Spontaneously Arising Tumours and Tumour-like Lesions of the Cervix and Uterus in 83 Pet Guinea Pigs (Cavia porcellus).

Tumours and tumour-like lesions are rare findings in the genital system of guinea pigs. The aim of the present study was to characterize nodular lesions in the cervix and uterus of guinea pigs submitted for histopathological diagnosis. Samples from 83 pet animals were investigated. Cases included 64 surgically excised masses including complete uteri (n = 37), parts from uteri containing masses (n = 8), complete masses (n = 12) or samples from masses (n = 7) and 19 complete necropsy examinations. In 55 of the cases, only solitary changes were observed; in 28 cases two or more lesions were diagnosed. Histopathological diagnoses included polyps in the vagina, cervix or uterus (n = 8), hyperplastic lesions of the endocervix (n = 10) and seven adenomas and two adenocarcinomas of the endocervix. Endometrial alterations included single small glandular cysts (n = 3), nodular glandular-cystic hyperplasia (n = 8), adenoma (n = 20) and adenocarcinoma (n = 3). Four placentas, 10 focal decidualizations and six deciduomas were found. Furthermore, 18 leiomyomas and nine leiomyosarcomas were diagnosed. Uterine malignant mixed Müllerian tumours were observed in seven cases. Overall, benign lesions outnumbered malignant tumours in the female genital tract of pet guinea pigs. Therefore, surgical excision or ovariohysterectomy should be recommended as therapy.

Prototheca species and Pithomyces chartarum as Causative Agents of Rhinitis and/or Sinusitis in Horses.

Pyogranulomatous rhinitis associated with an algal infection was diagnosed in a 25-year-old gelding and a 23-year-old mare had necrotizing sinusitis with intralesional algae and pigmented fungi. Algae were identified immunohistochemically in both cases as Prototheca spp. In the gelding, further characterization by polymerase chain reaction and sequencing revealed that the organism was Prototheca zopfii genotype 2. Fungi from the mare were identified as Pithomyces chartarum by molecular analysis. Prototheca species are achlorophyllous algae and P. chartarum represents a dematiaceous fungus; they are saprophytes and facultative pathogens. Prototheca spp. and P. chartarum should be considered as rare respiratory pathogens of horses.

[Sporadic cutaneous lymphosarcoma of T-cell origin with involvement of lymph nodes and internal organs in a Holstein cow]. / Sporadische kutane T-Zell-Leukose mit Beteiligung von Lymphknoten und inneren Organen bei einer Holstein-Kuh.

Sporadic lymphosarcomas in adult cattle are rare entities with an unknown etiology. This case report describes the course of the disease in a 3.5-year-old cow of the breed German Holstein, which was presented to the veterinarian due to multifocal nodular skin lesions. Several superficial lymph nodes (Lymphonodi mandibulares, parotidei and mammariae) were enlarged, had a tight-elastic consistency and were freely movable. The histopathological and immunohistochemical examination of skin biopsies showed the presence of multifocal cutaneous T-cell lymphosarcomas consistent with a skin leukosis. Bovine leukemia virus infection was excluded by serological investigation of a milk sample and virological examination of a tissue sample, respectively. Seven weeks after the first clinical examination, the cow deteriorated rapidly and was euthanized. A post mortem examination revealed the presence of neoplastic cells within lymph nodes (all superficial lymph nodes of the carcass and Lymphonodi pulmonales), kidney and lungs as well as a liver rupture. Additionally, an overview of the case reports of sporadic bovine cutaneous lymphosarcomas published during the previous 15 years will be provided. The legal background for a further utilization of affected animals for milk and meat production will be discussed. This case report illustrates that sporadic bovine leukosis represents an important differential diagnosis for viral-, bacterial- and parasitic-induced skin lesions and enlargement of lymph nodes in adult cattle.

Prototheca zopfii Genotype 2-induced Nasal Dermatitis in a Cat.

