Sonographic Evaluation of Liver Hemodynamic Indices in Overweight and Obese Dogs

In vivo pharmacokinetic study and PBPK modeling: Comparison between 3D-printed nanocrystals and solid dispersions

The solubility of drugs remains one of the most challenging aspects of formulation development. Several technologies exist to enhance the properties of poorly soluble drugs, with nanocrystal (NC) and solid dispersion (SD) technologies being among the most important. This work compared NCs and SDs under identical conditions using albendazole as a model drug and 3D printing technology as the delivery method. SDs were initially prepared and characterized, and then compared to the NCs system. Techniques such as TGA, DSC, XRD, FTIR, SEM, and confocal Raman microscopy were employed to assess the solid-state properties and formulation homogeneity. Solubility and dissolution profiles were evaluated under simulated gastric and intestinal conditions. An in vivo pharmacokinetic study was performed in dogs comparing 3D-printed formulations (NC-3D and SD-3D) with a control group treated with the pure drug (ABZ-C). A PBPK model was developed also in dogs to further analyse the results. While no statistically significant differences were observed in the in vitro dissolution profiles in 0.1 N HCl, differences emerged in precipitation time and solubility at intestinal pH (6.8). The pharmacokinetic study revealed improvements in the pharmacokinetic profile of both systems compared to the control, as expected. Between the NCs and the SD, the NC system demonstrated significantly superior pharmacokinetic parameters of interest. The PBPK model helped to explain the differences observed in the in vivo study. The results suggest that nanocrystal technology is more effective at enhancing the in vivo performance of Class II drugs, at least when using albendazole as the model drug.

Body Weight Development in Adult Dogs Fed a High Level Resistant Starch Diet

This study investigated the effect of Dodamssal rice, which has a high content of resistant starch, on obesity and hematologic properties in dogs. In Experiment 1, 24 spayed dogs were divided into three feeding groups: normal-fat basal diet (control), high-fat diet with 12% normal amylose type rice (hNAR), and high-fat diet with 12% high amylose type rice (Dodamssal rice; hHAR). In Experiment 2, 8 spayed dogs were assigned to a normal amylose type rice (NAR) group and a high amylose type rice group (HAR) with a normal-fat basal diet. After 24 weeks, an increase in weight and blood cholesterol was observed in both high-fat diet groups for Experiment 1. Specifically, an increase in serum alanine aminotransferase was observed over time in the hNAR group compared with that of the control; however, no such patterns were present in the hHAR group. Further, a significant weight-loss effect was observed in the HAR group in Experiment 2 at 4 weeks. The effect on body weight was due to the reduced digestibility of amylose and thereby lower dietary ME content. Overall, this confirmed that Dodamssal rice had a positive effect on weight loss in dogs, and these results suggest that Dodamssal rice has potential value as a raw ingredient for preventing obesity in dogs.

Ultrasonographic characteristics of the portal venous system of 37 healthy, unsedated, student-owned cats: A prospective study

OBJECTIVE

The aim of this study was to determine portal vein and divisional branch diameters and portal vein velocities in healthy, unsedated cats, using B-mode and Doppler ultrasound.

ANIMAL

Thirty-seven healthy, adult cats, all owned by students.

PROCEDURE

Enrollment of cats in the study was done prospectively. Ultrasonographic imaging in both the longitudinal and transverse planes was assessed, with all examinations and measurements done by the same person. The assessment included the following 3 sites: extra-hepatic portion of the portal vein, intra-hepatic branches of the portal vein, and the aorta at the level of the porta hepatis. The Shapiro-Wilk test was used for normality and P < 0.05 was used to define statistical significance.

RESULTS

Both the extra-hepatic portion of the portal vein and the porta hepatis were identified in all 37 cats (100%), whereas the aorta was recorded in 31 (84%), and the left and right intra-hepatic branches of the portal vein were seen in 29 (78%). Pulsed-wave Doppler ultrasound of the portal vein was obtained in 32 cats (86%). In longitudinal view, average maximal diameter of the extra-hepatic portal vein was 3.6 mm (± 0.7 mm), and the mean portal flow velocity was 14.6 cm · s (± 4.3 cm · s). In transverse view, average maximal diameter was 4.8 mm (± 0.8 mm) for the extra-hepatic portal vein, and 3.1 mm (± 0.8 mm) and 2.6 mm (± 0.7 mm) for the left and right intra-hepatic branches, respectively. The portal-vein-to-aorta ratio averaged 1.2 (± 0.2).

