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White SD. Approach to the pruritic horse. J Am Vet Med Assoc 2023; 261:S66-S74. [PMID: 36638000 DOI: 10.2460/javma.22.10.0444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 12/05/2022] [Indexed: 01/14/2023]
Abstract
Pruritus in the horse may be due to several causes, the most common being a hypersensitivity response to salivary proteins in the Culicoides genera, which may coexist with atopic dermatitis, also known as an environmental allergy to pollens, molds, dust, storage mites, etc. Less common etiologies are food allergy and contact allergy, the latter often caused by owners applying various products to the skin. Other ectoparasites, such as Chorioptes mites, may also initiate pruritus. Secondary bacterial infections (usually Staphylococcus spp) may be pruritic in and of themselves. This article reviews the questions that need to be asked of owners to obtain a relevant history, always important for any organ system, but perhaps none more so than the skin. The various clinical findings such as alopecia and crusts and their location on the horse, diagnostic methods such as intradermal or serum testing for allergies, and subsequent hyposensitization are also discussed. Therapeutic options currently available for the potential underlying diseases, in particular for the hypersensitivity reactions to Culicoides spp or environmental allergens, are reviewed with the studies of hyposensitization over the last 40 years, as well as medications that may be effective. While the most common causes of pruritus in the horse are known, the current understanding of the pathophysiology still needs to be investigated, and consequently, the most effective treatments for those causes need to be improved. Newer research is discussed that may eventually add to the diagnostic and therapeutic options currently available for the pruritic horse.
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Affiliation(s)
- Stephen D. White
- School of Veterinary Medicine, University of California-Davis, Davis, CA
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Raizner NT, Gedon NKY, Zablotski Y, Kania SA, Kühnle HF, Kühnle C, Mueller RS. Epidemiological observations on pastern dermatitis in young horses and evaluation of essential fatty acid spot-on applications with or without phytosphingosine as prophylactic treatment. Vet Dermatol 2022; 33:221-e62. [PMID: 35293641 DOI: 10.1111/vde.13066] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 01/11/2022] [Accepted: 01/13/2022] [Indexed: 12/19/2022]
Abstract
Background - Equine pastern dermatitis (EPD) is a common multifactorial clinical syndrome in horses. Treatment can be difficult; pathogenesis and triggering factors cannot always be determined. Objectives - To assess risk factors for developing EPD in a large group of horses kept under the same conditions and to analyse whether or not a spot-on containing essential fatty acids and antimicrobial agents is able to prevent the development of EPD or accelerate the healing process. Conclusion and clinical importance - Moisture and lack of pigmentation predisposed to EPD. Topical application of the tested spot-on once weekly did not prevent the disease. A positive effect of both spot-on products on the severity of EPD lesions was detected.
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Affiliation(s)
- Nicola T Raizner
- Centre for Clinical Veterinary Medicine, Ludwig-Maximilian University Munich, Munich, Germany
| | - Natalie K Y Gedon
- Centre for Clinical Veterinary Medicine, Ludwig-Maximilian University Munich, Munich, Germany
| | - Yury Zablotski
- Centre for Clinical Veterinary Medicine, Ludwig-Maximilian University Munich, Munich, Germany
| | - Stephen A Kania
- Department of Comparative medicine, Institute of Biomedical Engineering, University of Tennessee, Knoxville, TN, USA
| | - Harald F Kühnle
- Veterinary Practice Dr. Kühnle, Parkstr. 7, 74532 Ilshofen, Germany
| | - Christoph Kühnle
- Equine Hospital, Equine Department, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Ralf S Mueller
- Centre for Clinical Veterinary Medicine, Ludwig-Maximilian University Munich, Munich, Germany
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Kaiser-Thom S, Hilty M, Ramseyer A, Epper P, Gerber V. The relationship between equine pastern dermatitis, meteorological factors, and the skin microbiota. Vet Dermatol 2021; 33:165-e48. [PMID: 34888974 PMCID: PMC9300176 DOI: 10.1111/vde.13045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 08/11/2021] [Accepted: 09/01/2021] [Indexed: 11/28/2022]
Abstract
BACKGROUND Equine pastern dermatitis (EPD) is a multifactorial syndrome, with prolonged exposure to moisture assumed to be a predisposing or primary factor. HYPOTHESIS/OBJECTIVES To examine the course of EPD lesion severity, changes in bacterial skin microbiota, and the influence of meteorological factors. ANIMALS Prospective, longitudinal cohort study over a one-year period, with six Franches-Montagnes stallions, four affected by EPD and two unaffected, that were kept under the same conditions. METHODS AND MATERIALS Pasterns were scored for lesion severity and sampled once a month for 12 consecutive months. Lesion severity, the skin microbiota and meteorological factors were examined for associations. RESULTS EPD lesions tended to worsen in autumn and at the beginning of spring. The relationship between lesion severity and the meteorological factor precipitation was not clearly evident; high scores were preceded by both low or high rates of precipitation. Microbiota in affected pasterns appeared to have experienced a reduction in alpha diversity. Beta diversity analyses demonstrated that bacterial community structures were altered in affected versus unaffected pasterns, and that alterations were more pronounced with higher EPD scores (P = 0.005). Meteorological factors also had considerable influences on the bacterial composition, whereby these influences appeared to be more marked in the affected pasterns (P = 0.001, F = 3.19) than in unaffected ones (P = 0.005, F = 1.83). CONCLUSIONS AND CLINICAL RELEVANCE Our study provides preliminary observations of the relationships between lesion severity, meteorological factors and cutaneous bacteria. The population was too small to draw firm conclusions, and further studies on environmental factors and the involvement of bacteria in this multifactorial disease are needed.
