Alopecia areata in Eringer cows

Alopecia areata is a hair loss disorder in humans, dogs and horses with a suspected autoimmune aetiology targeting anagen hair follicles. Alopecia areata is only sporadically reported in cows. Recently, we observed several cases of suspected alopecia areata in Eringer cows. The aim of this study was to confirm the presumptive diagnosis of alopecia areata and to define the clinical phenotype and histopathological patterns, including characterization of the infiltrating inflammatory cells. Twenty Eringer cows with alopecia and 11 Eringer cows without skin problems were included in this study. Affected cows had either generalized or multifocal alopecia or hypotrichosis. The tail, forehead and distal extremities were usually spared. Punch biopsies were obtained from the centre and margin of alopecic lesions and normal haired skin. Histological examination revealed several alterations in anagen hair bulbs. These included peri‐ and intrabulbar lymphocytic infiltration, peribulbar fibrosis, degenerate matrix cells with clumped melanosomes and pigmentary incontinence. Mild lymphocytic infiltrative mural folliculitis was seen in the inferior segment and isthmus of the hair follicles. Hair shafts were often unpigmented and dysplastic. The large majority of infiltrating lymphocytes were CD3⁺ T cells, whereas only occasional CD20⁺ lymphocytes were present in the peribulbar infiltrate. Our findings confirm the diagnosis of T‐cell‐mediated alopecia areata in these cows. Alopecia areata appears to occur with increased frequency in the Eringer breed, but distinct predisposing factors could not be identified.     

Resolution of paraneoplastic alopecia following surgical removal of a pancreatic carcinoma in a cat

A 13-year-old female neutered domestic longhaired cat was presented with a five-month history of progressive weight loss and bilaterally symmetrical alopecia of the ventrum, limbs and perineum. The alopecic skin had a shiny appearance and hair in the non-alopecic areas was easily epilated. Fine needle aspirate cytology of a palpable cranial abdominal mass revealed it to be of epithelial or glandular origin. A pancreatic mass was excised by left pancreatectomy during exploratory laparotomy, and histopathology and skin biopsies confirmed a diagnosis of pancreatic carcinoma with concurrent paraneoplastic alopecia. No evidence of metastases was found on liver and lymph node biopsies. At re-examination 10 weeks after surgery, the hair had fully regrown. Skin signs recurred after 18 weeks and metastatic spread of the tumour was confirmed on postmortem examination. This case confirms that paraneoplastic alopecia associated with internal malignancies is a potentially reversible process if the internal neoplasm is excised.     

P-89 Aeromonas hydrophila-associated skin lesions and septicaemia in a Nile crocodile

Mites are frequent agents of skin diseases in veterinary dermatology, particularly in rodents. The authors report an original case of infestation in two guinea pigs of the same household. Two adult guinea pigs were presented with a 3-month history of alopecia, matted hair, erythema, scales and mild pruritus. The first guinea pig showed almost complete truncal alopecia with mild scaling, whereas the other one had only recently developed mild alopecia of the abdomen and mild pruritus. Numerous live, long-legged mites were present both in adhesive tape and skin scrapings. Mycology (Wood's lamp and DTM agar culture) was negative. Histopathological examination of a skin biopsy did not reveal any significant inflammatory disease and morphological changes were limited to hair follicles in the telogen phase. Mites were identified as hypopodes of Acarus farris ( Acaridae ), but no adult stages were present. Hypopodes were also found in the hay. Control was obtained with acaricidal treatment with Phoxim 0.05% once weekly for 4 weeks, and the elimination of contaminated hay. The lesions and the alopecia resolved rapidly. Hypopodes are additional nymphal stages of some mites of the suborder Astigmata . They develop for dispersing or dormancy under disadvantageous conditions. They can be active or inert, and some can be phoretic on the skin surface or intrafollicular. Although nonparasitic, they may cause dermatitis. Acarus farris have been rarely mentioned in the literature as a cause of dermatitis. This condition could be underdiagnosed or misdiagnosed in veterinary dermatology.
Funding: Self-funded.     

