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Abstract
Noninflammatory alopecia is common in dogs and is a frequent cause to consult a veterinarian. It is also a common reason to take biopsies. Noninflammatory alopecia can be attributed to a decreased formation or cytodifferentiation of the hair follicle or the hair shaft in utero, resulting in congenital alopecia. Congenital alopecia often has a hereditary cause, and examples of such disorders are ectodermal dysplasias associated with gene variants of the ectodysplasin A gene. Noninflammatory alopecia may also be caused by impaired postnatal regeneration of hair follicles or shafts. Such disorders may have a clear breed predilection, and alopecia starts early in life. A hereditary background is suspected in those cases but has not been proven. They are referred to as follicular dysplasia although some of these disorders present histologically like a hair cycle disturbance. Late-onset alopecia is usually acquired and may be associated with endocrinopathies. Other possible causes are impaired vascular perfusion or stress. As the hair follicle has limited possible responses to altered regulation, and histopathology may change during the course of a disease, a detailed clinical history, thorough clinical examination including blood work, appropriate biopsy site selection, and detailed histological findings need to be combined to achieve a final diagnosis. This review aims to provide an overview about the known noninflammatory alopecic disorders in dogs. As the pathogenesis of most disorders is unknown, some statements are based on comparative aspects or reflect the authors' opinion.
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Bauer A, Hadji Rasouliha S, Brunner MT, Jagannathan V, Bucher I, Bannoehr J, Varjonen K, Bond R, Bergvall K, Welle MM, Roosje P, Leeb T. A second KRT71 allele in curly coated dogs. Anim Genet 2018; 50:97-100. [PMID: 30444027 DOI: 10.1111/age.12743] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/09/2018] [Indexed: 01/20/2023]
Abstract
Major characteristics of coat variation in dogs can be explained by variants in only a few genes. Until now, only one missense variant in the KRT71 gene, p.Arg151Trp, has been reported to cause curly hair in dogs. However, this variant does not explain the curly coat in all breeds as the mutant 151 Trp allele, for example, is absent in Curly Coated Retrievers. We sequenced the genome of a Curly Coated Retriever at 22× coverage and searched for variants in the KRT71 gene. Only one protein-changing variant was present in a homozygous state in the Curly Coated Retriever and absent or present in a heterozygous state in 221 control dogs from different dog breeds. This variant, NM_001197029.1:c.1266_1273delinsACA, was an indel variant in exon 7 that caused a frameshift and an altered and probably extended C-terminus of the KRT71 protein NP_001183958.1:p.(Ser422ArgfsTer?). Using Sanger sequencing, we found that the variant was fixed in a cohort of 125 Curly Coated Retrievers and segregating in five of 14 additionally tested breeds with a curly or wavy coat. KRT71 variants cause curly hair in humans, mice, rats, cats and dogs. Specific KRT71 variants were further shown to cause alopecia. Based on this knowledge from other species and the predicted molecular consequence of the newly identified canine KRT71 variant, it is a compelling candidate causing a second curly hair allele in dogs. It might cause a slightly different coat phenotype than the previously published p.Arg151Trp variant and could potentially be associated with follicular dysplasia in dogs.
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Affiliation(s)
- A Bauer
- Institute of Genetics, Vetsuisse Faculty, University of Bern, Bern, 3001, Switzerland.,Dermfocus, Vetsuisse Faculty, University of Bern, Bern, 3001, Switzerland
| | - S Hadji Rasouliha
- Institute of Genetics, Vetsuisse Faculty, University of Bern, Bern, 3001, Switzerland.,Dermfocus, Vetsuisse Faculty, University of Bern, Bern, 3001, Switzerland
| | - M T Brunner
- Dermfocus, Vetsuisse Faculty, University of Bern, Bern, 3001, Switzerland.,Institute of Animal Pathology, Vetsuisse Faculty, University of Bern, Bern, 3001, Switzerland
| | - V Jagannathan
- Institute of Genetics, Vetsuisse Faculty, University of Bern, Bern, 3001, Switzerland.,Dermfocus, Vetsuisse Faculty, University of Bern, Bern, 3001, Switzerland
| | - I Bucher
- Dermfocus, Vetsuisse Faculty, University of Bern, Bern, 3001, Switzerland.,Division of Clinical Dermatology, Department of Clinical Veterinary Medicine, Vetsuisse Faculty, University of Bern, Bern, 3001, Switzerland
| | - J Bannoehr
- Dermfocus, Vetsuisse Faculty, University of Bern, Bern, 3001, Switzerland.,Division of Clinical Dermatology, Department of Clinical Veterinary Medicine, Vetsuisse Faculty, University of Bern, Bern, 3001, Switzerland.,Dermatology Department, Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk, CB8 7UU, UK
| | - K Varjonen
- Department Clinical Sciences and Services, Royal Veterinary College, Hatfield, AL9 7TA, UK.,Anicura Albano Animal Hospital, Danderyd, 18236, Sweden
| | - R Bond
- Department Clinical Sciences and Services, Royal Veterinary College, Hatfield, AL9 7TA, UK
| | - K Bergvall
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, Box 7054, Uppsala, 750 07, Sweden
| | - M M Welle
- Dermfocus, Vetsuisse Faculty, University of Bern, Bern, 3001, Switzerland.,Institute of Animal Pathology, Vetsuisse Faculty, University of Bern, Bern, 3001, Switzerland
| | - P Roosje
- Dermfocus, Vetsuisse Faculty, University of Bern, Bern, 3001, Switzerland.,Division of Clinical Dermatology, Department of Clinical Veterinary Medicine, Vetsuisse Faculty, University of Bern, Bern, 3001, Switzerland
| | - T Leeb
- Institute of Genetics, Vetsuisse Faculty, University of Bern, Bern, 3001, Switzerland.,Dermfocus, Vetsuisse Faculty, University of Bern, Bern, 3001, Switzerland
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Lee HA, Hong S, Choe O, Kim O. Mural folliculitis and alopecia with cutaneous candidiasis in a beagle dog. Lab Anim Res 2011; 27:63-5. [PMID: 21826163 PMCID: PMC3145986 DOI: 10.5625/lar.2011.27.1.63] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2011] [Revised: 02/26/2011] [Accepted: 02/28/2011] [Indexed: 11/21/2022] Open
Abstract
A one-year-old male Beagle dog showed dermatitis, alopecia and scales. Examination of the affected dog revealed generalized alopecia, patchy erythema, and superficial erosions with histological evidence of mural folliculitis. External tests for parasites in scraped skin samples were negative. However, fungal culture tests and polymerase chain reaction revealed the existence of Candida in the lesion. These results suggest that cutaneous candidiasis may induce mural folliculitis and alopecia in dogs.
