A retrospective observational cohort study on the postoperative respiratory complications and their risk factors in brachycephalic dogs undergoing BOAS surgery: 199 cases (2019-2021).

OBJECTIVES: To observe the occurrence of postanaesthetic respiratory complications and to determine their prevalence and risk factors in dogs undergoing brachycephalic obstructive airway syndrome surgery. MATERIALS AND METHODS: Data from 199 clinical records were retrospectively analysed. Univariable logistic regression followed by multivariable logistic regression was used to identify associations between the dependent variables (set as the postoperative respiratory complications observed in the study dogs) and various independent covariates. The quality of model-fit was assessed using the likelihood ratio test. P≤0.05 was considered statistically significant. RESULTS: Four postoperative respiratory complications were observed: hypoxaemia (n=10/199; 5%), dyspnoea requiring tracheal re-intubation (n=13/199, 7%), dyspnoea requiring tracheostomy (n=10/199, 5%) and aspiration pneumonia (n=12/199, 6%). Univariable logistic regression showed an association between postoperative aspiration pneumonia and increasing body condition score and American Society of Anaesthesiology classification; however, when these covariates were evaluated in the multivariable model significance was not maintained. Risk factors for tracheostomy were preoperative and postoperative aspiration pneumonia (odds ratio: 9.52, 95% confidence interval: 1.56 to 57.93) and increasing brachycephalic obstructive airway syndrome grade (odds ratio: 4.65, 95% confidence interval: 0.79 to 27.50). CLINICAL SIGNIFICANCE: High brachycephalic obstructive airway syndrome grade and aspiration pneumonia, either developing peri-operatively or as pre-existing condition, may represent risk factors for postoperative tracheostomy. Preoperative diagnosis of aspiration pneumonia may further increase the risk of postoperative complications.

A One Health review of aerodigestive disease in dogs.

This review article seeks to define and describe aerodigestive disease in dogs, and review current and emerging methods of diagnostic evaluation. Aspiration of gastric contents into the respiratory tract is associated with the development and progression of numerous respiratory diseases in humans. In veterinary medicine the term "aspiration" is considered synonymous with "aspiration pneumonia" which, while frequently encountered, does not accurately reflect the breadth of aspiration associated respiratory syndromes (AARS). In the clinical veterinary literature, the effect of alimentary dysfunction on respiratory disease and vice versa (aerodigestive disease) is rarely investigated despite evidence in the human literature, animal models, and some studies and case reports linking alimentary and respiratory disease in small animals. Current methods of investigating aerodigestive diseases in veterinary patients are limited by inadeqate  sensitivity or specificity, potential for bias, cost, and availability. This necessitates investigations into advanced diagnostics to identify potentially underrecognized animals with AARS. Additionally, similarities in anatomy, physiology, and several disorders between dogs and humans, make experimental and naturally occurring canine models of AARS integral to translational research. Thus, evaluating dogs with aerodigestive disease might represent an area of substantial clinical relevance in human as well as veterinary medicine.

Computed tomographic findings in dogs with suspected aspiration pneumonia: 38 cases (2014-2019).

OBJECTIVES: To describe computed tomographic (CT) findings in dogs diagnosed with aspiration pneumonia and to assess for any correlation with patient outcome. MATERIALS AND METHODS: Retrospective analysis of 38 cases with a presumptive diagnosis of aspiration pneumonia at two UK referral centres. Medical records were reviewed for signalment, history, physical examination and clinicopathologic data. CT examinations of the thorax were reviewed by the European College of Veterinary Diagnostic Imaging board-certified radiologist for all dogs to describe the characteristics and distribution of the pulmonary lesions. RESULTS: The most common CT findings were lung lobe consolidation associated with air bronchograms (100%) followed by ground-glass attenuation (89.4%), bronchial wall thickening (36.8%), bronchiolectasis (31.5%) and bronchiectasis (15.7%). Large-breed dogs were overrepresented. Duration of hospitalisation ranged between 0 and 8 days (mean 3 days). Overall, 89.4% of dogs survived the aspiration event and were discharged from the hospital. The four dogs that did not survive to discharge had five or more lobes affected on CT. CLINICAL SIGNIFICANCE: CT findings in dogs with aspiration pneumonia are described. CT is a useful imaging modality to diagnose aspiration pneumonia.