Feline lymphangiosarcoma--definitive identification using a lymphatic vascular marker

Abstract   Three cases of feline exudative dermatitis associated with lymphangiosarcoma are described. The animals, an 11-year-old, neutered male and two 10-year-old, neutered female short hair European cats, presented with a 2-month history of transparent liquid oozing from the skin of the groin and caudal abdomen. On physical examination the neutered male cat and one of the females were slightly depressed and showed loss of weight. Skin lesions were similar in all cats and characterized by the presence of alopecia and moist dermatitis in the ventral abdomen, groin and inner thigh. The hair at the periphery appeared matted by the fluid. In all three cases, histopathological examination of skin biopsies from the abdomen identified poorly defined neoplasia involving dermis and subcutis, characterized by proliferation of spindle cells aligned along pre-existing collagen bundles. The dissection of collagen bundles gave rise to irregular shaped anastomosing, often blind-ending vascular channels and trabeculae. Vascular spaces were mostly optically empty. These histological features were strongly suggestive of lymphangiosarcoma. Neoplastic cells were positive for the blood vascular marker Von Willebrand factor, and a lymphatic vascular marker LYVE-1 (Lymphatic Vessel Endothelial receptor – 1), demonstrating the mixed vascular origin of the tumour. Ultrastructural findings confirmed the final diagnosis of lymphangiosarcoma.     

An analysis of factors underlying hypotrichosis and alopecia in Irish Water Spaniels in the United Kingdom

A survey on the occurrence of dermatoses in the Irish Water spaniel (IWS) was carried out in the United Kingdom. A group of 20 dogs was selected and examined clinically. All dogs had a nonpruritic, noninflammatory, regionalized hair loss affecting the same areas of the body in males and females, although an initial cyclical pattern associated with the oestrus cycle was identified. Hormonal investigations showed features suggestive of an abnormality of steroidogenesis. Histopathology revealed features similar to canine recurrent flank alopecia (CRFA) and follicular dysplasia associated with abnormal melanization, as in colour dilution alopecia, although the clinical features did not correlate with those conditions. Dietary changes improved coat and skin quality in most of the cases in this series but the role of the diet was not investigated further. This study suggests that hair loss in IWS is influenced by dietary factors and sexual hormones. Abnormalities of the steroidogenic pathways may contribute to the severity of the condition.     

FC-12 Diagnostic value of skin biopsy in feline symmetric alopecia

Hair loss in Chesapeake Bay retrievers has been increasingly recognized by breeders in recent years. Anecdotal reports suggest an endocrine disorder or follicular dysplasia as the underlying cause, but no scientific study has been done to investigate the underlying problem. A prospective study was carried out in collaboration with the American Chesapeake Club. Affected dogs were recruited into the study. Routine dermatological and hormonal (blood and urine) tests, and skin biopsies were performed. Ten dogs (age 1.5–10 years), seven females (two spayed) and three males (two neutered), were included in the study. All dogs had mild or severe hair loss affecting the lateral ventral chest, flanks, rump and thighs. Affected dogs were clinically healthy. Hormonal tests revealed normal thyroid hormone panels, insulin-like growth factor-1 levels, and urinary cortisol:creatinine ratios in samples collected for ten consecutive days. In six of 10 dogs, an adrenal hormone panel showed slight or moderate increased values pre- and/or post-ACTH stimulation of cortisol (three of six), 17-hydroxyprogesterone (five of six), androstenedione (three of six), estradiol (two of six) and progesterone (six of six). The major histopathologic changes resembled canine flank alopecia and follicular dysplasia with pronounced infundibular hyperkeratosis, mild follicular atrophy, and occasional melanin clumping with dystrophic hair shafts. Chesapeake Bay retrievers suffer from a type of hair loss that is likely related to an abnormal production of adrenal sex hormone. Further studies are currently underway to determine if there is a heritable basis for this disease and to evaluate therapeutic options.
Funding: University of Pennsylvania.     