Few published cases of feline protothecosis exist; all of these were restricted to the skin and speciation of the causative organism revealed an infection with Prototheca wickerhamii in each case. This report describes Prototheca zopfii genotype 2-induced inflammation of the nasal skin and cutaneous mucosa of the right nostril in a 14-year-old neutered female domestic shorthair cat. Microscopical examination revealed marked pyogranulomatous inflammation with numerous intralesional algae. These had a round to ovoid shape, were 8-21 µm in diameter, formed endospores and displayed a positive immunoreaction for Prototheca zopfii antigen. By 18S rRNA gene amplification and sequencing the intralesional algae were confirmed as Prototheca zopfii and further characterized as Prototheca zopfii genotype 2. This case report reveals Prototheca zopfii as an additional Prototheca species associated with feline protothecosis.

Mixed Glioma (Oligoastrocytoma) in the brain of an African Hedgehog (Atelerix albiventris).

This report describes an oligoastrocytoma in the brain of a 3.5-year-old female pet African hedgehog (Atelerix albiventris) that showed progressive central nervous system signs for 6 months. Microscopical examination of the brain revealed a widely infiltrative, deep-seated glioma within the white matter of the cerebral hemispheres, basal nuclei, hippocampus, thalamus, midbrain, pons and the medulla of the cerebellum with extension of neoplastic cells into the cerebral cortex and overlying leptomeninges. Morphological features of the neoplastic cells, together with variable immunohistochemical expression of glial fibrillary acidic protein, Olig-2 and Nogo-A, indicated the presence of intermingled astrocytic and oligodendroglial tumour cells with an astrocytic component of approximately 40% consistent with an oligoastrocytoma. The distribution of the tumour is consistent with gliomatosis cerebri.

Tumors and tumor-like lesions in the mammary gland of 24 pet rabbits: a histomorphological and immunohistochemical characterization.

The aim of this retrospective study (2004-2011) was to examine mammary tumors and tumor-like lesions in 24 pet rabbits by histopathology and immunohistochemistry. Rabbits were aged 2 to 8 years. Seventeen were female and 7 female-spayed. Diagnosed tumor-like lesions were lobular hyperplasia (2 rabbits) and multiple cysts (10 rabbits). Tumors included cystadenoma (7 tumors; 3 rabbits), intraductal papilloma (2 tumors; 1 rabbit), intraductal papillary carcinoma (1 tumor), adenocarcinoma (14 tumors; 13 rabbits), adenosquamous carcinoma (2 tumors; 2 rabbits), and matrix-producing carcinoma (1 tumor). The most frequently diagnosed lesion was invasive carcinoma (n = 17). Ten rabbits had several lesions. Immunohistochemistry for calponin and p63 showed that the diagnosed tumor-like lesions, benign tumors, and noninvasive carcinoma had a peripheral myoepithelial layer that was lacking in the invasive carcinomas. In 13 of 14 (93%) of the invasive carcinomas, however, there were variable numbers of calponin- and/or p63-immunopositive cells ranging from 0.1% to 40% with morphological features of either retained nonneoplastic myoepithelial cells or neoplastic epithelial cells with a myoepithelial differentiation. Tumor recurrence was reported in the rabbit with the matrix-producing carcinoma and in 3 rabbits with mammary adenocarcinomas displaying ≥20 mitotic figures in 10 high-power fields and high numbers of neoplastic cells with a myoepithelial differentiation (19%-39%). The rabbit with the matrix-producing mammary carcinoma developed cutaneous metastases confirmed by histopathology. This study shows that different types of mammary tumor-like lesions and tumors can occur in pet rabbits.

Unusual features in four canine meningiomas.

Several subtypes of canine meningioma are recognized. This report describes four canine meningiomas with previously unreported features. The four affected dogs were of different breeds. Three of the affected dogs were male and aged 7-10 years. In one dog, age and gender were not recorded. Meningiomas were located intracranially (three dogs) or within the vertebral canal (one dog). Two meningiomas resembled gemistocytic astrocytomas, while one had focal features of a rhabdoid tumour; these three meningiomas also contained amyloid deposits. The fourth tumour, a secretory meningioma, was rich in amianthoid fibres (i.e. unusual collagen deposits containing giant collagen fibres). All of these features are also described in human meningiomas.

GM2 gangliosidosis in an adult pet rabbit.