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Affiliation(s)
- Hyun-A Lee
- Center for Animal Resources Development, Wonkwang University, Iksan, Republic of Korea
- Institute of Animal Experiment & Efficacy Evaluation, Wonkwang University, Iksan, Republic of Korea
| | - Sunhwa Hong
- Center for Animal Resources Development, Wonkwang University, Iksan, Republic of Korea
- Institute of Animal Experiment & Efficacy Evaluation, Wonkwang University, Iksan, Republic of Korea
| | - Ohmok Choe
- Center for Animal Resources Development, Wonkwang University, Iksan, Republic of Korea
| | - Okjin Kim
- Center for Animal Resources Development, Wonkwang University, Iksan, Republic of Korea
- Institute of Biotechnology, Wonkwang University, Iksan, Republic of Korea
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Moura E, Cirio SM. Follicular dysplasia of the adult doberman pinscher. J Am Anim Hosp Assoc 2010; 46:143-7. [PMID: 20194372 DOI: 10.5326/0460143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This paper presents the case of an adult female, red Doberman pinscher affected by permanent hypotrichosis, limited to the dorsolumbar region and sides of the trunk. The hypotrichosis began at approximately the age of 2 years and progressed slowly with no skin hyperpigmentation. The clinical and histopathological characteristics are of an uncommon form of follicular dysplasia.
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Affiliation(s)
- Enio Moura
- Service of Medical Genetics, Faculty of Veterinary Medicine, Campus São José, Pontifícia Universidade Católica do Paraná, Rua Imaculada Conceição, 1155, Prado Velho, Curitiba, Paraná 80215-901 Brazil
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Reichler IM, Welle M, Eckrich C, Sattler U, Barth A, Hubler M, Nett-Mettler CS, Jöchle W, Arnold S. Spaying-induced coat changes: the role of gonadotropins, GnRH and GnRH treatment on the hair cycle of female dogs. Vet Dermatol 2008; 19:77-87. [PMID: 18336424 DOI: 10.1111/j.1365-3164.2008.00652.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Although spaying can result in qualitative hair coat changes in dogs, the influence of spaying on the hair growth cycle has never been described. The study aims were to examine the effect of spaying and gonadotropin-releasing hormone (GnRH) treatment on canine hair coat, cycle stages of hair follicles, plasma gonadotropin concentrations and mRNA transcription of luteinizing hormone (LH) and GnRH receptors in hair follicles. Fifteen female dogs were examined before and 1 year after spaying and 24 spayed dogs before and after GnRH treatment. Spaying resulted in increased plasma gonadotropin concentrations and increased anagen : telogen ratio of hair follicles, but only 20% of the dogs developed coat changes. No differences were found in mRNA transcription of LH and GnRH receptors. GnRH treatment resulted in reduced plasma gonadotropin concentrations and improvement of coat changes in 79% of patients. This was associated with an increase in catagen hair follicles without changes in the anagen : telogen ratio. The present study demonstrated that spaying had an effect on the anagen : telogen ratio of hair follicles. Spaying-induced coat changes did not correlate with the anagen : telogen ratio. GnRH treatment reduced gonadotropin concentrations and reversed coat changes in some dogs, but had no effect on the hair growth cycle other than increasing the number of catagen hair follicles. A weak positive correlation between the plasma LH concentration and the anagen : telogen ratio was noted; however, our data did not suggest a direct receptor-mediated hormonal effect on the hair follicle. The present study did not identify the pathomechanism of spaying-induced coat changes.
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Affiliation(s)
- Iris Margaret Reichler
- Section of Small Animal Reproduction, Clinic of Reproductive Medicine, Vetsuisse Faculty, University of Zurich, 8057 Zurich, Switzerland.
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