P-35 Nonlethal junctional epidermolysis bullosa in a dog

A 3-year-old Burmese cat was presented with a history of nonresolving crusted and papular lesions of the face and prior treatment with prednisolone. Skin biopsies revealed typical pox lesions with hyperplasia and ulceration of the epidermis and eosinophilic cytoplasmic inclusion bodies in the epidermal cells. In the upper dermis there was prominent diffuse mast cell infiltration and mild neutrophilic and eosinophilic inflammation. Rare cytoplasmic inclusion bodies were also present in swollen endothelial cells of dermal venules, which showed no other degenerative changes. Histological diagnosis was confirmed by electron microscopic evidence of pox virus particles in inclusion bodies of epidermal cells. The lesions resolved within 6 weeks with systemic antibiotic therapy and supportive care. A 2-year-old domestic short-haired cat was presented with multiple disseminated papular and ulcerative pox lesions with central eschar over the entire body. Histologically, large epidermal inclusion bodies (up to 6 μm in diameter) were present. Widespread haemorrhage and vascular wall necrosis was visible in the dermis and subcutis. Some subcutaneous vessels showed neutrophilic vasculitis. In addition to diffuse dermal neutrophilic and eosinophilic inflammation, a lymphohistiocytic panniculitis was also present. The cat died as a result of massive haemorrhage and lymphedema, despite supportive care.
Funding: Self-funded.     

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.     

Dermatoses caused by infestations of immature Ixodes spp. on dogs and cats in Sydney, Australia

Infestations of larval and nymphal Ixodes spp. were identified in 16 dogs and 16 cats from several small animal clinics in Sydney. Cases occurred in late summer or autumn, peaking in February, and were seasonally recurrent in some individuals. Clinical signs of infestation included a papular dermatitis and irritation or pruritus that ranged from severe to mild or absent. The distribution of tick attachment tended to be cranial and ventral, with the face, legs, axillae and ventrum the most commonly affected sites. The estimated number of ticks in each infestation varied from less than 10 to more than 100. Basic morphological examination of ticks collected from affected animals was performed by attending veterinarians using light microscopy, and larvae and nymphs belonging to the Ixodes genus were identified. Ticks collected from 17 animals and submitted to the Department of Medical Entomology, Westmead Hospital were putatively identified as I. trichosuri (57%) and I. holocyclus (25%) larvae. Histopathological samples of attachment sites collected from three dogs and one cat were characterised by ticks attached in well-demarcated invaginations of the skin ('tick craters') associated with variable epidermal and/or dermal necrosis, focal eosinophilic intraspinous pustules, mild to marked eosinophilic and neutrophilic, superficial to deep, dermal perivascular to interstitial inflammation, and moderate to marked superficial dermal oedema and red cell extravasation. A range of topical acaricidal preparations, including fipronil and synthetic pyrethroids, were used for treatment.     

Ulcerative pododermatitis in a cat associated with Anatrichosoma sp.

A 9-year-old castrated male Chartreaux cat was presented for an ulcerative pododermatitis of all 4 paws. A clinical exam was inconclusive and supportive therapy did not improve the condition. Histologic examination revealed an ulcerative and eosinophilic dermatitis associated with epidermal and dermal nematodes and ova consistent with the aphasmid Anatrichosoma sp. Treatment with ivermectin completely resolved the skin lesions. Anatrichosomiasis should be included in the differential diagnosis of ulcerative pododermatitis in cats, at least in the southwestern United States.     

Spongiotic vesicular dermatitis as a cutaneous reaction pattern in seven horses

Over a 6-year period seven adult horses of different breeds and genders developed multifocal, exudative, oozing dermatitis characterized histologically by epidermal spongiotic vesicles and perivascular eosinophilic, neutrophilic and mixed mononuclear inflammation. Three horses were pruritic. Systemic disease was not noted. Two horses had a history of recurrent urticaria (hives) and one horse had nodules or welt-type lesions that progressed to exudative, oozing lesions. Interepithelial immunoglobulin (Ig)G was detected by avidin-biotin complex-peroxidase staining, but the pattern of staining was more consistent with epithelial oedema than specific IgG deposition associated with pemphigus. The exudative oozing lesions developed under circumstances suggesting that dermal oedema progressed to intracellular and intercellular epidermal oedema, which in turn progressed to the spongiotic vesicular epidermal lesions.     

