Body fat assessment by computed tomography and radiography in normal Beagle dogs

Use of computed tomography in the evaluation of the body condition of blue-fronted Amazon parrots (Amazona aestiva)

BACKGROUND

We aimed to evaluate the body condition score (BCS) of blue-fronted Amazon parrots (Amazona aestiva) using computed tomography scans to correlate muscle measurements with BCS and identify the primary fat deposit areas.

METHODS

Forty-two blue-fronted Amazon parrots were allocated into five groups based on their BCS: 1 (very thin), 2 (thin), 3 (ideal), 4 (ideal) and 5 (obese). Muscle and fat areas were measured using computed tomography imaging.

RESULTS

Significant between-group differences were observed in the width of the pectoral muscles and the muscle area of the left humerus, with a strong positive correlation with BCS. The fat areas in the caudal coelom region, pelvic region and axillary area showed a significant increase in birds with a BCS of 5, with a moderate correlation between fat deposit CT measurements and BCS.

LIMITATIONS

Given the minimal differences in weight among animals with a BCS of 2-4, weight was a point of contention when categorising the animals into each score category.

CONCLUSION

The pectoral muscle was found to be the most reliable indicator for determining BCS in blue-fronted Amazon parrots. However, the primary fat deposit areas should also be included in the BCS assessment, with the caudal coelom, pelvic region and axillary region being critical areas to consider.

Correlation Between Hyperlipidemia-Related Diseases and Thorax/Thigh Circumference Ratio Along with Body Condition Score in Dogs Focusing on Molecular Mechanism: A Pilot Study and Literature Review

There are some limitations to using the body condition score (BCS) for client education to prevent obesity, hyperlipidemia-related diseases, and orthopedic diseases in dogs because it is hard to quantify in detail. Especially in small dogs, patellar luxation is a common orthopedic disease that is related to obesity and the hind leg muscle. In this pilot study, the author evaluated the thorax/thigh circumference ratio as a prognostic evaluation index, along with the BCS, for assessing patellar dislocation and other hyperlipidemia-related diseases and states such as hypertriglyceridemia and obesity-related orthopedic disease in small dogs. Eleven client-owned dogs were selected randomly among patients that visited Bundang New York Animal Hospital, South Korea from June 2021 to August 2024. According to the results, triglycerides (TG) showed a negative correlation with thorax/thigh value (R = -0.585, p-value = 0.059) and a strong positive correlation with thigh circumference (R = 0.749, p-value = 0.008). Total cholesterol (TC) showed a strong positive correlation with thigh circumference (R = 0.776, p-value = 0.005), whereas the thorax/thigh value showed a negative correlation with the medial patella luxation (MPL) grade with low significance (R = -0.343, p-value = 0.302). These data indicate that thigh circumference can be an excellent negative indicator for hyperlipidemia and thorax/thigh value shows no correlation with medial patella luxation, which has many factors such as varus and trochlear groove. Despite the limitations of this study due to the small sample size, this pilot study is significant as it is the first trial to introduce a new indicator for monitoring hyperlipidemia at home by using a simple tape measure. Also, the author reviews molecular pathways including the ApoA-1, ApoE, and LPL genes, which are related to hyperlipidemia, to explain the results.

Supplementation with heat-killed Akkermansia muciniphila EB-AMDK19 counteracts diet-induced overweight in beagles

Obesity is a major health problem in dogs and is strongly associated with an increased risk of chronic inflammatory and metabolic diseases. The microaerophilic human gut bacterium Akkermansia muciniphila has been proposed as a potential preventive and therapeutic agent against obesity in both humans and mice; however, the protective effects of human-derived A. muciniphila against canine obesity remain unstudied. We previously demonstrated that the heat-killed A. muciniphila strain EB-AMDK19 (AMDK19-HK) isolated from the faeces of a healthy Korean exerts similar protective effects as the live bacterium in mice with high-fat-diet (HFD)-induced obesity. Here, we evaluated the effects of AMDK19-HK on body weight, body fat mass, haematological and biochemical parameters, and faecal microbiota composition in beagles fed an HFD for 12 weeks. AMDK19-HK supplementation effectively suppressed body weight increase, body fat deposition and serum triglyceride increase in the canine model; however, no significant changes in the overall haematological and biochemical parameters were observed, reflecting the direct anti-obesity effect of AMDK19-HK. Additionally, 16S rRNA gene sequencing revealed that AMDK19-HK supplementation induced significant changes in the faecal bacterial community, with an increased abundance of Firmicutes and a decreased abundance of Bacteroidota. These results suggest that AMDK19-HK can be used as a dietary supplement to counteract diet-induced overweight in dogs.

