Morphologic changes in the bovine mammary gland during involution and lactogenesis

Morphologic changes developing during bovine mammary involution were examined. Quarter biopsy specimens were obtained weekly from 5 cows beginning the day milking was discontinued through parturition. Light and electron microscopic examination of mammary tissue indicated a gradual reduction in synthetic and secretory activity of alveolar epithelium as involution progressed. Light microscopic morphologic analysis revealed increases in stroma and nonactive secretory epithelium, with concomitant decreases in epithelium, lumen, and fully active secretory epithelium during the first 2 weeks of involution. Electron microscopic analysis of alveolar epithelium revealed decreased number of organelles associated with milk synthesis and secretion during this time. These changes reversed gradually beginning 2 weeks before parturition, and by the time of calving, cell structure was typical of lactating glands. Tissue from infected quarters had less synthetic and secretory ability as indicated by significantly higher percentages of stroma and nonactive cells, but lower percentages of lumen and moderately active cells, compared with uninfected quarters. Infected quarters also had more leukocytes infiltrating the epithelium, lumen, and stroma, compared with uninfected quarters. Microscopic examination of macrophages and neutrophils suggested these cells removed milk components and cellular debris during involution. Large numbers of plasma cells, with distended cisternae of rough endoplasmic reticulum, suggested local antibody production during the periparturient period.     

Osteoarthritis in cats: a retrospective radiological study

OBJECTIVES: To provide basic information about natural feline osteoarthritis (OA) as part of more extensive studies. METHODS: A retrospective study of cats (greater than one year of age) radiographed for any reason at a first opinion and referral veterinary practice was performed. Cats were classified as either having or not having radiographic OA. Computerised histories were searched for records of potential causes and clinical signs of OA. The genders and ages of the affected cats were compared with a control population using chi-squared tests. RESULTS: Of 491 cats, 292 (59 per cent) had undergone a diagnostic radiograph of at least one synovial joint. Sixty-three of 292 cats (22 per cent) showed evidence of radiographic OA; 21 (33 per cent) of which also had clinically evident OA. A potential cause of OA had been recorded in only seven of 63 cats (11 per cent). The population of cats with radiographic evidence of OA was older than the control population (P<0.001). CLINICAL SIGNIFICANCE: Radiographic OA was found in 22 per cent of the test population. In many cases there was no clinical evidence of OA recorded in the history, suggesting that either there is little correlation between clinical and radiographic OA or that clinical signs of OA in cats may not have been observed or recorded. Idiopathic/primary OA was common.     

Complex carcinomas of the mammary gland in cats: pathological and immunohistochemical features

Biphasic epithelial myoepithelial (complex) carcinomas of the feline mammary gland are rare. This article describes the pathological and immunohistochemical features and clinical outcome of eight cases of feline mammary carcinomas displaying complex morphology. This tumour type is a low grade malignancy that shows histopathological features distinctive from more common feline mammary carcinomas and from complex mammary carcinomas of dogs. It appears to have a better overall survival than other carcinomas of the mammary gland of cats.     

Multiple myeloma in 16 cats: a retrospective study

BACKGROUND: There is limited published information regarding feline multiple myeloma. Diagnostic criteria are derived from canine studies and to our knowledge, have not been critically reviewed for cats. OBJECTIVE: To evaluate the clinical and laboratory findings in cats with multiple myeloma and appraise diagnostic criteria. METHODS: Retrospective evaluation of medical records was performed. Inclusion required an antemortem diagnosis of multiple myeloma using 2 of 4 criteria: 1) >or=20% plasma cells in the bone marrow, or >or=10% if atypical plasma cells; 2) paraproteinemia; 3) radiographically-evident osteolysis; 4) light chain proteinuria. Alternatively, a postmortem diagnosis was based on the findings of multiple plasma cell neoplasms, with marrow involvement. RESULTS: Sixteen cats were diagnosed with multiple myeloma between 1996 and 2004, with a median age of 14.0 years; 9 of 16 (56%) were castrated males, and 7 of 16 (44%) were spayed females. Laboratory abnormalities included hyperglobulinemia (14/16, 87.5%), with 11/14 (78.5%) monoclonal and 3/14 (21.4%) biclonal gammopathies; hypoalbuminemia (4/16, 25%); light chain proteinuria, (4/9, 44.4%); hypocholesterolemia (11/16, 68.7%); hypercalcemia, (3/15, 20%); nonregenerative anemia, (11/16, 68.7%); regenerative anemia, (1/16, 6.2%); neutropenia (5/15, 33.3%); thrombocytopenia (8/16, 50%); and marrow plasmacytosis (14/15, 93.3%). Plasma cells were markedly immature, atypical, or both in 10 of 12 (83.3%) cats. Focal or multifocal osteolysis was noted in 6 of 12 (50%) cats for which radiographs were available for review; generalized osteopenia was found in 1 (8.3%) cat. Noncutaneous, extramedullary tumors were found in all cats assessed, 7/7 (100%), including spleen (6), liver (3), and lymph nodes (4). The disease in 1 of 2 cats with cutaneous tumors progressed to plasmacytic leukemia. CONCLUSIONS: Common findings in feline multiple myeloma include atypical plasma cell morphology, hypocholesterolemia, anemia, bone lesions, and multi-organ involvement. Based on the results of this study, we advocate modifying diagnostic criteria in cats to include consideration of plasma cell morphology and visceral organ infiltration.     

