Nutritional evaluation of commercial dry dog foods by near infrared reflectance spectroscopy

Near infrared reflectance spectroscopy (NIRS) was used to predict the nutritional value of dog foods sold in Chile. Fifty-nine dry foods for adult and growing dogs were collected, ground and scanned across the visible/NIR range and subsequently analysed for dry matter (DM), crude protein (CP), crude fibre (CF), total fat, linoleic acid, gross energy (GE), estimated metabolizable energy (ME) and several amino acids and minerals. Calibration equations were developed by modified partial least squares regression, and tested by cross-validation. Standard error of cross validation (SE(CV)) and coefficient of determination of cross validation (SE(CV)) were used to select best equations. Equations with good predicting accuracy were obtained for DM, CF, CP, GE and fat. Corresponding values for and SE(CV) were 0.96 and 1.7 g/kg, 0.91 and 3.1 g/kg, 0.99 and 5.0 g/kg, 0.93 and 0.26 MJ/kg, 0.89 and 12.4 g/kg. Several amino acids were also well predicted, such as arginine, leucine, isoleucine, phenylalanine-tyrosine (combined), threonine and valine, with values for and SE(CV) (g/kg) of 0.89 and 0.9, 0.94 and 1.3, 0.91 and 0.5, 0.95 and 0.9, 0.91 and 0.5, 0.93 and 0.5. Intermediate values, appropriate for ranking purposes, were obtained for ME, histidine, lysine and methionine-cysteine. Tryptophan, minerals or linoleic acid were not acceptably predicted, irrespective of the mathematical treatment applied. It is concluded that NIR can be successfully used to predict important nutritional characteristics of commercial dog foods.     

Prediction of digestible protein content of dry extruded dog foods: comparison of methods

The aim of this study was to check the accuracy of laboratory methods to predict the apparent protein digestibility (CPd, %) and digestible protein content (DP, g/kgDM) of dog foods, avoiding the use of experimental animals in digestion trials. Twenty‐eight commercial dry extruded dog foods were tested by three different methodologies: an adaptation of the in vitro incubation method described by Hervera et al. (J Anim Physiol Anim Nutr 2007, 91 : 205) for estimation of digestible energy of commercial dog foods, a modification of the pH drop methodology proposed by Hsu et al. (J Food Sci 1977, 42 : 1269) for protein evaluation of human foods and the Near Infra Red Spectroscopy (NIRS) technology. All the methods assessed revealed very good, similar accuracy in the prediction of DP content either using the in vitro method (r = 0.99; RSD = 6.76; CV = 2.31%), the pH drop method (r = 0.99; RSD = 6.94; CV = 3.02%) or the NIRS (R2 = 0.96; SECV = 10.50) method, although the in vitro digestion method showed the highest accuracy approach of in vivo crude protein apparent digestibility: CPd in vitro (r = 0.81; RSD = 2.01; CV = 2.41%); CPd pH‐drop (r = 0.78; RSD = 2.48; CV = 2.98%) and NIRS (r²cv = 0.53; SECV = 2.37).     

ELISA testing for common food antigens in four dry dog foods used in dietary elimination trials

This study evaluated four over the counter venison dry dog foods available from one on-line retail vendor for potential contamination with common known food allergens: soy, poultry or beef. An amplified, double sandwich type enzyme linked immunosorbent assay (ELISA) test of soy, poultry and beef proteins were performed by an independent accredited food laboratory. The ELISA test for poultry protein was found to be unreliable when testing in dry dog foods because false negatives occurred. ELISA testing of control diets for both soy and beef proteins performed as expected and could be useful in antigen testing in dry dog foods. Three of the four over the counter (OTC) venison canine dry foods with no soy products named in the ingredient list were ELISA positive for soy; additionally one OTC diet tested positive for beef protein with no beef products listed as an ingredient list. One OTC venison diet was not found to be positive for soy, poultry or beef proteins. However, none of the four OTC venison diets could be considered suitable for a diagnostic elimination trial as they all contained common pet food proteins, some of which were readily identifiable on the label and some that were only detected by ELISA. Therefore, if the four OTC venison products selected in this study are representative of OTC products in general, then the use of OTC venison dry dog foods should not be used during elimination trials in suspected food allergy patients.     