Preliminary study evaluating the assessment of changes in pulmonary function associated with body positioning in dogs with suspected aspiration pneumonia.

OBJECTIVE: To evaluate the variability in arterial blood gas (ABG) assessment of pulmonary function with different body positioning in dogs with suspected aspiration pneumonia. KEY FINDINGS: The median differences in alveolar-arterial gradient, Pao2 , and Paco2 values in different recumbencies were not statistically significantly different, both within patients and across the study population. No difference was noted in ABG values in the subgroups with unilateral or bilateral disease or that were more affected on the right side versus the left side. SIGNIFICANCE: This preliminary study provides data that can be used to calculate appropriate sample sizes for subsequent studies investigating the impact of recumbency on pulmonary function in patients with aspiration pneumonia.

Impact of cytidine diphosphocholine on oxygenation in client-owned dogs with aspiration pneumonia.

BACKGROUND: New drugs for veterinary patients with acute respiratory distress syndrome (ARDS) are urgently needed. Early or late postinfection treatment of influenza-infected mice with the liponucleotide cytidine diphosphocholine (CDP-choline) resulted in decreased hypoxemia, pulmonary edema, lung dysfunction, and inflammation without altering viral replication. These findings suggested CDP-choline could have benefit as adjunctive treatment for ARDS in veterinary patients (VetARDS). OBJECTIVES: Determine if parenterally administered CDP-choline can attenuate mild VetARDS in dogs with aspiration pneumonia. ANIMALS: Dogs admitted to a veterinary intensive care unit (ICU) for aspiration pneumonia. METHODS: Subjects were enrolled in a randomized, double-blinded, placebo-controlled trial of treatment with vehicle (0.1 mL/kg sterile 0.9% saline, IV; n = 8) or CDP-choline (5 mg/kg in 0.1 mL/kg 0.9% saline, IV; n = 9) q12h over the first 48 hours after ICU admission. RESULTS: No significant differences in signalment or clinical findings were found between placebo- and CDP-choline-treated dogs on admission. All dogs exhibited tachycardia, tachypnea, hypertension, hypoxemia, hypocapnia, lymphopenia, and neutrophilia. CDP-choline administration resulted in rapid, progressive, and clinically relevant increases in oxygenation as determined by pulse oximetry and ratios of arterial oxygen partial pressure (Pa O2 mmHg) to fractional inspired oxygen (% Fi O2 ) and decreases in alveolar-arterial (A-a) gradients that did not occur in placebo (saline)-treated animals. Treatment with CDP-choline was also associated with less platelet consumption over the first 48 hours, but had no detectable detrimental effects. CONCLUSIONS AND CLINICAL IMPORTANCE: Ctyidine diphosphcholine acts rapidly to promote gas exchange in dogs with naturally occurring aspiration pneumonia and is a potential adjunctive treatment in VetARDS patients.

Antimicrobial discontinuation in dogs with acute aspiration pneumonia based on clinical improvement and normalization of C-reactive protein concentration.

BACKGROUND: Evidence regarding optimal treatment duration in dogs with aspiration pneumonia (AP) and the role of thoracic radiographs (TXR) and lung ultrasonography (LUS) in the long-term follow-up of affected dogs is lacking. C-reactive protein (CRP) is a reliable acute phase protein to monitor bacterial pneumonia in dogs. HYPOTHESIS: Investigate the safety of antimicrobial discontinuation based on clinical improvement and serum CRP normalization, as well as the usefulness of TXR and LUS for follow-up. ANIMALS: Dogs diagnosed with AP and treated with antimicrobials. METHODS: Prospective observational study. Antimicrobials were discontinued based on clinical improvement and serum CRP normalization after 1, 3, or 5 weeks. At each consultation, a quality-of-life questionnaire, physical examination, serum CRP, TXR, and LUS were assessed. Short- (2 weeks) and long-term (>1 month) follow-ups after treatment discontinuation were performed to monitor for possible relapses. RESULTS: Seventeen dogs were included. Antimicrobials were discontinued after 1 week in 12 dogs (70.6%) and 3 weeks in the remaining 5 dogs (29.4%). Short-term relapse was not observed in any dog and long-term relapse was diagnosed in 3 dogs. Thoracic radiographs and LUS were useful for diagnosis, but did not add additional information during follow-up, because image normalization lagged behind clinical improvement and serum CRP normalization. CONCLUSION AND CLINICAL IMPORTANCE: Dogs with AP can be safely and effectively treated using a short-term antimicrobial regimen discontinued after clinical improvement and serum CRP normalization. Imaging might still be useful for complicated cases with a less favorable response to treatment.

