Objectives The aim of this study was to test the hypothesis that intranasally administered maropitant citrate would reduce the severity of clinical signs of feline upper respiratory disease (FURD) in shelter cats with naturally acquired disease. Methods Shelter cats with clinical signs of FURD were randomly assigned to receive either intranasal maropitant diluted in saline (maropitant citrate 10 mg/ml q12h, diluted 1:10 with sterile 0.9% saline) or intranasal 0.9% saline q12h for 7 days. Clinical disease severity was measured at entry into the study and again after completion of 7 days of treatment using a visual analogue scale to assess four separate clinical signs: conjunctivitis, blepharospasm, ocular discharge and nasal discharge. Total disease severity was also calculated. Cats received other medications for FURD as per standard shelter protocols, and all investigators were masked to group assignments. A Mann–Whitney U-test was performed to compare the clinical improvement score (CIS) between the treatment and control groups. Results There were 34 cats in the maropitant treatment group; 27 cats served as placebo controls. Groups did not differ in age, sex distribution, nature of disease, administration of other medications for FURD or baseline clinical disease severity. There was no significant difference in CIS between the maropitant treatment and control groups for conjunctivitis, blepharospasm, ocular discharge, nasal discharge or total disease severity after 7 days. Conclusions and relevance This study found no significant difference in outcomes for cats with FURD when treated with intranasal maropitant compared with treatment with intranasal saline. Further investigations would be required before intranasal maropitant could be recommended as the standard of care for FURD.

Bacterial pneumonia can present in both dogs and cats as either acute or chronic disease, and clinical signs may suggest respiratory or systemic impairment. Aspiration pneumonia, a common form of disease, can be caused by esophageal or laryngeal disease, vomiting, or altered mentation, such as with CNS disease or general anesthesia. Bacterial pneumonia can also develop due to inhaled airway foreign bodies, reduced local immune function, or impaired clearance of respiratory secretions. Rapid identification of the etiology and associated risk factors for pneumonia can help veterinarians develop a targeted therapeutic plan and prevent recurrence of disease.

AbstractBackgroundPulmonary hypertension (PH) in dogs with myxomatous mitral valve disease (MMVD) is caused by increased pulmonary venous pressure. Thrombosis, vascular remodeling, and vasoconstriction mediated by platelets could exacerbate PH.HypothesisDogs with PH will exhibit a hypercoagulable state, characterized by increased platelet activation, platelet‐leukocyte, and platelet‐neutrophil aggregate formation.AnimalsEleven dogs (≥3.5 kg) diagnosed with MMVD and PH and 10 dogs with MMVD lacking PH.MethodsProspective cohort ex vivo study. All dogs underwent echocardiographic examination, CBC, 3‐view thoracic radiographs, and heartworm antigen testing. Severity of PH and MMVD were assessed by echocardiography. Viscoelastic monitoring of coagulation was assessed using thromboelastography (TEG). Platelet activation and platelet‐leukocyte/platelet‐neutrophil interactions were assessed using flow cytometry. Plasma serotonin concentrations were measured by ELISA.ResultsUnstimulated platelets from dogs with MMVD and PH expressed more surface P‐selectin than MMVD controls (P = .03). Platelets from dogs with MMVD and PH had persistent activation in response to agonists. The number of platelet‐leukocyte aggregates was higher in dogs with MMVD and PH compared with MMVD controls (P = .01). Ex vivo stimulation of whole blood resulted in higher numbers of platelet‐neutrophil aggregates in dogs with MMVD and PH (P = .01). Assessment of hypercoagulability based on TEG or plasma serotonin concentrations did not differ between groups.Conclusion and Clinical ImportancePlatelet hyperresponsiveness and increased platelet‐neutrophil interaction occur in dogs with MMVD and PH, suggesting that platelets play a role of in the pathogenesis of PH. Clinical benefits of antiplatelet drugs in dogs with MMVD and PH require further investigation.