Lymphangiosarcomas in cats: a retrospective study of 12 cases

Clinical, macroscopic, and histologic features of 12 lymphangiosarcomas in cats are described. Nine tumors were located in the subcutaneous tissue at the caudoventral abdominal wall (eight cats) or in the neck (one cat). The remaining three cats had lymphangiosarcomas around the cranial mesenteric artery (two cats) or precardial in the mediastinum (one cat). Macroscopically, the tumors were noncircumscribed, white, edematous, and intermixed with fat tissue. Histologic features varied from cleft-forming and cavernous growth to papilliform and solid patterns. Follow-up data were available for seven cats with subcutaneous lymphangiosarcomas. All these cats died or were euthanatized within 6 months after surgery because of poor wound healing, local recurrence, or distant metastases. The cats with abdominal or thoracic masses were either euthanatized at surgery or within 6 months after the first surgery because of recurrent chylothorax, chyloperitoneum, or distant metastases.     

Pericardial effusion in cats: a retrospective study of clinical findings and outcome in 146 cats

BACKGROUND: Pericardial effusion (PE) in dogs most often is associated with neoplasia or idiopathic pericarditis, and frequently causes cardiac tamponade. Studies of PE in the cat are limited. HYPOTHESIS: Congestive heart failure (CHF) is the most common cause of PE in the cat. ANIMALS: All cats diagnosed with PE on echocardiographic examination at the Matthew J. Ryan Veterinary Hospital of the University of Pennsylvania (MJR-VHUP) from 2000 to 2005. METHODS: The clinical and pathologic findings in 146 cats with PE were reviewed. Records were examined retrospectively to identify additional underlying conditions. Follow-up status and cause of death were determined by review of the medical records or phone interviews with the owners. RESULTS: The most common cause of PE in this study was CHF (75%). Biochemical abnormalities were uncommon, but aspartate aminotransferase (AST) activity frequently was increased (85%). Follow-up information was available on 108 cats (74%). Median survival time (MST) was 144 days for cats that were not euthanized within 24 hours (n = 85). The MST of cats with heart failure was 41 days, whereas the MST of cats without heart failure was 361 days, when those euthanized within 24 hours were excluded. CONCLUSIONS: Survival time of cats with heart failure in this study was significantly shorter than previously reported, and significantly shorter than in cats without heart failure as a cause of PE.     

Neutropenia in dogs and cats: a retrospective study of 261 cases

Case records of 232 dogs and 29 cats with neutropenia were reviewed to examine the spectrum of underlying etiologies causing the neutropenia. Six etiological categories included nonbacterial infectious disease; increased demand due to marked inflammation, bacterial sepsis, or endotoxemia; drug-associated neutropenia; primary bone-marrow disease; immune-mediated neutropenia; and diseases of unclear etiology. The largest single category associated with the development of neutropenia was nonbacterial infectious disease (e.g., feline leukemia virus [FeLV], feline immunodeficiency virus [FIV], histoplasmosis, cryptococcosis, and parvovirus), with parvovirus infection accounting for 47.1% of all cases. The least common (0.38%) cause was naturally occurring immune-mediated neutropenia.     

