Overexpression of c-Ras in hyperplasia and adenomas of the feline thyroid gland: an immunohistochemical analysis of 34 cases

Formalin-fixed, paraffin-embedded thyroid glands from 18 cats diagnosed with hyperthyroidism were evaluated immunohistochemically for overexpression of the products of oncogenes c-ras and bcl2 and the tumor suppressor gene p53. Fourteen thyroid glands from euthyroid cats without histologically detectable thyroid lesions were examined similarly as controls. Results from these investigations showed that all cases of nodular follicular hyperplasia/adenomas stained positively for overexpression of c-Ras protein using a mouse monoclonal anti-human pan-Ras antibody. The most intensely positively staining regions were in luminal cells surrounding abortive follicles. Subjacent thyroid and parathyroid glands from euthyroid cats did not stain immunohistochemically for pan-Ras. There was no detectable staining for either Bc12 or p53 in any of the cats. These results indicated that overexpression of c-ras was highly associated with areas of nodular follicular hyperplasia/adenomas of feline thyroid glands, and mutations in this oncogene may play a role in the etiopathogenesis of hyperthyroidism in cats.     

IMAGING FINDINGS IN PANCREATIC NEOPLASIA AND NODULAR HYPERPLASIA IN 19 CATS

Pancreatic neoplasia in cats is rare and associated with a poor prognosis, but pancreatic nodular hyperplasia is a common incidental finding. The purpose of this study was to describe radiographic and ultrasonographic findings in cats with pancreatic neoplasia or nodular hyperplasia. Fourteen cats (age 3-18 years) were diagnosed with malignant pancreatic tumors: carcinoma/adenocarcinoma (n = 11), lymphoma (n = 1), squamous cell carcinoma (n = 1), and lymphangiosarcoma (n = 1). The most common radiographic findings were an abdominal mass or mass effect (6/6) and lack of serosal margin detail (4/6). On ultrasound, the most common finding was a focal pancreatic mass or nodule, with a size range from 0.4 cm to more than 7.0 cm (8/14). Lymphadenopathy (7/14) and abdominal effusion (7/14) were frequently seen. Five cats (age 10-16 years) with adenomatous/nodular hyperplasia had an abdominal mass or mass effect as the most common radiographic finding (3/3). On ultrasound, all cats had multiple hypoechoic nodules between 0.3 and 1.0 cm associated with the pancreas. Other common findings were pancreatic thickening (2/5), lymphadenopathy (2/5), and abdominal effusion (2/5). The only imaging finding unique to malignant pancreatic tumors was the presence of a single pancreatic nodule or mass exceeding 2cm in at least one dimension (4/14). Although there was a tendency for neoplastic lesions to manifest as single larger lesions and for nodular hyperplasia to manifest as multiple smaller lesions, there was overlap of the imaging findings in both entities. Radiographs and ultrasound can complement but not replace cytology and histopathology in the diagnosis of feline pancreatic neoplasia.     

Protothecosis in two cats

Protothecosis was diagnosed in 2 cats from Florida with nodular skin lesions. Microscopically, lesions were composed of macrophages and multinucleated giant cells arranged in solid sheets in the dermis and subcutis. In both cats, characteristic algal endospores identified as Prototheca wickerhamii were observed within the cytoplasm of infiltrating cells.     

Ante mortem diagnosis of pancreatitis in four cats

The ante mortem detection of pancreatitis in four cats is reported. Clinical findings included vomiting, lethargy and constipation in all the cats, diabetes mellitus in two cats and severe jaundice and a vitamin K responsive coagulopathy in one cat. Serum amylase was normal in all the cats and serum lipase was elevated in one azotaemic cat. Ultrasonography revealed predominantly hypoechoic masses in the right cranial quandrant of the abdomen of each cat. The anatomical location of these masses was consistent with the pancreas. Gross examination supported these ultrasonographic observations. The pancreatic lesions were characterised histologically as acute necrotising pancreatitis, acute necrotising pancreatitis with abscessation, chronic active pancreatitis with cystic dilatation of the pancreatic duct causing bile duct obstruction and chronic active pancreatitis with nodular hyperplasia. This report indicates that pancreatitis is a clinically significant disease in cats that may be diagnosed ante mortem.     

