Hepatoblastoma in a cat

Hepatoblastomas are neoplasms that originate from putative pluripotential stem cells of the liver. A hepatic mass from an 8-year-old Abyssinian cat was composed of cords and sheets of neoplastic cells, with scattered rosettes and small ductal structures. Most neoplastic cells had a pale eosinophilic cytoplasm and a round to ovoid nucleus. The tumor also had short spindle cells with an oval nucleus. Immunohistochemically, neoplastic cells were weakly positive for embryonic hepatocellular markers, such as alpha-fetoprotein and cytokeratin (CK) 8/18, but negative for the hepatocellular marker Hepatocyte Paraffin 1. The cells were also positive for CD56/neural cell adhesion molecule and for the biliary epithelial markers CK 7, CK 8/18, CK CAM5.2, and vimentin, but negative for CK 20. Some neoplastic cells expressed neuroectodermal or neuroendocrine markers, such as protein gene product 9.5 and synaptophysin, but were negative for chromogranin A and not argyrophilic by the Grimelius technique. The cat died soon after the biopsy without clinical improvement.     

Progressive retinal atrophy in the Abyssinian cat

Hereditary and progressive retinal atrophy is described in the Abyssinian cat and two cases are recorded in this breed in the United Kingdom. The wide range of age of onset in the cat is discussed and compared with the age incidence of similar conditions in the dog.     

Functional and structural assessment of retinal sheet allograft transplantation in feline hereditary retinal degeneration

Purpose  To investigate whether sheets of fetal retinal allografts can integrate into the dystrophic Abyssinian cat retina with progressive rod cone degeneration.
Methods  Fetal retinal sheets (cat gestational day 42), incubated with BDNF microspheres, were transplanted to the subretinal space of four cats at an early disease stage. Cats were studied by fundus examinations, bilateral full-field flash ERGs, and indocyanine green and fluorescein angiograms up to 4 months following surgery. E42 donor and transplanted eyes were analyzed by histology and immunohistochemistry for retinal markers.
Results  Funduscopy and angiography showed good integration of the transplants in two of four cats, including extension of host blood vessels into the transplant and some scarring in the host. In these two, transplants were found in the subretinal space with laminated areas, with photoreceptor outer segments in normal contacts with the host retinal pigment epithelium. In some areas, transplants appeared to be well-integrated within the host neural retina. Neither of these two cats showed functional improvement in ERGs. In the other two cats, only remnants of donor tissue were left. Transplants stained for all investigated cellular markers. No PKC immunoreactivity was detected in the fetal donor retina at E42, but developed in the 4-month-old grafts.
Conclusions  Fetal sheet transplants can integrate well within a degenerating cat retina and develop good lamination of photoreceptors. Functional improvement was not demonstrated by ERG in cats with well-laminated grafts. Transplants need to be further evaluated in cat host retinas with a more advanced retinal degeneration using longer follow-up times.     

Orbital plasmacytoma in a cat

An Abyssinian cat presented with epistaxis, melaena and retinal vascular changes. Plasma protein levels were markedly elevated and a monoclonal gammopathy was present on serum protein electrophoresis. Based on these laboratory findings, hyperviscosity syndrome was assumed to be responsible for the clinical signs. The cat responded initially to fluid therapy, but relapsed and then developed unilateral exophthalmia. The animal was euthanased and an extramedullar plasmacytoma of the right orbit was diagnosed at postmortem examination.     

Progressive retinal atrophy in Abyssinian and Somali cats in the Netherlands (1981-2001)

From 1981 to 2001, 248 Abyssinian and 127 Somali cats in the Netherlands were examined for hereditary eye disease. Distinct ophthalmoscopic signs consistent with hereditary progressive retinal atrophy (PRA) were observed in 11 Abyssinian cats, and subtle signs in 3 Abyssinian cats. A familial relationship was detected in 13 out of 14 of these cats, which supports a hereditary basis to the condition. Distinct funduscopic signs of retinal degeneration were observed at a median age of 4 years. One cat with advanced retinal degeneration was only 7 months old, whereas the remaining 10 cats were between 2 and 12 years old at the time of diagnosis. These differences in the age of onset are suggestive of at least two types of PRA occurring in Abyssinian cats in the Netherlands: a dysplastic, early-onset and a late-onset retinal degeneration. A large-scale and systematic examination programme for hereditary eye disease will be necessary to assess the incidence of PRA in the Dutch population of Abyssinian and Somali cats as a whole, and to provide a basis for a preventive breeding programme.     