Dermal mass aspirate from a Persian cat

A 1-year-old spayed female Persian cat with alopecia and weight loss had numerous variably ulcerated dermal nodules. Cytologic examination of an aspirate of one of the nodules revealed pyogranulomatous inflammation along with septate hyphae and basophilic round bodies, 0.5–1.0 μm in diameter, surrounded by a thin clear halo (arthrospores). The cytologic diagnosis was dermatophytic pseudomycetoma. Histologically, there were dermal granulomas containing poorly staining, septate hyphae with bulbous spores embedded within abundant amorphous eosinophilic material (Splendore-Hoeppli reaction), and the histologic diagnosis was pseudomycetoma-associated chronic multifocal severe granulomatous dermatitis with lymphocytic perifolliculitis and furunculosis. Microsporum canis was cultured from the lesion. Pseudomycetomas are distinguished from fungal mycetomas, or eumycotic mycetomas, by the findings of multiple lesions, lack of a history of skin trauma, an association with dermatophytes, most commonly Microsporum canis , and, histologically, lack of true cement material and a more abundant Splendore-Hoeppli reaction in pseudomycetomas. Additionally, pseudomycetomas differ from dermatophytosis, in which lesions are restricted to epidermal structures. Persian cats have a high incidence of pseudomycetoma formation, suggesting a heritable predisposition. The prognosis is fair with systemic antifungal therapy. When examining cytologic specimens from Persian cats with single or multiple dermal nodules, especially if pyogranulomatous inflammation is present, a diagnosis of pseudomycetoma should be suspected and is warranted if arthrospores and refractile septate hyphae are present.     

Sheep pox: experimental studies with a west african isolate

Under conditions of a maximum security laboratory, four cross-bred sheep were inoculated intradermally only or intradermally and intratracheally with a West African isolate of sheep pox virus. All sheep had increased temperature and depression by the fourth or fifth day after infection. Nasal and lacrimal discharge and coughing occurred in all sheep but were more severe in sheep receiving the virus via the tracheal route. From the fifth day after infection, numerous papular erythematous skin lesions developed at the inoculation sites. These were 3-7 mm in diameter and gradually became nodular. Some of these lesions healed and others coalesced to form tumorlike masses. In one sheep, euthanized 14 days after intradermal and intratracheal inoculation, nodular lesions were found in the skin around the eyes, nostrils, oral and perianal regions, the mucosa of the rumen and throughout the lungs. Histologically, skin nodules were characterized by ischemic necrosis, vasculitis, microvesicualtion, eosinophilic cytoplasmic inclusions in the dermal epithelial cells and vacuolar nuclear degeneration. The pulmonary lesion was that of proliferative alveolitis with occasional cytoplasmic inclusions in the alveolar cells and macrophages. Ultrastructurally, large cuboidal virus particles were found both in the skin lesion and inoculated tissue cultures. The sheep pox virus structure was easily distinguished from contagious ecthyma virus, a parapoxvirus which causes sporadic disease in Canada. Serum neutralizing antibodies developed in all the sheep by 14 days postinfection.

The clinical and pathological characteristics of experimental sheep pox produced with this West African isolate were similar to those caused by Neethling virus of lumpy skin disease in cattle.

     

Ulcerative facial and nasal dermatitis and stomatitis in cats associated with feline herpesvirus 1

Ulcerative dermatitis of the nasal planum or haired skin of the face, associated with intranuclear inclusion bodies compatible with herpesvirus, was identified in nine cats. Clinically, lesions were ulcerative and crusted, and often persistent. A tenth cat had focal proliferative ulcerative stomatitis, also associated with intranuclear inclusion bodies. Microscopically, there was necrosis and ulceration associated with prominent eosinophilic inflammation. Intranuclear inclusion bodies were noted in all cases, within the surface or adnexal epithelium. Ultrastructural examination of skin from two cats revealed virions morphologically compatible with a herpesvirus. Polymerase chain reaction (PCR) specific for feline herpesvirus 1 on DNA extracted from fresh-frozen or formalin-fixed paraffin-embedded biopsy samples and/or consensus primer PCR with DNA sequencing performed on DNA extracted from formalin-fixed paraffin-embedded biopsy samples from seven cats revealed that the virus was indistinguishable from feline herpesvirus 1. PCR was negative in one of eight cats tested.     