Case summary A 10-year-old male castrated domestic shorthair cat was presented for evaluation of a 3-day history of increased inspiratory effort. The cat had received prednisolone 1 mg/kg PO q24h for 1 year due to chronic diarrhea. On physical examination, the patient exhibited severe stridor, intermittent open-mouth breathing and bilateral mucopurulent nasal discharge. Subcutaneous emphysema was palpated over the dorsal cervical region. Mild hypoventilation (PvCO 2 55.1 mmHg; approximate reference interval 35–45 mmHg) was identified. Cervicothoracic radiographs showed marked gas tracking within cervical soft tissues with concurrent laryngeal thickening, pulmonary nodules, a bronchial pulmonary pattern, pneumomediastinum and aerophagia. The cat was hospitalized and treated overnight with oxygen and intravenous fluid therapy before anesthesia the next day. On laryngoscopy, a large tracheal mass was observed arising from the right subglottic region and was removed using biopsy forceps. CT revealed an additional mass at the level of the tracheal bifurcation causing marked luminal narrowing of the trachea and proximal main bronchi. The cat made a good initial recovery, although moderate stridor persisted. Five days later, the cat was re-examined due to recurrence of respiratory distress and orthopnea, and the owner elected euthanasia. Histopathology revealed severe nodular obstructive eosinophilic plasmacytic laryngotracheitis with intranuclear inclusion bodies positive for feline herpesvirus-1 on immunohistochemistry. Relevance and novel information This report describes the presentation and management of a cat with respiratory distress secondary to intratracheal eosinophilic masses caused by feline herpesvirus-1. Although the outcome was ultimately unsatisfactory, to the authors’ knowledge, this clinical presentation has not been previously reported.

BackgroundCurrently available treatment options for nasopharyngeal stenosis and imperforate nasopharynx in dogs and cats are fraught with complications and failures.ObjectiveTo develop patient-specific nasopharyngeal stents using 3D-printed molds and to assess placement and fit of stents within the nasopharynx.AnimalsSix canine cadavers.MethodsPatient-specific nasopharyngeal silicone stents were generated using 3D-printed molds based on CT scans. A placement protocol was developed. Post-placement, goodness of fit within the nasopharynx was evaluated and compared to currently used methods. Mechanical properties of silicone stents were compared to catheter-based and nitinol stents.ResultsDevelopment and placement of stents was successful in all six cadavers. Silicone stents offered stiffness (force required for compression, N) and post-load deformation comparable to nitinol stents (1.8–6.2 vs. 1.2–3.3 N and 0.02–0.08 vs. 0.01–0.14 mm, respectively). Patient-specific stents offered superior goodness of fit in the nasopharynx (81–90%) compared to bilateral red rubber catheters (16.2–33.8%).ConclusionDevelopment and placement of patient-specific stents using 3D printed molds was successful in all six cadavers. The novel stents exhibited similar mechanical properties and superior goodness of fit compared to commercially available stents, potentially offering a better alternative to commercially available stents. Further investigation is needed in animals with nasopharyngeal stenosis to determine efficacy and to assess utility in live patients.

Sibling female and male Chihuahuas were evaluated for a 9-month history of tachypnea that failed to respond to fenbendazole, doxycycline, amoxicillin-clavulanate, and prednisone. Physical examination identified tachypnea, hyperpnea, and harsh bronchovesicular lung sounds. Fundic examination disclosed diffuse chorioretinitis, manifested as multifocal chorioretinal granulomas in the female dog and occasional chorioretinal scars in the male dog. Thoracic radiographs indicated moderate to severe interstitial to broncho-interstitial infiltrates in both dogs. Serum and urine antigen and antibody testing in the female dog failed to identify infectious agents, but cytologic assessment of hepatic lymph node, liver, and splenic aspirates identified Pneumocystis trophozoites. Infection was confirmed in both dogs by 28S rRNA PCR sequencing from multiple tissue samples. The female dog responded well to trimethoprim-sulfamethoxazole, but the male dog was euthanized because of liver failure, presumably related to antimicrobial treatment.

