Risk factors, clinical signs, and survival in cats with a clinical diagnosis of idiopathic hypertrophic cardiomyopathy: 74 cases (1985-1989).

Population characteristics, risk factors, and survival characteristics were evaluated in 74 cats with hypertrophic cardiomyopathy (HC) seen at North Carolina State University veterinary teaching hospital from 1985 to 1989, and compared with 82 clinically normal cats. The mean (+/- SD) age of cats with HC was 6.5 (4.0) years. Neutered males were at significantly greater risk (odds ratio 3.1) than neutered females. Breed, body weight, or coat color were not determined to be risk factors for HC. Tricolor cats were significantly underrepresented, probably reflecting the male predisposition for HC and not a true risk reduction associated with coat color. Forty-one cats were without clinical signs of heart disease (murmur and/or gallop sound only), 24 were in congestive heart failure, and 9 had systemic arterial embolism, 3 of which had concomitant congestive heart failure. The median survival time for 61 cats with HC, for which survival information could be obtained and that were not euthanatized on day 1, was 732 days. Survival was not affected by age at diagnosis, breed, body weight, or sex. However, clinical signs were important in determining prognosis; cats with heart rates greater than 200 beats/min survived significantly longer (median survival greater than 1,830 days) than those with heart rates greater than or equal to 200 beats/min (median survival = 152 days). Cats without clinical signs (median survival greater than 1,830 days) survived longer than those with clinical signs, and cats in heart failure survived a median of 92 days, compared with 61 days for those with systemic arterial embolism. Analysis of survival revealed no significant difference between the 2 groups of cats with clinical signs; however, all cats with embolism and only 60% of cats with heart failure were dead 6 months after diagnosis.     

Population and survival characteristics of cats with hypertrophic cardiomyopathy: 260 cases (1990-1999)

OBJECTIVE: To determine current population characteristics of, clinical findings in, and survival times for cats with hypertrophic cardiomyopathy (HCM). DESIGN: Retrospective study. ANIMALS: 260 cats with HCM. PROCEDURE: Information was obtained from the medical records. Cats were classified into 1 of 4 clinical groups (congestive heart failure [CHF] group, arterial thromboembolism [ATE] group, syncope group, or cats without clinical signs [subclinical group]) on the basis of the primary clinical signs at the initial examination. RESULTS: 120 cats were classified in the CHF group, 43 in the ATE group, 10 in the syncope group, and 87 in the subclinical group. Antecedent events that may have precipitated CHF included i.v. fluid administration, anesthesia, surgery, and recent corticosteroid administration. Median survival time was 709 days (range, 2 to 4,418 days) for cats that survived > 24 hours. Cats in the subclinical group lived the longest (median survival time, 1,129 days; range, 2 to 3,778 days), followed by cats in the syncope group (654 days; range, 28 to 1,505 days), cats in the CHF group (563 days; range, 2 to 4,418 days), and cats in the ATE group (184 days; range, 2 to 2,278 days). Causes of death included ATE (n = 56), CHF (49), sudden death (13), and noncardiac causes (27). In univariate analyses, survival time was negatively correlated with left atrial size, age, right ventricular enlargement, and thoracentesis. Cats with systolic anterior motion of the mitral valve lived longer than cats without this echocardiographic finding. In multivariate analyses, only age and left atrial size remained significant predictors of survival time. CONCLUSIONS AND CLINICAL RELEVANCE: Although overall survival time for cats with HCM was similar to earlier reports, survival times for cats with CHF or ATE were longer than previously reported.     

Population characteristics and survival in 127 referred cats with hypertrophic cardiomyopathy (1997 to 2005)

Objectives : To evaluate the characteristics and survival of a recent population of cats with hypertrophic cardiomyopathy. Methods : Records at the Royal Veterinary College Queen Mother Hospital for Animals were searched for cats diagnosed with hypertrophic cardiomyopathy between 1997 and 2005. Referring veterinarians and owners were contacted to determine survival times. Results : Cats with hypertrophic cardiomyopathy were evaluated for population characteristics (n=127) and survival times (n=109). Overall median survival from date of hypertrophic cardiomyopathy diagnosis at the Queen Mother Hospital for Animals was 1276 days. Cats with hypertrophic cardiomyopathy were younger (P=0·009), and more likely to be male (P<0·001) compared to a hospital control group (n=1473), and Ragdolls were over-represented (P<0·05). Characteristics associated with increased survival in univariate analysis included younger age (P=0·007), asymptomatic status (P<0·001), normal left atrial size (P<0·001) and presence of systolic anterior motion of the mitral valve (P=0·003). Systolic anterior motion was associated with asymptomatic status, and did not influence survival in asymptomatic cats or those in congestive heart failure. Age, left atrial size and breed were significantly associated with survival time in a multivariate analysis. Clinical Significance : Cats with hypertrophic cardiomyopathy and left atrial enlargement have a poorer prognosis. The positive influence of systolic anterior motion on survival is likely to be linked to its association with asymptomatic status.     