山羊痘的病理形态学观察

对发生在贵州省的山羊痘进行了病理形态学观察.山羊痘以全身皮肤、呼吸道及消化道粘膜出现痘疹为特征.皮肤疹最初为红斑,红斑肿胀隆起形成结节状丘疹,然后丘疹发生凝固性坏死,脱落而形成痂皮.组织学检查早期皮肤病变可见充血,水肿和多量的巨噬细胞和中性白细胞浸润,随着病变的发展可见更多的巨噬细胞,淋巴细胞,浆细胞和一些体积较大的所谓"山羊痘细胞"出现.在真皮的病变细胞和痘细胞中可见嗜酸性胞浆内包涵体.引起水肿和坏死的血管炎常伴有血栓和梗死.上皮的变化包括棘细胞增生,空泡变性,不全角化,过度角化和坏死等.其他器官的病变也有相似的细胞浸润和血管炎变化.但发生在上呼吸道及上消化道时常出现溃疡.透射电镜观察在感染的皮肤和肺上皮细胞的胞浆内发现有大量不同成熟阶段的典型的山羊痘病毒颗粒.受感染的细胞除可见胞浆内散在的病毒颗粒或形成病毒包涵体外,通常可见细胞水肿、线粒体肿胀、内质网和高尔基复合体扩张.     

A case of superficial suppurative necrolytic dermatitis of miniature schnauzers with identification of a causative agent using patch testing

A 9‐year‐old, castrated male, miniature schnauzer presented with malaise, anorexia, fever and severe inflammatory skin lesions on the dorsum, thighs and pinnae. The lesions developed 2 days after bathing with a commercial shampoo. Histopathological examination of skin samples revealed neutrophilic exocytosis, parakeratosis, epidermal hyperplasia and neutrophilic infiltration in the superficial dermis. Skin lesions resolved completely after 14 days of treatment with prednisolone and ofloxacin. Patch testing performed on the patient and a clinically healthy dog showed erythema at the site exposed to the culprit shampoo 48 h later only on the patient. Histopathological findings of the erythematous reaction were similar to those of the spontaneous skin lesions. Based on these findings, the dog was diagnosed with superficial suppurative necrolytic dermatitis of miniature schnauzers. The patch test results suggested that contact dermatitis to a commercial shampoo played a role in the pathogenesis of this disease.     

Acute necrotizing dermatitis and septicemia after application of a d-limonene-based insecticidal shampoo in a cat

A 2-year-old female spayed domestic shorthair cat was examined because of lethargy, inappetance, vocalization, and abnormal aggressive behavior of 1 day's duration. The cat had been groomed the previous day with a d-limonene-based insecticidal shampoo. Skin lesions consisted of coalescing erythematous patches. Despite supportive care, the cat's condition deteriorated. Dermatohistopathologic changes included multifocal areas of acute coagulative epidermal necrosis. The dermis was infiltrated by a dense population of bacilli. d-Limonene toxicosis has been rarely described in dogs and cats. Toxic effects such as hypersalivation, ataxia, shivering, hypothermia, scrotal irritation, hypotension, and erythema multiforme major have been reported. Treatment for septicemia and disseminated intravascular coagulation, along with intensive supportive care, may be necessary.     

Extensive lesions of monkeypox in a prairie dog (Cynomys sp)

Monkeypox with extensive lesions was diagnosed in a prairie dog that was involved in a recent human outbreak of monkeypox in the Midwestern United States. Gross lesions included oral ulcers, pulmonary consolidation, enlarged cervical and thoracic lymph nodes, and multifocal, small, white umbilicated plaques in the gastrointestinal wall. Microscopic lesions were extensive in the lungs and consisted of fibrinonecrotic bronchopneumonia with vasculitis and poorly defined eosinophilic intracytoplasmic inclusion bodies in cells thought to be alveolar epithelial cells, histiocytes, and fibroblasts. Multifocal necrotizing lesions, often accompanied by myxedema, were also present in most of the other examined organs. Aggregates of pox viral particles were observed within lesions by transmission electron microscopy. Monkeypox virus infection was confirmed by real-time polymerase chain reaction and virus culture at the Centers for Disease Control and Prevention. This report highlights the difficulties of rapid diagnosis of exotic or emerging diseases and further substantiates the prairie dog as an animal model of monkeypox.     