Permethrin toxicity in cats: a retrospective study of 20 cases

OBJECTIVE: Permethrin is a synthetic pyrethroid widely used in flea control products for small animals. Accidental toxicity can occur with off-label usage, and cats are particularly susceptible. METHODS: Retrospective study of 20 cases of permethrin toxicity in cats treated at an emergency clinic in Brisbane, Queensland from October 2004 to June 2005. RESULTS: The diagnosis of permethrin toxicity was made on the basis of a history of exposure and characteristic clinical signs, including seizures, muscle fasciculations, and tremors. Decontamination and appropriate seizure or muscle fasciculation control were the basis of treatment. The outcome was good after rapid intervention and 19 of the 20 cats were successfully treated, with the only death occurring in a kitten for which treatment was delayed for 24 h. No long-term complications were reported by the cats' owners at 4-month follow-up after discharge from hospital. CONCLUSIONS: Owner education, together with more appropriate product labelling, may help eliminate this problem in the future.     

Chronic diseases of the nose and nasal sinuses in cats: a retrospective study

In this retrospective study of 41 cats with chronic nasal disease diagnoses included nasal neoplasia (n = 19), idiopathic chronic rhinosinusitis (ICRS) (n = 12), nasopharyngeal polyps (n = 3), foreign bodies (n = 2), nasopharyngeal stenosis (n = 1) and nasal aspergillosis (n = 1). In 3 cats diagnosis could not be established despite thorough work-up. Gender, indoor or outdoor housing, quality or quantity of nasal discharge, bacteriological findings of nasal flushes, radiology and CT findings did not differ significantly between cats with neoplasia and cats with ICRS. Cats with neoplasia were older (3 - 15, median 11 years) and showed clinical signs for a shorter period of time (1 - 8, median 2 months) than cats with ICRS (age 1 - 13, median 7.5 years; signs: 1 - 36, median 5 months). In all cats with neoplasia a mass was detected rhinoscopically, while this was only seen in 30 % of cats with ICRS. The exact diagnosis has to be established by examination of biopsy samples. A combination of physical examination, imaging studies and rhinoscopy with cytological and histopathological examination of samples enhances the likelihood for a correct diagnosis.     

Obese appearance, mammary development and retardation of hair growth following megestrol acetate administration to cats

Prepubertally ovariectomized kittens were given megestrol acetate orally, 5 mg or 15 mg twice weekly for 12–13 weeks. The higher dose treated animals were generally fatter and some showed marked abdominal distention, but there were no statistical differences in body weight gain when compared with controls. Subsequent laparotomy was followed by hair growth retardation when kittens were given 2·5 mg megestrol acetate weekly for a further 12 weeks. Another two ovariectomized kittens had very rapid mammary development after 4 weeks of 2·5 mg megestrol acetate administration weekly.     

Meningiomas in cats: a retrospective clinical study of 36 cases.

Thirty-six cases of meningiomas in cats were reviewed as to the clinical signs and anatomic location. Age, breed, and sex also were noted. It was found that, in general, meningiomas affected older cats, with two thirds of them being greater than or equal to 10 years old. There was no breed predilection, although there was a majority of male cats. In most cases, the anatomic location was supratentorial, with only one case being infratentorial, and no tumors were below the foramen magnum. A number of cats had multiple maningiomas, and this often complicated the anatomic localization by neurologic examination. Tentorial herniation (6 cases) was associated with positional nystagmus or tetraparesis, or both, in addition to the deficits caused by the tumor.     

Nocardia infections in cats: a retrospective multi-institutional study of 17 cases

OBJECTIVE: To record 17 cases of nocardiosis in cats from eastern Australia and to compare this series with cases previously reported. DESIGN: Retrospective/prospective study. RESULTS: Nocardia spp infections were diagnosed in 17 cats over 14 years from the three eastern states of Australia. There were no isolates from dogs during this period, but one isolate from a koala and two from dairy cows. The majority of cats presented with spreading lesions of the subcutis and skin associated with draining sinus tract(s). Early cutaneous lesions consisted of circumscribed abscesses. Infections spread at a variable rate, generally by extension to adjacent tissues. Lesions were generally located in regions subjected to cat bite or scratch injuries, including limbs, body wall, inguinal panniculus and nasal bridge. In some other cases, lesions were situated on distal extremities. The clinical course was variable, from chronic, indolent, initially localised infections to acute fulminating disease. Of the 17 cats, 14 were domestic crossbreds and three were purebreds. There was a preponderance of male cats (12 castrated, 1 entire young adult, 1 entire kitten). Nine of 17 cats were 10 years or older. Interestingly, the majority of infections were attributable to N nova. Immediate and/or predisposing causes could be identified in all cases, and included: renal transplantation [one cat]; chronic corticosteroid administration [three cats]; catabolic state following chylothorax surgery [one cat]; fight injuries [seven cats]; FIV infections [three of seven cats tested]. Of the 17 cats, three were apparently cured. Four were thought to be cured, but infection recurred after several months. Three cats responded partially but were euthanased, while another was improving when it died of unrelated complications. Two died despite treatment and two were euthanased without an attempt at therapy. For two cats there were either insufficient records or the patient was lost to follow up. CONCLUSION: Nocardiosis is a rare, serious disease. Currently it is more common in cats than dogs. Nocardial panniculitis may be clinically indistinguishable from the syndrome caused by rapidly growing mycobacteria. Although the prognosis is guarded, patients with localised infections caused by N nova often respond to appropriate therapy. If definitive treatment is delayed because of misdiagnosis, the disease tends to become chronic, extensive and refractory. Insufficient duration of therapy leads to disease recurrence.     