Aetiology and outcome in 90 cats presenting with dyspnoea in a referral population

O bjectives : Dyspnoea is an unspecific severe presenting sign, which can be life threatening and requires prompt treatment. Dyspnoeic cats often have significant underlying disease. Underlying aetiologies in cats that presented with dyspnoea were reviewed, and associations with patient signalment and outcome were investigated.
M ethods : The case records of 90 dyspnoeic cats were retrospectively reviewed and separated into different groups depending on aetiology (cardiac, respiratory, neoplastic and trauma). Duration of clinical signs, presentation, hospitalisation length and survival were analysed.
R esults : Cardiac (38 per cent), respiratory (32 per cent) and neoplastic (20 per cent) diseases were common causes of feline dyspnoea. Cats with respiratory causes had longer duration of clinical signs (P<0·001) before presentation. Cats with neoplasia were significantly older (P<0·001). No significant difference in respiratory rates was present between the groups (P = 0·154). High heart rates (P<0·001) and abnormalities on cardiac auscultation were more likely in the cardiac group.
Clinical Significance: Frequent causes of dyspnoea in cats were cardiac disease followed by respiratory causes and neoplastic conditions. Heart rate on presentation and presence of heart murmurs or gallops are useful to identify cardiac causes. Improved proportion surviving was found in the respiratory group (P = 0·027), whereas cats with neoplasia had the worst outcome.     

RADIOGRAPHIC AND ECHOCARDIOGRAPHIC ASSESSMENT OF LEFT ATRIAL SIZE IN 100 CATS WITH ACUTE LEFT‐SIDED CONGESTIVE HEART FAILURE

The aims of this study were to evaluate left atrial size in cats with acute left‐sided congestive heart failure. We hypothesized that left atrial size as determined by thoracic radiography can be normal in cats with acute left‐sided congestive heart failure. One hundred cats with acute left‐sided congestive heart failure in which thoracic radiography and echocardiography were performed within 12 h were identified. Left atrial size was evaluated using right lateral and ventrodorsal radiographs. Measurements were compared to two‐dimensional echocardiographic variables of left atrial size and left ventricular size. On echocardiography, left atrial enlargement was observed in 96% cats (subjective assessment) whereas maximum left atrial dimension was increased (>15.7 mm) in 93% cats. On radiographs left atrial enlargement (subjective assessment) was found in 48% (lateral view), 53% (ventrodorsal view), and 64% (any view) of cats whereas left atrial enlargement was absent in 36% of cats in both views. Agreement between both methods of left atrial size estimation was poor (Cohen's kappa 0.17). Receiver operating characteristic curve analysis identified a maximum echocardiographic left atrial dimension of approximately 20 mm as the best compromise (Youden index) between sensitivity and specificity in the prediction of radiographic left atrial enlargement. Left atrial enlargement as assessed by thoracic radiography may be absent in a clinically relevant number of cats with congestive heart failure. Therefore, normal left atrial size on thoracic radiographs does not rule out presence of left‐sided congestive heart failure in cats with clinical signs of respiratory distress.     

