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.     

A retrospective study of diagnosis in 109 cases of canine lower respiratory disease

Between 1983 and 1988, 109 cases of canine lower respiratory tract disease were examined and categorised according to clinical, radiographic and bronchoscopic findings and cytology of bronchial mucus. Non-specific chronic tracheobronchitis was diagnosed in 19 cases, bronchopneumonia (subacute or chronic) in 12 cases, bronchiectasis in 10 cases, parasitic bronchitis due to Oslerus osleri in 20 cases, eosinophilic bronchitis with or without bronchiectasis or alveolar infiltration in 25 cases, bronchial foreign bodies, mainly cereal ears, in 14 cases, primary neoplasia (adenocarcinomas) in six cases and miscellaneous disease in three cases. Features of these conditions are discussed. Although the aetiology of chronic bronchial disease may not always be ascertained, it is important to assign a dog to a diagnostic category so that the owner can be given a more accurate prognosis.     

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.     

Endogenous lipid pneumonia in cats: 24 cases (1985-1998)

OBJECTIVE: To determine clinical signs, radiographic and histologic abnormalities, and concurrent diseases in cats with endogenous lipid pneumonia (EnLP) and to determine the pathologic importance of EnLP in cats. DESIGN: Retrospective study. ANIMALS: 24 cats. PROCEDURE: Medical records of cats in which EnLP was confirmed by histologic examination of necropsy specimens were reviewed. Information collected from the medical records included signalment, body weight, clinical signs, and results of clinicopathologic tests. Thoracic radiographs were reviewed by a radiologist; histologic specimens were reviewed by a pathologist. RESULTS: All cats had nonspecific clinical abnormalities, such as lethargy, anorexia, or weight loss; 16 had signs of respiratory tract disease. All cats had concurrent systemic diseases, and clinicopathologic abnormalities were reflective of these conditions. Nonspecific abnormalities were detected on thoracic radiographs from 9 of 11 cats. Most cats had macroscopic, multifocal, subpleural lesions; inflammatory infiltrates, cholesterol clefts, and multinucleated giant cells were common. Ten cats had an underlying obstructive pulmonary disease that was the likely cause of EnLP. Lesions of EnLP were not considered to be severe enough or extensive enough to be the cause of death in any of these cats. CONCLUSIONS AND CLINICAL RELEVANCE: EnLP is an uncommon respiratory tract disorder of cats with no pathognomonic clinical, laboratory, or radiographic findings. Although EnLP was not the cause of death in any of these cats, results of the present study do suggest that EnLP may be a marker for potentially severe underlying obstructive pulmonary disease.     

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.     

Chronic respiratory disease in the dog.

This paper describes the essential features of the conditions causing chronic respiratory disease in the dog including: chronic bronchitis, bronchiectasis, primary and secondary lung tumours, filaroidiasis, actino-mycotic infections and tuberculosis. Epidemiology, diagnostic clinical signs and methods of treatment are emphasized. A consideration of hypertrophic pulmonary osteoarthropathy is included since it frequently occurs in conjunction with chronic respiratory disease and may be a useful diagnostic marker.     

Immotile cilia syndrome in two Old English Sheepdog litter-mates

Two Old English Sheepdog litter-mates with chronic respiratory disease since birth had ultrastructural abnormalities of their respiratory tract cilia. The ciliary defects included lack of inner dynein arms, abnormal radial spokes and nexin links, and microtubule doublet displacement. Similar ciliary defects in man result in immotile cilia with the subsequent development of sinusitis, bronchitis or bronchiectasis, male sterility, and, in some cases, situs inversus. Both dogs had sinusitis and bronchiectasis, and one of the dogs also had situs inversus.     

Association of bovine respiratory syncytial virus with atypical interstitial pneumonia in feedlot cattle

Thirty-three cattle with fatal respiratory tract disease were examined for gross and histologic lesions and for the presence of viral and bacterial agents in the lungs. Fifteen cattle had lesions characteristic of atypical interstitial pneumonia (AIP), and 18 had other respiratory tract diseases, including infectious bovine rhinotracheitis, shipping fever pneumonia, bronchopneumonia, pulmonary abscess, and edema of the trachea. Gross necropsy findings in the cattle with AIP were uncollapsed and emphysematous lungs; histopathologic findings included interstitial edema, thickening of alveolar walls, hyaline membrane formation, and hyperplasia of type-II pneumonocytes. The infective agents found in the lungs of the 33 cattle included bovine respiratory syncytial virus, bovine herpesvirus type 1, Pasteurella sp, mycoplasmas, and Corynebacterium pyogenes. Bovine respiratory syncytial virus was detected by use of immunofluorescence and immunoperoxidase on lung tissue sections; bovine herpesvirus type 1 was detected by these techniques and by isolation of the virus. Bovine respiratory syncytial virus was significantly (P = 0.01) associated with lesions of AIP (11 of 15), compared with those of other respiratory tract diseases (5 of 18).     

