Background: The use of biological dressings has recently emerged in the management of burns and wounds. The aim of the present study was to evaluate the Nile tilapia skin as a biological dressing for full-thickness cutaneous metacarpal wounds in donkeys. The study was conducted on nine clinically healthy donkeys (n = 9). Here, fish skin dressings were obtained from fresh Nile tilapia(Oreochromis niloticusand sterilized by immersion in silver nanoparticles (AgNPs) solution for 5 min, with no change in collagen content. Bilateral, circular full-thickness excisional skin wounds (2 cm in diameter) were created on the dorsal aspect of the mid-metacarpals of each donkey. Wounds on the right metacarpals (treated wounds,n = 9) were dressed with sterile fish skins, while wounds on the left metacarpals (control wounds,n = 9) were dressed with sterile non-adherent dressing pads without any topical applications. Wound dressings were changed weekly. Wounds were evaluated microbiologically, grossly, and histologically on days 7, 14, and 21 post-wound inductions.Results: Fish skin-dressed wounds showed a significant (P < 0.0001) reduction in microbial counts (Total viable bacterial count, Staphylococcal count, and Coliform count), a significant (P < 0.0001) decrease in the wound size, and a significant reduction (P < 0.0001) in the epithelial gap compared to the untreated wounds. No frequent dressing changes were needed.Conclusions: Fish skin dressing accelerated the wound healing process and efficiently inhibited the local microbial activity and exuberant granulation tissue formation suggesting its reliable and promising application for metacarpal wounds of donkeys.

For the last few years, researchers have been interested in developing a method for chemical sterilization which may be a better alternative to surgical castration. An ideal chemical sterilant would be one that effectively arrests spermatogenesis and androgenesis as well as libido with absence of toxic or other side effects. Calcium chloride in various solutions and concentrations has been tested in many animal species, but few studies have been evaluated it in equines as a chemical sterilant. So, the objective of this study was to evaluate the clinical efficacy of chemical castration with 20 % calcium chloride dissolved in absolute ethanol in comparison with surgical castration in donkeys based on the changes in the serum testosterone level and the histopathological changes in treated testes. Twelve clinically healthy adult male donkeys were used in this study. Donkeys were divided randomly and equally into two groups: a surgical (S) group (n = 6) and a chemical (C) group (n = 6). Animals in the (S) group were subjected to surgical castration while those in the (C) group received a single bilateral intratesticular injection of 20 % calcium chloride dissolved in absolute ethanol (20 ml/testis). Animals were kept under clinical observation for 60 days. Changes in animals' behavior and gross changes in external genitalia were monitored daily. Serum concentrations of testosterone were measured prior to treatment and at 15, 30, 45 and 60 days post-treatment. Testicles in the (C) group were examined histopathologically at the end of the experiment. Chemical castration with intratesticular calcium chloride vs. surgical castration failed to reduce serum concentrations of testosterone throughout the whole duration of the study; however it induced orchitis that was evident by focal necrotic areas in seminiferous tubules, cellular infiltration of neutrophils, proliferative intertubular fibrosis with a compensatory proliferation of Leydig cells. Donkeys tolerated the intratesticular injection of calcium chloride. There were no detectable changes in the general health status of the animals with the exception of swelling in external genitalia, scrotal ulcerations and fistulas. Food and water consumption and the gait of animals remained unaffected. Intratesticular calcium chloride can’t be considered an effective method for chemical castration in donkeys.

Background: Castration is a husbandry practice raising important questions on the welfare and physiological status of farm animals. Searching for effective castration methods that minimally compromise the body physiology is worthy of attention. Therefore, this study aimed to evaluate the differential response of biological systems in donkeys to surgical castration versus the chemical one by CaCl₂ with special emphasis on stress, lipid profile, and oxidative stress biomarkers. Donkeys were divided randomly and equally into two groups; the chemical (Ch) and surgical (S) groups (n = 6). The Ch group was chemically castrated by intratesticular injection of 20% CaCl₂ dissolved in absolute ethanol. Blood samples were collected prior to castration and at 15, 30, 45, and 60 days after the beginning of experiment. Results: Surprisingly, the Ch group at the end of the experiment was characterized by significantly higher cortisol level compared to the S group. TC and LDL-C levels in the S group significantly decreased at day 45, while TG levels significantly increased at days 45 and 60 in comparison with day 0. HDL-C levels at days 30 and 60 in the Ch group significantly increased in comparison with day 0. At day 30 post-castration, HDL-C was significantly higher and LDL-C was significantly lower in the Ch group than the S group. A significant elevation in TC and LDL-C was observed at day 45 and in HDL-C at the end of experimental duration in the Ch group when compared with the S group. TPX level was significantly lower and TAC was significantly higher in the Ch group at day 45 than the S group. Conclusion: Surgical castration evoked less stress and minor changes in lipid profile and oxidant/antioxidant balance relative to chemical castration by intratesticular 20% CaCl₂ dissolved in absolute ethanol.