Combined use of body condition score, radiography, ultrasonography and computed tomography in body condition evaluation of crab-eating fox (Cerdocyon thous)

This study aimed to evaluate the application of radiography, ultrasonography, and computed tomography (CT) as auxiliaries in the determination of body fat and musculature in crab-eating foxes (Cerdocyon thous). Eight animals were evaluated and classified based on the body condition score (BCS) scale. The total cut volume, total visceral volume, total subcutaneous volume, visceral fat volume, subcutaneous fat volume, and total fat volume were measured. The correlation of the BCS with the other data was determined. In the ultrasound, there was a correlation of the vertebral epaxial musculature score (VEMS) with body weight, BCS, muscle mass score (MMS), animal's height, and height at the withers. In the radiographic analysis, the amount of subcutaneous fat obtained in L3 vertebrae did not present a significant correlation with BCS, as opposed to L6. In the tomographic analysis, TFV/L6, VFV/L6, and SFV/L6 correlated with BCS in L3, and only SFV /L6 in L6. When the ratios between fat volumes were correlated, the correlation with BCS occurred only in L6 in the TFV/TBV, SFV/SVC, and VFW variants. Radiography and CT were effective and had a good association with BCS. With the CT it was possible to demonstrate the distribution of total fat at the level of the L3 slice. The ratio of calculations considering the length of the L6 vertebra was more adequate, while at the level of L6 the ratio between the volumes of the compartments was more effective.

Postoperative Computed Tomographic Assessment of the Complete Resection of an Infiltrative Lipoma Compressing the Spinal Cord in a Dog

Infiltrative lipomas, which are locally invasive tumors composed of well-differentiated adipocytes, are histologically identical to lipomas but have a tendency to infiltrate adjacent muscle and fibrous tissue without metastasis, such as muscle; connective tissue; bone; and, in rare cases, peripheral nerves and the spinal cord. They differ from liposarcomas yet also exhibit neoplastic cell infiltration and often recur despite surgical removal. A 10-year-old spayed Maltese female dog presented with hindlimb paresis and back pain for two months. Computed tomography and magnetic resonance imaging revealed an extensive fatty mass impinging on the vertebral canal, compressing the spinal cord, and extending into the surrounding muscle layers and thoracic cavity. The mass was surgically removed, and subsequent postoperative computed tomography confirmed complete removal of the mass using Vitrea® advanced visualization fat measurement. Histopathological analysis confirmed that the mass was an infiltrative lipoma. The patient's symptoms completely resolved after surgery, with no recurrence reported at the 2-year follow-up. This case highlights the benefits of using postoperative computed tomography combined with the automated fat measurement technique to determine whether reoperation is necessary or to predict patient prognosis by identifying potential residual lipoma post-surgery.

Field-based adipose tissue quantification in sea turtles using bioelectrical impedance spectroscopy validated with CT scans and deep learning

Loss of adipose tissue in vertebrate wildlife species is indicative of decreased nutritional and health status and is linked to environmental stress and diseases. Body condition indices (BCI) are commonly used in ecological studies to estimate adipose tissue mass across wildlife populations. However, these indices have poor predictive power, which poses the need for quantitative methods for improved population assessments. Here, we calibrate bioelectrical impedance spectroscopy (BIS) as an alternative approach for assessing the nutritional status of vertebrate wildlife in ecological studies. BIS is a portable technology that can estimate body composition from measurements of body impedance and is widely used in humans. BIS is a predictive technique that requires calibration using a reference body composition method. Using sea turtles as model organisms, we propose a calibration protocol using computed tomography (CT) scans, with the prediction equation being: adipose tissue mass (kg) = body mass - (-0.03 [intercept] - 0.29 * length2/resistance at 50 kHz + 1.07 * body mass - 0.11 * time after capture). CT imaging allows for the quantification of body fat. However, processing the images manually is prohibitive due to the extensive time requirement. Using a form of artificial intelligence (AI), we trained a computer model to identify and quantify nonadipose tissue from the CT images, and adipose tissue was determined by the difference in body mass. This process enabled estimating adipose tissue mass from bioelectrical impedance measurements. The predictive performance of the model was built on 2/3 samples and tested against 1/3 samples. Prediction of adipose tissue percentage had greater accuracy when including impedance parameters (mean bias = 0.11%-0.61%) as predictor variables, compared with using body mass alone (mean bias = 6.35%). Our standardized BIS protocol improves on conventional body composition assessment methods (e.g., BCI) by quantifying adipose tissue mass. The protocol can be applied to other species for the validation of BIS and to provide robust information on the nutritional and health status of wildlife, which, in turn, can be used to inform conservation decisions at the management level.

