First-Intention Incisional Wound Healing in Dogs and Cats: A Controlled Trial of Dermapliq and Manuka Honey

This study aimed to compare incisional wound healing in cats and dogs after the topical application of Μanuka honey and a new medical device, Dermapliq. Comparisons were made between each treatment and control, between the two treatments, and between dogs and cats. Twelve cats and twelve dogs were included in this study, and the impact of the two substances was examined through cosmetic, clinical, ultrasonographical, and histological evaluation. The use of Dermapliq in first-intention wound healing achieved a significantly better cosmetic evaluation score and better total clinical score at days 20-41, compared to the control, in both dogs and cats. The ultrasonographically estimated wound area was smaller with Dermapliq compared to the control. Wounds treated with Dermapliq showed histologically less inflammation compared to the control. The use of Manuka honey did not show a significantly better cosmetic score compared to the control. Skin thickening was significantly higher after using Manuka honey compared to the control and so was the total clinical score. However, the median wound area, as was evaluated ultrasonographically, was significantly smaller when wounds were treated with Manuka honey, the difference being more apparent in dogs. Dermapliq was proven to be a better choice in achieving favorable wound healing than Manuka honey in dogs and cats in first-intention healing. In our study, cats had a statistically better cosmetic score and less skin thickening and scar width compared to dogs. Histologically, cats showed significantly less edema, higher inflammation and angiogenesis scores, and lower fibroblast and epidermis thickening scores when compared to dogs.

Comparison of Two Surgical Techniques Based on the Semitendinosus Myocutaneous Flap in Cats

The objective of this experimental study was to compare the semitendinosus (ST) to the split-semitendinosus (SST) myocutaneous flap in covering distal limb skin defects in cats. Twenty-eight purpose-bred laboratory DSH cats were used and allocated into two groups (ST-group (A); n = 14, SST-group (B); n = 14). ST flaps, based on the distal muscle pedicle, and SST flaps, after longitudinal division of the muscle based on both muscle pedicles, were tested over skin defects created on the medial distal tibia. Clinical assessment, planimetry, CT-angiography (CTA) and histological examination were compared between groups. Days to complete flap healing between ST and SST-flaps (30.36 ± 9.1, 32.29 ± 5.44, respectively) and final total flap areas (68.36% ± 27.18, 51.83% ± 22.48, respectively) revealed no significant differences. On CTAs, the caliber of the distal caudal femoral vein on day 10 was statistically significant higher (p < 0.001) for group A and a significantly higher caliber of the distal caudal femoral artery on day 30 for group B (p = 0.021). Histology revealed statistically higher degeneration at 6 months (p = 0.047) for group A, and statistically higher fibrosis at 12 months (p = 0.019) for group B. Both ST and SST flaps had similar healing times and provided coverage of skin tibial defects in cats.

Use of a semitendinosus myocutaneous flap for the coverage of hindlimb full-thickness skin defects in cats

BACKGROUND

The management of feline hindlimb full-thickness skin defects is challenging. On the other hand, the use of a semitendinosus (ST) myocutaneous flap for their coverage has not been reported.

OBJECTIVES

To describe the ST flap and compare it with second intention healing for managing hindlimb full-thickness skin defects.

METHODS

In 12 purpose-bred laboratory domestic short-haired cats, two wounds were made on each tibia. The wounds in group A (n = 12) were covered with ST flaps, and those in group B (n = 12) were left to heal by second intention. In both groups, clinical assessment scoring and planimetry were performed between one-30 d postoperatively. Computed tomography-angiography (CTA) was performed on days zero, 10, and 30, and histological examinations were performed on days zero and 14 and at 6 and 12 mon postoperatively.

RESULTS

Statistically significant differences in the clinical assessment scores were observed between groups A and B on days 14 (p = 0.046) and 21 (p = 0.016). On the other hand, the time for complete healing was similar in the two groups. CTA revealed significant differences in the muscle width (day 0 compared to days 10 and 30 [p = 0.001, p = 0.026, respectively], and days 10 to 30 [p = 0.022]), ST muscle density, and the caliber of the distal caudal femoral artery and vein (day 0 compared to day 10 [p < 0.001], and days 10 to 30 [p < 0.001]). Histologically significant differences in inflammation, degeneration, edema, neovascularization, and fibrosis were observed on day 14 compared to zero and 6 mon, but no differences were found between the time interval of 6 and 12 mon.