B‐cell lymphoma with Mott cell differentiation in a cat

A 12‐year‐old, male castrated Domestic Shorthair cat was presented to Animal Medical Center of Gifu Univeristy with anorexia and vomiting. Physical examination revealed an enlarged left tonsil and right mandibular lymph node (approximately 2–3× the normal size), and a submucosal mass on the right side of the epiglottis (1.5 × 2.0 cm). On computed tomography images, an enlarged left tonsil, and enlarged right mandibular, right pharyngeal, and left and right cervical lymph nodes were observed. Cytologic examination of smears of tonsil and lymph nodes revealed numerous medium‐ to large‐sized neoplastic lymphoid cells, approximately half of which contained one or several light‐blue homogenous globoid cytoplasmic inclusions (5–10 μm), which stained magenta with periodic acid–Schiff (PAS) stain. Histopathologic examination of the left tonsil revealed diffuse proliferation of medium‐ to large‐sized neoplastic lymphoid cells effacing the original lymphoid architecture. Half of the cells contained one or several eosinophilic globoid cytoplasmic inclusions, which stained magenta with PAS and showed positive immunohistochemical reactions for immunoglobulin M (IgM) and λ light chain. Neoplastic lymphoid cells were also CD20⁺, Pax5⁺, and MUM1⁺, and CD3^?. Thus, the neoplastic lymphoid cells expressed a B‐cell immunophenotype, and the globoid cytoplasmic inclusions represented an aberrant IgM λ light chain accumulation, similar to Russell bodies. B‐cell lymphoma with Mott cell differentiation was diagnosed based on cytologic, histopathologic, and immunohistochemical features. This is the first report of B‐cell lymphoma with Mott cell differentiation in a cat.     

小尾寒羊绵羊痘病例的诊断

旨在对甘肃某羊场小尾寒羊疑似绵羊痘进行确诊,并深入探讨其病理变化特点。对临诊疑似患绵羊痘的小尾寒羊进行了羊痘间接ELISA抗体检测和PCR检测确诊,并对6只病羊进行病理剖检、病理组织学和超微结构研究。结果如下：羊痘间接ELISA抗体检测显示6例病羊样品均为阳性;同时,对2例病羊样品进行PCR检测,均扩增出绵羊痘病毒（SPV）585 bp的目的基因片段,表明本次小尾寒羊所患疫病为绵羊痘。病理剖检显示,病羊皮肤无毛或少毛处充血,局部有红斑和坏死,尾部常有感染化脓形成溃疡;消化道黏膜,尤其舌和瘤胃黏膜有大小不等痘疹与坏死病灶,局部甚至形成糜烂或溃疡。肺膈叶以及肝、脾等常有痘疹和坏死病灶。病理组织学观察显示,肺痘疹病灶主要呈现渗出-增生结节和坏死-增生结节变化,病灶内血管、细支气管等周围常有大量绵羊痘细胞,胞质内有嗜酸性包涵体;病变消化道黏膜局部,上皮细胞程度不等增生、水泡变性,固有层及黏膜下层充血、水肿,有大量绵羊痘细胞,其细胞质内包涵体明显。肝、脾、肾也有程度不等坏死-增生结节变化。肺超微结构观察显示,肺泡上皮细胞肿大,细胞核浓缩、染色质聚集,线粒体程度不等肿胀、嵴断裂、空泡化,可见细胞质内包涵体。研究证明,除局部皮肤病变外,消化道黏膜和肺等实质器官的痘疹病变是患绵羊痘小尾寒羊具代表性的病理变化,尤其痘疹病灶中大量绵羊痘细胞的出现具有证病性意义。     

Histopathological differences between canine idiopathic sebaceous adenitis and canine leishmaniosis with sebaceous adenitis