Using bioelectrical impedance analysis for modeling regression and predicting body fat accumulation in dogs in East Thailand

Background and Aim: Obesity in dogs leads to several health problems, such as premature death, and contributes to other diseases. Recently, body fat percentage has been considered to represent the body condition of dogs, and bioelectrical impedance analysis (BIA) is the most effective method for accurately measuring body fat in dogs. In Thailand, information on the body condition of dogs is limited, and there is no standard body fat level for Thai or mongrel dogs. This study was designed to evaluate and analyze the body fat percentage in dogs through BIA using a handheld instrument. The results of this study can help enhance the quality of life and health of dogs and aid in setting a standard body fat level for Thai or mongrel dogs. Materials and Methods: The body fat percentage of 340 Thai and mongrel dogs in East Thailand was measured in the standing position, and the body condition score (BCS) (range, 1–5), sex, sterilization status, age, type of diet, and lifestyle were recorded. A linear regression model was developed to compare the variables and the predicted body fat percentage, and multiple linear regressions were used to analyze the factors for body fat increment. Results: The linear regression model used to estimate the percentage of body fat (y) for each BCS (x) was y = 0.84 + 8.36x (R2 = 0.7219; p < 0.0001); the average body fat percentage was 27.52% for all studied dogs; specifically, 24.83% for the Thai Bangkaew, 26.42% for the Thai Ridgeback, and 27.65% for mongrels. The median body fat percentage was significantly higher in female than in male dogs. We found that as age increases, body fat percentage also increases; this increasing trend begins at the age of 5 years. However, increasing the level of activity and decreasing meal frequency leads to an increase in body fat percentage in neutered male dogs. Conclusion: The average body fat percentage of dogs in East Thailand is 27.52% and this value is expected to increase when these dogs reach the age of 5 years. BIA is a valid and effective measurement tool for detecting the body fat percentage in dogs.

Effects of Synbiotic Preparation Containing Lactobacillus gasseri BNR17 on Body Fat in Obese Dogs: A Pilot Study

Simple Summary

The present study evaluated the effectiveness of a synbiotic preparation containing L. gasseri BNR17 on body fat in obese dogs. Body weight and the body condition score showed a significant reduction after 10 weeks of synbiotic preparation administration compared with those at baseline (0-week). The subcutaneous fat mass at the level of the third lumbar vertebra and its proportion, compared with the body mass, reduced significantly after 10 weeks of synbiotic preparation administration, compared with those at baseline. Following synbiotic supplementation, microbiome analysis revealed increased microbial diversity, and functional analysis of the microbiota showed an increased abundance of carbohydrate and lipid metabolism. Based on these results, we consider that synbiotic preparation containing L. gasseri BNR17 may play a role in reducing body fat and resolving obesity.

Abstract

Obesity is an important health concern in humans and dogs. It can cause a variety of secondary problems, including low bacterial diversity. Several approaches have been tried to solve this problem; one of them is probiotic supplementation. Lactobacillus gasseri BNR17 is derived from breast milk and has been proven to be effective for obesity in humans. However, there have been no studies using a synbiotic preparation containing L. gasseri BNR17 for obesity management in dogs. Therefore, the present study evaluated the effectiveness of a synbiotic preparation containing L. gasseri BNR17 in reducing body fat in obese dogs. A group of obese dogs were fed a synbiotic preparation for 10 weeks. Obesity variables included body weight, body condition score, subcutaneous fat thickness, subcutaneous fat mass and proportion of the fat mass. In addition, feces collected at 0-week and 10-week time points were analyzed for the intestinal microbiome. Results showed a significant decrease in body weight, body condition score, and subcutaneous fat mass and proportion at the level of the third lumbar vertebra. Diversity and functional analysis of the microbiota in obese dogs showed increased microbial diversity, and increased abundance of metabolism of carbohydrate, and lipid after supplementation with a synbiotic preparation. This study was conducted as a pilot study, and the results demonstrated that a synbiotic preparation containing L. gasseri BNR17 may play a role in reducing body fat and resolving the obesity in dogs.

Evaluation of visceral fat mass in dogs by computed tomography

In human medicine, computed tomography (CT) is the gold standard for visceral fat measurement. Research shows that the visceral fat area (VFA) of the umbilical slice is significantly correlated with the visceral fat volume (VFV). In veterinary medicine, however, few studies have evaluated visceral fat using CT. This study aimed to evaluate the visceral fat in dogs using CT images, and determine if the slice significantly correlated with VFV to simplify visceral fat measurements. This retrospective study includes data on 90 dogs that underwent whole-body CT scans for diagnostic purposes. VFV was calculated as the product of VFA and thickness in each CT slice; the correlation between VFV and VFA was analyzed at the level of each lumbar vertebra. Visceral fat percentage (VF%) was calculated as the ratio of the product of VFV and fat density to the body weight. Visceral fat area percentage (VFA%) was calculated as the ratio of VFA to the body area, and its correlation with the VF% and the body condition score (BCS) was analyzed. VFA was highly correlated with VFV at the level of each lumbar vertebra, with the highest correlation (r=0.964) at the L3 level. VFA% was significantly correlated with VF% (r=0.930) and weakly correlated with BCS (r=0.523). This study demonstrates that it is sufficient to use only the L3 slice for visceral fat evaluation and that the evaluation can be based on VFA% of the L3 level.