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in Journal of the American Veterinary Medical Association

Abstract

Objective—To evaluate cartilage and bone biomarkers and body composition in growing large-breed dogs consuming a diet designed for growth.

Animals—43 large-breed 2 month-old-puppies.

Procedures—Dogs were randomly assigned to receive 1 of 2 foods until 18 months of age. Dogs were evaluated at 2, 5, 12, and 18 months of age via dual energy x-ray absorptiometry (DEXA), CBC, serum biochemical profile, and concentrations or activities of taurine, vitamin E, fatty acids, glutathione peroxidase, C-propeptide of type II collagen (CPII), cartilage oligomeric matrix protein (COMP), carboxy-terminal cross-linked fragment of type II collagen (CTXII), bone specific alkaline phosphatase (BAP), osteocalcin, ghrelin, and growth hormone.

Results—Blood components largely reflected the composition of the foods. Dogs fed the food with a higher concentration of protein, calcium, n-3 fatty acids, and antioxidants had a lower percentage of body fat and greater percentage of lean body mass at 5, 12, and 18 months of age, and higher CPII:CTXII ratio and lower COMP at 18 months of age. The BAP activity, osteocalcin concentration, and CTXII concentration declined with age, whereas COMP concentration and CPII concentration were similar at all time points for both foods.

Conclusions and Clinical Relevance—The BAP activity, osteocalcin concentration, and CTXII concentration were greater during growth than at 18 months of age. The food that was proportionately higher in protein, calcium, n-3 fatty acids, and antioxidants increased lean body mass and may have positively affected cartilage turnover as maturity was attained. Whether the rate of cartilage turnover during growth affects development of orthopedic disease or arthritis in adulthood has yet to be determined.

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in American Journal of Veterinary Research

Abstract

Objective—To determine the effects of 3 rations (low grain, fat, high grain) on plasma creatine kinase (CK) activity and lactate concentration in Thoroughbred horses with recurrent exertional rhabdomyolysis (RER).

Animals—5 Thoroughbreds with RER and 3 healthy Thoroughbreds (control horses).

Procedures—Rations were formulated to meet (lowgrain and fat rations) or exceed (high-grain ration) daily energy requirements. Each ration was fed to horses in a crossover design for 3 weeks. Horses were exercised on a treadmill Monday through Friday; maximum speed on Monday and Friday was 11 m/s (6% slope), on Tuesday and Thursday was 9 m/s, and on Wednesday was 4.5 m/s. Plasma CK activity and lactate concentration were determined before and after exercise.

Results—Horses with RER fed the high-grain ration had significantly greater CK activity and change in CK activity 4 hours after exercise, compared with those fed the low-grain ration. Horses with RER exercised at the trot or canter had significantly greater increases in CK activity, compared with those exercised at the gallop. Plasma lactate concentrations after exercise were similar in control and affected horses. Lactate concentration and CK activity were not correlated in horses with RER.

Conclusions and Clinical Relevance—Rations high in grain and formulated to exceed daily energy requirements may increase episodes of rhabdomyolysis in Thoroughbred horses susceptible to RER. (Am J Vet Res 2000;61:1390–1395)

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in American Journal of Veterinary Research

Abstract

Objective—To determine the effect of feeding a food with coconut oil and supplemental l-carnitine, lipoic acid, lysine, leucine, and fiber on weight loss and maintenance in dogs.

Design—Prospective clinical study

Animals—50 overweight dogs.

Procedures—The study consisted of 2 trials. During trial 1, 30 dogs were allocated to 3 groups (10 dogs/group) to be fed a dry maintenance dog food to maintain body weight (group 1) or a dry test food at the same amount on a mass (group 2) or energy (group 3) basis as group 1. During trial 2, each of 20 dogs was fed the test food and caloric intake was adjusted to maintain a weight loss rate of 1% to 2%/wk (weight loss phase). Next, each dog was fed the test food in an amount calculated to maintain the body weight achieved at the end of the weight loss phase (weight maintenance phase). Dogs were weighed and underwent dual-energy x-ray absorptiometry monthly. Metabolomic data were determined before (baseline) and after each phase.

Results—During trial 1, dogs in groups 2 and 3 lost significantly more weight than did those in group 1. During trial 2, dogs lost a significant amount of body weight and fat mass but retained lean body mass (LBM) during the weight loss phase and continued to lose body fat but gained LBM during the weight maintenance phase. Evaluation of metabolomic data suggested that fat metabolism and LBM retention were improved from baseline for dogs fed the test food.

Conclusions and Clinical Relevance—Results suggested that feeding overweight dogs the test food caused weight loss and improvements in body condition during the weight-maintenance phase, possibly because the food composition improved energy metabolism.