A 1.5-year-old neutered male rabbit was presented with chronic nasal discharge and ataxia. Rapid progression of neurological signs was noted subsequent to general anaesthesia and the rabbit was humanely destroyed due to the poor prognosis. At necropsy examination there were no gross changes affecting the brain or spinal cord. Microscopical examination revealed that the perikarya of numerous neurons in the brain and spinal cord were distended by the intracytoplasmic accumulation of pale, finely granular to vacuolar material. Transmission electron microscopy showed this to be composed of concentric membranous cytoplasmic bodies. Thin layer chromatography revealed elevation of GM2 ganglioside in the brain of this rabbit compared with that of an unaffected control rabbit. Enzymatically, there was markedly reduced activity of tissue ß-hexosaminidase A in brain and liver tissue from the rabbit. This was a result of an almost complete absence of the enzymatic activity of the α-subunit of that enzyme. These findings are consistent with sphingolipidosis comparable with human GM2 gangliosidosis variant B1.

Nonsuppurative encephalitis in a dog.

A 4-year-old male German Hunting Terrier presented with tremor, dyspnea, trismus, spasms of the musculature of the larynx and pharynx, and hypothermia and subsequently died despite intensive clinical care. Prior clinical signs included vomitus and diarrhea. Microscopic examination of the brain revealed a multifocal nonsuppurative brain stem encephalitis; a few intralesional neurons contained intranuclear inclusions. By immunohistochemistry, Aujeszky disease virus (Suid herpesvirus 1) antigen was detected in neurons in the brain and in ganglion cells of the trigeminal ganglia. Viral culture of brain tissue confirmed the presence of Aujeszky disease virus. Histopathologic findings in the brain with the identification of Aujeszky disease virus by immunohistochemistry and polymerase chain reaction are consistent with Aujeszky disease virus-induced encephalitis. Sequencing revealed a 100% homology of the isolated Aujeszky disease virus with Aujeszky disease virus isolates of wild boar from Eastern Germany.

Fatal equine meningoencephalitis in the United Kingdom caused by the panagrolaimid nematode Halicephalobus gingivalis: case report and review of the literature.

A fatal case of eosinophilic and granulomatous meningoencephalitis caused by the free-living panagrolaimid nematode Halicephalobus gingivalis is reported in a 10-year-old Welsh gelding in the United Kingdom. Clinical examination first revealed behavioural abnormalities which rapidly progressed to severe ataxia, reduced mentation status and cranial nerve signs. Despite symptomatic treatment no amelioration of neurological signs was achieved and the horse was subjected to euthanasia. A complete post mortem examination revealed eosinophilic and granulomatous meningoencephalitis mainly affecting the cerebellum and brain stem with intralesional adult nematodes, larvae and eggs. There was also eosinophilic meningitis of the cervical spinal cord. The intralesional nematodes were morphologically consistent with the panagrolaimid nematode H. gingivalis. Although infection by this facultative neurotropic parasite is extremely rare, it needs to be considered in the differential diagnosis of central nervous signs in horses and, in particular, other equine helminthic infection of the central nervous system. This fatal case is unusual since lesions were locally very extensive and the nematodes did not colonise haematogenously to other organs as seen often in equine halicephalobosis. As the taxonomy of H. gingivalis has changed and some recent reports in the literature still refer to this species as Micronema deletrix or Halicephalobus deletrix, we here provide a short update of the species and some insights on the order Tylenchida, which contains free-living nematodes with parasitic tendencies.

Cutaneous schwannomas in 22 horses.

Schwannomas are uncommonly recognized in horses. This study describes cutaneous schwannomas in 22 horses aged 8 to 25 years: 12 male, 7 female, and 3 of unknown sex. The horses had solitary cutaneous masses: 9 on the head, 3 on the neck, and the others on the shoulder, hip, thorax, abdomen, rump, extremities, or tail. The location of 1 tumor was unknown. The dermal tumors were well demarcated and expansile. Twelve had a multinodular pattern, whereas 10 formed a single nodule. Antoni A areas were observed in all tumors, and 10 tumors contained Antoni B areas. In Antoni A areas, the densely packed spindle-shaped neoplastic cells were arranged in short fascicles with nuclear palisading. In the hypocellular Antoni B areas, neoplastic cells were separated by abundant myxomatous stroma. Tumors commonly had hyalinization of stroma and vessel walls and ancient change. Cellular vacuolation was observed in 18 tumors. In all 22 cases, neoplastic cells were immunopositive for S100 protein. Expression of laminin and glial fibrillary acidic protein was observed in all 6 tumors evaluated by immunohistochemistry for these markers. One tumor was examined ultrastructurally: Neoplastic cells had branched cytoplasmic processes and were surrounded by an external lamina. Follow-up information was available 8 months to 10 years postexcision for 9 horses, for which surgical excision of the tumor was curative. The equine cutaneous schwannomas in this study had microscopic features like those of human schwannoma and had benign clinical behavior. Correct classification of equine cutaneous schwannoma will facilitate accurate prognosis and appropriate treatment.