THE RADIOGRAPHIC APPEARANCE OF PULMONARY HISTOPLASMOSIS IN THE CAT

A retrospective study of 18 cats with pulmonary histoplasmosis was conducted to evaluate radiographic patterns of disease and to determine age, breed, and sex distributions. All cats had active disease confirmed by biopsy/aspiration cytology (lung, bone marrow, peripheral lymph nodes, pleural fluid) or necropsy examination. Cats 3 years of age or less had the highest incidence of disease; females outnumbered males 2 to 1. Radiographically, most cats had an interstitial pattern which appeared as a fine, diffuse or linear pattern, or as a more distinct nodular pattern. An alveolar pattern was an uncommon radiographic finding. Tracheobronchial lymphadenopathy and calcified lymph nodes or pulmonary parenchymal lesions were not identified in these cats.     

NODULAR FAT NECROSIS IN THE FELINE AND CANINE ABDOMEN

The radiographic appearance of nodular fat necrosis is described in ten cats and one dog. The most common radiographic sign was the presence of a focal mineralized circular to oval soft tissue mass in the abdominal fat as present in 9 cats. These masses had a distinct eggshell-like rim encapsulating the lesion. In one cat and one dog multiple masses were present, without radiographic signs of mineralization. Abdominal ultrasound was performed in three cats and one dog, findings included the presence of hyperechoic masses with associated acoustic shadowing, some with a hypoechoic centre. Almost all animals were old and obese. In three cats and one dog, changes were confirmed with biopsy or post mortem examination. Lesions having the appearance of those in this paper are most likely incidental findings and should not be confused with abdominal masses of neoplastic origin. Ultrasound can be helpful in identifying such lesions.     

Histopathologic study of uveitis in cats: 139 cases (1978-1988)

Histopathologic findings in 158 globes obtained from 139 cats by enucleation or at necropsy, with histopathologic diagnosis of uveitis, were compared, and morphology was correlated with clinical and/or histopathologic diagnosis. The most common morphologic feature was a lymphocytic-plasmacytic anterior uveal infiltrate that was either diffuse or nodular; specific cause could not be associated with this nongranulomatous anterior uveitis. In decreasing order of frequency, other common causes of uveitis in cats included feline infectious peritonitis; FeLV-associated lymphosarcoma; trauma; and lens-induced uveitis.     

Fine-needle aspirate cytology suggesting hepatic lipidosis in four cats with infiltrative hepatic disease

Four cats are reported in which cytology smears obtained by ultrasound-guided fine needle aspiration of the liver were interpreted as indicative of hepatic lipidosis. However, histopathology of hepatic tissue samples obtained with Tru-Cut-like needles or wedge biopsy revealed that the cats had inflammatory or neoplastic hepatic disease causing their clinical signs. Fine needle aspiration and cytology may not detect infiltrative lesions, particularly those that are nodular, multifocal, or localised around the portal regions. Fine needle aspirate cytology is a useful diagnostic procedure with many advantages, but care must be taken to avoid diagnosing hepatic lipidosis as the cause of illness when an infiltrative lesion is responsible.     

Clinical features of inflammatory liver disease in cats: 41 cases (1983-1993)

OBJECTIVE: To compare the clinical and clinicopathologic findings in and prognosis for cats with lymphocytic portal hepatitis (LPH) versus cats with acute or chronic cholangiohepatitis (CH). DESIGN: Retrospective study. ANIMALS: 25 cats with LPH; 16 cats with CH (7 acute, 9 chronic). PROCEDURE: Cats with LPH and CH were selected by evaluating records from liver biopsy specimens submitted to the University of Minnesota Veterinary Teaching Hospital during a 10-year period. Clinical and clinicopathologic data were retrieved. RESULTS: Cats with CH had higher segmented and band neutrophil counts, alanine aminotransferase activities, and total bilirubin concentrations than did cats with LPH. Cats with acute CH had higher segmented and band neutrophil counts and lower serum alkaline phosphatase activities and total bilirubin concentrations than did cats with chronic CH. Twelve of 14 cats with LPH or CH had coarse or nodular texture to the liver on ultrasonography, with loss of portal vein wall clarity noticed in 4 of 8 cats with LPH. Sixteen of 23 cats with LPH and 8 of 15 cats with CH survived > 1 year. Of those cats living < 1 year, all cats with LPH and 5 of 7 cats with CH had a serious concurrent illness that may have been responsible for their deaths. CLINICAL IMPLICATIONS: LPH and CH can be detected and tentatively differentiated through evaluation of clinical laboratory test results, but histologic evaluation of liver specimens is necessary for definitive differentiation. Survival time was good regardless of the type of inflammatory liver disease.     