Taurine deficiency retinopathy in the cat

The literature on feline central retinal degeneration is reviewed and an experiment reported which investigates whether taurine is essential in cats fed a purified diet. The development of taurine deficiency retinopathy is described and illustrated. The histopathological, ultrastructural and ERG changes are also described. Other retinal degenerations in the cat are discussed.     

Mammary mucinous carcinoma in the cat

Mucinous carcinoma of the mammary gland is a rare tumor characterized by excessive mucin production. In human and canine pathology, the diagnosis of mucinous carcinoma is based on the demonstration of an epithelial phenotype of mucus-producing cells and periodic acid-Schiff (PAS)-diastase positivity of the mucin. The histologic and immunohistologic characteristics of feline mucinous mammary carcinoma were examined. Of 656 cases of feline mammary neoplasms and dysplasias, 3.2% were found to be mucin-producing tumors. Cytokeratin 19 (16 cases positive, 4 heterogenous, and 1 negative) and vimentin (15 cases positive, 2 heterogenous, and 4 negative) expression were examined, and the mucin produced was alcian blue positive. PAS-diastase staining was variable (38.1%). Based on these findings, mucinous mammary carcinoma in the cat varies significantly from the human and canine varieties and alcian blue is the prominent stain in the diagnosis of feline mucinous carcinoma.     

Interstitial nephritis in cats inoculated with Crandell Rees feline kidney cell lysates

Parenteral administration of Crandell Rees feline kidney (CRFK) cell lysates or feline herpesvirus 1, calicivirus, and panleukopenia virus-containing vaccines (FVRCP) grown on CRFK cells induces antibodies against CRFK cells. These antibodies also react with feline renal cell extracts. The purpose of this study was to determine whether interstitial nephritis would be detected in cats that were immunologically sensitized with CRFK lysates, boosted with CRFK lysates, and then biopsied 2 weeks after the booster. Cats (2 per group) were immunologically sensitized against CRFK lysates by administering 10 microg, 50 microg, or 50 microg plus alum 13 times (12 times in the first 50 weeks) over 2 years. Two cats were inoculated three times, 4 weeks apart with an FVRCP vaccine for intranasal administration as kittens, boosted 50 and 102 weeks later, and then renal biopsies taken 2 weeks after the last booster. Neither of the cats vaccinated with the FVRCP for intranasal administration had detectable renal inflammation. One cat in each of the three CRFK lysate sensitization groups had lymphocytic-plasmacytic interstitial nephritis.     

Carcinocythemia: First report in a cat and literature review

A 6‐year‐old female neutered European Shorthair cat was presented with a 2‐day history of lethargy and hyporexia. On physical examination, the cat was slightly depressed and had a 2.5 cm nodule in the left 3^rd mammary gland. The hemogram revealed mild leukocytosis with mature neutrophilia and moderate thrombocytopenia. On blood smear evaluation, rare pleomorphic cells, possibly of epithelial origin, were observed mainly at the feathered edge. The animal died about 12 hours after presentation, and a necropsy was performed. On histopathology, the mammary nodule was diagnosed as a tubulopapillary adenocarcinoma with vascular invasion and widespread metastases. Immunocytochemical tests for cytokeratins (AE1/AE3) confirmed the epithelial phenotype of the neoplastic cells observed on the blood smear. The present report describes a feline mammary carcinoma with widespread metastases and the presence of malignant epithelial cells in the peripheral blood referred to as carcinocythemia. This condition has been previously described in people and dogs. To the author's knowledge, this is the first reported case of feline carcinocythemia. As in other species, the phenomenon was associated with a terminal phase of systemic malignancy.     

Inherited eye disease in the dog and cat

This paper describes the more common inherited eye conditions in the dog and cat, paying particular attention to the newer conditions, not all of which have previously been reported in the literature. These newer conditions include entropion in the shar pei, microphthalmos in the dobermann and miniature schnauzer, cataract in the German shepherd dog and Norwegian buhund, progressive retinal atrophy in the Tibetan terrier, Tibetan spaniel, miniature longhaired dachshund and two forms in the Abyssinian cat, multifocal retinal dysplasia in the English springer spaniel and other breeds, persistent hyperplastic primary vitreous in the Staffordshire bull terrier and dobermann and optic nerve hypoplasia in the toy poodle. Anatomical classification presents a convenient means of describing these conditions which may affect the whole globe, the eyelids, the nictitating membrane, the nasolacrimal duct system, the conjunctiva, the cornea, the aqueous, the iris, the lens and zonule, the vitreous, the retina, the choroid and sclera and the optic nerve.     