Feline pulmonary Langerhans cell histiocytosis (FPLCH) is a rare histiocytic proliferative disease of middle-aged to older domestic cats. Langerhans cells in the terminal airways proliferate and infiltrate the interstitium and the airways to a lesser degree, widely effacing normal parenchyma. Historically, definitive diagnosis has required postmortem evaluation where pulmonary lesions have a classic gross and histologic morphology. Here, we present the first documented antemortem diagnosis of FPLCH using bronchoalveolar lavage (BAL) cytology and immunocytochemistry (ICC) in a 9-year-old British shorthair mix. The cat had a 3-month history of respiratory difficulty that was refractory to steroids and antimicrobials. Pulmonary radiographs had marked diffuse changes with a complex bronchointerstitial and micronodular pattern. BAL cytology revealed neutrophilic inflammation and markedly increased histiocytes with morphology distinct from typical pulmonary macrophages. ICC characterized histiocytes as CD1a+ /E-cadherin+ /CD11b- /PanCK- , consistent with a Langerhans cell phenotype. The cat was humanely euthanized due to poor prognosis and presented for necropsy. Gross, histopathologic, immunophenotypic, and ultrastructural findings confirmed a diagnosis of FPLCH. Proliferative cells were E-cadherin+ /Iba-1+ /CD18+ /CD1a+ /CD5+ /MHCII+ /CD204- /CD4- ; transmission electron microscopy identified the presence of Birbeck granules in the proliferating histiocytes, consistent with previous reports of FPLCH.

BackgroundPyothorax, an accumulation of inflammatory fluid in the pleural space, is often caused by foreign body inhalation in dogs, whereas the etiology in cats can be more difficult to discern. ObjectiveCompare clinical, microbiologic findings, and etiology in cats and dogs with pyothorax. AnimalsTwenty-nine cats and 60 dogs. MethodsMedical records of cats and dogs diagnosed with pyothorax from 2010 to 2020 were reviewed. Clinical findings, fluid analysis, and microbiologic results were retrieved. ResultsAntimicrobials had been administered to equal proportions of cats and dogs before fluid sampling (45% and 47%). Groups did not differ in age or total protein concentration or percentage neutrophils in pleural fluid, but effusion cell count was significantly higher in cats than in dogs (P = .01). Neutrophils containing intracellular bacteria were identified in more cats (27/29, 93%) than dogs (44/60, 73%; P = .05). Penetrating damage to the thorax was implicated as the cause of pyothorax in equal percentages of cats (76%) and dogs (75%). Etiology could not be determined in 2 cats and 1 dog. Cats had higher numbers of bacterial isolates per patient (median, 3) than dogs (median, 1; P = .01) and anaerobes were isolated more often in cats (23/29, 73%) than in dogs (27/60, 45%; P = .003). Conclusions and Clinical ImportancePyothorax had similar etiologies in cats and dogs. Cats had higher fluid cell counts, higher numbers of bacterial isolates identified per patient, and intracellular bacteria detected more commonly than did dogs.

AbstractBackgroundGlucocorticoids are frequently required for management of cough because of inflammatory airway disease (IAD) and airway collapse (AWC).Objectives/HypothesisTo determine the efficacy and feasibility of inhaled administration of corticosteroids in controlling cough in dogs with noninfectious airway disease.AnimalsThirty‐six client‐owned dogs.MethodsDogs were prospectively recruited for this placebo‐controlled cross‐over study. Inflammatory airway disease was diagnosed through bronchoalveolar lavage cytology. Airway collapse was diagnosed through bronchoscopy, or if dogs were unsuitable anesthetic candidates, by crackles on auscultation, radiographic changes in airway diameter, or fluoroscopy. Dogs were randomly assigned to receive placebo or fluticasone propionate for the first 2 weeks of the trial then crossed over to fluticasone. A quality of life (QOL) survey (best score 0, worst score 85) was completed at 0 and 6 weeks. A visual‐analog cough survey was submitted at 0, 2, 4, and 6 weeks to assess cough, feasibility, and adverse effects of treatment.ResultsFor 32 dogs, QOL score at study end (mean 11.3 ± 9.7) was significantly lower (P < .0001) compared to entry (mean 28.1 ± 14.1), with a median change of 69% in QOL score, indicating improved quality of life. Cough frequency, duration, and severity were significantly (P < .0001) decreased at study end. Feasibility of aerosolized delivery improved with continued use (P = .05) with only 1 dog unable to accept inhaled medication.Conclusion and Clinical ImportanceThis study supports the utility of fluticasone propionate by inhalation in management of cough in dogs with IAD and AWC.

