Ultrasonographic evaluation of skin thickness in small breed dogs with hyperadrenocorticism

Computed tomographic findings and clinical features in dogs with canine cutaneous lymphoma: 10 cases (2007-2018)

OBJECTIVE

To report clinical features, CT findings, treatment protocols, and outcomes for dogs in which canine cutaneous lymphoma (CCL) was diagnosed.

ANIMALS

10 client-owned dogs with CCL.

PROCEDURES

Medical records of dogs in which a diagnosis of CCL had been made between September 2007 and July 2018 and in which CT had been performed prior to treatment were reviewed. All available CT studies were reviewed, and an anatomical reference system was developed to map observed lesions. Treatment protocols and patient outcomes were summarized.

RESULTS

14 CT examinations were performed on the 10 dogs, and 9 dogs had lesions consistent with CCL on CT images. Nodular lesions were present in 8 dogs, and cutaneous or subcutaneous mass lesions were seen in 3. Well-defined, diffusely distributed, contrast-enhancing, cutaneous or subcutaneous nodules were most common; mass lesions were more variable in appearance. Nine dogs had lymphadenopathy, with the mandibular and axillary lymph nodes most commonly affected. Four dogs had confirmed nodal involvement, and 4 had confirmed visceral involvement. Nine dogs received treatment with chemotherapy, and 5 had a complete response.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated that dogs with CCL may have a wide spectrum of CT findings. Many of these lesions, including affected lymph nodes, would be unlikely to be detected clinically, suggesting that CT may be a useful modality to assess the severity of disease and for guiding selection of local versus systemic treatment.

Soft Elastomeric Capacitor for Strain and Stress Monitoring on Sutured Skin Tissues

Sutures are ubiquitous medical devices for wound closures in human and veterinary medicine, and suture techniques are frequently evaluated by comparing tensile strengths in ex vivo studies. Direct and nondestructive measurement of tensile force present in sutured biological skin tissue is a key challenge in biomechanical fields because of the unique and complex properties of each sutured skin specimen and the lack of compliant sensors capable of monitoring large levels of strain. The authors have recently proposed a soft elastomeric capacitor (SEC) sensor that consists of a highly compliant and scalable strain gauge capable of transducing geometric variations into a measurable change in capacitance. In this study, corrugated SECs are used to experimentally characterize the inherent biomechanical properties of canine skin specimens. In particular, an SEC corrugated with a re-entrant hexagonal honeycomb pattern is studied to monitor strain and stresses for three specific suture patterns: simple interrupted, cruciate, and intradermal patterns. Stress is estimated using constitutive models based on the Fractional Zener and the Kelvin-Voigt models, parametrized using a particle swarm algorithm from experimental data and results from a validated finite element model. Results are benchmarked against findings from the literature and show that SECs are valuable for clinical evaluation of tensile force in biological skins. It was found that both the ranking of suture pattern performance and the sutured skin's Young's modulus using the proposed approach agreed with data reported in the literature and that the estimated stress at the suture level closely matched that of an approximate finite element model.

The effects of gel pad thickness on the evaluation of skin structures using ultrasonography in normal dogs

Gel pads are commonly used in skin ultrasonography; however, the effects of their thickness are unknown. This study investigated the effects of pad thickness on measurements of skin thickness in 10 beagle dogs. Sonograms to measure neck skin thickness were captured without pads and using pads with thicknesses of 3, 5, 10, and 20 mm. Without pads, acoustic shading was observed due to air bubbles in the coupling gel. With 20-mm pads, echogenic artifacts were observed on the skin surface. Entry echo with 20-mm pads was significantly higher than with 3-mm pads. This suggests that visibility of the skin structure could be affected when a gel pad is not used or when a thick gel pad is selected.