Hypercoagulability in cats with cardiomyopathy

BACKGROUND: Arterial thromboembolism (ATE) is a common complication of feline cardiomyopathy; however, the pathogenesis of ATE is unknown. HYPOTHESIS: Systemic activation of the coagulation cascade (hypercoagulability) and endothelial injury promote ATE in cardiomyopathic cats. ANIMALS: Healthy cats (n = 30) and 3 groups of cardiomyopathic cats: Group (1) left atrial enlargement only (LAE [n = 11]), ie, left atrial to aortic ratio >1.4; Group (2) LAE with spontaneous echocardiographic contrast, atrial thrombi or both (SEC-T [n = 16]); and Group (3) acute ATE with LAE (n = 16). METHODS: Hypercoagulability was defined by 2 or more laboratory abnormalities reflecting coagulation factor excess (high fibrinogen concentration or Factor VIII coagulant activity), inhibitor deficiency (low antithrombin activity), or thrombin generation (high thrombin-antithrombin complex [TAT] and d-dimer concentrations). High von Willebrand factor antigen concentration (vWF : Ag) was considered a marker of endothelial injury. Data were analyzed using nonparametric statistics. RESULTS: The 3 groups of cats with cardiac disease had higher median fibrinogen concentrations than did the healthy cats. Criteria of hypercoagulability were found exclusively in cats with SEC-T (50%) and ATE (56%). Hypercoagulability was not associated with left atrial size or congestive heart failure (CHF). ATE cats had significantly higher median vWF : Ag concentration than did the other groups. CONCLUSION AND CLINICAL IMPORTANCE: Systemic hypercoagulability is evident in many cardiomyopathic cats, often without concurrent CHF or overt ATE. Hypercoagulabilty may represent a risk factor for ATE. High vWF : Ag in ATE cats was attributed to downstream endothelial injury from the occlusive thrombus.     

Clinicopathologic and radiographic features and etiologic agents in cats with histologically confirmed infectious pneumonia: 39 cases (1991-2000)

OBJECTIVE: To determine clinicopathologic and radiographic features and etiologic agents in cats that died as a result of infectious pneumonia. DESIGN: Retrospective study. ANIMALS: 39 cats. PROCEDURE: Medical records of cats in which infectious pneumonia was confirmed by histologic examination of necropsy specimens were reviewed. Signalment, clinical signs, and results of a CBC, viral serologic tests, and thoracic radiography were evaluated. Infectious agents were classified as bacterial, viral, fungal, protozoal, or parasitic. Histologic features (severity, duration, anatomic location, and distribution) were analyzed. RESULTS: Clinical signs referable to the respiratory tract were not detected in 14 of 39 (36%) cats, and results of a CBC (4/18 cats) and radiography (3/13) were unremarkable. Sixteen of 39 (41%) cats lacked clinical signs of systemic illness. Etiologic agents identified included bacteria (n = 21), viruses (11), fungi (6), protozoa (2), and parasites (1). Cats with clinical signs related to the respiratory tract (19/24 [79%] cats) were more likely to have severe histologic changes than cats without signs related to the respiratory system (6/14). Twenty-nine of 38 (76%) cats had histologic evidence of systemic disease, whereas the remaining cats had lesions limited to the respiratory tract. CONCLUSIONS AND CLINICAL RELEVANCE: Infectious pneumonia is uncommon in cats. Cats with infectious pneumonia may lack clinical signs and have unremarkable results for a CBC and thoracic radiography, yet frequently have systemic infections. Therefore, clinicians should maintain an index of suspicion for pneumonia and evaluate the respiratory tract when infection is detected in other organ systems.     

Excessive moderator bands in the left ventricle of 21 cats

Excessive numbers of moderator bands bridging the left ventricular septum and free wall and entangling papillary muscles were associated with heart failure and death in 21 cats. Clinical findings included dyspnea, anorexia, hypothermia, cardiomegaly, pleural effusion, plumonary edema, heart murmurs, gallop rhythm, electrocardiographic abnormalities (especially conduction disturbances), increased left ventricular end-diastolic pressure, angiocardiographic evidence of left ventricular restriction, and aortic thromboembolism. Pathologic changes included a morphologically distinct network of abnormal numbers of moderator bands in the left ventricle, left ventricular hypertrophy (younger cats--mean age, 4 years) or dilatation (older cats--mean age, 8.7 years), left atrial enlargement and hypertrophy, and pulmonary edema with heart failure cells in the alveoli. Heart weights of affected cats were significantly less than those of cats with congestive, hypertrophic, and restrictive cardiomyopathy (endocardial fibrosis), but were not significantly less than heart weights of clinically normal cats. Pathologic changes were characteristic of the syndrome grossly and histologically, but clinical findings were not clearly definable.     