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in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine the effect of feeding a food with coconut oil and supplemental l-carnitine, lysine, leucine, and fiber on weight loss and maintenance in cats.

Design—Prospective clinical study.

Animals—50 overweight cats.

Procedures—The study consisted of 2 trials. During trial 1, 30 cats were allocated to 3 groups (10 cats/group) to be fed a dry maintenance cat food to maintain body weight (group 1) or a dry test food at the same amount on a mass (group 2) or energy (group 3) basis as group 1. During trial 2, each of 20 cats was fed the test food and caloric intake was adjusted to maintain a weight loss rate of 1%/wk (weight loss phase). Next, each cat was fed the test food in an amount calculated to maintain the body weight achieved at the end of the weight loss phase (weight maintenance phase). Cats were weighed and underwent dual-energy x-ray absorptiometry monthly. Metabolomic data were determined before (baseline) and after each phase.

Results—During trial 1, cats in groups 2 and 3 lost significantly more weight than did those in group 1. During trial 2, cats lost a significant amount of body weight and fat mass but retained lean body mass during the weight loss phase and continued to lose body weight and fat mass but gained lean body mass during the weight maintenance phase. Evaluation of metabolomic data suggested that fat metabolism was improved from baseline for cats fed the test food.

Conclusions and Clinical Relevance—Results suggested that feeding overweight cats the test food caused weight loss and improvements in body condition during the weight maintenance phase, possibly because the food composition improved energy metabolism.

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in Journal of the American Veterinary Medical Association

Abstract

Objective—To compare the efficacy and safety of using 2 commercially available, low-magnesium, urine-acidifying dry foods to dissolve sterile struvite uroliths in cats.

Design—Prospective, multicenter, randomized clinical trial

Sample—37 cats with presumed struvite uroliths.

Procedures—Cats were randomly assigned to be fed 1 of 2 low-magnesium, urine-acidifying dry foods (food A or B). For each cat, physical examination, urinalysis, and abdominal radiography were performed weekly to assess treatment response.

Results—32 cats had complete urolith dissolution. Mean ± SD times for a 50% reduction in urolith size (0.69 ± 0.1 weeks) and complete urolith dissolution (13.0 ± 2.6 days) were significantly shorter for cats fed food A, compared with those (1.75 ± 0.27 weeks and 27.0 ± 2.6 days, respectively) for cats fed food B. At study termination, mean ± SD urine pH (6.083 ± 0.105) for cats fed food A was lower than that (6.431 ± 0.109) for cats fed food B. In 5 cats, uroliths did not dissolve and were subsequently determined to be composed of 100% ammonium urate (n = 4) or 100% calcium oxalate (1). Adverse events associated with diet were not observed in any of the cats.

Conclusions and Clinical Relevance—Results indicated that dietary dissolution is safe and effective for eradication of sterile struvite uroliths in cats. Cats fed food A had faster urolith dissolution than did cats fed food B. Lack of a reduction in urolith size at 2 weeks after diet initiation was indicative of misdiagnosis or noncompliance.

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in Journal of the American Veterinary Medical Association

Abstract

Objective—To evaluate the effect of nutrition on recurrent clinical signs of lower urinary tract (LUT) disease in cats with idiopathic cystitis.

Design—Randomized, controlled, masked clinical trial.

Animals—31 cats with acute nonobstructive idiopathic cystitis.

Procedures—Cats were assigned to receive 1 of 2 foods (a cystitis prevention or control food) that differed in mineral (calcium, phosphorous, and magnesium), antioxidant, and fatty acid profiles. Owners documented LUT signs daily for up to 1 year. The primary endpoint was the number of recurrent episodes in which a cat had multiple (≥ 2 concurrent) LUT signs within a day (defined as multiple-sign day). Consecutive days in which a cat had multiple LUT signs were considered as a single episode.

Results—4 cats fed prevention food and 2 cats fed control food were excluded from analysis because of noncompliance, gastrointestinal signs, food refusal, or owner voluntary withdrawal. The proportion of cats fed prevention food that had ≥ 1 recurrent episode of multiple-sign days (4/11) was not significantly lower than that of cats fed control food (9/14). However, cats fed prevention food had significantly lower mean incidence rates for recurrent episodes of multiple-sign days (0.7 episodes/1,000 cat-days) and episodes of hematuria (0.3 episodes/1,000 cat-days), dysuria (0.2 episodes/1,000 cat-days), and stranguria (0.2 episodes/1,000 cat-days) as single LUT signs, compared with cats fed control food (5.4, 3.4, 3.1, and 3.8 episodes/1,000 cat-days, respectively). Significantly fewer cats fed prevention food required analgesics (4/11), compared with cats fed control food (12/14).

Conclusions and Clinical Relevance—Foods with differing nutritional profiles appeared to impact mean incidence rates of recurrent feline idiopathic cystitis-associated signs.