Use of keyhole lung biopsy for diagnosis of interstitial lung diseases in dogs and cats: 13 cases (1998-2001)

OBJECTIVE: To characterize interstitial lung diseases (ILDs) and evaluate use of keyhole lung biopsy for diagnosis of ILDs in dogs and cats. DESIGN: Retrospective study. ANIMALS: 11 dogs and 2 cats. PROCEDURE: Medical records of dogs and cats undergoing keyhole lung biopsy to confirm ILDs were reviewed. Signalment, clinical signs, results of thoracic radiography and other respiratory diagnostic tests, postoperative complications, and patient outcome were analyzed. RESULTS: Clinical respiratory signs included cough, tachypnea, exercise intolerance, and hemoptysis. Thoracic radiographic abnormalities included interstitial, alveolar, and bronchointerstitial patterns and multiple discrete pulmonary nodules. Lung biopsy and histologic examination revealed interstitial pulmonary fibrosis, bronchiolitis obliterans with organizing pneumonia, or unclassified lesions. Outcome after biopsy included no response to treatment, euthanasia, partial or complete remission while receiving medication, and cure. CONCLUSIONS AND CLINICAL RELEVANCE: Recognition and classification of ILDs in dogs and cats are likely to be important in guiding appropriate treatment and providing accurate prognostic information. Ancillary respiratory diagnostic tests are beneficial in ruling out infectious and neoplastic disorders that may mimic ILDs; however, their present use in the diagnosis of ILDs is limited. Results suggest that keyhole lung biopsy is an effective means for obtaining a specimen for histologic diagnosis in dogs and cats with ILDs.     

ACQUIRED CYSTIC BRONCHIECTASIS IN THE DOG: A CASE HISTORY REPORT

A 9-year-old neutered female mixed breed dog was examined for productive coughing, gagging, increased respiratory effort and restlessness. In survey chest radiographs a soft tissue opacity was present in the right middle lung lobe. In horizontal-beam radiographs, it was apparent that the opacity was a thin-walled cyst containing air and fluid. Peribronchial infiltration and bronchial dilation were present in all lung lobes. At necropsy, a diagnosis of chronic bronchitis and bronchiolitis and cylindrical and cystic bronchiectasis was made. Acquired bronchiectasis may result from any disease process which weakens the bronchial wall or obstructs drainage. Three forms of bronchiectasis have been described in man: cylindrical, saccular and cystic. Cylindrical bronchiectasis is tubular distention of larger, thick-walled bronchi; saccular bronchiectasis is circumscribed outpocketing of intermediate-sized bronchi and cystic bronchiectasis is a more pronounced manifestation of saccular bronchiectasis in terminal bronchi. Cylindrical and saccular bronchiectasis have been described in the dog; cystic bronchiectasis has not been described in the dog. Generalized bronchiectasis is an incurable condition due to the irreversible bronchial pathologic changes. Focal bronchiectasis can be surgically corrected by lobectomy and the prognosis is good. Aggressive antibiotic therapy should be used to treat chronic bronchitis in an effort to prevent bronchial destruction and development of bronchiectasis.     

Hyperglycemic, hyperosmolar syndrome in feline diabetics: 17 cases (1995–2001)