Acute aspiration pneumonia in common marmoset (Callithrix jacchus) with marmoset duodenal dilation syndrome: A case report.

A female common marmoset (Callithrix jachhus) suffered from weight loss exhibited tachypnea after anesthesia. We diagnosed marmoset duodenal dilation syndrome (MDDS) and aspiration pneumonia after post-anesthesia vomiting secondary to MDDS. If MDDS is suspected due to clinical symptoms such as weight loss, bloating, or vomiting, careful anesthesia and treatment of vomiting will be important to prevent aspiration pneumonia.

Comparison of lung ultrasound, chest radiographs, C-reactive protein, and clinical findings in dogs treated for aspiration pneumonia.

BACKGROUND: Comparison of clinical findings, chest radiographs (CXR), lung ultrasound (LUS) findings, and C-reactive protein (CRP) concentrations at admission and serial follow-up in dogs with aspiration pneumonia (AP) is lacking. HYPOTHESIS: Lung ultrasound lesions in dogs with AP are similar to those described in humans with community-acquired pneumonia (comAP); the severity of CXR and LUS lesions are similar; normalization of CRP concentration precedes resolution of imaging abnormalities and more closely reflects the clinical improvement of dogs. ANIMALS: Seventeen dogs with AP. METHODS: Prospective observational study. Clinical examination, CXR, LUS, and CRP measurements performed at admission (n = 17), 2 weeks (n = 13), and 1 month after diagnosis (n = 6). All dogs received antimicrobial therapy. Lung ultrasound and CXR canine aspiration scoring systems used to compare abnormalities. RESULTS: B-lines and shred signs with or without bronchograms were identified on LUS in 14 of 17 and 16 of 17, at admission. Chest radiographs and LUS scores differed significantly using both canine AP scoring systems at each time point (18 regions per dog, P < .001). Clinical and CRP normalization occurred in all dogs during follow up. Shred signs disappeared on LUS in all but 1 of 6 dogs at 1 month follow-up, while B-lines and CXR abnormalities persisted in 4 of 6 and all dogs, respectively. CONCLUSION AND CLINICAL IMPORTANCE: Lung ultrasound findings resemble those of humans with comAP and differ from CXR findings. Shred signs and high CRP concentrations better reflect clinical findings during serial evaluation of dogs.

Laryngeal Paralysis Following Endotracheal Intubation in a Dog: A Case Report.

The occurrence of laryngeal paralysis following endotracheal intubation in dogs is rare. A one-year-old canine was presented with aspiration pneumonia in the postoperative period following general anesthesia for acetabular denervation surgery. After a month of treatment for aspiration pneumonia, the patient had inspiratory stridor and dyspnea, and the diagnosis of unilateral laryngeal paralysis was made through laryngoscopy. Along with the benefits of endotracheal intubation come many risks. Laryngeal paralysis can be a serious complication, predisposing the patient to aspiration. This report is the second in veterinary medicine to describe laryngeal paralysis as a possible complication after endotracheal intubation in a dog.

Low incidence of postoperative nausea, vomiting, regurgitation, and aspiration pneumonia in geriatric dogs receiving maropitant, famotidine, and fentanyl as part of an anesthesia protocol.