Non-lymphoid hematopoietic neoplasia in cats: a retrospective study of 60 cases

Sixty cats with hematologic abnormalities indicative of non-lymphoid hematopoietic neoplasia were classified into two groups, myelodysplastic syndromes (MDS) and acute myelogenous leukemias (AML), using criteria developed for human patients with similar diseases. Cats with myeloblast counts in bone marrow of less than 30% were classed as MDS and cats with myeloblast counts of 30% or greater were classed as AML. The clinical, laboratory, and postmortem findings in each group were described and compared. Clinical signs of disease were similar in both groups, the most common being inappetance, lethargy, and weakness. Non-regenerative anemia, macrocytosis, neutropenia, and thrombocytopenia were frequent hemogram abnormalities in both groups. Diagnostically useful differences in physical and peripheral blood findings were a higher prevalence of splenomegaly and/or hepatomegaly, thrombocytopenia, and severe anemia in the AML group. Circulating myeloblasts were found only in cats in the AML group. Outcome of disease was similar in both groups; 85% of the cats in each group died or were euthanatized within one week of diagnosis. In cats that were necropsied, extramedullary leukemic infiltrates were found in all cats in the AML group and in none of the cats in the MDS group.     

Bromide-associated lower airway disease: a retrospective study of seven cats

Seven cats were presented for mild-to-moderate cough and/or dyspnoea after starting bromide (Br) therapy for neurological diseases. The thoracic auscultation was abnormal in three cats showing increased respiratory sounds and wheezes. Haematology revealed mild eosinophilia in one cat. The thoracic radiographs showed bronchial patterns with peribronchial cuffing in most of them. Bronchoalveolar lavage performed in two cats revealed neutrophilic and eosinophilic inflammation. Histopathology conducted in one cat showed endogenous lipid pneumonia (EnLP). All cats improved with steroid therapy after Br discontinuation. Five cats were completely weaned off steroids, with no recurrence of clinical signs. In one cat, the treatment was discontinued despite persistent clinical signs. The cat presenting with EnLP developed secondary pneumothorax and did not recover. Br-associated lower airway disease can appear in cats after months of treatment and clinical improvement occurs only after discontinuing Br therapy.     

Stress hyperglycemia in sick cats: a retrospective study over 4 years

Between January 1997 and December 2000 blood glucose concentrations were measured in 2278 sick cats at the time of their initial presentation at the hospital. In 827 cats (36%) hyperglycemia (blood glucose >8 mmol/l) was documented, 1388 cats (61%) had normal blood glucose levels, 63 cats (3%) were hypoglycemic. In 674 of 827 cats (81.5%) no further investigations were performed and the veterinarian judged the hyperglycemia to be stress related. In 153 of the 827 cats (18.5%) blood glucose measurements were repeated and/or serum fructosamine concentrations evaluated. In 106 cats (69%) stress hyperglycemia and in 47 (31%) diabetes mellitus was then diagnosed. Blood glucose concentrations in cats with stress hyperglycemia were between 8.1 and 60.4 mmol/l (Median 10.3), in cats with diabetes mellitus between 8.5 and 70.0 (Median 27.7). Blood glucose concentrations in cats with diabetes mellitus were significantly higher than in cats with stress hyperglycemia. Cats with stress hyperglycemia suffered from a variety of different diseases, the most frequently encountered were surgical problems, neoplasia, heart diseases, upper and lower urinary tract diseases. Blood glucose concentrations in cats with heart diseases and in cats with neoplasia was higher than in cats with other disorders, however, the difference was not significant. Cats with diabetes mellitus were significantly more frequent male castrated than cats with stress hyperglycemia. Cats with stress hyperglycemia were significantly older than cats with normoglycemia.