Sebaceous adenitis (SA) may be idiopathic (ISA) or associated with other disorders. The purpose of the present study was to compare the cutaneous histopathology of SA in cases in which Leishmania organisms were detected by immunohistochemistry (IHC) with that of cases diagnosed as ISA. Skin sections of 29 patients were evaluated histologically and divided into two groups, one characterized by several epidermal and subepidermal lesions, a granulomatous to pyogranulomatous nodular to diffuse dermatitis involving the sebaceous glands and a positive IHC for Leishmania spp. The other group was characterized by orthokeratotic hyperkeratosis, follicular keratosis with different degrees of pyogranulomatous to granulomatous SA, lack of nodular dermatitis and a negative IHC for Leishmania spp. Hidradenitis was present in both groups. From these results it can be concluded that SA in canine Leishmaniosis (CL) is usually present together with a nodular to diffuse dermal infiltrate and epidermal and subepidermal lesions, and that SA in the absence of dermal inflammation is probably not associated with or suggestive of CL, even in regions where the disease is endemic.     

Expornitic of avian pox in a zoo.

During a 6-week period at the San Diego Zoo, avian pox occurred in 9 pheasants representing 5 species. Lesions were limited to facial skin and consisted of epithelial cell hyperplasia, secondary inflammatory changes, and intracytoplasmic eosinophilic inclusion bodies which, by electron microscopy, were shown to contain pox virus. The disease was self-limiting in 7 pheasants, but 2 pheasants died. Free-ranging Indian red junglefowl were implicated as the source of the infection.     

Identification and partial sequencing of a crocodile poxvirus associated with deeply penetrating skin lesions in farmed Nile crocodiles, Crocodylus niloticus

When large numbers of crocodile skins were downgraded because of the presence of small pin prick-like holes, collapsed epidermal cysts were found deep in the dermis of juvenile crocodiles while forming cysts were observed in hatchlings. Histopathology of these forming cysts showed the presence of intracytoplasmic inclusions in proliferating and ballooning epidermal cells. Pox virions were seen in electron microscope preparations made from the scabs of such early lesions. The partial sequencing of virus material from scrapings of these lesions and comparison of it with the published sequence of crocodile poxvirus showed the virus associated with the deep lesions to be closely related, but different. To differentiate between the two forms of crocodile pox infection it is suggested that the previously known form should be called "classical crocodile pox" and the newly discovered form "atypical crocodile pox". The application of strict hygiene measures brought about a decline in the percentage of downgraded skins.     

Trombiculosis in a cat.

Trombiculosis (dermatitis caused by trombiculid mites) in a Domestic Shorthair cat was characterized by diffuse thickening and crusting of the skin of the abdomen and limbs and by multiple papules on the face, ears, and sides of the trunk. Skin biopsy revealed acanthosis and hyperkeratosis involving the epidermis and hair follicles, mites in epidermal tunnels, and edema of the dermis, with infiltration of eosinophils and mast cells. Mites from skin scrapings were identified as Walchia americana. The cat was treated systemically with a broad-spectrum antibiotic and topically with a carbaryl and pyrethrin powder preparation. The lesions were resolved within 2 months.     

Generalized fatal Cowpox virus infection in a cat with transmission to a human contact case

A 4-month-old female domestic shorthair cat was infected by a virus of the Poxvirus family. The animal developed a severe pneumonia and generalized ulcerating lesions of the skin. Histologically, typical eosinophilic intracytoplasmic inclusion bodies indicative of an Orthopoxvirus (OPV) infection were present. The lung showed grey-white to haemorrhagic nodular lesions with a central zone of complete necrosis of alveolar and bronchial tissue. Electron microscopy from skin and lung nodules revealed typical square-shaped OPV particles. Cultivation of the virus on chorio-allantoic membranes of embryonated chicken eggs resulted in haemorrhagic plaques. Restriction enzyme analysis, PCR and sequencing of the D8L gene identified the OPV isolate as a typical Cowpox virus. It was transmitted by the cat to a human contact person who developed a local nodular dermatitis at the inoculation site in association with signs of general infection and had an increase of OPV-specific neutralizing antibodies in paired serum samples.