Underlying medical conditions in cats with presumptive psychogenic alopecia

OBJECTIVE: To identify underlying medical conditions in cats with a presumptive diagnosis of psychogenic alopecia. DESIGN: Case series. ANIMALS: 21 adult cats referred with a presumptive diagnosis of psychogenic alopecia. PROCEDURES: A detailed behavior and dermatologic questionnaire was completed by the primary caregiver, and complete behavioral and dermatologic examinations were performed. A standard diagnostic testing protocol that included cytologic examination of skin scrapings, fungal culture of hairs, evaluation of responses to parasiticides and an exclusion diet, assessment for atopy and endocrinopathies, and histologic examination of skin biopsy specimens was used to establish a definitive diagnosis in all cats. Cats that did not respond to an elimination diet were treated with methylprednisolone acetate to determine whether pruritus was a factor. RESULTS: Medical causes of pruritus were identified in 16 (76%) cats. Only 2 (10%) cats were found to have only psychogenic alopecia, and an additional 3 (14%) cats had a combination of psychogenic alopecia and a medical cause of pruritus. An adverse food reaction was diagnosed in 12 (57%) cats and was suspected in an additional 2. All cats with histologic evidence of inflammation in skin biopsy specimens were determined to have a medical condition, but of 6 cats without histologic abnormalities, 4 had an adverse food reaction, atopy, or a combination of the 2, and only 2 had psychogenic alopecia. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that psychogenic alopecia is overdiagnosed in cats. Thorough diagnostic testing should be done before ascribing a behavioral cause to hair loss in cats.     

Pathogenesis of canine interdigital palmar and plantar comedones and follicular cysts, and their response to laser surgery

This study documents the presence of comedones and follicular cysts of palmar and plantar interdigital skin as an underlying cause of recurrent dermatitis, and describes the use of a carbon dioxide laser to surgically remove lesions. The 28 dogs included in the study had: (i) recurrent lameness, pain, and nodules, or draining sinuses in the dorsal interdigital skin, (ii) failed to respond to antibiotic therapy, and (iii) were negative for Demodex mites and dermatophytes. All 28 had laser surgery; nine dogs had two surgical procedures and two dogs had three surgical procedures for lesion recurrence. Fifteen dogs had skin samples collected for histopathology. Clinical features in ventral interdigital skin included alopecia, callus-like thickening, and comedones. Histological features included hyperkeratosis, acanthosis, comedones and follicular cysts, furunculosis, draining sinuses, and scarring. Surface trauma to the ventral interdigital skin appeared to contribute to lesion development. Laser surgery allowed removal of multiple layers of cysts and adjacent hair follicles and the tracking and removal of sinuses. One dog was euthanized for orthopaedic lameness 1 month after laser surgery, but post-surgical follow-up (1.0-8.0 years - mean 3 years) from the remaining 27 dogs revealed that laser therapy of affected skin and adjacent hair follicles resulted in resolution of interdigital lesions in 25. Two dogs continued to develop interdigital cysts.     

Congenital hypotrichosis in a French bulldog

The occurrence of congenital alopecia in one of a litter of four female French bulldogs is described. With the exception of the hair coat the affected bitch was clinically normal. The distribution of the sparse hair (head, tip of the tail and paws) mimicked that seen in the Chinese crested dog. Histopathological examination of skin biopsies revealed features frequently observed in congenital alopecia - a reduction in number of hair follicles, hypoplasia or absence of epidermal appendages and pronounced follicular hyperkeratosis, abnormalities of collagen and elastic fibres were not detected.     

Severe bilaterally symmetrical alopecia in a horse

A 9-year-old Tennessee Walking Horse gelding was presented for diagnosis of the cause of extensive alopecia. Complete hair loss was noted over the head, neck, shoulder, thigh, and proximal limbs, but the trunk, distal limbs, pelvic area, mane, and tail were unaffected. The alopecic areas were visually noninflammatory with no exudate or crust except on the shoulder and along the back, where multifocal patchy areas of alopecia with scales and crust were evident. The horse was slightly pruritic. Microscopically, the hair bulbs, inner and outer root sheaths of inferior segments, and perifollicular regions were infiltrated by small to moderate numbers of small lymphocytes. Similar inflammation was occasionally evident in isthmus follicular walls as well as some apocrine glands. No sebaceous glands were affected. Immunohistochemistry confirmed that the small lymphocytes were CD3(+) T lymphocytes. The epidermis from the skin with scale and crusts along the horse's back exhibited mild to moderate hyperplasia, mild lymphocytic exocytosis, mild eosinophilic dermatitis, and diffuse parakeratosis with numerous budding yeasts, consistent with Malassezia spp. The final disease diagnosis was made as alopecia areata with Malassezia dermatitis. Alopecia areata could be a contributing underlying factor for Malassezia dermatitis.