Alopecia areata with lymphocytic mural folliculitis affecting the isthmus in a thoroughbred mare

A 13-year-old, thoroughbred mare was presented with an 8-year history of multifocal, generalized, noninflammatory alopecia and a 3-month history of alopecia, erythema and scaling of the white star on the forehead and muzzle. Histopathological examination of biopsy samples from multiple sites on the body (mane, neck, shoulder, flank and gluteal region) showed a subtle lymphocytic inflammatory infiltrate affecting and surrounding the anagen hair bulbs, consistent with a diagnosis of alopecia areata. The biopsy sample from the star on the forehead showed atrophic hair follicles with perifollicular and mural mononuclear folliculitis affecting the isthmus. Immunohistochemical staining with a CD3 marker confirmed the T-lymphocytic origin of the inflammatory infiltrate in all the samples. The concurrent presence of lymphocytic infiltration at the bulbar and isthmic level of the hair follicles in the same horse is unusual. This finding may represent a variation of the histological appearance of alopecia areata.     

Concurrent follicular dysplasia and interface dermatitis in Boxer dogs

Recurrent or persistent follicular dysplasia and interface dermatitis are described in nine Boxers. Data on age, sex, seasonality of alopecia and histopathological features of the follicular dysplasia in these nine Boxers are comparable with those described in previous reports. The interface dermatitis was characterized by multifocal annular crusted lesions confined to the areas of follicular dysplasia. The inflammatory lesions were neither pruritic nor painful and affected dogs were otherwise healthy. Histopathologically the clinically inflammatory lesions were characterized as an interface dermatitis. Immunohistochemical studies failed to demonstrate immunoglobulins or complement at the basement membrane zone or within blood vessel walls. In dogs with recurrent or persistent disease, the follicular dysplasia and interface dermatitis ran identical, concurrent courses of spontaneous remission and recurrence, or persistence, respectively. One dog with persistent disease was treated successfully with tetracycline and niacinamide for the interface dermatitis, and melatonin for the follicular dysplasia. Although the aetiopathogenesis of this newly described condition and the relationship between the two histological reaction patterns are not known, photoperiod and genetic predisposition appear to play a role.     

Investigation of the reproductive and growth hormone status of dogs affected by idiopathic recurrent flank alopecia

The reproductive and growth hormone status of a group of 12 neutered dogs affected by idiopathic recurrent flank alopecia was investigated at both maximum and minimum photoperiod using the adrenocorticotrophic hormone (ACTH) stimulation test, the xylazine stimulation test and the insulin-like growth factor I (IGF-I) assay. When compared with a group of nine neutered control dogs, the plasma reproductive hormone concentrations were not significantly different with one exception; a significantly greater post-ACTH plasma progesterone concentration was detected in the affected group at minimum photoperiod (P<0–05). The significance of this finding in isolation is unclear. Growth hormone response to intravenous xylazine was assessed in the affected group at maximum photoperiod only and was found to be within normal limits in eight of the dogs. Serum IGF-I concentrations were significantly greater in the affected group at maximum photoperiod but the groups were not significantly different at minimum photoperiod. These results suggest that dogs with idiopathic recurrent flank alopecia are of normal reproductive and growth hormone status.     

Endocrine alopecia in a miniature poodle

Hypothyroidism and concurrent sex hormone imbalance associated with alopecia was diagnosed in a 5 year-old entire male Miniature Poodle. The dog had a 3-year history of alopecia, seborrhoea and recurrent superficial pyoderma. Abnormal thyrotropin releasing hormone stimulation test results supported a diagnosis of hypothyroidism. Partial hair regrowth occurred after interstitial cell tumours, which were present in both testicles, were removed by castration. Complete hair regrowth, however, occurred only after thyroid hormone supplementation. This case highlighted difficulties which may be encountered when interpreting serum hormone concentrations and endocrine function tests.     

Dermatitis associated with Dirofilaria repens microfilariae in three dogs in Saudi Arabia

The presence of microfilariae of the zoonotic nematode Dirofilaria repens is reported in three dogs from Saudi Arabia, manifesting as pruritic dermatitis with signs including erythema, alopecia, papules, crusting and hyperkeratosis. All dogs were found to have concurrent babesiosis. Specific treatments against the two conditions led to complete clinical recovery and disappearance of microfilariae from the blood one month later.     

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.     

Seasonal flank alopecia in affenpinschers

Two intact, distantly related, female affenpinschers, belonging to a breeder, were referred in March 1993 for the investigation of bilateral, symmetrical flank alopecia in one bitch and bilateral, symmetrical flank, dorsum and tail alopecia in the other; the alopecia occurred from November to May and January to May, respectively. During that period the bitches were kept in a conservatory without artificial heating or lighting. The owner reported that the mother of one bitch had had bilateral, symmetrical flank alopecia during one winter when kept in the conservatory, but was normal the following winter when kept in the house. Three other females and a male exhibited the same clinical signs when kept in the conservatory during the winter. Seasonal flank alopecia has not previously been reported in affenpinschers.     