The Influence of Skin Thickness on Flash Glucose Monitoring System Accuracy in Dogs with Diabetes Mellitus

Simple Summary

A flash glucose monitoring system (FGMS) has been validated for use in dogs with diabetes mellitus and diabetic ketoacidosis. It continuously measures the glucose in the interstitial fluid through a small filament (5 mm long) inserted under the skin. Interstitial glucose concentrations are reportedly comparable to whole blood glucose concentrations. However, several factors can influence the performance of interstitial sensors, including the proportion of interstitial fluid in a tissue. The influence of skin thickness on flash glucose monitoring system accuracy has not been investigated in previous studies; therefore, the aim of this study was to evaluate whether FGMS accuracy is affected by skin thickness. On the basis of our results, skin thickness seems to affect FGMS measurements; the mean bias was significantly inversely correlated (p = 0.02; r = −0.6) with the mean skin thickness, and clinical accuracy according to ISO 15197:2013 criteria was observed only in dogs with skin thickness > 5 mm, with 99% of the results falling in zone A + B of the Parkes consensus error grid analysis. In dogs with thin skin (<5 mm), the clinical accuracy was low, and the results should be interpreted with caution.

Abstract

A flash glucose monitoring system (FGMS) has been validated for use in diabetic dogs. However, it is unknown whether skin thickness affects FGMS measurements. The aim of this study was to evaluate whether FGMS accuracy is affected by skin thickness. Fourteen client-owned diabetic dogs on insulin treatment were prospectively enrolled in the study. The dogs were divided into two groups according to their ultrasound-measured skin thickness: dogs with skin thickness < 5 mm (Group 1) and dogs with skin thickness > 5 mm (Group 2). On days 1, 7 and 14, glucose curves were obtained simultaneously using the FGMS and a validated portable blood glucose meter. Paired measurements were used to calculate the mean bias and to determine accuracy according to ISO 15197:2013 criteria. The mean bias was significantly inversely correlated (p = 0.02; r = −0.6) with the mean skin thickness. Clinical accuracy was observed only in Group 2, with 99% of the results in zone A + B of the Parkes consensus error grid analysis. In conclusion, skin thickness seems to affect FGMS measurements, and the device is accurate in dogs with thicker skin (>5 mm); in dogs with thin skin (<5 mm), the clinical accuracy is low, and the results should be interpreted with caution.

Penetration depth study of 830 nm low-intensity laser therapy on living dog tissue

Background and Aim

Recent studies have shown that low-intensity laser therapy (LILT) enhances chronic wound healing, reduces pain, reduces inflammation, and improves post-operative rehabilitation. However, clinical outcomes in the veterinary use of LILT vary between different experimental studies. This is explained by improper laser parameter settings and limits of its penetration depth. This study aimed to investigate the penetration depth of 830 nm LILT on living dog tissue in different operating modes. This entailed continuous wave (CW) versus pulse wave (PW) and with contact versus non-contact techniques of the laser probe at different tissue-laser probe distances. The results can be applied for use in clinical practice.

Materials and Methods

Twenty-four dogs that had undergone abdominal surgery were included in this study. The laser parameters were set at 200 mW, fluence of 4 J/cm² and the laser power output denoted as mean output power (MOP) was measured by a power meter.

Results

The MOP of the 830 nm CW laser was significantly higher than the PW laser (p<0.05). The MOP of the contact technique was significantly greater than that of the non-contact technique in both CW and PW modes (p<0.05). The MOP through the skin tissue was between 16.09 and 18.60 mW (8.05-9.30%) for the contact technique and 8.73 and 19.36 mW (4.37-9.68%) for the non-contact technique. In the muscle-skin layer, the MOP was between 0.50 and 1.56 mW (0.25-0.78%) and the MOP was not detected using the non-contact technique with a 5 cm tissue-laser probe distance.

Conclusion

Our study indicates that 830 nm LILT (with laser parameter setting at 200 mW, fluence of 4 J/cm² for both contact and non-contact techniques, and tissue-laser probe distance up to 5 cm) was appropriate for treatments within 14 mm of depth. However, the use of 830 nm LILT for an application in which the target tissue is deeper than 14 mm may limit its positive effect.