutrition, 3rd éd.pp. 8/18-19, Mark Morris Assoc., Topeka, KS. 8. BARSANTI,J. A. & FINCO, D. R. (1985) Dietary management of chronic renal failure in dogs. /. Am. Anim. Hosp. Assoc. 21: 371-376.
012
4
12 16 weeks
20
24
28
FIGURE 6 Mean (and standard deviation) serum protein concentration of dogs fed CMP diet (•) or HMD (O). Each mean is compared with that at week 0 for the respective diet (*P < 0.05, "P < 0.01, *"P < 0.001). At week 0 there were 32 dogs in group CMP and 28 in group HMD. As explained in the text and Table 6, at week 28 there were 18 dogs in group CMP and 17 in group HMD.
9. AUSSCHUßFÜRBEDARFSNORMENDERGESELLSCHAFT FÜRERNÄH RUNGSPHYSIOLOGIE (1989) Energie- und Nährstoffbedarf/En ergy and nutrient requirements, Nr. 5, Hunde/dogs. pp. 43-55, DLG Verlag, Frankfurt (Main), Germany. 10. POLZIN, D. J., OSBORNE, C. A., STEVENS,J. B. & HAYDEN, D.W. (1982) Influence of modified protein diets on electrolyte, acid base, and divalent ion balance in dogs with experimentally induced chronic renal failure. Am. J. Vet. Res. 43: 1978-1986. 11. MASSRY,S. G. (1980) Requirements of vitamin D metabolites in patients with renal disease. Am. /. Clin. Nutr. 33: 1530-1535.
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In contrast to others (8) a significant reduction of serum phosphorus concentration was observed in this study. A dietary effect on serum phosphorus concen tration has also been demonstrated in dogs with ex perimentally induced CRF (10). Serum calcium con centration was always in the normal range. Due to the decrease of serum phosphorus concentration, serum [Ca x P] was reduced below the solubility product (11), which is important to avoid nephrocalcinosis. The concomitant decrease in serum creatinine con centration was unexpected. A possible explanation of this improvement of renal function might be the early stage of CRF with only mild renal dysfunction in most of the dogs whose kidneys were still capable of com pensatory processes. In conclusion, the results of the present study sug gest that elderly dogs show a mild or moderate CRF more frequently than is clinically diagnosed. In these dogs, blood chemistry parameters relevant to CRF and urinalysis should be determined to detect renal failure at an early stage. In mild and moderate cases of CRF, dietary treatment with medium protein and low phos phorus diets was effective in improving laboratory data as well as the clinical consequences of CRF, allowed a good quality of life and can be recommended for those dogs.
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