CYSTIC ENDOMETRIAL HYPERPLASIA AND BACTERIAL ENDOMETRITIS ASSOCIATED WITH AN INTRAUTERINE FOREIGN BODY IN A GUINEA PIG WITH OVARIAN CYSTIC DISEASE

A 3-year-old, 920 g intact female guinea pig presented with a 4-month history of nonpruritic hair loss on the ventral abdomen. The physical examination revealed flank and ventral abdominal alopecia, mucoid vulvar discharge, and abdominal distension. Bilateral rounded masses just caudal to the kidneys and structures consistent with enlarged uterine horns were detected on abdominal palpation. Abdominal ultrasound revealed bilateral ovarian cysts, thickened uterine horns, and multiple circular hypoechoic and anechoic structures in the uterine wall. The patient underwent ovariohysterectomy. Gross examination of the uterus revealed a piece of hay in the left uterine horn. A final diagnosis was hormonally active ovarian follicular cysts, cystic endometrial hyperplasia, and purulent bacterial endometritis caused by Escherichia coli, Fusobacterium nucleatum, and Arthrobacter spp. Cystic endometrial hyperplasia is infrequently reported in guinea pigs, and this report describes an associated bacterial endometritis and uterine foreign body with concurrent ovarian cysts.     

Putative Malassezia dermatitis in six goats

Histopathology submissions from 28 goats with dermatological disease were identified in an archival search of pathology files. Microscopic sections of skin biopsy specimens were examined for the presence of Malassezia spp. organisms. Six cases with many Malassezia yeasts were identified histopathologically. Based on the extent of clinical disease, three cases were regarded as localized and three were generalized infections. Clinical findings included alopecia with dry seborrhoea (four cases), greasy seborrhoea (one case), and no clinical findings specific to localized Malassezia infection when concurrent bacterial infection was present (one case). Mild pruritus was reported in two cases of generalized infection. No breed predilection was apparent. Three cases were male and three were female. Malassezia dermatitis occurred in goats from 10 months to 13 years of age. Three of six cases had concurrent bacterial infection. Skin lesions resolved following topical antifungal therapy in the two goats that were treated. Histopathological findings in all cases were severe follicular and epidermal orthokeratotic hyperkeratosis with minimal epithelial change and mild superficial perivascular to interstitial nonsuppurative inflammation. Numerous budding yeasts were visible within the stratum corneum of all cases; however, Malassezia was not isolated in the three cases in which culture was attempted. Based upon these findings, the authors suggest that the diagnosis Malassezia dermatitis in goats is most likely to be made by cytological examination of skin impressions or by examination of skin biopsy samples.     

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.     

Dermatitis and lymphadenitis resembling juvenile cellulitis in a four-year-old dog

A four-year-old, entire male toy poodle was presented with a two-and-a-half-week history of ocular discharge progressing to periorbital alopecia, depigmentation, alopecia and ulceration around the muzzle. There was also a haemorrhagic discharge from the ears, pyrexia, lethargy and generalised lymphadenopathy. The clinical, cytological, bacteriological and histopathological findings were consistent with a diagnosis of dermatitis resembling juvenile cellulitis in an adult dog. Glucocorticoid therapy led to rapid resolution of the clinical signs and the dog has remained in remission for two years after cessation of treatment.     

Systemic lupus erythematosus in a cat: fulfillment of the American Rheumatism Association criteria with supportive skin histopathology

Systemic lupus erythematosus (SLE) was diagnosed in a 9-year-old castrated male Persian cat. The cat described is the first to fulfil four of 11 American Rheumatism Association criteria for the diagnosis of SLE in humans (symmetrical facial dermatitis, thrombocytopenia, positive antinuclear antibodies, oral ulceration) with supportive skin histopathology. Haematological abnormalities included a mild anaemia and severe thrombocytopenia. Skin disease consisted of symmetrical multifocal alopecia with crusting, predominantly on the face. Histopathology of the skin revealed interface dermatitis and interface folliculitis with follicular atrophy. Complete remission was obtained with corticosteroid therapy.     