Evaluation of respiratory parameters at presentation as clinical indicators of the respiratory localization in dogs and cats with respiratory distress

Objective ? To describe clinical respiratory parameters in cats and dogs with respiratory distress and identify associations between respiratory signs at presentation and localization of the disease with particular evaluation between the synchrony of abdominal and chest wall movements as a clinical indicators for pleural space disease. Design ? Prospective observational clinical study. Setting ? Emergency service in a university veterinary teaching hospital. Animals ? Cats and dogs with respiratory distress presented to the emergency service between April 2008 and July 2009. Interventions ? None. Measurements and Main Results ? The following parameters were systematically determined at time of admission: respiratory rate, heart rate, temperature, type of breathing, movement of the thoracic and abdominal wall during inspiration, presence of stridor, presence and type of dyspnea, and results of thoracic auscultation. Abdominal and chest wall movement was categorized as synchronous, asynchronous, or inverse. Diagnostic test results, diagnosis, and outcome were subsequently recorded. Based on the final diagnoses, animals were assigned to 1 or more of the following groups regarding the anatomical localization of the respiratory distress: upper airways, lower airways, lung parenchyma, pleural space, thoracic wall, nonrespiratory causes, and normal animals. One hundred and seventy‐six animals (103 cats and 73 dogs) were evaluated. Inspiratory dyspnea was associated with upper airway disease in dogs and expiratory dyspnea with lower airway disease in cats. Respiratory noises were significantly associated and highly sensitive and specific for upper airway disease. An asynchronous or inverse breathing pattern and decreased lung auscultation results were significantly associated with pleural space disease in both dogs and cats (P<0.001). The combination is highly sensitive (99%) but not very specific (45%). Fast and shallow breathing was not associated with pleural space disease. Increased or moist pulmonary auscultation findings were associated with parenchymal lung disease. Conclusions ? Cats and dogs with pleural space disease can be identified by an asynchronous or inverse breathing pattern in combination with decreased lung sounds on auscultation.     

Heterogeneity of Hypertrophy in Feline Hypertrophic Heart Disease

Eighty-six cats with non-dilated left ventricular myocardial hypertrophy were studied retrospectively. Cats were categorized by two-dimensional echocardiography as having symmetric ventricular hypertrophy (Type I), asymmetric with predominant septal thickening hypertrophy (Type II), and asymmetric hypertrophy with predominant free-wall thickening (Type III). The distribution of hypertrophy was judged subjectively and objectively. Subjective and objective results were similar (P= 0.03) although overlap existed between groups. Morphologic patterns (Types I, II, and III) were compared with breed, age, sex, heart rate, percent fractional shortening, left atrial size, serum creatinine concentration, and the presence (yes/no) of pleural effusion, pulmonary edema, pericardial effusion, heart murmur, dyspnea, thromboembolism, hyperthyroidism, and being alive at the time of study. Interventricular septal thickness, left ventricular free wall thickness, percent fractional shortening, and left atrial size additionally were compared to 3-month survival. Cats with Type HI hypertrophy were more likely to experience thromboembolism than cats with Type II hypertrophy (P= 0.05) and cats with Type I hypertrophy were more likely to have heart murmurs than cats with Type III (P= 0.02). No other significant associations were found in comparison to pattern of hypertrophy. Both left atrial size and percent fractional shortening significantly correlated with 3-month survival (P < 0.001 for each). The degree of interventricular septal wall thickness was associated with 3-month survival (P= 0.02) when known hyperthyroid cats were excluded from the study group, while left ventricular free wall thickness consistently was not associated with survival. This study demonstrates the heterogeneity of hypertrophy in cats with hyper-trophic heart disease and provides predictors of survival (left atrial size, percent fractional shortening, and interventricular septal wall thickness when compared with euthanasia/spontaneous death data).     

Atrial fibrillation in cats: 50 cases (1979-2002)