Feline exocrine pancreatic disorders.

Despite the uncommon clinical diagnosis, cats frequently suffer from disorders of the exocrine pancreas. Pancreatitis is the most common feline exocrine pancreatic disorder. Pancreatitis can be acute or chronic and mild or severe. The etiology of most cases of feline pancreatitis is idiopathic. Some cases have been associated with severe abdominal trauma, infectious diseases, cholangiohepatitis, and organophosphate and other drug intoxication. The clinical presentation of cats with pancreatitis is nonspecific. Vomiting and signs of abdominal pain, which are the clinical signs most commonly observed in humans and dogs with pancreatitis, are only uncommonly observed in cats with pancreatitis. Routine laboratory findings are also nonspecific. Abdominal ultrasonography is a valuable diagnostic tool in feline patients with pancreatitis. Serum activities of lipase and amylase are rarely increased in cats with pancreatitis; however, these cats often have elevated serum fTLI concentrations. The goals of management are removal of the inciting cause, provision of supportive and symptomatic therapy, and careful monitoring for and aggressive treatment of systemic complications. Exocrine pancreatic insufficiency is a syndrome caused by insufficient synthesis of pancreatic digestive enzymes by the exocrine portion of the pancrease. The clinical signs most commonly reported are weight loss, loose and voluminous stools, and greasy soiling of the hair coat. Serum fTLI is subnormal in affected cats. Treatment of cats with EPI consists of enzyme supplementation with powdered pancreatic extracts or raw beef pancreas. Many cats with EPI have concurrent small intestinal disease. Most cats with EPI also have severely decreased serum cobalamin concentrations and may require parenteral cobalamin supplementation. Pancreatic adenocarcinoma is the most common neoplastic condition of the exocrine pancreas in the cat. At the time of diagnosis, the tumor has already metastasized in most cases, and the prognosis is poor. Pancreatic pseudocyst, pancreatic abscess, pancreatic parasites, pancreatic bladder, and nodular hyperplasia are other exocrine pancreatic disorders, that are less commonly seen in cats.     

Congestive heart failure associated with a large transverse left ventricular moderator band in a cat

Cardiomyopathy associated with abnormal trabecular bands of tissue traversing one or both ventricles is reported rarely in cats. The case of a 9-year-old cat which presented in congestive heart failure is reported. Multiple cardiac abnormalities were found, including a large trabecular tissue bridge which bisected the left ventricle. Other findings included arrhythmia, thrombocytopaenia and raised serum creatine kinase. The cat was euthanased due to clinical deterioration. Necropsy findings included increased cardiac weight, the division of the left ventricle by a large trabecular band composed of connective tissue and cardiac myofibres consistent with a moderator band, nodular thickening of the mitral valve, left atrial dilation, and fibroplasia/fibrosis of the left ventricular myocardium associated with widespread myofibre necrosis due to infarction. Pathological findings in this case differ from previous reports of ventricular transverse bridging tissue in cats with cardiac disease.     

Nerve sheath tumours in the dog and cat

Schwannomas were diagnosed in twelve dogs and five cats at Massey University Small Animal Clinic and Hospital over a 15-year period (1977-92). A further two feline cases were reported at the Batchelar Animal Health Laboratory. In six dogs, the tumour involved nerves of the brachial plexus. Clinical signs observed in these dogs were forelimb lameness, muscle wasting and pain on movement of the affected limb or neck. Hindlimb paresis was observed in two dogs. Surgical excision of the brachial plexus tumour was attempted in one dog, leading to an 8-month remission of signs. In one dog, the tumour involved the sacral nerves, and in two dogs the cranial nerves were affected. Three dogs had skin nodules. Seven of the twelve affected dogs were destroyed. In five cats, the tumours developed on the carpus, tarsus or interdigital area of a forelimb or hindlimb as a slowly developing nodular lesion. In the other two cats, the site of the tumour was the flank and the lateral thigh respectively. Surgical excision of the tumour was successful in three cats.     

