Five horses with lesions compatible with dermatomycosis were selected and skin scrapings were taken from all affected areas. Samples were then treated with 10% KOH and observed by direct microscopic examination; fungal cultures using Mycobiotic Agar and Borelli Agar were also preformed; Trichophyton mentagrophytes was identified in two cases, whereas Candida albicans was identified in the other three. Skin lesions in cases 1 and 2 were treated topically with ketoconazol ointment, while in the remaining cases a weekly bath with propolis-based shampoo and application of propolis-based ointment on the lesions 2 to 3 times a week were implemented. Treatment in all cases lasted 4 weeks. Pictures were taken before and after treatment and, making use of the Image Pro-Express ® software, therapy efficacy was determined by measurement of lesion area diameter and a significant reduction in lesion size was observed by the end of the 4 weeks of treatment with ketoconazole and propolis-based products. Thus proving the effectiveness of such propolis-based products, making them a natural therapeutic alternative for the treatment of cutaneous mycoses in horses, and carrying none of the toxic side effects of conventional pharmaceuticals.
Superficial and cutaneous mycoses are fungal infections that involve the superficial layers of the skin, hair, and claws/hoofs. The microorganisms involved are often keratinophilic dermatophytes, such as those belonging to the genus Microsporum, Trichophyton and Epidermophyton; however, other fungi like the yeasts Candida, Malassezia and Trichosporon may also produce superficial mycoses [
A total of 5 horses of both genders (Thoroughbred and American Quarter) were selected from different stables, ages ranging from 2 to 7 years, and weights between 430 and 540 kg, each of them presented clinical signs compatible with cutaneous mycosis (annular areas of peripherally expanding alopecia, with or without erythematous borders, and fragile hair) but without any other apparent health alteration that could interfere with the results. The number and size of the lesions in each horse, as well as their distribution, was recorded in a work sheet that depicted the anatomical regions of the horse; such evaluation was made before and after treatment. Case 1: American Quarter horse, 5 years old, sorrel. Showed a large alopecic region that covered the caudal aspect of the head, from the ear base to the bottom of the jaw, and another small alopecic lesion on the temple, both on the right side on the face (
Case 2: American Quarter mare, 7 years of age, light sorrel. Showed multiple annular alopecic lesions on the lacrimal, zygomatic, and maxillary bone regions, on the right and left side of the face (
Case 3: Thoroughbred filly, 2 years of age, dark bay. Showed multiple annular alopecic lesions on the craneo- ventral part of the barrel (
Case 4: Thoroughbred colt, 2 years of age, brown. Showed multiple annular alopecic on the breast (
Case 5: Thoroughbred filly, 2 years of age, brown. Presented several annular alopecic lesionson the girth, of approximately 2 cm in diameter each (
For each mycological examination, hair samples were taken and scales were collected from the edges of thelesions for direct microscopic examination with 10% KOH. These samples were then used to inoculate plates containing Mycobiotic Agar (Bioxon®) and Borelli Agar [
whose whitish, creamy appearance corresponded to that observed in Candida spp. cultures. A germ tube test, also known asmycelial growth test, was then performed in order to identify the species [
In case 1, ketoconazole ointment (Nizoral, Janssen-Cilag®) was applied on the affected areas; In case 2, ketoconazole ointment was also applied, but only on the lesions on the right side of the face, whereas propolis-based products were used to topically treat the lesions on the left side. The three remaining cases were only treated with propolis-based compounds, a weekly bath was given with propolis-based shampoo (consisting of both, oily- and soapy-phases, excipients and 3% propolis) and 15% propolis ointment (the composition of which was taken from a previous publication by Cruz [
Photographs of the lesions were taken before and after treatment; the pictures were then analyzed with the Image-Pro Express 4.5 software and data corresponding to lesion size changes and distribution were recorded. After that, an ANOVA test (GraphPad Prism software) of the data corresponding to the size of the lesions before and after treatment was carried out and a p value < 0.005 was obtained, so that a statistically significant reduction in lesion size was confirmed.
Samples were treated with 10% KOH and a direct microscopic examination was performed. In cases 1 and 5, ectothrix parasitism of hair shafts was observed and, in both cases, the dermatophyte Trichophyton mentagrophytes was isolated, whereas in the remaining cases (2, 3, and 4) the yeast Candida albicans was identified.
