Diet and lifestyle variables as risk factors for chronic renal failure in pet cats.

A case-control study examining diet and lifestyle variables to generate hypotheses of potential risk factors for chronic renal failure in pet cats was conducted in five private practices in Texas, USA and at the Texas A&M University Veterinary Medical Teaching Hospital. A telephone questionnaire was used to gather information from owners of 38 cats newly diagnosed with CRF between December 1994 and 1995 and from owners of 56 control cats. Factor analysis was used to determine whether composite variables should be constructed to summarize the nutritional predictors adequately. The composite variables and other lifestyle variables were analyzed with logistic-regression. Three final exploratory models were developed: ad libitum feeding with fiber; ad libitum with Factor-2 (a composite variable composed of fiber, magnesium, protein, sodium and ash); and fiber alone. Ad libitum feeding and increased ash intake were associated with increased odds of CRF; increased dietary fiber, magnesium, protein and sodium were associated with decreased odds of CRF.

Effects of dietary flax seed and sunflower seed supplementation on normal canine serum polyunsaturated fatty acids and skin and hair coat condition scores.

This prospective study involved supplementing 18 normal dogs with flax seed (FLX) and sunflower seed (SUN) and evaluating their effects on skin and hair coat condition scores and serum polyunsaturated fatty acids (PUFA) concentrations. Skin and hair coat were evaluated in a double-blinded fashion using a numeric scoring system and serum PUFA concentrations were determined. Our hypothesis was that changes in serum PUFA concentrations are associated with improvements in skin and hair coat and that serum PUFA would provide an objective method for making dietary fatty acid supplement recommendations. Although a numerical improvement was found in hair coat quality in both groups, this improvement was not sustained beyond 28 days. The relative per cent of 18:3n-3 concentrations in serum phospholipids increased in the FLX treated dogs but these concentrations remained unchanged in the SUN treated dogs. Also, elevations in relative per cent of 18:2n-6 concentrations in serum phospholipids were seen in the FLX group. The ratio of serum polyunsaturated to saturated fatty acids also showed a transient increase. These increases preceded the peak skin condition score peak value by approximately 14 days. It was concluded that a 1-month supplementation with either flax seed or sunflower seed in dogs provides temporary improvement in skin and hair coat. These changes appeared to be associated with increased serum 18 carbon PUFA.

Validation of predictive equations for use of deuterium oxide dilution to determine body composition of dogs.

OBJECTIVE: To validate equations predicting body composition of dogs, using deuterium oxide dilution. ANIMALS: 38 female and 37 male dogs selected by defined body weight and body condition criteria. PROCEDURE: Measured equilibrated deuterium concentration in serum after i.v. administration of isotope was used to determine isotope space and predict body water, fat, nitrogen, and ash contents determined from analysis of homogenized carcass. Equations predicting body composition were derived, using regression analysis, and were validated, using data-splitting techniques. RESULTS: Deuterium space (in kilograms) overestimated kilograms of body water content by mean 21.8% +/- SD of 4.18%. Regression equations were derived and validated to predict kilograms of body water and ash from kilograms of deuterium space, and proportion of body water, fat, nitrogen, and ash from proportion of deuterium space. Coefficients of determination (r2) and means of standard errors of estimating new values (SEE) were, respectively, 0.993 and 0.4 kg for body water content, and 0.942 and 0.08 kg for ash content. For proportions, SEE were 2.0, 2.7, 0.1, and 0.4% for body water, fat, nitrogen, and ash, respectively. Two factors, time for isotope equilibration and whether samples were processed by vacuum sublimation, improved SEE for proportion of body water from 2.0 to 1.3% and of fat from 2.7 to 1.8%. Equations predicting absolute quantities of fat and nitrogen could be derived but not validated. CONCLUSIONS: Deuterium dilution can be used to predict body composition of dogs with precision equal to that determined for other species.

Foods and techniques for managing obesity in companion animals.

Management of obesity should initially involve assessment of the pet to rule out other possible medical problems and provide an accurate dietary history. It is essential to obtain a good estimate of the existing caloric intake, including calories from table scraps, pet treats, or other sources. Assessing the owner's willingness to make a commitment to a major lifestyle change for their pet is also an important part of any successful weight-reduction program. In some instances, this motivation can be linked to a recent, expensive bill for orthopedic or other procedures performed on their pet. Once a candidate has entered a program, calculated restriction of energy while maintaining protein, vitamin, and mineral intake should be recommended. It may be surprising to find out that the calculated amounts of food may be more than the amount a pet is currently being fed. In these animals, it is imperative to use a high-protein, obesity-management diet and not a low-protein, "light," or senior type of diet containing high fiber. If possible, treats should be restricted altogether and begging actively discouraged. Any snacks should be placed in the pet's feeding bowl so that an association between eating and the bowel become established. Of equal importance is use of a realistic exercise program that owners will encourage their pet to follow. Various products for weight reduction are available. Use of these specially formulated products to restrict caloric intake, while maintaining essential nutrient intake and increasing energy expenditure by playing and other activities, are the hallmarks of successful weight loss programs.

Nutritional influences on immunity.

There is no doubt that nutrient deficiencies and excesses can influence immune responses. Despite advances in the development of therapeutic agents, a competent immune system is crucial for prevention and resolution of disease. Leukocytes are some of the most metabolically active cells in animals. We know that growing animals require nutrients to sustain growth and reach their full potential, whether that is size, strength, speed, or agility. We do not expect kittens to grow or greyhounds to run without provision of adequate nutrients. To expect the immune system to function in the face of nutrient deficiency neglects our knowledge of the physiological needs of metabolically active tissues. Immune responses may be modified through dietary manipulations. However, the clinician must answer the question "to what end or consequence will the response be changed?" No "golden" nutrient ensures an appropriate immune response in all conditions, just as no "golden" drug heals all diseases. Our knowledge of nutrient-immune system interactions is increasing. Yet, for all of the current knowledge of nutrient effects on immunity, the words of Dr R.K. Chandra hold sterling advice, "Moderation is a good dictum in biology and medicine, and it applies equally to nutritional immunology."