CLINICAL,IMAGING, AND PATHOLOGIC CHARACTERISTICS OF GURLTIA PARALYSANS MYELOPATHY IN DOMESTIC CATS FROM CHILE

Gurltia paralysans is a rare metastrongylid nematode of domestic cats that is found mainly in the veins of the spinal cord subarachnoid space and parenchyma. Endemic regions for G. paralysans mainly include Chile and Argentina. The ante mortem diagnosis of gurltiosis is difficult and based primarily on neurological signs, epidemiological factors, and the exclusion of other causes of feline myelopathies. The purpose of this retrospective case series was to describe clinical, imaging, and pathologic characteristics in nine domestic cats naturally infected with G. paralysans. Imaging tests included radiography, myelography, computed tomographic myelography (myelo‐CT), and magnetic resonance imaging (MRI). Neurological signs included paraparesis, paraplegia, pelvic limb ataxia and proprioceptive deficits, pelvic limb tremors, lumbosacral hyperesthesia, and tail trembling or atony. Complete blood count findings included a decrease in the mean corpuscular hemoglobin concentration value in eight cats. Eosinophilia in peripheral blood was observed in three cats, and thrombocytopenia was observed in three cats. Cerebrospinal fluid analysis revealed mononuclear pleocytosis in five cases. Myelo‐CT showed diffuse enlargement of the spinal cord at the midthoracic, lumbar, and sacral regions in all cats. Magnetic resonance image findings in the thoracic and lumbar region demonstrated multiple small nodular areas of T2 hyperintensity in the periphery of the spinal cord parenchyma. Localized intraparenchymal areas of increased T2 intensity were also observed in the thoracolumbar spinal cord and lumbosacral conus medullaris. In conclusion, G. paralysans should be considered as a differential diagnosis for domestic cats in endemic regions that have this combination of clinical and imaging characteristics.     

Dermatophytic pseudomycetomas in four cats

The aim of this retrospective study was to describe the clinical characteristics and treatment of four cats with dermatophytic pseudomycetoma. Four Persian cats, one female and three males, with age ranging from 1.4 to 5 years, were diagnosed with dermatophytic pseudomycetoma by histological examination and fungal culture. Wood's lamp examination revealed positive fluorescence of hairs in all four cats. Characteristic skin lesions consisted of multifocal, raised, firm and nodular to dome-shaped lesions varying in size from 1 to 8 cm in diameter, with ulcers or fistulas in some of the lesions. One cat was treated and cured with 3 months of oral itraconazole; lesions completely regressed, and at the time of writing there has been no recurrence. One cat was treated with surgical excision alone, and recurrence of lesions occurred after a disease-free interval of 15 months. Two cats were treated with surgical excision and systemic itraconazole therapy. Itraconazole therapy was started 1-2 months before surgery and continued for 3 months after surgery. Surgical margins were wide in both cats, and underlying adipose tissue and/or deeper fascia was removed. One cat relapsed, but had a disease-free interval of 18 months. The other cat has been disease free for 32 months. This case series suggests that aggressive, wide surgical excision and concurrent oral itraconazole are highly beneficial in treating dermatophytic pseudomycetoma in cats.     

