Energy expenditure in dogs with lymphoma fed two specialized diets

Effects of a high-protein, increased-fibre, dry diet supplemented with omega-3 fatty acids on quality of life in dogs undergoing chemotherapy

Quality of life (QOL) in dogs with cancer is a key consideration in the assessment of cancer treatment options. Despite interest in dietary strategies to improve management of oncology patients, there have been very few clinical studies showing the impact of diet on adverse effects of chemotherapy in dogs. This study was a randomised, controlled, double-blinded, multicenter clinical trial to investigate a high-protein, increased-fibre diet supplemented with omega-3 fatty acids, for dogs with cancer undergoing standard-of-care chemotherapy. Client-owned dogs with newly diagnosed grade 2 or higher mast cell tumours (or non-resectable/incompletely resected tumours) or multicentric lymphoma were randomised to receive the test diet (n = 24) or control diet (n = 21) for 8 weeks. Primary outcomes were QOL assessments, faecal scores, and blood concentrations of C-reactive protein and monocyte chemoattractant protein-1. Of 12 QOL parameters, 10 significantly improved from baseline to Week 8 in the test group compared with one in the control group. However, differences between the two groups were only statistically significant for 'frequency of signs of illness' (P = .009). There were no significant differences in the incidence of any adverse events, including gastrointestinal adverse events or clinically significant differences in laboratory parameters or faecal scores between the two groups. The absence of an observed negative impact of the test diet, combined with the magnitude of QOL improvements associated with the diet, suggest that a larger trial is warranted.

Predictive equations of maintenance energy requirement for healthy and chronically ill adult dogs

Maintenance energy requirement (MER) is the energy amount necessary for dogs to maintain their weight and body condition. Some factors can influence the MER, such as gender, age, neutering status and also diseases. The present retrospective study aimed to evaluate MER of adult dogs with several diseases and compare with the MER of healthy adult dogs, observing the influence of parameters such as body condition score (BCS), neutering status, gender, age, diagnosis and type of food on MER of these dogs. A total of 165 adult dogs with weight changes of ≤5% were included and divided in groups according to diagnosis. Mean MER for healthy dogs was 86.09 kcal/BW^0.75 , which differed from NRC and FEDIAF recommendations for inactive adult dogs (p = .047). Lowest MERs were of the endocrinopathies (78.52 ± 19.32 kcal/BW^0.75 ), orthopaedic diseases (59.71 ± 19.30 kcal/BW^0.75 ) and neurologic diseases (78.83 ± 32.66 kcal/BW^0.75 ) groups. Gastrointestinal diseases (99.59 ± 20.36 kcal/BW^0.75 ), orthopaedic diseases (59.71 ± 19.30 kcal/BW^0.75 ) and neoplasia (95.61 ± 21.02 kcal/BW^0.75 ) groups were the only groups that differed from the mean MER of healthy adult dogs. Regarding BCS, for each increasing point in a 9-point scale, there was a decrease of 9.8 kcal/BW^0.75 on MER, independent of diagnosis (p < .0001; r²  = .55). There was no difference regarding breed size gender and age, but neutered dogs presented lower MER (p = .031). Based on data obtained from the present study, it can be concluded that it is necessary to consider BCS, age, neutering status and diagnosis when calculating MER, both in healthy dogs and chronically ill dogs.

Energy requirements of adult dogs: a meta-analysis

A meta-analysis was conducted to determine the maintenance energy requirements of adult dogs. Suitable publications were first identified, and then used to generate relationships amongst energy requirements, husbandry, activity level, methodology, sex, neuter status, dog size, and age in healthy adult dogs. Allometric equations for maintenance energy requirements were determined using log-log linear regression. So that the resulting equations could readily be compared with equations reported by the National Research Council, maintenance energy requirements in the current study were determined in kcal/kg(0.75) body weight (BW). Ultimately, the data of 70 treatment groups from 29 publications were used, and mean (± standard deviation) maintenance energy requirements were 142.8±55.3 kcal·kgBW(-0.75)·day(-1). The corresponding allometric equation was 81.5 kcal·kgBW(-0.9)·day(-1) (adjusted R2 = 0.64; 70 treatment groups). Type of husbandry had a significant effect on maintenance energy requirements (P<0.001): requirements were greatest in racing dogs, followed by working dogs and hunting dogs, whilst the energy requirements of pet dogs and kennel dogs were least. Maintenance energy requirements were less in neutered compared with sexually intact dogs (P<0.001), but there was no effect of sex. Further, reported activity level tended to effect the maintenance energy requirement of the dog (P = 0.09). This review suggests that estimating maintenance energy requirements based on BW alone may not be accurate, but that predictions that factor in husbandry, neuter status and, possibly, activity level might be superior. Additionally, more information on the nutrient requirements of older dogs, and those at the extremes of body size (i.e. giant and toy breeds) is needed.

