RESUMO
A 4-year-old, female-spayed American Bulldog presented to the Ontario Veterinary College's Health Sciences Center's Clinical Nutrition Service for nutritional management of hepatic enzymopathy and suspected copper-associated hepatitis. Medical history revealed a 3-month history of gradually increasing serum ALT. Additional diagnostics included negative Leptospira titters, normal bile acids, and laparoscopic liver biopsy. Histopathology findings were consistent with diffuse moderate vacuole hepatocellular degeneration, mild positive copper staining, mild chronic lymphoplasmacytic hepatitis both portal and central, and mild biliary hyperplasia. Hepatic copper quantification results were above normal ranges (630 µg/g dry tissue), but below those seen in familial copper-associated hepatitis (>800-1,000 µg/g dry tissue). The patient was prescribed ursodeoxycholic acid, recommended to be fed a homemade diet (HMD), and referred for a nutrition consult. Two days before the nutrition consult, serum ALT fell within the normal range. The body condition score was 5/9, with a good muscle condition score and the dog's appetite and body weight remained stable. Energy intake was appropriate for maintenance. Key nutrient levels of all diets reported were compared to industry standards (AAFCO, NRC, and FEDIAF). Diet history included a commercially available raw meat-based diet (RMBD), of unknown copper content; a high energy commercial dry food (HEC), with copper content higher than the maximum recommended by FEDIAF and immediately prior to nutrition consult the patient had been eating an unbalanced homemade diet (HMD1) for 4 weeks. HMD1 was low in copper and deficient in the hepatoprotectant nutrients vitamin E and zinc. As per the owner's preference and to accommodate the patient's unique nutritional needs, a homemade diet addressing key nutrients for liver disease was formulated (HMD2), with copper content just above the recommended minimum. The new diet was found palatable and the patient's body weight, body, and muscle condition scores remained unchanged. Two months after starting HMD2, all bloodwork values remained within the normal range, including ALT. The reduction of dietary copper content likely reduced serum ALT. However, unbalanced diets cause a risk of nutrient deficiencies and excess. This dog was maintained with no known adverse effects on a complete and balanced HMD diet with a moderately low copper content, moderate protein, and inclusion of hepatoprotective nutrients.
RESUMO
The same food formulation processed to obtain two different starch gelatinisations (SG) and resistant starch (RS) contents was evaluated in old and adult dogs, regarding apparent total tract digestibility (ATTD) of nutrients, fermentation products in faeces, and postprandial glucose and insulin responses. A diet with corn was ground and extruded in two different ways, obtaining Low RS (2.2 g/kg DM; 99.9% of SG) and High RS (15.3 g/kg DM; 62.6% of SG). Each diet was fed to adults (4.0 ± 0.7 years) or old beagle dogs (11.5 ± 0.4 years) in a 2 (ages) x 2 (RS amounts) factorial arrangement with 8 dogs per food. Data were evaluated by analysis of variance, and postprandial responses by analysis of variance of repeated measurements over time (p < 0.05). Diet × age interaction was observed for protein ATTD, with lower values for old dogs fed High RS than those for the other treatments (p < 0.05). No age or diet effect was verified for the ATTD of other nutrients and faecal score. Faecal moisture and pH were higher for adults than that for old dogs (p < 0.05). The High RS food increased acetate, propionate and butyrate concentrations in faeces, regardless of age (p < 0.01). Old dogs presented lower acetate and total short-chain fatty acids (SCFA) and higher lactate and ammonia than adults (p < 0.05). Only for old dogs the intake of the High RS food reduced ammonia and increased faecal lactate (p < 0.05). An age × diet interaction was verified for glucose postprandial response, with lower values for old dogs fed High RS food (p < 0.05), while no differences were found for the other treatments. Old dogs had higher postprandial insulin secretion regardless of the diet (p < 0.05), and lower insulin increment at 180 min after the meal when fed the Low RS than when fed the High RS food (p < 0.05). In conclusion, the diet with lower SG and higher RS improved the intestinal microenvironment, with higher butyrate and total SCFA without altering faeces production or score. Old dogs presented less acetate and total SCFA and higher lactate and ammonia in faeces than adults. The High RS food increased lactate and reduced ammonia in faeces of old dogs, with possible positive influences for gut health. Old dogs had higher postprandial insulin secretion than that of adults to maintain blood glucose, and the diet with higher RS content reduced the postprandial glucose response of old dogs.