Dynamic lower airway obstruction is the primary component of canine bronchomalacia, but the ventilatory function remains underinvestigated. This prospective study analyzed tidal breathing characteristics in 28 dogs, comprising 14 with severe bronchomalacia diagnosed by bronchoscopy versus 14 without respiratory disease. Spirometry was conducted in all dogs. Bronchoscopy with bronchoalveolar lavage or brush under anesthesia was performed in 14 dogs with cough and expiratory effort. Severe bronchomalacia was defined by the severity of collapse and total number of bronchi affected. Ventilatory characteristics were compared between groups. Results revealed that dogs with severe bronchomalacia had lower minute volume (218 vs 338 mL/kg, p = .039) and greater expiratory-to-inspiratory time ratio (1.55 vs 1.35, p = .01) compared to control dogs. The tidal breathing pattern of dogs with bronchomalacia was different from that of normal dogs, and the pattern differed from the concave or flat expiratory curves typical of lower airway obstruction. Compared to control dogs, dogs with severe bronchomalacia had a significantly prolonged low-flow expiratory phase (p < .001) on the flow-time plot and a more exponential shape of the expiratory curve (p < .001) on the volume-time plot. Flow-time index ExpLF/Te (>0.14) and volume-time index Vt-AUCexp (≤31%) had a high ROC-AUC (1.00, 95% confidence interval 0.88 to 1.00) in predicting severe bronchomalacia. In conclusion, the tidal breathing pattern identified here indicates abnormal and complicated ventilatory mechanics in dogs with severe bronchomalacia. The role of this pulmonary functional phenotype should be investigated for disease progression and therapeutic monitoring in canine bronchomalacia.

Abstract Background Factors associated with outcome in dogs diagnosed with infective endocarditis (IE) are not well characterized. Objectives Evaluate outcome and prognostic factors in dogs with IE. Animals One hundred and thirteen dogs with IE. Methods Medical records for dogs that fulfilled the modified Duke criteria between 2005 and 2020 were retrospectively reviewed. Signalment, preexisting conditions, clinicopathologic findings, treatment regimen, and outcomes were recorded. Univariate logistic regression was performed to identify categorical factors associated with mortality, and then multivariate analysis was performed. Results Dogs were categorized as survivors (n = 47), non‐survivors (n = 57), or lost to follow‐up (n = 9). Survival to discharge and at 1 month was documented in 79 (70%) of 113 and 56 (54%) of 104 dogs, respectively, with median survival time (MST) of 72 days. Risk factors associated with mortality included development of congestive heart failure (odds ratio [OR], 11.8; 95% confidence interval [CI], 1.4‐97.8), thromboembolic events (OR, 5.7; 95% CI, 2.3‐14.4), and acute kidney injury (OR, 6.2; 95% CI, 2.0‐18.8). Administration of antithrombotic medications was associated with survival (OR, 0.35; 95% CI, 0.13‐0.97). Dogs that were not treated with antithrombotics had MST of 92 days, whereas dogs treated with antithrombotics did not reach MST during the study period. The heart valves involved and etiologic agent identified did not correlate with outcome. Conclusion and Clinical Importance Dogs with IE that had thromboembolic events, acute kidney injury, or congestive heart failure had higher risk of mortality. Administration of antithrombotics was associated with prolonged survival time.

