Heartworm infection in cats: 50 cases (1985-1997)

OBJECTIVE: To characterize risk factors, clinical findings, usefulness of diagnostic tests, and prognosis in cats with naturally occurring heartworm infection (HWI). DESIGN: Retrospective study. ANIMALS: 50 cats with Dirofilaria immitis infection. PROCEDURE: Medical records, thoracic radiographs, and echocardiograms were reviewed and findings compared with appropriate reference populations. RESULTS: Findings suggested that male cats were not predisposed to HWI, domestic shorthair cats were at increased risk, and indoor housing was only partially protective. Fewer cases of HWI were identified in the final quarter of the year, compared with other periods, and prevalence is not apparently increasing. Signs of respiratory tract disease were most common, followed by vomiting. Infection was diagnosed incidentally in > 25% of cats; conversely, 10% of infected cats died suddenly without other clinical signs. Serologic tests were most useful for diagnosis, followed by radiography and echocardiography. Eosinophilia supported the diagnosis. Overall median survival time was 1.5 years but exceeded 4 years in cats surviving beyond the day of diagnosis. CONCLUSIONS AND CLINICAL RELEVANCE: Sex does not appear to be a risk factor for HWI in cats, and indoor housing provides only incomplete protection. Signs of respiratory tract disease (dyspnea and cough) are the strongest indicators of HWI in cats, and some radiographic evidence of infection is detected in most cases. Antibody screening for HWI in cats is efficacious, and antigen testing and echocardiography are most useful for making a definitive antemortem diagnosis.     

Peritoneal effusion in cats: 65 cases (1981-1997)

OBJECTIVE: To determine signalment, diagnoses, presence of effusions in multiple sites, and outcome in cats with peritoneal effusion. DESIGN: Retrospective case series. ANIMALS: 65 cats. PROCEDURE: Medical records from 1981 to 1997 were reviewed to obtain information on cats with peritoneal effusion identified on physical examination, radiographs, abdominal ultrasonograms, or at necropsy. RESULTS: Conditions most commonly associated with peritoneal effusion in cats, in order of frequency, were cardiovascular disease, neoplasia, hepatic disease, renal disease, feline infectious peritonitis, peritonitis attributable to other causes, and urinary tract trauma. Dilated cardiomyopathy (DCM) was the most common disease associated with peritoneal effusion; however, DCM was diagnosed in most of these cats before taurine deficiency was found to be a primary cause of this form of cardiomyopathy in cats. Neoplasia was the most common cause after 1987. Right-sided congestive heart failure was the most commonly associated disorder in cats < 1 year old, whereas neoplastic disease was more common with increasing age. Most effusions were detected during the initial physical examination and were modified transudates. Peritoneal effusion was commonly accompanied by fluid accumulation elsewhere, particularly pleural effusion. The prognosis for a cat with abdominal effusion in this study was poor (mean survival time, 21 days; range, 1 to 350 days; median, 2.5 days). CLINICAL IMPLICATIONS: The primary differential diagnosis for peritoneal effusion in cats is neoplastic disease in older cats and right-sided heart failure in kittens. Diseases associated with peritoneal effusion generally have poor prognoses.     

Pulmonary thromboembolism in cats: 29 cases (1987-1997)

OBJECTIVE: To determine clinical signs, clinicopathologic abnormalities, radiographic findings, histologic abnormalities, and predisposing factors or diseases in cats with pulmonary thromboembolism (PTE). DESIGN: Retrospective study. ANIMALS: 29 cats in which PTE was confirmed at necropsy. PROCEDURE: Information on signalment, body weight, history, results of physical examination, results of CBC and serum biochemical analyses, whether PTE was suspected prior to death, type of indwelling venous catheter and duration of venous catheterization, results of thoracic radiography, and whether cats had any concurrent diseases was obtained from medical records. RESULTS: PTE was identified in cats of various ages (median, 8.7 years), weights (median, 4.1 kg [9 lb]), and breeds. The most common owner-reported problems included lethargy (17 cats), anorexia (14), weight loss (10), and difficulty breathing (8); physical abnormalities included lethargy (21), tachypnea or dyspnea (16), and dehydration (13). Clinicopathologic abnormalities reflected concurrent or underlying diseases. Common radiographic abnormalities included pulmonary vessel abnormalities (11), pleural effusion (8), and peripheral noncircumscribed consolidations (6). Underlying or predisposing conditions, including cardiac disease (12), neoplasia (10), corticosteroid administration (8), disseminated intravascular coagulation (5), protein-losing nephropathy (4) or enteropathy (4), immune-mediated hemolytic anemia (2), and sepsis (2) were identified in all cats. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that PTE can develop in cats of any age, sex, or breed. Because PTE is a serious, potentially life-threatening disease, it should be suspected in cats with thoracic radiographic changes suggestive of uneven distribution of blood flow between lung lobes, especially in cats that have predisposing factors or diseases.     