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in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine daily variation in urinary clearance and fractional excretion (FE) of electrolytes and minerals within and between horses and to compare volumetric and single-sample urine collection for determining FE values of diets with a range of dietary cation-anion balance (DCAB).

Animals—5 Thoroughbred and 6 mixed-breed mares.

Procedure—3 isocaloric diets with low, medium, and high DCAB values (85, 190, and 380 mEq/kg of dry matter, respectively) were each fed for 14 days. Daily blood samples, single urine samples collected by using a urinary catheter (5 mares), and volumetric urine collections (6 mares) were obtained during the last 72 hours of each diet.

Results—Urine and plasma pH values, plasma concentrations, and FE values of sodium, chloride, potassium, magnesium, phosphorus, and calcium were altered by varying the DCAB. Noticeable variation in clearance and FE values was detected within horses from day-to-day on the same diet as well as between horses. Fractional excretion values were not significantly different between single-sample and volumetric methods, except for magnesium in the high DCAB diet. Volumetric and single-sample collections revealed similar patterns of change in urinary FE values with varying DCAB, except for calcium and magnesium.

Conclusions and Clinical Relevance—Substantial variation in clearance and FE of electrolytes and minerals are evident within horses between 24-hour periods as well as between horses fed a specific diet. Three daily urine samples provide similar information regarding dietary-induced changes in clearance and FE values (excluding calcium and magnesium) as that obtained by volumetric urine collection. (Am J Vet Res 2003;64:284–291)

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in American Journal of Veterinary Research

Abstract

Objective—To determine whether plasma, urine, and fecal electrolyte and mineral concentrations differ between clinically normal horses and Thoroughbreds with recurrent exertional rhabdomyolysis (RER) after consumption of diets varying in cation-anion balance.

Animals—5 Thoroughbred mares with RER and 6 clinically normal mixed-breed mares.

Procedure—Each of 3 isocaloric diets designated as low, medium, and high on the basis of dietary cationanion balance (DCAB) values of 85, 190, and 380, respectively, were fed to horses for 14 days. During the last 72 hours, 3 horses with RER and 3 control horses had daily urine and fecal samples obtained by total 24-hour collection. Remaining horses had urine samples collected daily by single catheterization.

Results—For each diet, no differences existed between horses with RER and control horses in plasma pH, electrolyte concentrations, and creatine kinase activity or in urine pH and renal fractional excretion (FE) values. Plasma pH, strong ion difference, bicarbonate and total carbon dioxide concentrations, and base excess decreased and plasma chloride and ionized calcium concentrations increased with decreasing DCAB. Urine pH decreased with decreasing DCAB. The FE of chloride and phosphorus were greatest for horses fed the low diet. The FE values for all electrolytes exept magnesium did not differ between urine samples obtained by single catheterization and total 24-hour collection. Daily balance of calcium, phosphorus, sodium, chloride, and potassium did not differ significantly among horses fed the various diets.

Conclusions—In clinically normal horses and in horses with RER, the DCAB strongly affects plasma and urine pH and the FE of sodium, potassium, chloride, and phosphorus. (Am J Vet Res 2002;63:1053–1060)

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in American Journal of Veterinary Research

Abstract

Objective—To develop a diagnostic test for recurrent exertional rhabdomyolysis (RER) in Thoroughbreds that relied on in vitro contracture of muscle biopsy specimens and determine whether the inheritance pattern of RER diagnosed on the basis of this contracture test was consistent with an autosomal dominant trait.

Design—Clinical trial.

Animals—8 adult horses with RER and 16 control adult horses for development of the contracture test; 23 foals for inheritance of RER.

Procedure—External intercostal muscle biopsy specimens from the 24 adult horses were tested for contracture in response to halothane and caffeine, and criteria for a positive test result were determined. These criteria were then applied to results for the 23 foals to determine whether they had RER. Simple segregation analysis was performed to determine whether results were consistent with a dominant pattern of inheritance.

Results—Results of the contracture test were positive for 5 of the 12 colts and 4 of the 11 fillies. Results of segregation analysis were consistent with an autosomal dominant pattern of inheritance. Two sires with RER produced colts with RER, supporting the hypothesis that RER had an autosomal, rather than an X-linked, inheritance pattern. In addition, in 1 instance, an unaffected colt was produced by 2 affected parents, which was not consistent with a recessive mode of inheritance.

Conclusions and Clinical Relevance—Although the expression of the RER trait is influenced by sex, temperament, and diet, among other factors, results from the in vitro muscle contracture test and this breeding trial suggest that RER in Thoroughbreds can be modeled as a genetic trait with an autosomal dominant pattern of inheritance. ( J Am Vet Med Assoc 2005;227:762–767)

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in Journal of the American Veterinary Medical Association