CONCLUSIONS

An ST flap can be used effectively to manage hindlimb full-thickness skin defects.

Magnetic and radio-labeled bio-hybrid scaffolds to promote and track in vivo the progress of bone regeneration

This work describes the preparation, characterization and functionalization with magnetic nanoparticles of a bone tissue-mimetic scaffold composed of collagen and hydroxyapatite obtained through a biomineralization process. Bone remodeling takes place over several weeks and the possibility to follow it in vivo in a quick and reliable way is still an outstanding issue. Therefore, this work aims to produce an implantable material that can be followed in vivo during bone regeneration by using the existing non-invasive imaging techniques (MRI). To this aim, suitably designed biocompatible SPIONs were linked to the hybrid scaffold using two different strategies, one involving naked SPIONs (nMNPs) and the other using coated and activated SPIONs (MNPs) exposing carboxylic acid functions allowing a covalent attachment between MNPs and collagen molecules. Physico-chemical characterization was carried out to investigate the morphology, crystallinity and stability of the functionalized materials followed by MRI analyses and evaluation of a radiotracer uptake ([^99mTc]Tc-MDP). Cell proliferation assays in vitro were carried out to check the cytotoxicity and demonstrated no side effects due to the SPIONs. The achieved results demonstrated that the naked and coated SPIONs are more homogeneously distributed in the scaffold when incorporated during the synthesis process. This work demonstrated a suitable approach to develop a biomaterial for bone regeneration that allows the monitoring of the healing progress even for long-term follow-up studies.

Experimental study for evaluation of the efficacy of a biofilm-embedded bacteria-based vaccine against Staphylococcus chromogenes-associated mastitis in sheep

Although coagulase-negative staphylococci are the primary aetiological agents of subclinical mastitis in ewes, there is little information regarding vaccination against that infection. The objective of this study was to evaluate the efficacy of a vaccine against staphylococcal mastitis in ewes under experimental conditions. The antigen in the vaccine is based on a bacterin of Staphylococcus aureus strain, expressing the exopolysaccharide poly-N-acetylglucosamine (PNAG), which is involved in biofilm formation by these bacteria. Ewes in groups A (n = 17) or B (n = 6) were given an initial vaccination 5 weeks before expected lambing, followed by a repeat administration 21 days later. Ewes in groups C (n = 8) or D (n = 6) were unvaccinated controls. Ewes in group A (n = 17) or C (n = 8) were challenged with a biofilm-forming S. chromogenes; animals in subgroups A1 or C1 were challenged on the 10th and those in A2 or C2 on the 50th day after lambing. Ewes in groups B or D were uninoculated controls. Clinical examinations of ewes, ultrasonographic examinations of udder, milk yield measurements, blood sampling for detection of anti-PNAG specific antibodies and milk sample collection for bacteriological and cytological examinations were performed up to 52nd day post-challenge. Finally, biopsies were performed for mammary tissue collection for histopathological examination. Among group A ewes, 29% developed systemic signs and 59% signs in the inoculated gland; the respective figures for group C were 50% and 100% (P =  0.040 for mammary signs). The median total clinical score was 2.0 for A and 5.5 for C ewes (P =  0.025). For A, but not for C, clinical scores decreased progressively during the study (P =  0.018 and P =  0.47, respectively). The duration of mastitis was shorter in A (4 days) than in C (17.5 days) ewes (P =  0.022). Bacterial counts were lower in milk samples from A than from C ewes, for samples collected from the inoculated and the uninoculated (P <  0.01) mammary glands of these ewes. Somatic cell counts in samples from inoculated and uninoculated mammary glands of A ewes were higher than in samples of C ewes (P <  0.02). There were differences for gray-scale evaluations during ultrasonographic examination and for milk yield measurements between groups (P <  0.01). Median bacterial counts in tissue samples from A ewes (0 cfu g^-1) were lower than in ones from C (6.5 cfu g^-1) ewes (P =  0.041). The median score for histopathological findings in tissue samples from inoculated glands of A was lower than that for C ewes: 1 versus 2 (P =  0.014). It is concluded that mastitis was less severe in vaccinated animals, as indicated by a wide array of measures.