Radiographic patterns of periodontitis in cats: 147 cases (1998-1999)

OBJECTIVE: To determine patterns of alveolar bone loss (periodontitis) and other lesions evident on full-mouth survey radiographs of cats. DESIGN: Retrospective study. ANIMALS: 147 cats. PROCEDURE: Full-mouth radiographs were evaluated for evidence and severity of alveolar bone loss, odontoclastic resorption lesions (ORL), retained roots, missing teeth, signs of endodontic disease secondary to periodontitis, and apical resorption. RESULTS: 106 (72%) cats had some degree of periodontitis, 100 (68%) were missing teeth, 98 (67%) had ORL, 78 (53%) had expansion of the buccal alveolar bone at 1 or more canine teeth, 75 (51%) had retained roots, 48 (33%) had apical resorption, and 12 (8%) had signs of endodontic disease secondary to periodontitis. Cats < 4 years old were not significantly more likely than the general population to have normal alveolar bone height. Prevalence of ORL increased with age, but cats > or =13 years old were less likely than the general population to have moderate or severe generalized periodontitis. Purebred cats were not significantly more likely to have periodontitis or ORL than mixed-breed cats. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that periodontitis is common in cats and that horizontal bone loss is the most common radiographic pattern of alveolar bone loss. Purebred cats were not more likely than mixed-breed cats to have ORL or periodontitis, but when they did have periodontitis, it was more likely to be moderate to severe. Cats with ORL were less likely than cats without ORL to have normal alveolar bone height and more likely to have severe focal vertical bone loss.     

Acute intrinsic renal failure in cats: 32 cases (1997-2004)

OBJECTIVE: To determine patient demographics, clinicopathologic findings, and outcome associated with naturally acquired acute intrinsic renal failure (ARF) in cats. DESIGN: Retrospective case series. ANIMALS: 32 cats with ARF. PROCEDURES: Cats were considered to have ARF if they had acute onset of clinical signs (< 7 days), serum creatinine concentration > 2.5 mg/dL (reference range, 0.8 to 2.3 mg/dL) and BUN > 35 mg/dL (reference range, 15 to 34 mg/dL) in conjunction with urine specific gravity < 1.025 or with anuria or increasing serum creatinine concentration despite fluid therapy and normal hydration status, and no signs of chronic renal disease. Cases were excluded if cats had renal calculi or renal neoplasia. RESULTS: Causes of ARF included nephrotoxins (n = 18 cats), ischemia (4), and other causes (10). Eighteen cats were oliguric. For each unit (mEq/L) increase in initial potassium concentration, there was a 57% decrease in chance of survival. Low serum albumin or bicarbonate concentration at initial diagnosis was a negative prognostic indicator for survival. Initial concentrations of BUN, serum creatinine, and other variables were not prognostic. Seventeen (53%) cats survived, of which 8 cats had resolution of azotemia and 9 cats were discharged from the hospital with persistent azotemia. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that survival rates of cats with ARF were similar to survival rates in dogs and that residual renal damage persisted in approximately half of cats surviving the initial hospitalization.     

Use of echocardiography for the diagnosis of heartworm disease in cats: 43 cases (1985-1997)

OBJECTIVE: To determine the usefulness of echocardiography in the diagnosis of heartworm disease in cats and to compare this modality with other tests. DESIGN: Retrospective study. ANIMALS: 43 cats with heartworm infection that had echocardiographic examinations at 2 veterinary teaching hospitals between 1985 and 1997. Twenty-two of these 43 cats also underwent radiography of the thorax and heartworm antibody and heartworm antigen testing. PROCEDURE: Cats were determined to be infected with Dirofilaria immitis infection on the basis of 1 or more of the following findings: positive modified Knott or antigen test result, echocardiographic evidence of heartworm disease, or confirmation of the disease on postmortem examination. The percentage of echocardiographs in which heartworms were evident was compared with the percentage of radiographs in which pulmonary artery enlargement was evident and results of antigen or antibody tests in cats in which all tests were performed. RESULTS: Overall, heartworms were detectable by use of echocardiography in 17 of 43 cats, most often in the pulmonary arteries. In the 22 cats in which all tests were performed, antibody test results were positive in 18, antigen test results were positive in 12, and pulmonary artery enlargement was evident radiographically and heartworms were identifiable echocardiographically in 14. Heartworm infection was diagnosed exclusively by use of echocardiography in 5 cats in which the antigen test result was negative. CONCLUSIONS AND CLINICAL RELEVANCE: Although echocardiography was less sensitive than antigen testing, it was a useful adjunctive test in cats that had negative antigen test results in which there was a suspicion of heartworm disease. The pulmonary arteries should be evaluated carefully to increase the likelihood of detection of heartworms echocardiographically.     