OBJECTIVE: To determine signalment, clinical signs, diagnostic findings, treatment, and outcome for cats with atrial fibrillation (AF). DESIGN: Retrospective study. ANIMALS: 50 cats. PROCEDURE: Medical records of cats that met criteria for a diagnosis of AF (ECG consisting of at least 2 leads, clear absence of P waves, supraventricular rhythm, and convincingly irregularly irregular rhythm) and had undergone echocardiography were reviewed. RESULTS: There were 41 males (37 castrated) and 9 females (7 spayed). Forty-one were of mixed breeding; 9 were purebred. Mean +/- SD age was 10.2 +/- 3.7 years. The most common chief complaints were dyspnea, aortic thromboembolism, and lethargy. In 11 cats, AF was an incidental finding. Mean +/- SD ventricular rate was 223 +/- 36 beats/min. The most common echocardiographic abnormalities were restrictive or unclassified cardiomyopathy (n = 19), concentric left ventricular hypertrophy (18), and dilated cardiomyopathy (6). Mean +/- SD left atrial-to-aortic diameter ratio (n = 39) was 2.55 +/- 0.80. The most common thoracic radiographic findings were cardiomegaly, pleural effusion, and pulmonary edema. Median survival time (n = 24) was 165 days (range, 0 to 1,095 days). Eight of 24 cats lived for > or = 1 year after a diagnosis of AF was made. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that AF occurs primarily in older adult male cats with structural heart disease severe enough to lead to atrial enlargement. Atrial fibrillation in these cats was most commonly first detected when signs of decompensated cardiac disease were evident, but also was commonly identified as an incidental finding.     

Identification and characterization of an idiopathic pulmonary fibrosis-like condition in cats

Interstitial lung diseases are a heterogeneous group of disorders with a variety of causes. In veterinary medicine, such lung diseases with a prominent fibrotic component of unknown etiology are often called idiopathic pulmonary fibrosis (IPF). In human medicine, this term is reserved for a distinct disease entity with specific histologic findings labeled as usual interstitial pneumonia (UIP). We identified 23 cats displaying histologic criteria of UIP The purpose of this retrospective study is to describe the presentation and response to therapy of these cats to better define this disease entity. All but 2 cats were middle aged to older (median 8.7 years), with no apparent sex or breed predisposition. Complaints included respiratory distress (n = 18) and cough (13). Duration of signs was less than 6 months in 17 cats. Physical-examination abnormalities included tachypnea, inspiratory or mixed inspiratory and expiratory effort, and adventitial lung sounds. No consistent hematologic or biochemical abnormalities, parasites, or positive serologic results for feline retroviruses, heartworms, or toxoplasmosis were present. Radiographic changes included dense patchy or diffuse interstitial, bronchiolar, and alveolar infiltrates. Analysis of bronchial lavage fluid revealed mild neutrophilic inflammation (n = 6) with no consistent pathogen growth. Clinical condition of 5 cats worsened after lavage. Coincident pulmonary neoplasia was identified in 6 cats. Response to therapy (corticosteroids, antibiotics, bronchodilators, and diuretics) was poor, and most cats died within days to months. Cats with histologic changes compatible with UIP had signs that mimicked many of the clinical findings of human IPF, and treatment response was similarly unrewarding.     

Circulating natriuretic peptides in cats with heart disease

BACKGROUND: Circulating natriuretic peptide concentrations are increased in cats with myocardial dysfunction. HYPOTHESIS: Serum N-terminal fragment of proatrial natriuretic peptide (NT-proANP) and NT-probrain natriuretic peptide (proBNP) concentrations may predict the presence of heart disease (HD) and congestive heart failure (CHF). A positive relationship is also predicted among natriuretic peptide (NP) concentrations, a noninvasive estimate of left ventricular filling pressure (E/E(a)), and an echocardiographic measure of left atrial (LA) size (LA/aortic diameter [Ao]). METHODS: Serum NP concentrations were measured in 28 healthy control and 50 study cats using sandwich enzyme immunoassays. The study group comprised cats, with HD but no CHF (HD - CHF, n = 17) and cats with CHF (HD + CHF, n = 33). The relationship among NP concentrations, LA size, and E/E(a) was examined. The ability of NP to distinguish control from study cats, and HD - CHF from HD + CHF cats, was explored using receiver operator curve analysis. RESULTS: NP concentrations were significantly lower in control than in study cats (P= .0001). The NT-proBNP concentrations were positively correlated with LA/Ao ratio (rho= 0.34; P= .02) and with E/E(a) ratio (rho= 0.68; P < .05). An NT-proBNP concentration of 49 fmol/mL gave a sensitivity and specificity of 100 and 89.3%, respectively, for correctly distinguishing 96.2% of control from study cats. Pairwise comparisons of the areas under the curve identified a statistically significant difference (P= .011) between NT-proANP and NT-proBNP to distinguish control from study cats. NT-proANP and NT-proBNP concentrations were significantly higher in HD + CHF cats than in HD - CHF cats (P= .0023 and .0001, respectively). CONCLUSIONS: Serum concentrations of NT-proANP and particularly NT-proBNP were different in healthy control cats, asymptomatic cats with HD, and cats with CHF, suggesting that measurement of NP concentrations may prove clinically useful as an initial screening test for cats with suspected cardiac disease.     