OBJECTIVE: To determine the incidence of and potential risk factors for postoperative regurgitation and vomiting (PORV), postoperative nausea and vomiting (PONV), and aspiration pneumonia in geriatric dogs using premedication with maropitant and famotidine, intraoperative fentanyl, and postoperative fentanyl as part of an anesthetic protocol. ANIMALS: 105 client-owned geriatric dogs that underwent general anesthesia for a major surgical procedure between January 2019 and March 2020. PROCEDURES: Medical records were reviewed to collect data on signalment, historical gastrointestinal signs, American Society of Anesthesiologists (ASA) score, indication for surgery, duration of anesthesia and surgery, patient position during surgery, mode of ventilation, and perioperative administration of maropitant, famotidine, anticholinergics, opioids, colloidal support, NSAID, corticosteroids, and appetite stimulants. The incidence of postoperative regurgitation, vomiting, nausea, and aspiration pneumonia was calculated, and variables were each analyzed for their association with these outcomes. RESULTS: 2 of 105 (1.9%) dogs regurgitated, 1 of 105 (1.0%) dogs developed aspiration pneumonia, 4 of 105 (3.8%) dogs exhibited nausea, and no dogs vomited. Identified possible risk factors included older age (≥ 13 years old) for postoperative regurgitation, regurgitation for postoperative aspiration pneumonia, and high ASA score (≥ 4) for both regurgitation and aspiration pneumonia. CONCLUSIONS AND CLINICAL RELEVANCE: The use of an antiemetic protocol including maropitant, famotidine, and fentanyl in geriatric dogs resulted in very low incidences of PORV, PONV, and aspiration pneumonia. Future prospective studies are warranted to further evaluate and mitigate postoperative risks.

Respiratory complications in dogs with tetanus: A retrospective study of 53 cases.

Tetanus can lead to respiratory complications, and the outcome of dogs affected by this disease is still largely unknown. This retrospective study aimed to evaluate the frequency and outcome of 53 dogs with tetanus and respiratory complications between February 2006 and January 2019. Medical records from dogs diagnosed with tetanus admitted to a referral teaching hospital were reviewed. Fifty-three dogs were diagnosed with tetanus and respiratory complications were observed in 26.4% (14/53) of dogs; 8 developed aspiration pneumonia (AP), 5 developed upper airway obstruction (UAO) and 1 dog developed both. A total of 5 AP dogs were mechanically ventilated. Three dogs with UAO had tracheostomy tubes placed. Dogs with respiratory complications had a poorer outcome, with only 14.3% (2/14) surviving to discharge, compared to 94.8% (37/39) for dogs with no respiratory complications. Respiratory complications such as AP and UAO were common in dogs with tetanus, and this was associated with a poorer outcome.

Complications respiratoires chez des chiens affectés par le tétanos : une étude rétrospective de 53 cas. Le tétanos peut entrainer des complications respiratoires et les conséquences de celles-ci sur le pronostic vital du patient sont souvent inconnues. Cette étude rétrospective d'observation a pour but d'évaluer l'incidence et les conséquences de complications respiratoires chez 53 chiens affectés par le tétanos entre février 2006 et janvier 2019.Les dossiers médicaux de chiens ayant le tétanos et admis dans un hôpital de référence furent analysés. Cinquantetrois chiens furent diagnostiqués du tétanos et des complications respiratoires ont été observé dans 26,4 % (14/53) des cas; huit développèrent une pneumonie par aspiration (AP), 5 développèrent une obstruction des voies aériennes supérieures (UAO), un patient eut les deux. Trois patients avec une UAO reçurent une trachéostomie. Les patients avec des complications respiratoires avaient une évolution plus néfaste, avec seulement 14,3 % (2/14) qui survécurent jusqu'à la sortie de l'hôpital, comparativement à 94,8 % (37/39) pour les patients sans complications respiratoires. Les complications respiratoires chez les chiens souffrant du tétanos sont courantes et ces patients ont un pronostic vital plus mitigé.(Traduit par les auteurs).

Bacterial infection in dogs with aspiration pneumonia at 2 tertiary referral practices.