Hypercalcemia in cats: a retrospective study of 71 cases (1991-1997)

A retrospective study was conducted to characterize the diseases, clinical findings, and clinicopathologic and ultrasonographic findings associated with hypercalcemia (serum calcium concentration >11 mg/dL) in 71 cats presented to North Carolina State University Veterinary Teaching Hospital. The 3 most common diagnoses were neoplasia (n = 21), renal failure (n = 18), and urolithiasis (n = 11). Primary hyperparathyroidism was diagnosed in 4 cats. Lymphoma and squamous cell carcinoma were the most frequently diagnosed tumors. Calcium oxalate uroliths were diagnosed in 8 of 11 cats with urolithiasis. Cats with neoplasia had a higher serum calcium concentration (13.5 ± 2.5 mg/dL) than cats with renal failure or urolithiasis and renal failure (11.5 ± 0.4 mg/dL; P <.03). Serum phosphorus concentration was higher in cats with renal failure than in cats with neoplasia ( P < .004). Despite the fact that the majority of cats with uroliths were azotemic, their serum urea nitrogen and creatinine concentrations and urine specific gravity differed from that of cats with renal failure. Additional studies are warranted to determine the underlying disease mechanism in the cats we identified with hypercalcemia and urolithiasis. We also identified a small number of cats with diseases that are not commonly reported with hypercalcemia. Further studies are needed to determine whether an association exists between these diseases and hypercalcemia, as well as to characterize the underlying pathophysiologic mechanism for each disease process.     

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.     

Horner's syndrome in dogs and cats: 100 cases (1975-1985)

The medical records of 74 dogs and 26 cats with Horner's syndrome (HS) that were admitted to the New York State College of Veterinary Medicine between January 1975 and October 1985 were reviewed. In dogs, but not cats, HS was associated significantly (P less than 0.01) with increasing age. Dogs with hypothyroidism (defined liberally but not rigorously), intracranial neoplasia, or thoracic neoplasia, cats with otitis media/interna (defined liberally), and dogs and cats with brachial plexus root avulsion were at greater risk for developing HS than were animals that were hit by a car. Dogs and cats with otitis externa were at less risk of developing HS than were animals that were hit by a car. The cause of HS could not be determined in 50% of dogs and 42.3% of cats. The results of topical adrenergic drug testing in dogs were inconclusive in localizing lesion site. In dogs and cats, HS appeared to be unassociated with gender, breed, or right vs left side. The important causes of HS in dogs and cats were trauma (hit by car), brachial plexus root avulsion, intracranial and thoracic neoplasia, and otitis media/interna.     

Hyperglycemia in dogs and cats with head trauma: 122 cases (1997-1999)

OBJECTIVE: To determine whether hyperglycemia is associated with head trauma in dogs and cats and whether the degree of hyperglycemia corresponds to severity of neurologic injury or outcome. DESIGN: Retrospective study. ANIMALS: 52 dogs and 70 cats with head trauma and 122 age- and species-matched control dogs and cats. PROCEDURE: Severity of head trauma was classified as mild, moderate, or severe. Blood glucose concentrations recorded within 1 hour after admission were compared between case and control animals and among groups when case animals were grouped on the basis of severity of head trauma or outcome. RESULTS: Blood glucose concentration was significantly associated with severity of head trauma in dogs and cats and was significantly higher in dogs and cats with head trauma than in the control animals. However, blood glucose concentration was not associated with outcome. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that dogs and cats with head trauma may have hyperglycemia and that degree of hyperglycemia was associated with severity of head trauma. However, degree of hyperglycemia was not associated with outcome for dogs and cats with head trauma. Because hyperglycemia can potentiate neurologic injury, iatrogenic hyperglycemia should be avoided in patients with head trauma.     

Radiographic, ultrasonographic, and endoscopic findings in cats with inflammatory bowel disease of the stomach and small intestine: 33 cases (1990-1997).