Contrast-enhanced power and color Doppler ultrasonography of the pancreas in healthy and diseased cats

Background: The diagnosis of feline pancreatic disease is difficult, because clinical abnormalities and routine noninvasive diagnostic tests are unreliable. Objective: The purpose of this study was to investigate by Doppler ultrasonography if vascularity and blood volume differs in the otherwise ultrasonographically normal and diseased feline pancreas. Animals: Thirty‐six client owned cats. Methods: The pancreas was examined with B‐mode and contrast‐enhanced color and power Doppler ultrasonography. Doppler images were analyzed with a computer program: parameter fractional area represents a vascularity index and color‐weighted fractional area assesses blood volume. Results: Based on the B‐mode findings, the pancreas was considered normal in 11 clinically healthy cats and diseased in 25 cats of which 4 were clinically healthy and 21 had clinical signs consistent with pancreatic disease. Histologic or cytologic samples were taken in all diseased pancreata. Fifteen samples were of diagnostic quality: purulent or mixed cellular inflammation (8), nodular hyperplasia (4), and neoplasia (3) were identified. Vascularity and blood volume for all Doppler methods was significantly higher in cats with pancreatic disease. Significantly higher Doppler values were detected with power Doppler than with color Doppler, and with postcontrast color and power Doppler than with precontrast Doppler technologies. Conclusion: Contrast‐enhanced Doppler ultrasonography appears feasible in the feline pancreas. Significant differences were found between normal cats and those with evidence of pancreatic pathology. Further studies are needed to evaluate its use for the differentiation of pancreatic disorders and in cats suspected to have pancreatic disease but without B‐mode ultrasonographic changes of the pancreas.     

Nodular granulomatous fungal skin diseases of cats in the United Kingdom: a retrospective review

IDEXX Laboratories database of cases submitted from the UK between March 2005 and February 2008 (36 months) was investigated for feline nodular granulomatous skin disease associated with fungal infection. Cytological and/or histological slides were reviewed and the diagnosis was based on the microscopic pattern of the inflammatory response and morphology of the causative organism. Aetiological diagnoses were hyalohyphomycosis (64 of 77 cases), phaeohyphomycosis (five of 77 cases) and dermatophytic pseudomycetoma (eight of 77 cases). All cases of hyalohyphomycosis were suspected to be alternariosis based on common features including anatomical distribution of lesions (48 of 64 cases involved the nostril and bridge of nose, face and ears), pattern of histological changes, morphology of the causative organism and results of fungal culture (Alternaria three of 16 and ‘saprophyte’ nine of 16 cases). Cases of phaeohyphomycosis were demographically and histologically similar to those of alternariosis, except the causative organisms were deeply pigmented brown and had a variety of morphologies that were different from Alternaria. Dermatophytic pseudomycetomas had a characteristic histological pattern including the presence of fungal microcolonies or grains within the tissue. These occurred most often on the trunk (five of eight cases) and four of eight cases were in Persian cats. These findings indicate that alternariosis is by far the most common nodular fungal skin disease of cats in the UK.     

Bronchoscopic findings in 48 cats with spontaneous lower respiratory tract disease (2002-2009)

Background: Diagnosis of lower respiratory disease requires collection of airway samples to confirm the etiology of disease. Bronchoscopic evaluation is commonly performed in dogs but less information is available in cats. Hypothesis: The presence and number of bronchoscopic abnormalities visualized during bronchoscopic evaluation of cats with lower respiratory disease will correlate with the type of disease and total and differential cell counts in bronchoalveolar lavage (BAL) fluid. Animals: Forty‐eight cats prospectively evaluated by a single bronchoscopist. Methods: Bronchoscopy was performed during clinical evaluation of cats presenting with cough, respiratory distress, or both. Cats were evaluated for airway hyperemia, stenosis, or collapse, mucus accumulation, bronchiectasis, and epithelial irregularities. Cats were placed into groups of bronchitis/“asthma,” pneumonia, or neoplasia based on BAL findings, histopathology, and response to appropriate medical therapy. Summation of bronchial abnormalities and total and differential cell counts were compared among groups. Results: Endobronchial abnormalities were common in cats with feline bronchitis/asthma, pneumonia, and neoplasia and no differentiating features were found. Excessive mucus accumulation was common (83%), followed by stenosis of bronchial openings and nodular epithelial irregularities (56%), airway hyperemia (54%), airway collapse (48%), and bronchiectasis (27%). Total bronchoscopic score and total cell count did not differ among groups, although differential cell counts were significantly different. A weak correlation (R²= 0.16, P= .006) between age and total bronchoscopic score was noted. Conclusions and Clinical Relevance: Bronchoscopic abnormalities are common in cats with lower respiratory tract disease, and visualization of the airways provides additional nonspecific clinical information in cats.     

