Histopathological study of feline eosinophilic dermatoses

A retrospective study was conducted on skin specimens from 24 cats with eosinophilic granuloma complex. The specimens were stained with haematoxylin and eosin and Gallego's trichrome stain. In all specimens, flame figures and/or large foci of so-called "collagen degeneration" were detected and histopathological features were not predictive of the clinical picture. Use of the term eosinophilic dermatosis was advocated in diagnostic dermatopathology. On trichrome-stained sections, normally stained collagen fibres were identified in the middle of both flame figures and large foci of "collagen degeneration" and the debris surrounding collagen bundles showed the same tinctorial properties as eosinophil granules. Eosinophil degranulation around collagen bundles seemed to represent the major pathogenetic event in these lesions, analogous with human flame figures. The term flame figures might therefore be more accurately used to designate those foci of eosinophilic to partly basophilic debris commonly referred to as "collagen degeneration".     

Feline gastrointestinal adenocarcinoma: a review and retrospective study

Feline gastrointestinal adenocarcinomas are the most common nonhematopoietic gastrointestinal tumors in cats. They are highly malignant tumors causing intestinal obstruction due to the annular, stenosing nature to their growth. Current literature is largely based on surveys of pathology records. Therefore, a retrospective study was conducted to evaluate clinical course and prognosis with surgical excision of the tumor. In published reports feline gastrointestinal adenocarcinoma represented 20-35% of gastrointestinal neoplasia in the cat; the average age was greater than ten years; and there was a greater incidence in Siamese. The small intestine accounted for 70% of cases. In this retrospective study, cats usually had a long history of non-specific gastrointestinal disease; weight loss and vomiting were the most common signs. Abdominal radiographs demonstrate intestinal obstruction, and an abdominal mass is often palpable. With intestinal resection and anastomosis, median survival time was 2.5 months (range: 0-24 months). Tubular adenocarcinomas may have a better prognosis than other histological types, especially if metastasis is not present at the time of surgery. A significant disease-free interval is possible in some cases.     

Feline urate urolithiasis: a retrospective study of 159 cases

The objective of the study was to characterize the signalment, clinicopathologic data, and diagnostic imaging of cats with urate urolithiasis, as well as the salts of uric acid present in the uroliths. A retrospective analysis of feline urate uroliths submitted to the GV Ling Urinary Stone Analysis Laboratory between 2000 and 2008 was included. From these data, records were assimilated from referring veterinarians (143); furthermore, all recorded cases from within the William R Pritchard Veterinary Medical Teaching Hospital (16) were included. Median values for the complete blood count and chemistry panels available were within the reference intervals, when provided, with only a few outliers present. Of all cases evaluated, seven had a portosystemic shunt (PSS). Cats with urate uroliths and a PSS were younger than cats without a PSS (2 years vs 7 years). The pathogenesis of urate uroliths in cats is poorly understood. Most cats were not completely evaluated for a PSS, however, clinicopathologic parameters indicating hepatic dysfunction were seldom noted; more sensitive diagnostics such as serum bile acids were rarely performed to confirm or negate the presence of a shunt. Studies are warranted to evaluate pathogenesis of urate uroliths to tailor proper management and breeding strategies.     

Feline pyothorax: a retrospective study of 27 cases in Australia

Pyothorax was diagnosed in 27 cats between 1983 and 2002. In 21 (78%) of the cases, pleural fluid culture and/or cytology was consistent with a mixed anaerobic bacterial infection of oropharyngeal origin. In six cases (22%), infection was caused by unusual pathogens or pathogens of non-oropharyngeal origin, including a Mycoplasma species, Cryptococcus gattii, Escherichia coli, Salmonella typhimurium and Staphylococcus aureus. The overall mortality rate was 22%. Treatment was successful in 18 of 19 cases (95%) where closed thoracostomy tubes were inserted. One case resolved only after thoracotomy. Actinomyces species were isolated in three cases and in contrast to dogs where thoracotomy is recommended, they were resolved with tube thoracostomy. Mechanical complications occurred in 58% of the cats with indwelling chest tubes. Probable mechanisms of pleural space infection were identified in 18 cats (67%) including haematogenous infection (n=1), direct inoculation of bacteria into the pleural space (n=1), intrathoracic oesophageal rupture (n=1) and parapneumonic extension of infection (n=15; 56%). Of the latter, perioperative aspiration was suspected in two cats, parasitic migration in two and antecedent upper respiratory tract infection was implicated in seven. Parapneumonic spread of infection after colonisation and invasion of lung tissue by oropharyngeal flora appears to be the most frequent cause of feline anaerobic polymicrobial pyothorax and contests the widespread belief that direct inoculation of pleural cavity by bite wounds is more common.     