Tularemia is a rare zoonotic disease found worldwide. The agent responsible for disease, Francisella tularensis, is one of the most highly infectious pathogens known, one that is capable of causing life-threatening illness with inhalation of <50 organisms. High infectivity explains concerns of its use in bioterrorism. This case describes a 4-year-old male neutered Australian shepherd presented for evaluation of hyporexia and fever. Physical examination revealed marked enlargement of the right superficial cervical lymph node. Tularemia lymphadenitis was diagnosed by lymph node aspiration cytology and culture. Public health officials were advised of the isolation of this zoonotic pathogen, and contact tracing was instituted. Seven individuals associated with the aspiration event were screened for tularemia and treated with prophylactic ciprofloxacin. All were negative, and none became sick. The dog was treated with doxycycline for 3 weeks, and clinical signs and physical examination abnormalities were resolved fully. The owner, a solid organ transplant recipient, was also screened for disease and received prophylactic doxycycline due to a history of shared exposure. The owner remained well throughout the course of his dog's disease and has heightened awareness of potential zoonoses. This case highlights the importance of animals as a sentinel for human health threats and for coordination of human and veterinary care.

Infectious disease testing is critical for the effective diagnosis of nasal, airway, parenchymal, and pleural space disease in dogs and cats because appropriate therapy requires an accurate diagnosis. While performing rhinoscopy, tracheal wash, bronchoscopy, or thoracocentesis, the clinician should be mindful of tests available for various infectious disease while procuring samples; these tests include cytology, bacterial and fungal cultures, histopathology, and polymerase chain reaction testing. Confirming a role for infection in respiratory disorders will allow appropriate antimicrobial stewardship and avoid development of resistant infections.

AbstractBackgroundNorwich terriers are affected by an upper airway syndrome (NTUAS) but little is known about outcome in affected dogs.ObjectiveTo determine outcome in dogs with NTUAS using owner questionnaires.AnimalsThirty‐four client‐owned dogs.MethodsAt initial assessment, owners were questioned about respiratory noises and exercise tolerance. A NTUAS score was prospectively constructed based on the number and severity of obstructive lesions detected endoscopically (range, 0‐25). Owner questionnaires on respiratory noises, exercise tolerance, and quality of life (QOL) were obtained 2.2‐9.3 years (median, 4.2 years) after endoscopy.ResultsDogs ranged from 0.5 to 10.7 years of age (median, 4.75 years) at initial examination and no correlation was found between age and NTUAS score (median, 13; range, 1‐25). Of 5 possible laryngeal abnormalities, 7 dogs had 1‐2, 10 dogs had 3, and 17 dogs had 4‐5 abnormalities (median, 3.5). Surgery was performed in 15 dogs, which had higher NTUAS scores (18.5 ± 6.3) than dogs that did not have surgery (7.7 ± 4.7, P < .0001). Scores for QOL ranged from 0 to 31 out of 40, with higher scores indicating worse QOL. Owner surveys resulted in QOL scores of ≤3 in 25/31 dogs (81%), with worse scores in dogs that had surgery performed (median 5, vs 0; P = .003). No correlation was noted between NTUAS and QOL scores, but age at follow‐up was weakly associated with worse QOL.Conclusions and Clinical ImportanceDespite variable severity of NTUAS scores, owners reported excellent QOL for most Norwich terriers examined.

Objectives The aim of this study was to determine famciclovir content (strength) in compounded formulations and to determine if potency changed over time. Methods Four concentrations of oral oil suspension in three distinct flavors, three concentrations of oral paste, three chew treats and 62.5 mg tablets from one compounding pharmacy were evaluated for famciclovir content. Specific sample preparation procedures were used for each drug formulation prior to determination of famciclovir content through mass spectrometry tandem liquid chromatography. Analysis was performed on arrival from the compounder and on days 7, 14, 28, 56 and 120. Samples were run in triplicate and concentration determined by comparison with a standard curve. Content was considered appropriate if within 90–110% of the labeled concentration. Results On arrival from the compounding pharmacy, 5/12 oral oil suspensions of varying concentrations were <90% of the labeled concentration and 3/3 oral pastes were >110%. Famciclovir content in oil suspensions ranged from 72% to 118% of the label value while oral pastes ranged from 95% to 202% of the label concentration over the 120 study days, and all concentrations varied in an unpredictable fashion. Tablets contained 90–110% of the labeled value throughout the study period. Chew treats could not be successfully analyzed. Conclusions and relevance This study found substantial variation in famciclovir content in the compounded products evaluated, which, in turn, raises concerns that substandard dosing could result in lack of efficacy or a failed treatment trial. Drug toxicity might also be encountered. Veterinarians must be aware that while compounded medications can improve compliance, they might not deliver the drug dose expected.