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Affiliation(s)
- Sarah Kaiser-Thom
- Swiss Institute of Equine Medicine (ISME), Department of Clinical Veterinary Medicine, Vetsuisse Faculty, University of Bern, and Agroscope, Länggassstrasse 124, Bern, 3012, Switzerland
| | - Markus Hilty
- Institute for Infectious Diseases, University of Bern, Friedbühlstrasse 51, Bern, 3010, Switzerland
| | - Alessandra Ramseyer
- Swiss Institute of Equine Medicine (ISME), Department of Clinical Veterinary Medicine, Vetsuisse Faculty, University of Bern, and Agroscope, Länggassstrasse 124, Bern, 3012, Switzerland.,Swiss Institute of Equine Medicine (ISME), Department of Clinical Veterinary Medicine, Vetsuisse Faculty, University of Bern, and Agroscope, Les Longs-Prés, Avenches, 1580, Switzerland
| | - Pascale Epper
- Swiss Institute of Equine Medicine (ISME), Department of Clinical Veterinary Medicine, Vetsuisse Faculty, University of Bern, and Agroscope, Länggassstrasse 124, Bern, 3012, Switzerland.,Swiss Institute of Equine Medicine (ISME), Department of Clinical Veterinary Medicine, Vetsuisse Faculty, University of Bern, and Agroscope, Les Longs-Prés, Avenches, 1580, Switzerland
| | - Vinzenz Gerber
- Swiss Institute of Equine Medicine (ISME), Department of Clinical Veterinary Medicine, Vetsuisse Faculty, University of Bern, and Agroscope, Länggassstrasse 124, Bern, 3012, Switzerland
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Kaiser-Thom S, Hilty M, Axiak S, Gerber V. The skin microbiota in equine pastern dermatitis: a case-control study of horses in Switzerland. Vet Dermatol 2021; 32:646-e172. [PMID: 33830562 PMCID: PMC9290916 DOI: 10.1111/vde.12955] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 09/28/2020] [Accepted: 11/16/2020] [Indexed: 01/04/2023]
Abstract
Background Equine pastern dermatitis (EPD), a multifactorial syndrome, manifests as skin lesions of variable severity in the pastern area. Despite the widespread use of antibacterial therapy for treating this condition, little is known about the contributing bacteria. Hypothesis/Objectives To investigate the bacterial skin microbiota in EPD‐affected and unaffected (control) pasterns. Animals Case‐control study with 80 client‐owned horses; each with at least one EPD‐affected and one control pastern. Methods and materials Horses were grouped by the form of EPD (mild, exudative or proliferative), the assigned severity grade and type of pretreatment (disinfectant, topical antibacterial or no antibacterial pretreatment). Skin swabs were obtained, and the microbiota composition was compared between the groups. Results Bacterial alpha diversity was reduced in affected pasterns (P < 0.001) and this reduction was significantly associated with the EPD forms (P < 0.001), and not with the type of pretreatment (P > 0.14). Analyses of beta‐diversity confirmed a disordering of the skin microbiota (P = 0.004) in affected versus control pasterns, that was particularly profound in more severe lesions. The type of pretreatment was not significantly associated with this disordering. Four differentially abundant families were detected, of which Staphylococcaceae was the most distinct. The relative abundance of staphylococci was significantly increased in affected pasterns (P = 0.011), particularly in those that had received antibacterial treatment previously. Conclusions and clinical relevance Changes in the microbiota are associated with the EPD form or severity of lesions. The role of bacteria in the pathogenesis of EPD as well as the propriety and consequences of antibacterial treatment should therefore be further investigated.
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Affiliation(s)
- Sarah Kaiser-Thom
- Swiss Institute of Equine Medicine (ISME), Department of Clinical Veterinary Medicine, Vetsuisse Faculty, University of Bern, and Agroscope, Länggassstrasse 124, 3012, Bern, Switzerland
| | - Markus Hilty
- Institute for Infectious Diseases, University of Bern, Friedbühlstrasse 51, 3010, Bern, Switzerland
| | - Shannon Axiak
- Clinical Anaesthesiology, Department of Clinical Veterinary Medicine, Vetsuisse Faculty, University of Bern, Länggassstrasse 124, 3012, Bern, Switzerland
| | - Vinzenz Gerber
- Swiss Institute of Equine Medicine (ISME), Department of Clinical Veterinary Medicine, Vetsuisse Faculty, University of Bern, and Agroscope, Länggassstrasse 124, 3012, Bern, Switzerland
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