Polymyositis following Vogt-Koyanagi-Harada-like syndrome in a Jack Russell terrier.

A male Jack Russell terrier developed bilateral uveitis and glaucoma at 1 year of age. Since the ocular disease was painful and unresponsive to treatment, both globes were enucleated. Microscopical evaluation of one enucleated globe revealed panuveitis, with pigment dispersion and phagocytosis consistent with the ocular lesions of canine Vogt-Koyanagi-Harada (VKH)-like syndrome. Three years later the dog was represented with severe muscle disease and skin lesions. Due to rapid clinical deterioration the dog was humanely destroyed. Necropsy examination revealed lichenoid interface inflammation in the skin and mucous membranes, with pigmentary incontinence consistent with VKH-like syndrome and lymphocytic and histiocytic polymyositis with marked muscle atrophy. Canine VKH-like syndrome is an autoimmune disease that targets melanocyte antigens. Some human patients with VKH disease develop additional autoimmune diseases. To our knowledge this is the first reported case of polymyositis subsequent to VKH-like disease in a dog. In addition, VKH-like disease has not been previously reported in a Jack Russell terrier.

Abdominal fibrosarcoma associated with a retained surgical swab in a dog.

An abdominal fibrosarcoma surrounding a retained surgical swab was identified in a 3-year-old neutered female rottweiler dog presented with chronic inappetence and lethargy. Laparotomy revealed a mass within the omentum, multiple hepatic masses and enlarged mesenteric lymph nodes. The dog was humanely destroyed and submitted for necropsy examination. Microscopically, the omental mass was consistent with a sarcoma surrounding centrally located fibres of foreign material and was infiltrated by epithelioid macrophages containing intracytoplasmic fibre fragments. Sarcoma tissue was also present in mesenteric lymph nodes, liver, spleen and lungs, and some affected lymph nodes contained intralesional epithelioid macrophages with fibre fragments. Immunohistochemical and electron microscopical examinations were consistent with a diagnosis of fibrosarcoma. By fibre analysis and electron microscopy, the intratumoural fibres were identified as cotton fibres with features identical to those obtained from a surgical swab. To our knowledge this is the first description of an abdominal fibrosarcoma associated with a retained surgical swab in a dog. Other examples of foreign body-associated sarcomas in the veterinary literature are vaccine- and implant-induced sarcomas.

Localized, plexiform, diffuse, and other variants of neurofibroma in 12 dogs, 2 horses, and a chicken.

In humans, neurofibroma and schwannoma are distinct entities within the group of benign peripheral nerve sheath tumors. In the veterinary literature, these tumors are often classified together simply as benign peripheral nerve sheath tumors, and diagnostic criteria for their subclassification are not well established. We describe peripheral nerve sheath tumors with microscopic, immunohistologic, and ultrastructural features similar to those in subtypes of human neurofibroma in 12 dogs, 2 horses, and 1 chicken. Dogs were of different breeds and were aged 2 months to 15 years. The canine tumors were located in the skin, peripheral nerve, tongue, and large intestine. The 2 horses were 11 and 12 years old. The equine tumors were located in the subcutis of the neck and axilla. The chicken was a mature white Leghorn chicken with an ocular neoplasm. Neurofibromas of this study had localized, plexiform, diffuse and combined plexiform and diffuse growth patterns, and microscopic features similar to those in classic, collagenous, cellular, myxoid, and pigmented neurofibromas of humans. One diffuse neurofibroma contained areas of schwannian differentiation (hybrid neurofibroma-schwannoma). Two plexiform neurofibromas occurred together with diffuse ganglioneuromatosis in the large intestine of young dogs, as has also been reported in humans. This investigation shows the existence of identical subtypes of neurofibroma in animals and humans and identifies similarities in tumor location and patient age between animals and humans. This report will allow a more discriminating classification of benign peripheral nerve sheath tumors and probably has a bearing on epidemiology, pathogenesis and prognosis.