Hybrid cutting balloon dilatation for treatment of cor triatriatum sinister in a cat

A hybrid surgical approach and balloon dilatation were performed successfully in a cat with cor triatriatum sinister and clinical signs of congestive heart failure. Left lateral thoracotomy was used to access the heart and cutting balloon followed by standard balloon dilatation were utilized to dilate the perforation in the anomalous left atrial membrane. Clinical signs resolved completely after dilation of the anomalous left atrial membrane. Based upon the outcome of this case, balloon dilatation appears to be a viable treatment option for cats affected with cor triatriatum sinister.     

Evaluation of a novel immunotherapy for treatment of chronic rhinitis in cats

The pathogenesis of chronic rhinitis in cats is poorly understood and consistently effective therapies are not currently available. Therefore, randomized clinical trials were conducted to evaluate a novel immunotherapy for treatment of chronic rhinitis in adult (n=12) and young cats (n=28). In addition, cytokine profiles in cats with chronic rhinitis were compared to those of healthy cats. Cats were treated with a potent stimulator of innate immunity (liposome-IL-2 DNA complexes) and the effects of treatment on clinical signs and immune function were assessed. In adult cats with chronic rhinitis, immunotherapy led to significant improvement in frequency of sneezing but not in other clinical signs when compared to the placebo group, whereas immunotherapy failed to improve clinical signs in younger cats. Analysis of cytokine expression in cats with rhinitis did not reveal evidence of a Th2 cytokine bias in cats with rhinitis. We conclude that chronic rhinitis in cats is not a Th2-biased disease and that immunotherapy may lead to clinical improvement in adult cats with the disease.     

Multi-centered investigation of a point-of-care NT-proBNP ELISA assay to detect moderate to severe occult (pre-clinical) feline heart disease in cats referred for cardiac evaluation

ObjectiveTo prospectively evaluate the diagnostic accuracy of a point-of-care (POC) N-terminal pro-B-type natriuretic peptide (NT-proBNP) ELISA to assess the likelihood of moderate to severe occult heart disease (OcHD) in a clinical population of cats suspected to have heart disease.AnimalsOne hundred and forty-six asymptomatic client-owned cats with a heart murmur, gallop rhythm, arrhythmia, or cardiomegaly.MethodsPhysical examination, blood pressure measurement and echocardiography were performed prospectively. Point-of-care ELISA was visually assessed as either positive or negative by a reader blinded to the echocardiographic results.ResultsForty-three healthy cats, 50 mild OcHD, 31 moderate OcHD, 6 severe OcHD, and 16 cats equivocal for OcHD were examined. Cats with OcHD included 65 with hypertrophic cardiomyopathy, 6 with restrictive or unclassified cardiomyopathy, 1 with arrhythmogenic right ventricular cardiomyopathy, and 15 with non-cardiomyopathic forms of heart disease. Point-of-care ELISA differentiated cats with moderate or severe OcHD with sensitivity/specificity of 83.8%/82.6% and overall accuracy of 82.9%. Positive POC ELISA increased likelihood of moderate or severe OcHD by a factor of 4.8 vs. those that tested negative. Point-of-care ELISA differentiated cats with moderate or severe cardiomyopathic OcHD with sensitivity/specificity of 88.6%/81.3% and overall accuracy of 83.2%.ConclusionIn a select sample of cats referred for cardiac evaluation, positive POC NT-proBNP ELISA increases likelihood of moderate to severe OcHD while negative POC NT-proBNP ELISA result excludes moderate to severe OcHD.     

Smoke exposure in cats: 22 cases (1986-1997).