Herpesvirus dermatitis in two cats without facial lesions

Background – Cats with feline herpesvirus (FeHV‐1)‐associated dermatitis typically present with ulcerative lesions on the rostral muzzle and nasal planum. This report describes FeHV‐1 dermatitis in the flank region, in the absence of facial lesions. Hypothesis/Objectives – Clinicians should be aware of this unusual manifestation of FeHV‐1 dermatitis to prevent potential misdiagnosis. Animals – A 12‐year‐old male castrated Bengal cat and a 3‐year‐old male castrated Siamese cat with plaques and ulcers in the flank region are described. Methods – Formalin‐fixed biopsy samples were obtained from lesional skin. Histopathology and FeHV‐1 immunohistochemistry were performed. Results – Each sample had epidermal and follicular necrosis with a dense dermal infiltrate of eosinophils. Few to moderate numbers of intranuclear inclusion bodies were present in keratinocytes. The presence of FeHV‐1 in the lesions was confirmed with immunohistochemistry. Conclusions and clinical importance – Feline herpesvirus‐associated dermatitis should not be ruled out based on the location of the lesion, because a correct diagnosis is imperative for proper treatment. Future studies to assess the cause of lesions at this unusual site are warranted.     

Clinicopathological,ultrasonographic, and histopathological findings of superficial necrolytic dermatitis with hepatopathy in a cat

This report describes the antemortem diagnosis and antemortem and postmortem findings of superficial necrolytic dermatitis with hepatopathy (i.e., hepatocutaneous syndrome) in a cat. A 5-year-old Maine coon was evaluated because of a history of pruritic alopecia and liver enzyme elevations. Abdominal ultrasonography revealed a reticular pattern to the hepatic parenchyma. Histopathological findings of the liver were nodular regeneration with bands of vacuolated hepatocytes and bile duct hyperplasia, characteristic of the hepatopathy frequently associated with superficial necrolytic dermatitis. Skin histopathology revealed multifocal parakeratosis, midepidermal spongiosis, and basal cell hyperplasia consistent with superficial necrolytic dermatitis.     

Pemphigus foliaceus in a goat

Abstract A 7-year-old-female goat was referred with a 3-month history of chronic dermatitis, which partially responded to combined corticosteroid and antibiotic therapy. At dermatological examination diffuse alopecia, pustules and crusts were observed on the head, neck, dorsum and perianal area. Dermatophyte culture and skin scrapings were negative. Trichoscopic examination revealed a concurrent infestation with Damalinia caprae , which was successfully treated with ivermectin. Cytological examination of pus from intact pustules revealed nondegenerate neutrophils, absence of bacteria and numerous nucleated, irregularly shaped keratinocytes. Histopathological examination of lesional skin revealed intracorneal pustules containing neutrophils and acantholytic cells, and a mixed cell superficial perivascular dermatitis. Immunohistochemical stains of lesional skin showed intercellular IgG deposits in the spinous layer. Remission of the dermatitis was obtained with injectable dexamethasone-21-isonicotinate, every two months for one year. This is the first report to describe the cytological appearance of impression smears from intact pustules of pemphigus foliaceus in a goat and to document the presence of IgG deposits in lesional skin by means of immunohistochemistry.     

Clinical, histopathological and therapeutic considerations in a flock of sheep with facial staphylococcal-associated dermatitis

In a flock of 290 sheep, a total of 20 ewes (6.9%) with an age range of 1.5-4 years, developed a nonpruritic dermatitis characterized by alopecia/hypotrichosis, erythema, hyperpigmentation, crusting, superficial ulcers, exudation and thickening of the skin that was localized mainly to the peri-ocular area. Frequent and massive feeding of swarming sucking flies on the lesional sites was witnessed. In every instance (n = 6), Staphylococcus aureus was cultured from the exudate and the aseptically obtained skin biopsy samples from both recurrent and new cases. The main predisposing factor was the presence of small troughs, which forced the sheep to compete for food. Intramuscular administration of cefalexin for 7 days resulted in the resolution of lesions over a 2-week period. No further cases or recurrences were seen over the 16-month follow-up period. The main histopathological feature of this skin disease was a superficial and deep, perivascular to interstitial eosinophilic and mononuclear dermatitis.     

Alopecia areata (pelade) in a cow

A case of alopecia areata (pelade) is described in a cow. Alopecia areata is a rare idiopathic dermatosis of cattle. It is characterized by asymptomatic, solitary or multiple, annular areas of noninflammatory alopecia. Scrapings and cultures are negative, and the diagnosis is confirmed by skin biopsies taken from early lesions, which reveal accumulations of lymphocytes around the bulbs of anagen hair follicles. There is no known effective and practical treatment for affected cattle. The dermatitis is a cosmetic problem, but does not seem to affect general health and production, and spontaneous remission may occur.     

Color dilution alopecia in a blue Doberman pinscher crossbreed

A 6-year-old male, blue Doberman pinscher crossbreed was presented with coat abnormalities; in particular, flank alopecia and pruritus. Based on medical the history, clinical evidence, and histopathological examination, color dilution alopecia was diagnosed. The dog was with oral melatonin treated for 3 months without success.     

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.