Feline exocrine pancreatic carcinoma: a retrospective study of 34 cases

Thirty‐four cases were reviewed in this retrospective study for information on clinical presentation, prognostic indicators, survival time and response to various therapies. The most common presenting clinical signs were weight loss, decreased appetite, vomiting, palpable abdominal mass and diarrhoea. Metastatic disease was confirmed in 11 cats. The overall median survival was 97 days. The median survival times for patients who received chemotherapy or had their masses surgically removed was 165 days. Those patients who had an abdominal effusion present at the time of diagnosis survived a median of 30 days. Cats that received non‐steroidal anti‐inflammatory drug therapy had a median survival of 26 days. This study confirms that exocrine pancreatic carcinoma in cats is an aggressive tumour with a high metastatic rate and poor prognosis, although three patients survived over 1 year. Fifteen percent of the patients were diabetic, which raises the question as to what the link between diabetes and pancreatic cancer in people and cats may be.     

Mouse hepatoblastomas: a histologic, ultrastructural, and immunohistochemical study

Hepatoblastomas from B6C3F1 and BALB/c mice were examined by light and electron microscopy and by immunohistochemical reactions for alpha-fetoprotein, keratin, and vimentin. Tumors occurred in one group of a chronic bioassay for the interaction of diet, genetic strain, and the carcinogen, 2-acetylaminofluorene. Tumors had several populations (including epithelial and mesenchymal cells) in various stages of differentiation. Neoplastic epithelial cells had features of embryonal hepatocytes, such as sparse cytoplasmic organelles, absence of glycogen, abundant free ribosomes, occasional bile canaliculi, and peroxisome-like dense bodies. Embryonal fibroblast-like cells had pleomorphic and folded nuclei with prominent perinuclear chromatin and dispersed cytoplasmic organelles. Fibroblast-like cells were surrounded by bundles of collagen fibrils. Intermediate or transitional types of cells were seen. No tumor cells were immunoreactive for mouse alpha-fetoprotein (AFP) antibody, unlike those in hepatocellular adenomas or carcinomas. Epithelial and mesenchymal tumor cells contained intermediate filaments throughout the cytoplasm; some of these cells stained for keratin but not for vimentin. These findings suggest that mouse hepatoblastomas are derived from bipotential liver blastema cells and are composed of a mixture of several cell populations.     

A quantitative ultrastructural study of the extracellular matrix of the sheep incisor periodontium

The ultrastructure of the matrix of the sheep central incisor periodontium was quantitatively analysed. Ewes with healthy mouths were selected. The distribution of collagen fibril diameters was bimodal in the lower dental pad with a population standard deviation significantly larger than the unimodal distribution of fibril diameters found in the periodontal ligament. The lower dental pad connective tissue also contained significantly more oxytalan fibres, some of which resembled mature elastin. These results are consistent with the view that the sheep central incisor is supported primarily by tension within the fibres of the lower dental pad.     

FC-23 Feline plasma cell pododermatitis: a retrospective study of 26 cases

The objective of this open pilot study was to evaluate the efficacy of topical tacrolimus ointment for treatment of plantar fistulae in German shepherd dogs. Seven dogs (four males, three females) were included. All subjects had a 6-month to 2-year history of plantar fistulae involving the plantar aspect of two to four metatarsi/metacarpi. No other skin lesions were present and the dogs appeared otherwise healthy. Before treatment with tacrolimus, all dogs received antibiotics for 4–8 weeks. Hair was clipped to visualise the lesions. The presence of erythematous papules, oedema and fistulae was recorded for each foot. All dogs served as their own controls. Dogs with four legs involved had one front and one hind leg treated. Dogs with two to three feet affected had only one foot treated. Tacrolimus 0.1% ointment (Protopic^®) was applied twice daily onto the site of lesions. Partial improvement of treated lesions was seen in all cases within 3 weeks. After 6 weeks, treated lesions were in complete remission in four dogs, while the other three subjects had palpable but invisible lesions. Signs had not improved on the untreated legs. Follow-up varied between 4 months and 2 years. Lesion remission persisted in six dogs with the intermittent application of tacrolimus. Adverse effects of treatment were not seen. In conclusion, the application of topical tacrolimus seems to provide a safe and effective treatment option for plantar fistulae in German shepherd dogs.
Funding: Self-funded.     