Physiological response of bovine subcommissural organ to endothelin 1 and bradykinin.

The circumventricular organs (CVOs) regulate certain vegetative functions. Receptors for bradykinin (BDK) and endothelin (ET) have been found in some CVOs. The subcommissural organ (SCO) is a CVO expressing BDK-B2 receptors and secreting Reissner's fiber (RF) glycoproteins into the cerebrospinal fluid. This investigation was designed to search for ET receptors in the bovine SCO and, if found, to study the functional properties of this ET receptor and the BDK-B2 receptor. Cryostat sections exposed to (125)I ET1 showed dense labeling of secretory SCO cells, whereas the adjacent ciliated ependyma was devoid of radiolabel. The binding of (125)I ET1 was abolished by antagonists of ETA and ETB receptors. The intracellular calcium concentration ([Ca(2+)](i)) was measured in individual SCO cells prior to and after exposure to ET1, BDK, or RF glycoproteins. ET1 (100 nM) or BDK (100 nM) caused an increase in [Ca(2+)](i) in 48% or 53% of the analyzed SCO-cells, respectively. RF glycoproteins had no effect on [Ca(2+)](i) in SCO cells. ET and BDK evoked two types of calcium responses: prolonged and short responses. Prolonged responses included those with a constant slow decline of [Ca(2+)](i), biphasic responses, and responses with a plateau phase at the peak level of [Ca(2+)](i). ET1-treated SCO explants contained a reduced amount of intracytoplasmic AFRU (antiserum to RF glycoproteins)-immunoreactive material compared with sham-treated control explants. Our data suggest that ET1 and BDK regulate [Ca(2+)](i) in bovine SCO cells, and that the changes in [Ca(2+)](i) influence the secretory activity of these cells.

Arteriovenous haemangioma in two dogs and a cat.

Haemangiomas are benign vascular tumours and several types can be distinguished based on microscopical features. Capillary and cavernous haemangiomas are most commonly reported in man and domestic animals. Arteriovenous haemangiomas are rare variants in man and herein we describe this subtype in two dogs and one cat. One dog and the cat presented with a cutaneous vascular lesion, the other dog with a bleeding mass in the tongue. Surgically excised masses comprised non-encapsulated proliferations of variably sized arterial- and venous-like vessels, accompanied by clusters of capillaries and immature vascular structures in the feline cutaneous tumour and the canine lingual neoplasm. All vasoformative elements had von Willebrand factor-positive endothelia enclosed by a smooth muscle actin-positive tunica media or by pericytes. The results of this study expand the range of differential diagnoses for vascular neoplasms in the dog and cat.

Neuropathological findings in a Staffordshire bull terrier with l-2-hydroxyglutaric aciduria.

l-2-Hydroxyglutaric aciduria (l-2-HGA) is a hereditary neurometabolic disorder reported in human beings and dogs. An 11-month-old Staffordshire bull terrier was suspected to have the disease, on the basis of clinical signs and magnetic resonance imaging findings. l-2-HGA was confirmed by urinary organic analysis and DNA testing and the dog was humanely destroyed. Post-mortem findings consisted only of microscopical lesions in the brain, characterized by marked spongiform changes and predominantly affecting the grey matter of the cerebral cortex, thalamus, cerebellum and brainstem. The spongiform changes were characterized by well-demarcated, clear vacuoles located at perineuronal and perivascular sites. Immunohistochemical and ultrastructural examination confirmed that the affected cells were astrocytes.

Heart failure in two West Highland white terriers caused by congenital angiomatous cardiac anomaly.

The paper describes the clinical and pathological characteristics of an unusual cystic congenital cardiac anomaly that caused clinical signs of congestive heart failure, respiratory distress and cardiac arrhythmias in two West Highland white terrier puppies. In both dogs a definitive diagnosis was made postmortem.