Abstract Background The clinical relevance of echocardiographic measurements of right heart size and function in dogs with pulmonary hypertension (PH) is unknown. Objective To determine if echocardiographic measurements of right heart size and right ventricular (RV) function are associated with survival times in dogs with PH. Animals Eighty‐two client‐owned dogs. Methods Retrospective study where data from medical records and baseline echocardiographic examinations were collected and measured in a standardized manner. Owners or primary veterinarians were contacted for outcome data. Results Enlargement of the right atrium (88%), RV (69%), and pulmonary artery (72%) was common. One‐third of the cases had reduced RV function quantified by two‐dimensional echocardiography‐derived tricuspid annular plane systolic excursion (TAPSE). Decreased TAPSE was significantly (P = .008) more common in dogs with PH not secondary to left heart disease (LHD; 43%) compared to dogs with PH secondary to LHD (14%) but median survival times (182, 95% confidence interval [CI] = 39‐309 versus 298, 95% CI = 85‐314 days, respectively) were not significantly different (P = .78). Right atrial area (hazard ratio [HR] = 2.72, 95% CI = 1.58‐4.70), TAPSE < 3.23 mm/kg0.284 (HR = 2.19, 95% CI = 1.28‐3.74), and right heart failure (HR = 2.05, 95% CI = 1.18‐3.57) were independently associated with shorter survival time (P ≤ .04). Conclusions and Clinical Importance Right atrial area, RV function (TAPSE < 3.23 mm/kg0.284), and right heart failure offer clinically relevant prognostic information in dogs with PH. Results support the quantitative assessment of right heart size and function in dogs with PH.

RATIONALE AND OBJECTIVES:To establish a proof-of-principle for combined assessment of pulmonary ventilation and perfusion using single-energy computed tomography (CT) and image processing/analysis (denoted as single-energy CT ventilation/perfusion imaging). MATERIALS AND METHODS:Breath-hold CT scans were acquired at end-expiration and end-inspiration before injection of iodinated contrast agents, and repeated at end-inspiration after contrast injection for 17 canines (8 normal and 9 diseased lung subjects). Ventilation images were calculated with deformable image registration to map the end-expiratory and end-inspiratory CT images and quantitative analysis for regional volume changes as surrogates for ventilation. Perfusion images were calculated by subtracting the end-inspiratory precontrast CT from the deformably registered end-inspiratory postcontrast CT, yielding a map of regional Hounsfield unit enhancement as a surrogate for perfusion. Ventilation-perfusion matching, spatial heterogeneity, and gravitationally directed gradients were compared between two groups using a Wilcoxon rank-sum test. RESULTS:The normal group had significantly higher Dice similarity coefficients for spatial overlap of segmented functional volumes between ventilation and perfusion (median 0.40 vs. 0.33, p = 0.05), suggesting stronger ventilation-perfusion matching. The normal group also had greater Spearman's correlation coefficients based on 16 regions of interest (median 0.58 vs. 0.40, p = 0.09). The coefficients of variation were comparable (median, ventilation 0.71 vs. 0.91, p = 0.60; perfusion 0.63 vs. 0.75, p = 0.27). The linear regression slopes of gravitationally directed gradient were also comparable for ventilation (median, ventilation -0.26 vs. -0.18, p = 0.19; perfusion -0.17 vs. -0.06, p = 0.11). CONCLUSION:These findings provide proof-of-principle for single-energy CT ventilation/perfusion imaging.