Evaluation of storage mite contamination of commercial dry dog food

Storage mites may be considered important allergens in dogs with atopic dermatitis. High sensitization rates to Tyrophagus , Acarus , and Lepidoglyphus species have been reported in atopic dogs, and dry pet food has been suggested as a potential source of storage mite exposure. The aim of the present study was to evaluate commercial dry dog food for contamination with storage mites, and how storage time and conditions could influence the risk of contamination. Ten different premium commercial dry dog foods formulated for skin disorders were selected. Food bags were opened and stored for 6 weeks under two different environmental conditions. At different time points, samples from each bag were collected and analysed by microscopy, guanine test, storage mite-specific traps, and a modified flotation technique.
On opening, two storage mites identified as Acarus siro were isolated from one of the 10 bags by flotation technique, indicating that storage mites can be present in packaged dry dog food bags. After 5 weeks of storage under environmental conditions optimal for mite growth (23.2 ± 2.1 °C and 71 ± 5.6% of relative humidity), mites were detected by microscopic observation in nine of the 10 diets. When mites were identified by the flotation technique, Tyrophagus spp. were found to be the most common contaminating species. These results show that dry dog food can be a suitable substrate for storage mite reproduction, and that environmental and storage conditions may influence food contamination and mite development.     

The effect of ingredients in dry dog foods on the risk of gastric dilatation-volvulus in dogs

Using dry dog food label information, the hypothesis was tested that the risk of gastric dilatation-volvulus (GDV) increases with an increasing number of soy and cereal ingredients and a decreasing number of animal-protein ingredients among the first four ingredients. A nested case-control study was conducted with 85 GDV cases and 194 controls consuming a single brand and variety of dry food. Neither an increasing number of animal-protein ingredients (P=0.79) nor an increasing number of soy and cereal ingredients (P=0.83) among the first four ingredients significantly influenced GDV risk. An unexpected finding was that dry foods containing an oil or fat ingredient (e.g., sunflower oil, animal fat) among the first four ingredients were associated with a significant (P=0.01), 2.4-fold increased risk of GDV. These findings suggest that the feeding of dry dog foods that list oils or fats among the first four label ingredients predispose a high-risk dog to GDV.     

The impact of dietary protein source on observed and predicted metabolizable energy of dry extruded dog foods

Fifty-five observations were used to determine the ME content of 8 foods containing different protein sources. The major protein sources tested included low-oligosaccharide whole soybeans; 2 low-oligosaccharide, low-phytate whole soybeans; 2 conventional soybean meals; low-ash poultry meal; low-oligosaccharide, low-phytate soybean meal; and conventional whole soybeans. The ME content of all foods ranged from 3,463 to 4,233 kcal/kg of DM. The first objective was to utilize the observed ME data and test the accuracy of the modified Atwater equation. In this study, the modified Atwater equation generally underpredicted ME compared with the observed ME (residual mean = 247 kcal/kg). The second objective was to use individual data to develop an equation, based on the chemical composition of the food, to predict the ME content of the foods. A multivariate regression analysis was used to predict ME content based on chemical composition. Five models were fitted to the data. Model 1 included CP, ether extract (EE), and crude fiber (CF). Because the foods varied in protein sources, and the ratio of total AA (TAA) to non-AA (NAA) CP ranged from 3.5:1 to 14.4:1, it was hypothesized that accounting for the proportion of TAA and NAA in CP would improve the fit of the model. Therefore, model 2 included TAA, NAA, EE, and CF. Defining CP in terms of TAA and NAA improved the r2 of the model from 0.46 to 0.79. Subsequently, models 3, 4, and 5 replaced the CF term with ADF, NDF, and hemicellulose (HEM). Model 3 included TAA, NAA, EE, and NDF. Model 4 included TAA, NAA, EE, ADF, and HEM. Model 5 included TAA, NAA, EE, and HEM. Defining dietary fiber in terms of HEM improved the r2 of model 2 from 0.79 to 0.81. Residual analysis suggested that replacing the CF term with HEM (model 5) improved the prediction of ME content. In contrast, defining fiber in terms of NDF (model 3) did not result in an improvement over model 2, whereas the ADF term (model 4) did not (P > 0.34) contribute to the overall model. Fractionating CP into TAA and NAA components further defined the chemical composition of the food. These data suggest that defining protein composition improves the accuracy of predicting the ME content of dog foods.     

Comparison of procedures for assessing adequacy of dog foods.

Dog foods with similar claims for nutritional adequacy were tested by chemical analysis and the American Association of Feed Control Officials' growth trial. All foods tested were similar chemically, however, dogs given one regionally marketed food had lower growth rate and food efficiency as well as suboptimal PCV and hemoglobin values during the growth trial. Pups fed this diet also had clinical signs typical of zinc and copper deficiencies. We concluded that American Association of Feed Control Officials' approved feeding tests provide valid assessment of pet food quality, and procedures involving only chemical analysis or calculated values may not.     