Objective: The purposes of this study were to characterize the hyperglycemic, hyperosmolar syndrome (HHS), also known as nonketotic hyperosmolar diabetes, in cats; to determine the prevalence of HHS in the diabetic cat population in the emergency room; to document the outcome in cats with HHS; and to identify any predisposing factors or predictors of survival. Design: Retrospective study. Setting: An emergency service at a veterinary teaching hospital located in a major metropolitan area. Animals: The case records of 17 cats with hyperglycemic, hyperosmolar syndrome presenting from 1995 to 2001 were evaluated. An additional 37 cats with diabetic ketoacidosis and 80 cats with diabetes mellitus served as comparison groups. Interventions: None. Measurements and main results: Signalment, history, physical examination findings, clinico‐pathologic data, concurrent disease, and outcome were recorded. Hyperglycemic, hyperosmolar syndrome was seen in older cats that were often long‐standing diabetics receiving insulin for many months. Client concerns included polydipsia, polyuria, and lethargy. Neurologic and respiratory signs occurred frequently. Evaluation at presentation revealed profound dehydration, lactic acidosis, and azotemia. Serious concurrent diseases that likely contributed to the development of the HHS crisis were diagnosed in 88% (15/17) of the HHS cats. The most common concurrent diseases were renal failure, respiratory compromise, infection, congestive heart failure, neoplasia, and gastrointestinal tract disease. Pancreatitis and hepatic disease did not occur frequently in this diabetic cat population. Sixty‐five percent of HHS cats did not survive the initial hospitalization, with most dying or being euthanized within 10 hours of presentation. The long‐term survival rate was low (12%). Conclusions: HHS is a serious life‐threatening form of diabetic crisis and cats with HHS often have other severe systemic diseases. Cats with diabetes and concurrent disease, especially renal failure and congestive heart failure, are at increased risk of HHS and should be closely monitored for signs of crisis. The mortality rate for HHS cats is high.     

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.     

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 signs in cats with nasal disease

Radiographic signs in 64 cats that had radiography as part of the diagnostic work-up for suspected nasal disease were reviewed in a blinded fashion. Final diagnoses in these cats were rhinitis in 27, primary nasal neoplasia in 21 and non-nasal disease in 16. The signs with highest predictive value for nasal neoplasia were displacement of midline structures (73%), unilateral generalised soft tissue opacity (70%), unilateral generalised loss of turbinate detail (69%) and evidence of bone invasion (64%). The only radiographic finding that occurred more frequently in cats with rhinitis was a nasal cavity within normal limits, and the predictive value of this sign was only 38%. Radiographic signs in cats with nasal neoplasia are similar to those reported in dogs, whereas the radiographic signs in cats with rhinitis are variable and non-specific, and may be absent.     

Broncholithiasis in a cat: clinical findings, long-term evolution and histopathological features

A 14-year-old neutered male Persian cat was evaluated because of an acute exacerbation of a chronic cough of 2-3 years of duration. Physical examination was normal except for the auscultation of accentuated breath sounds and wheezes cranially on both sides of the chest. Complete blood count, biochemical parameters and urinalysis were normal. Thoracic radiographs showed a generalised nodular pattern with multiple mineral opacities. Oral prednisone and doxycycline were prescribed. Two weeks later, the frequency of the cough was significantly reduced. Terbutaline was recommended for relief of acute exacerbations. Three years later the cat was evaluated again due to a non-related disease that led to the euthanasia of the cat. Concerning its respiratory disease, the cat had experienced nearly asymptomatic periods of 3-6 weeks of duration punctuated by acute exacerbation periods of 7-10 days, during which terbutaline was useful to relieve the cough. Thoracic radiographs showed a mild increase in the size and extent of the pulmonary mineralisation. Histopathologically, mild bronchitis and bronchiectasis were evident, accompanied by calcified bronchial plugs and marked hyperplasia and hypertrophy of the seromucinous glands. Based on clinical and pathoanatomical findings, a final diagnosis of miliary broncholithiasis and bronchiectasis was made. Broncholithiasis should be considered in differential diagnosis of pulmonary mineralisation in cats. When no concomitant diseases are present, this rare disease appears to have a slowly progressive evolution that does not appear to carry a bad prognosis and may be satisfactorily managed with combinations of bronchodilators and corticosteroids.     

Evaluation of serologic and viral detection methods for diagnosing feline herpesvirus-1 infection in cats with acute respiratory tract or chronic ocular disease