CONCLUSION

This study produced sonographic data of the portal venous system in healthy, conscious adult cats, which may be useful during investigation of liver diseases, including congenital and acquired liver diseases.

Sedation with dexmedetomidine is associated with transient gallbladder wall thickening and peritoneal effusion in some dogs undergoing abdominal ultrasonography

Background

Dexmedetomidine often is used for sedation before or during abdominal ultrasonography. The effect of dexmedetomidine on gallbladder wall thickness is unknown.

Hypothesis/Objectives

To investigate the relationship between dexmedetomidine administration and gallbladder wall thickening in dogs. The hypothesis was that sedation with dexmedetomidine will cause transient gallbladder wall thickening. Gallbladder wall thickness will be associated with duration of sedation and recumbency position.

Animals

Seventy‐nine client owned dogs and 10 healthy research dogs.

Methods

A prospective observational study (n = 79) was used to establish the prevalence of gallbladder wall thickening (> 2.0 mm) after sedation with dexmedetomidine. A randomized, crossover study (n = 10) was used to evaluate the effect of time and recumbency position on the development of gallbladder wall thickening. Linear mixed models were used.

Results

The proportion of client‐owned dogs that developed gallbladder wall thickening was 24.05% (19/79; 95% confidence interval [CI], 15.1%‐35.0%) with a median dose of dexmedetomidine of 5.0 μg/kg (range, 2.0‐12.5 μg/kg). After sedation, the proportion of research dogs that developed gallbladder wall thickening in left lateral (5/10, 50%; 95% CI, 18.7%‐81.3%) and dorsal (7/10, 70%; 95% CI, 34.8%‐93.3%) recumbency did not differ significantly (P = .45). Gallbladder wall thickening developed within 20 to 40 minutes. Duration of sedation was significantly associated with thickening of the gallbladder wall (P < .001). Five dogs developed 9 instances of peritoneal effusion in both lateral (5) and dorsal (4) recumbency.

Conclusions and Clinical Importance

Sedation with dexmedetomidine is associated with gallbladder wall thickening (> 2.0 mm) and peritoneal effusion that could be confused with pathologic etiologies.

Canine and Feline Obesity Management

Obesity and overweight have an impact on more than half of pet cats and dogs. Effective and team-based communication is essential for creating an effective weight loss plan. The diet should meet all essential nutrient requirements during energy/calorie restriction. There are several ways to initiate a weight loss plan, and regular monitoring is essential for determining if a plan is working or needs to be adjusted.

Characterization of Doppler spectrum of hepatic veins and correlation with structural and functional variables of the right ventricle in healthy dogs

Background

Spectral Doppler assessment of hepatic veins may provide information on heart function.

Hypothesis/Objectives

To assess the normal pattern of hepatic venous flow using spectral Doppler ultrasound examination; to correlate this information with structural and functional variables of the right ventricle (RV), and to analyze the impact of age, sex, body weight quartiles, heart rate, cardiac rhythm, and systolic arterial pressure on the results in healthy dogs.

Animals

Sixty‐five healthy dogs.

Methods

Cross‐sectional observational study. The direction and maximum velocity of each of the 4 possible components of venous flow were determined from pulsed‐wave Doppler examination of the hepatic veins. In addition, structural and functional parameters (TAPSE, longitudinal strain, FAC%, S′, E_t/A_t, and E′_t/ A′_t) of the RV were evaluated.

Results

The same phase patterns for different waves were seen in all animals: A and V were retrograde waves, and S and D were anterograde waves. The velocity of the spectral waves increased with body weight (P < .05) and could be correlated with functional indices of the RV. A significant difference was found when comparing morphometric indices with body weight quartiles (P < .05). In addition, intra‐and inter‐observer assessments showed low variability. The mean duration of the examinations was 5.2 minutes.

Conclusions and Clinical Importance

Hepatic spectral Doppler findings can be correlated with systolic and diastolic indices of the RV and vary with body weight.