Epitheliotropic T-cell gastrointestinal tract lymphosarcoma with metastases to lung and skeletal muscle in a cat

An Abyssinian cat examined because of hypoproteinemia and weight loss was found to have epitheliotropic T-cell lymphosarcoma of the gastrointestinal tract. Neoplastic lymphocytes infiltrated the epithelium and lamina propria of the stomach, small intestine, and large intestine. Metastatic foci were found in the lungs and the musculature of the right hind limb. Chemotherapy resulted in transient shrinkage of the lung and limb masses; however, these masses grew to approximately their original size within 2 weeks after initiation of treatment, and the cat was euthanatized.     

Abnormal erythroid cell proliferation and myelofibrosis in a cat

A cat was presented with severe progressive anemia despite marked erythroblastosis. The cat was negative for feline leukemia virus antigen and feline immunodeficiency virus antibody. Bone marrow cytology revealed an excess of erythroid cells with a predominance of prorubricytes and basophilic rubricytes. No response to immunosuppressive therapy was obtained, and a tentative diagnosis of myelodysplastic syndrome was made. The cat showed a partial response to low-dose cytarabine (20 mg/m(2) subcutaneously q24) but died 51 days after the 1st admission. Histopathological examination revealed fibrosis in the bone marrow and marked infiltration of erythroid cells into other organs.     

Acquired myasthenia gravis in a cat with thymoma

A 4-year-old castrated Abyssinian cat was evaluated for profound neuromuscular weakness. Results of electromyography and repetitive nerve stimulation tests were normal. Thoracic radiography revealed a cranial mediastinal mass, which was excised and identified as a thymoma. Serum acetylcholine receptor antibodies were detected at high concentration, supporting a diagnosis of acquired myasthenia gravis. Clinical signs of disease responded to treatment with pyridostigmine and corticosteroids.     

Late onset cerebellar degeneration in a middle-aged cat

Cerebellar degeneration (abiotrophy) (CD) is a spontaneous and accelerated degeneration of one or several mature cerebellar neuronal cell populations and has been described in many domestic animals, especially in dogs, with numerous breed-related cases. In cats, CD is mentioned as a rare sporadic entity. Late onset CDs are exceptionally uncommon and only two cases are reported in young adults, both aged 18 months. This report describes clinical and pathological findings of a late onset feline CD in a 9-year-old male Persian cat. The cat was presented with a history of progressive ataxia lasting 2 years. Neurological examination revealed severe neurological deficits such as generalised and severe ataxia, hypermetria in all four limbs, and bilateral absence of menace response. The lesion was diffusely localised in cerebellum. On gross pathology, the cerebellum appeared of normal size and shape and kidneys were characterised by mild hyperaemia. Histologically, lesions were limited to the cerebellum and kidneys. In the cerebellum, all cerebellar folia of both hemispheres and the vermis were affected. Changes were characterised by severe and diffuse loss of Purkinje cells, loss of cellularity in the granular layer, mild astrogliosis associated with moderate hypertrophy of Bergmann's glia. Immunohistochemistry for feline parvovirus antigen revealed a negative result. Renal lesions consisted of chronic fibrosis associated with chronic interstitial nephritis. CD is a rare disease and occurs commonly in puppies or young animals, who are clinically normal at birth and usually develop neurological signs within a few weeks or months after birth. This report represents the first case of CD in a middle-aged cat.     

Partial deficiency of antidiuretic hormone in a cat

Marked polydipsia and polyuria developed subsequent to trauma in a 1 1/2-year-old male Abyssinian cat. Diabetes insipidus was suspected, inasmuch as intramuscualr vasopressin administration resulted in amelioration of polydipsia and polyuria. However, hypertonic (3%) saline solution given intravneously resulted in anuria, an indication of antidiuretic hormone activity. Polyuria and polydipsia were abolished by oral chlorpropamide therapy, which was indirect evidence for partial deficiency of antidiuretic hormone.