OBJECTIVE: To characterize imaging findings in cats with confirmed inflammatory bowel disease (IBD) of the upper gastrointestinal tract (i.e., stomach and small intestine) and relate these findings to clinical signs and histologic changes. DESIGN: Retrospective study. ANIMALS: 32 cats with clinical and histopathologic diagnoses of IBD. PROCEDURE: Medical records were reviewed for signalment, clinical signs, clinicopathologic findings, radiographic and ultrasonographic findings, and results of endoscopic examination. Histologic findings were reviewed and characterized by severity and type of inflammatory infiltrate. RESULTS: All cats had 1 or more clinical signs (e.g., vomiting, diarrhea, weight loss, and anorexia) consistent with IBD. Lymphocytic and plasmacytic infiltrates were observed in histologic sections of gastrointestinal tissue. Crypt distortion, villous blunting and fusion, and fibrosis were most commonly seen in cats with moderate or severe IBD. Clinicopathologic findings of some cats included anemia, leukocytosis or leukopenia, hypocholesterolemia, and hyper- or hypoproteinemia. Abnormalities were not found on abdominal radiographic views in 9 of 9 cats. However, contrast studies using barium revealed radiographic abnormalities in 1 of 3 cats. In 13 of 17 cats, abdominal ultrasonography revealed several intestinal abnormalities (e.g., poor intestinal wall layer definition, focal thickening) and large mesenteric lymph nodes with hypoechoic changes consistent with IBD. Endoscopic observation revealed findings (e.g., erythema, plaques, mucosal friability) consistent with inflammation in 9 of 18 cats. CONCLUSIONS AND CLINICAL RELEVANCE: Compared with endoscopy of the gastrointestinal tract or abdominal radiography, clinical signs and ultrasonographic findings appear to have the best association with histologic grade of IBD in cats.     

Cholecystoenterostomy for treatment of extrahepatic biliary tract obstruction in cats: 22 cases (1994-2003)

OBJECTIVE: To identify factors associated with outcome in cats with extrahepatic biliary tract obstruction (EHBTO) that undergo biliary diversion surgery. DESIGN: Retrospective case series. ANIMALS: 22 cats. PROCEDURES: Medical records of cats with surgically confirmed EHBTO that underwent cholecystoenterostomy were reviewed. RESULTS: Clinical signs and physical examination findings included vomiting, anorexia, icterus, lethargy, weakness, and weight loss. Common clinicopathologic abnormalities included high serum hepatic enzyme activities and serum bilirubin concentration. Abdominal ultrasonography was performed in 21 cats, and all 21 had findings consistent with EHBTO. Eleven of 15 cats in which blood pressure was monitored had intraoperative hypotension. Eighteen cats had anemia following surgery, and 14 cats had persistent hypotension. Extrahepatic biliary tract obstruction was a result of neoplasia in 9 cats and chronic inflammatory disease in 13. Fourteen cats survived long enough to be discharged from the hospital, but only 6 survived > 6 months after surgery, all of which had chronic inflammatory disease. Median survival time for cats with neoplasia (14 days) was significantly shorter than that for cats with inflammatory disease (255 days). No other variable was associated with outcome. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that cats with EHBTO secondary to neoplasia have a poorer prognosis than cats with EHBTO secondary to chronic inflammatory disease. However, the overall prognosis for cats with EHBTO undergoing cholecystoenterostomy must be considered guarded to poor, and the incidence of perioperative complications is high.     

Doppler echocardiography-derived evidence of pulmonary arterial hypertension in dogs with degenerative mitral valve disease: 86 cases (2001-2005)

OBJECTIVE: To determine the prevalence of Doppler echocardiography-derived evidence of pulmonary arterial hypertension (DEE-PAH) in dogs with mitral valve disease (MVD) classified according to the International Small Animal Cardiac Health Council (ISACHC) heart failure classification scheme and various echocardiographic and Doppler indices of MVD severity. DESIGN: Retrospective case series. ANIMALS: 617 dogs examined from 2001 to 2005 with MVD in ISACHC classes I to III. PROCEDURES: Dogs were examined echocardiographically. Criteria used for systolic and diastolic DEE-PAH were detection of high tricuspid (> or = 2.5 m/s) and telediastolic pulmonic (> or = 2.0 m/s) valvular peak regurgitant jet velocities, respectively, by use of continuous-wave Doppler echocardiography. RESULTS: 86 (13.9%) dogs with MVD had a diagnosis of DEE-PAH. Severity and prevalence of DEE-PAH increased with ISACHC class (3.0%, 16.9%, 26.7%, and 72.2% prevalences for ISACHC classes Ia, Ib, II, and III, respectively). A significant correlation between systolic or diastolic pulmonary arterial pressure and left atrial-to-aortic diameter ratio (LA/Ao) was detected. Doppler echocardiography-derived evidence of pulmonary arterial hypertension was detected in 18 dogs with values of LA/Ao within reference range, all of which had moderate (n = 2 dogs) or severe (16) mitral valve regurgitation on color Doppler imaging. CONCLUSIONS AND CLINICAL RELEVANCE: The prevalence and degree of DEE-PAH were related to the severity of MVD. Changes associated with DEEPAH may be detected in early stages of the disease, but only in dogs with severe mitral valve regurgitation.     