Collagen integrity should be considered on using a sterilizing agent for fish skin grafts. This study defined the optimal concentration of silver nanoparticles (Ag NPs) for sterilization of fish skin grafts without disrupting collagen content based on microbiological and histological evaluation. Strips of tilapia skin (n = 5) were randomly allocated to be immersed in Ag NPs solution at different concentrations of 25, 50, 100, and 250 µg/mL, respectively, for 5 min. The treated skin strips underwent bacteriological and histological evaluation. Yeast and fungi were more sensitive to Ag NPs than bacteria. On increasing the nanoparticles concentration, the total counts of aerobic bacteria decrease giving 933.3 ± 28.67, 601 ± 27.66, 288 ± 16.8, 15 ± 4.08 (CFU/cm² ± S.D) at 25, 50, 100, and 250 µg/mL, respectively, comparing with untreated sample (1453.3 ± 57.92). Yeasts and filamentous fungi also exhibited a similar response, achieving a complete inhibition at 100 and 250 µg/mL. Bacillus cereus and Escherichia coli were the dominant aerobic bacteria, Candida albicans and Rhodotorula glutinis were the dominant aerobic yeasts, whereas Aspergillus niger, Aspergillus fumigatus, and Rhizopus stolonifer were the dominant aerobic fungi. The collagen fibers were loose with a wavey pattern at 25 µg/mL, wavey and slightly disorganized at 50 µg/mL, highly disorganized at 100 µg/mL, and compactly arranged and slightly loose at 250 µg/mL. Ag NPs at a concentration of 250 µg/mL could be considered a reliable and feasible method for the sterilization of fish skin grafts before application on human skin with an effective antimicrobial effect and less disrupting impact on collagen content.

Background and Aims: The use of ketamine-xylazine for total intravenous anesthesia (TIVA)by constant rate infusion (CRI) has not been well-documented in literature. The present studyaimed to define the optimal dosage of ketamine-xylazine for TIVA in dogs and its effects onphysiological body parameters.Materials and Methods: Twenty mongrel dogs were randomly assigned to four treatment protocols (n=5): A (0.5 mg kg-1, ketamine+ 0.25 mg kg-1, xylazine and 0.6 mg kg-1 h-1, ketamine+0.3mg kg-1 h-1, xylazine ), B (5 mg kg-1, ketamine+0.5 mg kg-1, xylazine and 10 mg kg-1 h-1, ketamine+1 mg kg-1 h-1, xylazine), C (2 mg kg-1, ketamine+0.5 mg kg-1 xylazine and 5 mg kg-1 h-1,ketamine+0.5 mg kg-1 h-1 xylazine), and D (2 mg kg-1 ketamine+1 mg kg-1 xylazine and 10 mgkg-1 h-1, ketamine+1 mg kg-1 h-1 xylazine) for induction and maintenance of anesthesia, respectively.Results: The anesthesia was deep in protocols B, C, and D (pedal reflex of grade=0), butlight in the protocol A (pedal reflex of grade=3). Animals in both protocols B and C showedpaddling and tonic clonic convulsions. All the protocols recorded a non-significant increasein the body temperature but; a significant decrease in the respiratory rate. There was a nonsignificant decrease in the heart rate in protocols A and C; while a non-significant increase wasrecorded in protocols B and D.Conclusion: The protocol D could be considered as the optimal dosage of ketamine-xylazinefor TIVA by CRI in dogs, with minimal effects on vital body parameters, for extended surgicalinterventions.