BACKGROUND: In dogs, antimicrobial drugs are widely prescribed for aspiration pneumonia (AP) despite poor documentation of bacterial infection in AP (b-AP) using bronchoalveolar lavage fluid (BALF) analysis. Interpretating discordant cytology and culture results is challenging, contributing to lack of a criterion standard, and highlighting differences between veterinary and human medical criteria for b-AP. OBJECTIVES: Determine how many dogs with AP had BALF collection and differences in diagnosis of b-AP using veterinary vs human medical criteria. Report findings of noninvasive markers (e.g. fever, band neutrophilia, radiographic severity score) in dogs with and without b-AP. ANIMALS: Retrospective cohort study of client-owned dogs (n = 429) with AP at 2 university veterinary hospitals. Twenty-four dogs met enrollment criteria. METHODS: Inclusion criteria were radiographic diagnosis of AP, ≥1 risk factor, CBC findings, and BALF cytology and culture results. Veterinary medical b-AP criteria were cytology findings compatible with sepsis with or without positive culture, or cytology findings not consistent with sepsis and positive culture (≥1.7 × 103  cfu/mL). Human medical b-AP criteria required culture with ≥104  cfu/mL or > 7% cells with intracellular bacteria on cytology. RESULTS: Only 24/429 dogs met all enrollment criteria; 379/429 dogs lacked BALF collection. Diagnosis of b-AP differed using veterinary (79%) vs human (29%) medical criteria. Fever, band neutrophils and high radiographic scores were noted in dogs with and without b-AP. CONCLUSIONS AND CLINICAL IMPORTANCE: Lack of routine BALF collection hampers definitive recognition of bacterial infection in AP. Differences in dogs meeting veterinary vs human medical definitions for b-AP and usefulness of noninvasive markers warrant further study to improve understanding of the role of bacteria in AP.

Successful management of aspiration pneumopathy without antimicrobial agents: 14 dogs (2014-2021).

OBJECTIVES: To describe clinical cases of aspiration pneumonitis and pneumonia in dogs, which were successfully managed without antimicrobials. MATERIALS AND METHODS: Retrospective case review of dogs presenting to a referral teaching hospital between February 2014 and February 2021. Cases were included when a clinical diagnosis of aspiration pneumopathy was made (requiring one or more of the following: radiographic evidence of an aspiration pneumopathy, endotracheal airway sampling consistent with aspiration and/or a positive endotracheal airway sample culture) which was not treated with antimicrobial therapy. RESULTS: Fourteen cases were identified of which nine had respiratory signs including increased respiratory rate or effort (n=8), arterial hypoxaemia (n=2), or a clinician-determined requirement for oxygen therapy (n=4). Where haematology was performed, five of nine displayed a normal neutrophil count with toxic changes, three displayed neutrophilia and one displayed neutropenia with toxic changes. Endotracheal airway sample cytology in four cases revealed neutrophilic inflammation with bacteria, plant material, yeasts and unidentified foreign material. Where respiratory signs were present, these resolved within 12 to 36 hours. CLINICAL SIGNIFICANCE: In this case series, immunocompetent dogs sustaining aspiration events, even with classical evidence of pneumonitis or pneumonia, have been managed successfully without antimicrobials. Radiography alone cannot be used to determine the requirement for antimicrobials. Better characterisation of the pathogenesis and clinical trajectory of aspiration pneumopathy is required, which may enable a reduction in inappropriate antimicrobial prescriptions.

Aerodigestive Disease in Dogs.

Aerodigestive disorders (AeroDs) in people encompass a wide range of clinical syndromes, reflecting the complex relationship between the respiratory and digestive tracts. In veterinary medicine, aspiration is used interchangeably with aspiration pneumonia. Although aspiration pneumonia is a common disorder in dogs, it does not reflect the breadth of AeroDs. Unfortunately, AeroDs rarely are investigated in veterinary medicine because of lack of clinical recognition, limitations in available diagnostics, and the fact that AeroDs may be caused by occult digestive disease. Recognizing patients with AerodD represents an area of significant clinical importance that may provide additional areas of clinical intervention.

Pulmonary complications in dogs with acute presentation of pancreatitis.