Menhaden oil administration to dogs treated with radiation for nasal tumors demonstrates lower levels of tissue eicosanoids

Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) or menhaden oil may reduce inflammatory eicosanoids (prostaglandin E₂, thromboxane B₂, leukotriene B₄, and 11-dehydro thromboxane B₂), matrix metalloproteinases (MMPs), and blood lactate in dogs with nasal carcinomas receiving radiation therapy. We hypothesized that menhaden oil would reduce inflammation from radiation damage and lower blood lactate levels in dogs with nasal carcinoma. In a randomized, double-blind, placebo-controlled clinical study, 12 dogs with malignant carcinomas of the nasal cavity were given dietary menhaden oil (DHA and EPA) or soybean oil (control) and then received radiation therapy. Megavoltage radiation was delivered in 18 fractions to a total dose of 56 Gy. Blood levels of DHA, EPA, insulin, glucose, lactic acid, and MMPs 2 and 9; resting energy expenditure; and inflammatory eicosanoids from nasal biopsies were measured throughout radiation therapy. Samples were obtained from each patient 1 week before the start of radiation therapy, at start of radiation, and 7, 18 (end of radiation therapy), and 42 days after radiation was initiated. Dogs that are fed with menhaden oil had significantly (P < .05) higher plasma concentration of DHA by 500% and EPA by 200% and had significantly lower tissue inflammatory eicosanoids and decreased resting energy expenditure by 20% when compared with controls. Increased plasma DHA was significantly associated (P < .05) with decreased plasma lactic acid and MMPs. These data may suggest that dietary fish oil could reduce some detrimental inflammatory eicosanoids and metabolic consequences of radiation therapy.

Making sense of blood gas results

Recent technologic advances have allowed the production and marketing of cage-side blood gas analyzers to private practitioners. The widespread use of cage-side portable blood gas analyzers in veterinary practices has increased the need to develop the basic skills of blood gas analysis as part of a tool kit for practicing veterinarians. Rapid expansion of emergency and critical care medicine as a specialty and increased numbers of veterinary emergency and veterinary specialty practices have occurred concurrently with the availability of blood gas analyzers that are affordable for private practitioners. As a result, evaluation of blood gas results is no longer an activity confined to academic institutions and has become a daily part of many practicing veterinarians' activities.

Challenges in measuring energy expenditure in companion animals: a clinician's perspective

Standard recommendations as to how much to feed dogs and cats are based on the average requirements of unstressed healthy laboratory dogs and cats of normal body condition undertaking modest amounts of exercise in a thermoneutral environment, but most clinical patients do not conform to these norms. Most clinicians estimate the energy expenditure of patients using a factorial calculation that adjusts for any differences from the norm, but little information exists upon which to base these adjustments. Furthermore, individual variation in energy expenditure is substantial even in dogs and cats under closely defined physiological conditions, and the estimate of energy expenditure obtained by using a factorial calculation can differ by a substantial margin from the energy expenditure of an individual. Detailed dietary histories provide an estimate of individual energy requirements but are time consuming to perform and rely on several assumptions. There are also no readily available point-of-care methods for measuring the energy expenditure of dogs and cats. There is a need, therefore, for further research concerning factors that affect energy expenditure of dogs and cats and methods of measuring energy expenditure in individual patients.

Resting energy expenditure and body composition of Labrador Retrievers fed high fat and low fat diets

A high dietary fat intake may be an important environmental factor leading to obesity in some animals. The mechanism could be either an increase in caloric intake and/or a decrease in energy expenditure. To test the hypothesis that high fat diets result in decreased resting energy expenditure (REE), we measured REE using indirect calorimetry in 10-adult intact male Labrador Retrievers, eating weight-maintenance high-fat (HF, 41% energy, average daily intake: 8018 +/- 1247 kJ/day, mean +/- SD) and low-fat (LF, 14% energy, average daily intake: 7331 +/- 771 kJ/day) diets for a 30-day period. At the end of each dietary treatment, body composition measurements were performed using dual-energy X-ray absorptiometry. The mean +/- SD REE was not different between diets (4940 +/- 361 vs. 4861 +/- 413 kJ/day on HF and LF diets respectively). Measurements of fat-free mass (FFM) and fat mass (FM) also did not differ between diets (FFM: 26.8 +/- 2.3 kg vs. 26.3 +/- 2.5 kg; FM: 3.0 +/- 2.3 vs. 3.1 +/- 1.5 kg on HF and LF diets respectively). In summary, using a whole body calorimeter, we found no evidence of a decrease in REE or a change in body composition on a HF diet compared with LF diet.

Metabolic alterations in dogs with osteosarcoma

OBJECTIVE

To evaluate changes in resting energy expenditure (REE) as well as protein and carbohydrate metabolism in dogs with osteosarcoma (OSA).