OBJECTIVE: To determine the value of virus isolation (VI), immunofluorescent antibody (IFA) assay, serum neutralization (SN), and ELISA for the diagnosis of clinical feline herpesvirus-1 (FHV-1) infection in cats. ANIMALS: 46 clinically normal cats, 17 cats with signs of acute respiratory tract disease, and 38 cats with signs of chronic ocular disease. PROCEDURE: Conjunctival swabs for VI, conjunctival scrapings for IFA testing, and venous blood samples for SN or ELISA testing were obtained from all cats. RESULTS: FHV-1 was detected in 10.9 and 28.3% of clinically normal cats and in 18.2 and 33.3% of cats with FHV-1-associated disease by VI and the IFA assay, respectively. There were no significant differences in the viral detection rate between cats with acute respiratory tract disease and cats with chronic ocular disease or between diseased cats and clinically normal cats; however, FHV-1 was never detected by both methods in clinically normal cats. Overall FHV-1 seroprevalence was 97% when tested by ELISA and 66% when tested by SN. Seroprevalence did not vary significantly among the 3 groups for either serologic test. Magnitude of SN and ELISA titers varied greatly but independently of presence or absence of clinical signs of FHV-1-associated disease. Sensitivity, specificity, and positive and negative predictive values were assessed for VI and the IFA assay--jointly and individually--and for each SN and ELISA titer magnitude. Values never all exceeded 50%. CLINICAL IMPLICATIONS: Because FHV-1 can be detected commonly in clinically normal cats by the IFA assay or VI, neither test appears to aid in the clinical diagnosis of FHV-1 infection. Seroprevalence does not appear to vary between affected and clinically normal cats. SN, ELISA, VI, and the IFA assay appear to be of limited value in the diagnosis of FHV-1-associated disease in cats. Concurrent assessment of the IFA assay and VI results may permit exclusion of FHV-1 as an etiologic agent if results of both tests are negative.     

ECHOLARYNGOGRAPHY IN CATS

Twenty-five cats with clinical signs of upper respiratory tract disease and five cats without upper respiratory signs underwent echolaryngography. Direct inspection of the larynx under general anesthesia was undertaken in all cats and used as the 'gold standard' for the diagnosis of laryngeal diseases. The aims were to: (a) establish which anatomic structures of the larynx are visible ultrasonographically in cats without upper respiratory tract disease, (b) establish which laryngeal abnormalities can be detected and accurately localised using ultrasonography and (c) evaluate in which conditions the technique may provide complementary information or an alternative method of investigation. The ultrasound investigation accurately indicated the presence and location of cysts and masses. Abnormal laryngeal movements were also detected, although it was difficult to confirm whether these were unilateral or bilateral. Vocal cord thickening was seen but the underlying cause could not be established with this technique.     

UTILITY OF MAGNETIC RESONANCE IMAGING FOR DISTINGUISHING NEOPLASTIC FROM NON-NEOPLASTIC BRAIN LESIONS IN DOGS AND CATS

The aim of this study was to identify magnetic resonance (MR) signs that aid differentiation of neoplastic vs. non-neoplastic brain diseases in dogs and cats. MR images of 36 dogs and 13 cats with histologic diagnosis of intracranial disease were reviewed retrospectively. Diagnoses included 30 primary and three metastatic brain tumors, 11 infectious/inflammatory lesions, three vascular, one degenerative disease, and one developmental malformation. Upon univariate analysis of 21 MR signs, there were seven that had a significant association with neoplasia: single lesion (P = 0.004), shape (P = 0.015), mass effect (P = 0.002), dural contact (P = 0.04), dural tail (P = 0.005), lesions affecting adjacent bone (P = 0.008), and contrast enhancement (P = 0.025). Increasing age was also found to be associated with neoplasia (P = 0.0001). MR signs of non-neoplastic brain diseases in dogs and cats were more variable than those of brain neoplasia.     

Kartagener's syndrome in an old miniature poodle

A 12-year old male miniature poodle with a chronic progressive cough of two years duration was found to have situs inversus totalis, rhinitis, bronchiectasis and bronchopneumonia with metaplasia. Clinical and pathological findings satisfy the clinical criteria for a diagnosis of Kartagener's syndrome. However, the dog had no history of respiratory disease during it's first year of life, it sired at least one healthy puppy and electron microscopic examination of tracheal cilia showed only minimal microtubular abnormalities. This is the first report of a miniature poodle with Kartagener's syndrome. Kartagener's syndrome and mild forms of primary ciliary dyskinesia (PCD) may play an important role in the development of chronic respiratory disease in older dogs.     

Immotile cilia syndrome in an aged dog

An 11-year-old Dalmatian was examined and treated for bilateral nasal discharge and cough of 6 months' duration. Response to medical treatment and surgical intervention was unsatisfactory. Histologic examination of lung tissue revealed chronic severe catarrhal bronchitis and bronchiolitis with bronchiectasis. Histologic findings and barium sulfate bronchography indicated abnormal mucociliary clearance in the respiratory tract. Electron microscopy revealed abnormalities or deletions of outer and/or inner dynein arms in 26% of the ciliary profiles from the affected dog. Similar abnormalities were not found in 500 ciliary profiles from age- and gender-matched control dogs.