BACKGROUND: In humans, respiratory complications in patients with acute pancreatitis (AP) are a common life-threatening comorbidity. Since possible lung impairment has not been individually evaluated in canine AP, the aims of the present study were to: (1) describe the prevalence, types and severity of pulmonary complications in dogs with acute presentation of AP, and (2) evaluate their association with mortality. AP diagnosis was based on compatible clinical and laboratory parameters, abnormal canine pancreatic-lipase test, and positive abdominal ultrasound within 48 h from admission. The canine acute pancreatitis severity score (CAPS) was calculated for each dog at admission. Arterial blood gas analysis and thoracic radiography were performed at admission. Thoracic radiography was classified on the basis of pulmonary pattern (normal, interstitial or alveolar) and a modified lung injury score (mLIS) was applied to the ventrodorsal projections for each dog. VetALI/VetARDS were diagnosed using current veterinary consensus. Dogs were divided into non-survivors or survivors (hospital discharge). Clinical, radiological and blood gas parameters collected at presentation were compared between survivors and non-survivors and associated with mortality. RESULTS: This prospective cohort study included twenty-six client-owned dogs with AP. Twelve out of twenty-six dogs (46%) died or were euthanized. At admission, thirteen dogs showed respiratory distress at physical examination, which was associated with death (P < 0.001). Radiographic abnormalities were found in twenty-one dogs: alveolar (n = 11) and interstitial pattern (n = 10). Radiographic alterations and mLIS score were both associated with death (P = 0.02 and P = 0.0023). The results of the arterial blood-gas evaluation showed that non-survivors had lower PaCO2 and HCO3- levels, and higher A-a gradient than survivors (P = 0.0014, P = 0.019 and P = 0.004, respectively). Specifically, three dogs had aspiration pneumonia, and VetALI was diagnosed in nine dogs (34.6%), and no dogs met the criteria for VetARDS. The presence of VetALI was associated with mortality (P < 0.001). CONCLUSIONS: As with humans, possible lung impairments, such as VetALI, should be investigated in dogs with acute presentation of pancreatitis.

Nasogastric Intubation as Health and Safety Risk in Equine Practice-A Questionnaire.

Placing a nasogastric tube can be a life-saving act for a horse but is considered an occupational hazard for veterinarians. An online questionnaire was performed to assess and specify potential risks. 123 equine veterinarians completed the survey, and the majority admitted using the mouth to handle the end of the nasogastric tube (sucking or blowing air) and having accidentally swallowed or aspirated stomach content or medications. This can potentially lead to aspiration pneumonia or pneumonitis. Mineral oil seems to be especially dangerous as aspiration may be asymptomatic at the beginning and lipoid pneumonitis may develop. Furthermore, 60% of responders would also handle the tube with their mouth if the horse was presented with fever and diarrhea or reflux formation, which might be affected by Salmonella sp. or Clostridium difficile producing toxins. The fact that nasogastric tubes are rarely being disinfected increases the risk of infection. 50% of veterinarians would use their mouth to suck or blow air into the tube during nasogastric intubation, even if the patient was presented with suspected poisoning. Rodenticide zinc phosphide is particularly dangerous as its breakdown product is a highly toxic gas. Inhalation leads to serious symptoms in humans, including pulmonary edema and neurological signs. Alternatives to mouth use (lavage, big syringe, or suction pump) when passing a tube should be considered, especially if a patient is presented with duodenitis-proximal jejunitis, diarrhea, or suspected poisoning. Awareness needs to be raised among veterinarians that nasogastric intubation is an extremely hazardous occupational practice.

ASPIRATION BRONCHOPNEUMONIA BY ACINETOBACTER BAUMANNII IN A WILDLIFE EUROPEAN HARE (LEPUS EUROPAEUS) IN BRAZIL.

Acinetobacter baumannii is a major cause of illness in hospitalized patients and the most important and common pathogen in nosocomial outbreaks worldwide. In animals, A. baumannii has been associated with respiratory infections in a group of minks, leading to pneumonia and acute mortality. This report documents a case of aspiration bronchopneumonia in a wild European hare caused by A. baumannii. A free-ranging, adult male European hare was submitted to necropsy after acute trauma due to being hit by a car. Its lungs showed consolidation with abscess in the middle and cranial lobes. Histopathologic evaluation revealed liquefactive necrosis associated with neutrophilic infiltration, cellular debris, plant material, and bacterial myriads surrounded by moderate neutrophils, macrophages, multinucleated giant cells, lymphocytes, and plasma cell inflammation. Acinetobacter baumannii was isolated from lung tissue.