Structural remodelling of the heart valves extracellular matrix during embryo development

Alterations in heart valve development represent more than 20% of congenital cardiovascular malformations. Most of the functional properties of heart valves depend on extracellular matrix. Despite its relevance, little is known about fibrillar components on developing stages. Our objective is to define histological changes on valves fibrillar components in late embryonic development of Mus musculus. We found type III collagen as the predominant fibre type in the ECM in prenatal stages followed by a switch to a type I predominance for postnatal ages. The change in fibrillar components is necessary to support the normal mechanical function of adult heart valves.     

Feline dysautonomia in the Midwestern United States: a retrospective study of nine cases

Dysautonomia of domestic animals is pathologically characterized by chromatolytic degeneration of the neurons in the autonomic nervous ganglia that results in clinical signs related to dysfunction or failure of the sympathetic and parasympathetic nervous systems. The exact cause is unknown. It has a poor prognosis among all species reported and no definitive treatment is available currently. To date, most reported feline cases have occurred in the United Kingdom and Scandinavia. The cases reported here highlight the clinical signs, physical examination findings, and results of autonomic nervous system function testing in nine cats with dysautonomia in the US. Feline dysautonomia is uncommon in the US, but may have a regional prevalence, as is seen in dogs with most cases reported in Missouri and Kansas.     

Feline chondrosarcoma: a retrospective study of 67 cats (1987-2005)

The histories of 67 cats diagnosed with chondrosarcoma (CSA) from 1987 to 2005 were reviewed. The mean age was 9.6 years, and males were 1.9 times more likely to be affected than females. Chondrosarcomas were diagnosed in the following sites: appendicular and axial skeleton, nasal cavity, facial bones, and extraskeletal sites. Of the 46 (70%) CSA associated with bone, 63% arose in long bones and 37% arose in flat bones. The remaining (30%) CSA arose in the subcutis. In cases available for follow-up (n=24), no definitive evidence of metastases was found. Cats that underwent radical surgical therapies were more likely to achieve long-term control or cure.     

Feline histoplasmosis: a retrospective study of 22 cases (1986-2009)

Twenty-two cases of feline histoplasmosis seen at the Virginia-Maryland Regional College of Veterinary Medicine Teaching Hospital between 1986 and 2009 were reviewed. The median age of affected cats was 9 yr (mean, 8.8 yr). Female domestic shorthairs were more commonly affected. The clinical presentation of most cases was nonspecific. The most common presenting complaints included weakness, lymphadenopathy, weight loss, and anorexia. Less frequent clinical signs included vomiting, diarrhea, blindness, and lameness. Less than half of the cats had clinical evidence of pulmonary disease on admission. Anemia and hypoalbuminemia were common laboratory abnormalities. An interstitial pattern was the most common radiographic pattern observed with pulmonary disease. Diagnosis was based on identification of the organism on cytology or histopathology. Fifteen of the 22 cats were treated, and itraconazole was the most common antifungal agent prescribed. Median duration of the antifungal treatment was 5 mo for cats that survived to discharge. Overall survival at time of discharge for cats in this study was 55%.     

Feline pemphigus foliaceus: a retrospective analysis of 57 cases

Fifty-seven cases of feline pemphigus foliaceus were identified from biopsy specimens submitted to University of Pennsylvania School of Veterinary Medicine's Laboratory of Pathology and Toxicology by veterinary dermatologists from 1991 to 2002. Age at onset ranged from less than 1 year to 17 years; median 5 years. Eighty per cent of cats were reported to have been pruritic. At the time of biopsy, the distribution of lesions varied, but included some combination of face/head, paws, dorsum or ventrum and consisted of crusts, erosions, scale and alopecia. The histological features of 208 biopsy specimens were reviewed and included the following. Acantholytic cells were found in large numbers in both intact and degenerating pustules in most cases. Mast cells were found in the dermal infiltrate more often than reported previously. Seventeen cases were receiving corticosteroids at the time of biopsy; reducing the percentage of diagnostic biopsies per case. Forty-four cases were followed for 1-54 months (median 9 months). Triamcinolone was more successful at inducing remission without significant adverse effects than prednisone or prednisone in combination with chlorambucil. Only 4/44 cats died from their disease or therapy during the study period.     

Feline mammary carcinoma: a retrospective evaluation of 17 cases

Seventeen biopsies of feline mammary carcinoma submitted to the Veterinary Pathology Laboratory, Nova Scotia Department of Agriculture and Marketing were reviewed. All 17 cases were female cats. Data on age, reproductive status (sexually intact vs. neutered), therapy, outcome of the cases and histological features were consistent with data on feline mammary carcinoma previously reported. Four of these 17 cats had a history of receiving exogenous progestin prior to tumor development. The possible role of progestins as initiators or promoters of feline mammary carcinoma was discussed. The use of feline mammary carcinoma as a model for carcinoma of the breast in women was reviewed.