OBJECTIVE: To review clinical findings and clinical course for cats exposed to smoke in residential fires and to determine clinical variables that may have prognostic importance. DESIGN: Retrospective study. ANIMALS: 22 cats admitted to our veterinary teaching hospital between 1986 and 1997 with a history of smoke exposure during a residential fire. PROCEDURE: Medical records were reviewed for history, clinical signs, physical examination findings, changes in respiratory tract signs, initial hematologic analysis, treatment, results of thoracic radiography, and outcome. RESULTS: Fifteen of 22 (68%) cats were categorized in the uncomplicated group, 5 (23%) in the complicated group, and 2 (9%) were discharged after a short period because of financial considerations. Twenty (91%) cats survived, but 2 (9%) were euthanatized because of severe respiratory compromise or neurologic changes. Predominant thoracic radiographic changes were diffuse interstitial pattern (6 cats) and focal alveolar pattern (5). The majority (8/13) of cats that were stable or had improved by the day after admission had an uncomplicated clinical course while hospitalized, whereas cats that were worse on the day after admission tended to have a complicated clinical course. CONCLUSIONS AND CLINICAL RELEVANCE: Cats that survive a residential fire and are admitted to a hospital have a good chance to be discharged. Cats that do not have signs of respiratory tract dysfunction at admission probably will not develop severe respiratory complications. For cats with signs of respiratory dysfunction at admission, better prognostic information will be determined by monitoring progression of the respiratory condition on the day after admission.     

Congestive heart failure associated with hyperthyroidism in cats

Hyperthyroidism was diagnosed in 4 cats with congestive heart failure. Dyspnea and anorexia were observed in 3 of the 4 cats. In each cat, a holosystolic left and/or right apical heart murmur was auscultated. In 3 cats, a prominent extra heart sound (gallop rhythm) was auscultated. All cats had a palpably large thyroid lobe(s) and weight loss. The laboratory and ECG changes were similar to those reported for feline hyperthyroidism. Moderate-to-severe pleural effusion and cardiomegaly were detected via radiography in all cats. Some cats had radiographic signs of pulmonary venous engorgement and pulmonary edema. Echocardiography revealed cardiac dilatation and low left ventricular shortening fraction (wall motion) in all cats. Three cats responded initially to cardiac drugs and propylthiouracil or thyroidectomy. One of these died later, presumably from an adverse reaction to propylthiouracil, and the others died from recurrent congestive heart failure (1) or postoperative cardiac arrest (1). One cat did not respond to treatment, and died 2 days after diagnosis.     

Acromegaly in 14 Cats

Acromegaly was diagnosed in 14 middle-aged to old cats of mixed breeding. Thirteen (93%) of the cats were male and one was female. The earliest clinical signs in the 14 cats included polyuria, polydipsia, polyphagia, all of which were associated with untreated diabetes mellitus. All developed severe insulin resistance within a few months; peak insulin dosages required to control severe hyperglycemia ranged from 20 to 130 U per day. Other clinical findings weeks to months after diagnosis included enlargement of one or more organs (e.g., liver, heart, kidneys, and tongue) (n = 14), cardiomyopathy (n = 13), increase in body size and weight gain (n = 8), nephropathy associated with azotemia and clinical signs of renal failure (n = 7), degenerative arthropathy (n = 6), and central nervous system signs (i.e., circling and seizures) caused by enlargement of the pituitary tumor (n = 2). The diagnosis of acromegaly was confirmed by demonstration of extremely high basal serum growth hormone concentrations (22 to 131 micrograms/l) in all cats. Computerized tomography disclosed a mass in the region of the pituitary gland and hypothalamus in five of the six cats in which it was performed. Two cats were treated by cobalt radiotherapy followed by administration of a somatostatin analogue (octreotide), whereas two cats were treated with octreotide alone. Treatment had little to no effect in decreasing serum GH concentrations in any of the cats. Eleven of the 14 cats were euthanized or died four to 42 months (median survival time, 20.5 months) after the onset of acromegaly because of renal failure (n = 2), congestive heart failure (n = 1), concomitant renal failure and congestive heart failure (n = 3), progressive neurologic signs (n = 2), persistent anorexia and lethargy of unknown cause (n = 1), the owner's unwillingness to treat the diabetes mellitus (n = 1), or unknown causes (n = 1). Results of necropsy examination in ten cats revealed a large pituitary acidophil adenoma (n = 10), marked left ventricular and septal hypertrophy (n = 7), dilated cardiomyopathy (n = 1), arthropathy affecting the shoulder, elbow, or stifle (n = 5), and glomerulopathy characterized by expansion of the mesangial matrix and variable periglomerular fibrosis (n = 10).