防暴犬攻击持枪案犯实战技能训练方法初探

在2004年度全警岗位大练兵的热潮中,我们对使用防暴犬攻击制服持枪案犯的实战技能进行了训练研究探索,取得了初步成果,并在第二届全国警犬技术比赛开幕式上进行了汇报演练。现将训练方法介绍如下：     

Identification and concentration of soy phytoestrogens in commercial dog foods

OBJECTIVE: To identify and determine the concentrations of phytoestrogens in commercial dog foods. SAMPLE POPULATION: 24 commercial dog foods, including 12 moist or dry extruded commercial dog foods that contained soybeans or soybean fractions and 12 foods without any soybean-related ingredients listed on the label. PROCEDURE: Foods were analyzed for phytoestrogen content, including 4 isoflavones (genistein, glycitein, daidzein, and biochanin A), 1 coumestan (coumestrol), and 2 lignans (secoisolariciresinol and matairesinol) by use of acid-methanol hydrolysis and high-pressure liquid chromatography with UV-absorbance detection. Phytoestrogens were identified and quantified by reference to authentic standards. RESULTS: Isoflavones, coumestans, and lignans were undetectable in diets that did not list soybean-related ingredients on the label. Only 1 of the 12 diets that included soybean or soybean fractions had undetectable concentrations of phytoestrogens and that product contained soy fiber. The major phytoestrogens were the isoflavones daidzein (24 to 615 microg/g of dry matter) and genistein (4 to 238 microg/g of dry matter). CONCLUSIONS AND CLINICAL RELEVANCE: Soybean and soybean fractions are commonly used ingredients in commercial dog foods. Dietary intake of phytoestrogens may have both beneficial and deleterious health effects. Our results indicated that certain commercial dog foods contain phytoestrogens in amounts that could have biological effects when ingested long-term.     

Evaluation and use of pet foods: general considerations in using pet foods for adult maintenance

Questions regarding pet animal nutrition are probably among the most frequent queries encountered by companion animal veterinarians. Given the plethora of pet food products available and the amount of advertising used to promote them, it is not surprising that pet owners have concerns as to what they should feed their pets. This "practical" review of pet foods and feeding is designed to assist veterinarians in making nutritional recommendations to their clients, with respect to feeding normal adult pets at maintenance.     

Retinal degeneration associated with the feeding of dog foods to cats

Retinal degeneration was observed in cats fed commerical dog food. The retinal degenerative lesions ranged in size from small areas of focal atrophy centered in the area centralis to generalized retinal atrophy. Blindness developed only in cats with generalized retinal atrophy. Analysis of the dog food diets, both dry and canned, revealed that taurine was absent or was present in very low concentrations when compared with control cat food diets. Plasma amino acid analysis also revealed taurine deficiency.     

A baiting system suitable for the delivery of oral rabies vaccine to dog populations in Zimbabwe

A baiting system suitable for the delivery of oral rabies vaccine to dog populations in developing countries was studied in Zimbabwe. In a field trial, 369 sponge baits containing a placebo liquid, rhodamine B as a biomarker and a pungent attractant were distributed over an area of 60 sq km in a communal land in Manicaland with a dog population of over 500. Twenty-four hours later 21 per cent of the baits were recovered and 79 per cent of these had been significantly bitten or chewed. Twenty-five per cent of the dogs examined showed evidence of superficial staining by rhodamine B indicating that they had chewed baits or ingested their contents. It was concluded that the system would deliver an oral vaccine to dog populations more efficiently than had been the case in comparable studies in wildlife populations, but that the number of baits per unit area should in future studies be increased.     

Evaluation of screening tests for renal insufficiency in the dog

The use of creatinine and fractional excretion of phosphate as screening tests for early renal disease is examined. Their relative efficiency in detecting renal insufficiency is compared and the effect of different decision levels on interpreting test results is also discussed. The use of receiver operating curves to evaluate the relationship between specificity and sensitivity and their effects on the interpretation of results is shown. For all decision levels, creatinine is shown to be superior to fractional excretion of phosphate for the diagnosis of renal insufficiency.     

Evaluation of some drug combinations for sedation in the dog

A double blind trial was performed in order to investigate the effects of some sedatives in the dog. One hundred and forty-two dogs undergoing radiography for the BVA/KC hip dysplasia scheme were sedated with combinations of acepromazine with pethidine or buprenorphine, or with acepromazine alone. The degree of sedation, resistance to manipulation, sensitivity to noise and response to pain were assessed, and arterial blood samples taken for blood gas analysis. In all respects the combinations of acepromazine with buprenorphine or pethidine produced significantly better sedation than acepromazine alone. Pa0₂ and pH were lower and PaCO₂ higher in dogs receiving the combinations compared with those receiving acepromazine alone, but all values were within normal limits. It was concluded that combinations of pethidine or buprenorphine with acpromazine provide extremely effective and safe sedation in the dog.     

Comparison of corn gluten meal and meat meal as a protein source in dry foods formulated for cats

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.