Case summary An 8-year-old neutered male indoor cat was presented for evaluation of a year-long history of swelling over the bridge of the nose that extended from the subcutaneous tissue of the right upper eyelid to the dorsum of the skull. Intermittent regression of the mass lesion was reported with antibiotic or corticosteroid therapy; however, progressive swelling, malaise and hiding behavior persisted. CT revealed an aggressive osteolytic mass lesion in the right and left nasal cavities and extending into the frontal sinuses. Rhinoscopy using a 2.8 mm rigid telescope revealed somewhat normal-appearing turbinates rostrally and ventrally on the left side, with turbinate destruction on the right. After obtaining a biopsy from the right side of the nasal cavity, thick material filling the entire nasal cavity was visible caudally and was extracted endoscopically from a rostral approach. Surgical biopsy of the dorsal nasal bridge resulted in protrusion of inspissated material from the incision site. Rhinoscopic exploration revealed that the material extended into both frontal sinuses. Following extensive debridement and medical therapy, marked resolution of facial asymmetry was achieved. Relevance and novel information Facial distortion is often considered suggestive of a neoplastic process; however, it can also be seen with fungal and mycobacterial infections, and, in this case, an inflammatory condition of unknown etiology. In this cat, aggressive intervention and debridement of necrotic debris resulted in substantial bony remodeling of the skull and return to normal activity levels.

Background: Eosinophilic airway disease in cats is sometimes described as allergic in origin, but controversy exists in the documentation of allergy in cats and the utility of allergy testing for respiratory tract diseases. Objective: To examine serum immunoglobulin E (IgE) response to aeroallergens in cats with airway eosinophilia. Animals: Fifteen cats with idiopathic eosinophilic airway inflammation and 9 control cats. Methods: Prospective, case-control study. Surplus serum from cats with airway eosinophilia documented by bronchoscopic bronchoalveolar lavage was submitted for IgE measurement using ELISA polyclonal antibody methodology. Responses for regional allergens (fungal organisms, weeds, grasses, trees, mites, insects) were assessed. Results were reported as ELISA absorbance units with scores 0 to 79 considered negative, scores between 80 and 300 considered intermediate, and scores >300 considered positive. Results: Cats with airway eosinophilia had significantly more positive serum IgE responses (25/720) than did healthy controls (5/432, P = .02); however, the number of cats with positive IgE responses (5/15) did not differ from controls (1/9, P = .35). The allergen that most commonly resulted in positive serum IgE response in cats with airway eosinophilia was dust mite (n = 4) followed by 2 types of storage mites (n = 3 each). No control cat tested positive for these allergens. Conclusions and Clinical Importance: Serum IgE production against aeroallergens was found in some cats with eosinophilic airway inflammation, but the number of affected cats with positive results did not differ from controls. Further investigation in cats with eosinophilic, mixed, and neutrophilic airway disease in comparison to control cats is warranted.

Abstract Background Aspiration pneumonia (AP) and bronchopneumonia (BP) are poorly characterized diseases in cats that share clinical similarities to inflammatory airway disease (IAD). Objectives Describe clinicopathologic, radiographic, and microbiologic features in cats with AP and BP and compare findings to those in cats with IAD. Animals Thirty‐three cats with AP and 26 with BP; 44 cats with IAD. Methods Retrospective case‐control study. Results extracted for all cats included signalment, physical examination findings, historical details, and potential risk factors for aspiration. Diagnostic test results were summarized including CBC, bronchoalveolar (BAL) fluid analysis and microbial culture. Radiographs were reviewed in masked fashion and scored for severity. Results of BAL fluid analysis were assessed for evidence of septic inflammation. Results Cats with AP were less likely to be presented for evaluation of cough (P < .001) and more likely to be hypothermic (P = .01) than were cats with IAD or BP. Median duration of signs was significantly shorter in cats with AP (12 days) compared to cats with BP or IAD (270 and 180 days; P = .01). Radiographically, cats with AP were more likely to have an alveolar pattern and higher total score than were cats with BP or IAD. Mycoplasma spp. were the organisms most commonly cultured from BAL fluid in cats with BP, but were not cultured from any cats with AP. Conclusion and Clinical Importance Pneumonia must be distinguished from IAD in cats with cough and AP should be considered in cats with acute onset of tachypnea.