Auricular chondrosis in a horse

A 4-year-old crossbred, Welsh Mountain Pony gelding was presented with multiple, thick, round, raised, 3 to 8 mm diameter nodular lesions on the medial aspects of both ears. The nodules did not involve the epidermis and were observed to develop over several months. Punch biopsies were taken and histopathological examination returned a diagnosis of auricular chondrosis. Neither auricular chondrosis nor auricular chondritis has been reported in horses, although it has been recorded in cats, dogs, laboratory animals and humans.     

Recombinant human thyrotropin administration enhances thyroid uptake of radioactive iodine in hyperthyroid cats

BACKGROUND: Hyperthyroidism is the most diagnosed endocrine disorder in cats and radioiodine (131I) is the treatment of choice. The dose emission rate and radioactivity in urine, saliva, and on hair and paws are determined by the dose of administered 131I. A dose reduction of therapeutic 131I could possibly be achieved after recombinant human thyrotropin (rhTSH) administration as in humans with nodular goiter. HYPOTHESIS: rhTSH will increase radioiodine uptake in hyperthyroid cats. ANIMALS: Five hyperthyroid cats. METHODS: Twenty-five micrograms rhTSH (day 1) or 2 mL 0.9% sodium chloride (NaCl) (day 9) was injected IV. One hour later, 11.4 +/- 4.1 (mean +/- SD) MBq 123I was injected IV. Radioactive iodine uptake (RAIU) was measured 6, 12, and 24 hours after rhTSH (RAIU-rhTSH) or NaCl (RAIU-blanco) injection. Blood samples for measurement of TT4 were taken before injection of rhTSH or NaCl (TT4(0)) and at the time of imaging. RESULTS: Percentages of RAIU-rhTSH (and RAIU-blanco) at 6, 12, and 24 hours after administration of rhTSH were 34 +/- 18 (31 +/- 21), 46 +/- 20 (38 +/- 18), and 47 +/- 15 (36 +/- 14). There was a statistically significant effect of rhTSH administration on RAIU (P = .043) but not on serum TT4 concentration. Baseline serum TT4(0) concentration influenced RAIU-rhTSH significantly at 6 hours (P = .037). CONCLUSION AND CLINICAL IMPORTANCE: The increased RAIU observed after rhTSH administration in hyperthyroid cats could lead to a lower therapeutic dose of 131I after rhTSH administration in hyperthyroid cats and decreased risk of environmental and owner contamination during and after hospitalization.     

Lower respiratory tract infections in cats: reaching beyond empirical therapy

PRACTICAL RELEVANCE: Lower respiratory tract infections (LRTIs) in cats can be due to bacteria, parasites, fungi and viruses. This review details the practical investigation of these infections and highlights specific therapy where possible. The aim is to avoid the all-too-frequent temptation in practice to treat cats with lower respiratory tract signs empirically for feline bronchial disease (FBD)/asthma. This is potentially hazardous as immunosuppressive therapy for FBD/asthma could exacerbate disease due to a LRTI. Empirical treatment of suspected LRTI is also difficult to recommend given the wide range of potential pathogens. CLINICAL CHALLENGES: Making a clinical ante-mortem diagnosis of LRTI in a cat can be challenging. Consistent historical, clinical, haematological and radiographic abnormalities are often lacking and findings may be non-specific. Astute clinical acumen, thorough investigation and high quality laboratory analysis are usually required for a diagnosis. Bronchoalveolar lavage, if feasible, and tests for lungworm should be routine in cats with lower respiratory tract signs. Lung fine needle aspiration may be useful in cases of diffuse or nodular pulmonary disease. Histopathology is rarely employed in ante-mortem investigations. EVIDENCE BASE: The authors have reviewed a substantial body of literature to provide information on many of the reported bacterial, parasitic, fungal and viral pathogens, including some that occur in Asia. Attention has been given to specific therapy for each pathogen, with evidence-based comments when there is a deviation from routine recommendations.