By the end of the 4 weeks of treatment it was evident that the skin lesions of the horses treated with propolis- based shampoo and ointment showed a reduction in the size of the area involved, thus resulting in lesion size reduction of statistical significance. No recidivism of the lesions was observed in any case (
Previous works have already shown the antifungal activity of propolis against dermatophytesin dogs, cows and rabbits [
Case | Breed | Age (years) | Gender | Isolated microorganism | Treatment | Area before (cm) | Area after (cm) | Lesion reduction (%) |
---|---|---|---|---|---|---|---|---|
1 | American Quarter | 5 | Male | Trichophyton mentagrophytes | Ketoconazole | 55.27 | 2.44 | 95.58 |
2 | American Quarter | 7 | Female | Candida albicans | Ketoconazole(rs) Propolis(ls) | 86.15 31.9 | 0.24 0.16 | 99.72 99.50 |
3 | Thoroughbred | 2 | Female | Candida albicans | Propolis | 55.61 | 0.58 | 98.95 |
4 | Thoroughbred | 2 | Male | Candida albicans | Propolis | 20.01 | 0.60 | 97.05 |
5 | Thoroughbred | 2 | Female | Trichophyton mentagrophytes | Propolis | 20.17 | 0.30 | 98.51 |
*p = 0.005; rs = right side; ls = left side.
The effectiveness of propolis for the treatment of C. albicans in horses is probably due to its ability to inhibit yeast growth, blastoconidia formation and germ tube formation (an important virulence factor of C. albicans), as well as its damaging effect on cell membrane and wall. Such damages have also been reported by [
A synergic effect with the combined use of propolis-based shampoo and oitment was also observed. Tensoactive activity is provided by several components of the shampoo (sodium lauryl sulfate, amines, sugar alcohols, cocamidopropyl betaine), which eliminate sweat, ceruminous secretions, dead cells, and dirt form the environment, as mentioned by [
In the present study, topical treatment protocols were implemented for a period of 4 weeks, which has relevance when dealing with extensive skin lesions and correlates with a study in dogs by [
The regenerative and wound healing capacities of propolis on skin lesions in horses were also observed in this study, as was proven by size reduction of annular alopecic areas, which was also demonstrated by Howaida et al. [
The presence of substances such as caffeic acid (present in our propolis) and kaempferol could also play an important role in tissue regeneration. These substances induce the anagen phase of the hair cycle, as demonstrated by Miyata et al. [
Regarding case number 2, were the lesions on the right side of the face were treated with ketoconazole ointment, the presence of a mild hyperpigmentation of the area was observed after the resolution of the lesions, which did not happen on the left side, where instead propolis-based products were used, nor did it happen in case 1, where ketoconazole ointment alone was used. Such secondary effect of ketoconazole has not been documented, which lead the authors to consider it an isolated reaction.
The results here presented are non-conclusive, given the small amount of treated animals; however they do provide some guidance for further research on the subject. An important aspect worth of mentioning is that relating to treatment cost per animal, which was of approximately $100 (USD) for the whole treatment with ketoconazole ointment, and of approximately $30 (USD) when propolis-based products were used, hence, a significant reduction in treatment cost can be appreciated without compromising the outcome in lesion size reduction, which is similar with both treatments
These research paper adds up to the ever growing scientific literature that present the use of propolis as an attractive alternative therapeutic agent against fungal skin infections that can be safely employed in pediatric, geriatric and pregnant patients, and even in those with renal and/ or hepatic failure, which constitutes a significant advantage over treatments with conventional pharmaceuticals, that while is true are effective, their use is limited in the treatment of such patients, due to their hepatotoxic, embryotoxic and teratogenic effects, as well as many drug interactions [
After a thorough review of the currentscientific literature available on the subject, not a single paper about the use of propolis for the treatment of dermatomycosis in horses was found, so it is possible that this work constitutes the first written scientific report of the application of propolis for the treatment of dermatomycosis in this species.
The authors would like to express their gratitude to the UNAM DGAPA projects PAPIIT IT 223811-3 and IT 200915, PIAPIC 28C and support by CONACYT 713123.
Iris del Socorro FloresRodríguez,Maxs MorenoMonteagudo,Amparo LondoñoOrozco,Tonatiuh Alejandro CruzSánchez, (2016) Use of Mexican Propolis for the Topical Treatment of Dermatomycosis in Horses. Open Journal of Veterinary Medicine,06,1-8. doi: 10.4236/ojvm.2016.61001