Ultrasonographic findings in cats with clinical,gross pathologic,and histologic evidence of acute pancreatic necrosis: 20 cases (1994-2001)

OBJECTIVE: To determine ultrasonographic findings in cats with clinical, gross pathologic, and histologic evidence of acute pancreatic necrosis. DESIGN: Retrospective study. ANIMALS: 20 cats. PROCEDURE: Ultrasound reports and permanent ultrasonographic images were reviewed, and ultrasonographic findings were recorded. Thoracic and abdominal radiographs were also reviewed, when available. Anatomic localization of pancreatic necrosis was determined from the gross pathology report; duration and severity of pancreatic necrosis were determined by reviewing histologic specimens. The presence of concurrent disease was recorded from the final pathology report. RESULTS: The pancreas was considered ultrasonographically normal in 10 cats and was not observed in 3. Ultrasonographic findings were considered compatible with pancreatitis in the remaining 7 cats. Gross pathologic findings indicated that pancreatitis was multifocal in all 7 of these cats; histologically, pancreatitis was acute or subacute in 5 and associated with severe or moderate necrosis in 6. In the remaining 13 cats, gross pathologic findings indicated that pancreatitis was multifocal (n = 8) or focal (2), or gross pathologic findings were normal (3). Histologically, pancreatitis was peracute or acute in 11 of these 13 cats and associated with severe or moderate necrosis in 8. Thoracic and abdominal radiographic findings were nonspecific. CONCLUSIONS AND CLINICAL RELEVANCE: Results of ultrasonography were consistent with a diagnosis of pancreatitis in only 7 of 20 cats with acute pancreatic necrosis in the present study. This suggests that new diagnostic criteria must be established if abdominal ultrasonography is to be an effective tool in the diagnosis of pancreatitis in cats.     

Vaccine site-associated sarcoma and malignant lymphoma in cats: a report of six cases (1997-2002)

Six cats developed malignant lymphoma 3 to 45 months after treatment for vaccine site-associated sarcoma. During the same time period, 184 cats were evaluated in the teaching hospital for vaccine site-associated sarcomas. Feline vaccine site-associated sarcoma is not believed to be associated with feline leukemia virus (FeLV) infection. Five of six cats were negative by enzyme-linked immunosorbent assay for FeLV antigens at the times of diagnosis of both sarcoma and lymphoma, and no cats were infected with feline immunodeficiency virus.     

Third-degree atrioventricular block in 21 cats (1997-2004)

The effect of 3rd-degree atrioventricular block on long-term outcome in cats is unknown. Clinical findings and long-term outcome of 21 cats with 3rd-degree atrioventricular block were studied retrospectively. Median age of cats studied was 14 years (range 7-19 years). Presenting signs included respiratory distress or collapse, but 6 cats had no clinical signs of disease. Eight cats had congestive heart failure (CHF) at the time that 3rd-degree atrioventricular block was detected. Heart rates ranged from 80 to 140 beats per minute (bpm; median 120 bpm) with no difference in heart rate between cats with and those without CHF. Eleven of 18 cats that had echocardiograms had structural cardiac disease, and 6 cats had cardiac changes consistent with concurrent systemic disease. No atrioventricular nodal lesions were detected by echocardiography. One cat had atrioventricular nodal lesions detected on histologic examination. Median survival of 14 cats that died or were euthanized was 386 days (range 1-2,013 days). Survival did not differ between cats with or without CHF or between cats with or without structural cardiac disease. Thirteen cats with 3rd-degree atrioventricular block survived > 1 year after diagnosis, regardless of presenting signs or underlying cardiac disease. Third-degree heart block in cats is often not immediately life threatening. Survival was not affected by the presence of underlying heart disease or congestive heart failure at the time of presentation. Even cats with collapse might survive > 1 year without pacemaker implantation.