ANIMALS

15 weight-stable dogs with OSA that did not have other concurrent metabolic or endocrine illness and twelve 1-year-old sexually intact female Beagles (control dogs).

PROCEDURES

Indirect calorimetry was performed on all dogs to determine REE and respiratory quotient (RQ). Stable isotope tracers (15N-glycine, 4.5 mg/kg of body weight, IV; 6,6-deuterium-glucose, 4.5 mg/kg, IV as a bolus, followed by continuous-rate infusion at 1.5 mg/kg/h for 3 hours) were used to determine rate of protein synthesis and glucose flux in all dogs. Dual-energy x-ray absorptiometry (DEXA) scans were performed to determine total body composition.

RESULTS

Accounting for metabolic body size, REE in dogs with OSA was significantly higher before and after surgery, compared with REE of healthy control dogs. The RQ values did not differ significantly between groups. Dogs with OSA also had decreased rates of protein synthesis, increased urinary nitrogen loss, and increased glucose flux during the postoperative period.

CONCLUSIONS AND CLINICAL RELEVANCE

Alterations in energy expenditure, protein synthesis, urinary nitrogen loss, and carbohydrate flux were evident in dogs with OSA, similar to results documented in humans with neoplasia. Changes were documented in REE as well as protein and carbohydrate metabolism in dogs with OSA. These changes were evident even in dogs that did not have clinical signs of cachexia.

Day-night pattern of energy expenditure and body temperature in cachectic tumour-bearing rats

The implication of an increase in energy expenditure in cancer cachexia, which seems to be related to the type of tumour, remains unclear. We therefore investigated the energy metabolism and body temperature in anorectic and cachectic rats bearing the Yoshida sarcoma (TB), in comparison with pair-fed (PF) and ad-libitum fed (AL) control rats. The resting energy expenditure was higher in the TB than in the two control groups when corrected for the modifications of body composition. However, the total energy expenditure did not differ between the TB and the AL, presumably because of the drop of activity in TB. There was a temporal distribution of differences in energy expenditure with higher energy expenditure in TB than in AL during the diurnal phase and a lack of difference during the nocturnal phase. The TB presented a fever, which was limited to the diurnal period. Moreover, the acrophase of the body temperature rhythm was delayed in the TB. These results highlight the circadian effects of tumour development on the energy metabolism of the host and hint to the possible implication of cytokines.

Paraneoplastic syndromes

The importance of paraneoplastic syndromes is often underestimated in the horse. Clinically, paraneoplastic syndromes can cause greater morbidity than the actual physical presence of the malignant tumor. The appearance may be the first sign of a malignancy and may be so severe that appropriate therapy for the underlying cancer is not initiated. This article reviews some of the most common paraneoplastic syndromes that are likely to occur in the horse.

Interventional nutrition for the cancer patient

Dogs and cats with cancer have significant alterations in carbohydrate, protein, and fat metabolism, which can result in cancer cachexia and subsequently can decrease quality of life, reduce response to therapy, and shorten survival time. Nutritional modulation may be beneficial in the treatment of cancer patients to reverse these metabolic alterations. There is evidence that foods relatively low in simple carbohydrates with moderate amounts of high-quality protein, fiber, and fat (especially fats of the omega-3 fatty acid series) are beneficial for pets with cancer. In addition, certain supplemental nutrients may have potential to reduce the risk of developing cancer, or the growth and metastases of established malignant disease. Nutritional intervention can be a powerful tool for controlling malignant disease and for reducing toxicity associated with chemotherapy and radiation therapy.

The effect of levothyroxine treatment on resting energy expenditure of hypothyroid dogs

Thirty adult, client-owned dogs were diagnosed with hypothyroidism based on history, physical examination findings, hematologic and biochemical abnormalities, thyrotropin (TSH) response testing, endogenous canine thyrotropin (cTSH) concentration, or both, and total serum thryoxine concentration. All dogs received levothyroxine (L-thyroxine) at an initial dose of 22 micrograms/kg PO sid in either a tablet (13 dogs) or chewable form (17 dogs). Energy expenditure of each dog during apparent rest was estimated with an open-flow indirect calorimetry system by determining the rates of carbon dioxide production and oxygen consumption. Energy expenditure of apparent rest (EE) was lower in untreated hypothyroid dogs compared with reference values for EE. After treatment with L-thyroxine, EE of the hypothyroid dogs was significantly (P < .05) higher than pretreatment values.

Perioperative nutritional support for the animal with cancer

Tumors directly consume nutrients and produce paraneoplastic pathometabolic changes in food use efficiency. In combination with anorexia, negative energy balance and nutrient depletion can be extensive. Refeeding against catabolic changes supports general and specific host defenses. Enteral feeding methods are preferred to parenteral techniques and nutrient profiles are available that appear to favor host repletion.