Pneumonia In Dogs Research Articles

Clinical course and radiographic resolution of pneumonia in dogs treated with a shorter versus longer course of antimicrobials: a randomized, double-masked, placebo-controlled study.

To describe clinical and radiographic outcomes in dogs with uncomplicated pneumonia receiving a shorter (2-week) versus longer (4-week) duration of antimicrobial therapy. 30 client-owned dogs with radiographic evidence of pneumonia. Dogs were randomly assigned to either a 2-week course of antimicrobials followed by a 2-week course of placebo medication (2-week group) or a 4-week course of antimicrobials (4-week group). All study investigators and owners were masked to the treatment group. Dogs were reevaluated at 12 ± 2 days and again at 28 ± 2 days for a physical examination and thoracic radiography. Standard documentation at visits included owner-reported clinical signs, nurse-acquired history, the clinician's physical examination, the number of affected lung lobe segments, and the global radiographic severity scores assigned. Outcomes investigated included the persistence of clinical and radiographic signs of pneumonia. 28 dogs (93.3%) experienced complete resolution of clinical signs by the first visit, and no dogs in either group experienced relapse of clinical signs during the study period. Eighteen of 30 dogs (60%) and 25 of 30 dogs (83%) experienced complete resolution of radiographic lesions at the first and second study visits, respectively. The remaining 5 dogs (17%) had either stable (4 dogs) or continued (1 dog) improvement in radiographic lesions. Resolution of clinical and radiographic signs followed similar courses in dogs with uncomplicated pneumonia receiving a 2-week course of antimicrobials compared to a 4-week course. Clinical signs may be more useful for guiding discontinuation of antimicrobial therapy for pneumonia than radiographic signs.

Complete genome sequences of Mycoplasma cynos and Mycoplasma felis isolated from dogs and cats with infectious respiratory disease.

Mycoplasma cynos is a primary agent of pneumonia in dogs, and Mycoplasma felis is associated with upper respiratory tract disease in cats. We present complete genome sequences of 26 isolates from clinically affected dogs and cats. These genome sequences will facilitate new molecular and epidemiological analyses.

A lateral surgical approach to the larynx may impair cervical esophageal function in dogs.

To determine whether muscle-sparing laryngoplasty results in fewer changes in swallowing function compared to standard surgical treatment for laryngeal paralysis. 12 clinically normal sexually intact male Beagles. Group A dogs (n = 4) had a standard approach to the larynx, with left arytenoid cartilage lateralization. Group B dogs (n = 4) had a muscle-sparing laryngoplasty performed with the thyropharyngeus muscle fibers bluntly separated, and the cricoarytenoideus dorsalis muscle spared. Pre- and 24-hour postoperative fluoroscopic swallowing studies were performed and graded. Larynges were harvested after humane euthanasia, and glottic area was measured. Group C dogs (n = 4) acted as controls, with surgical dissection ending lateral to the thyropharyngeus muscle, arytenoid lateralization not performed, and the dogs not euthanized. The study was performed between October 15, 2011 and May 15, 2021. Changes in pharyngeal and upper esophageal sphincter function were not detected in any group. There was no difference in glottic area between treatment groups. Aspiration of liquid was not a consistent finding. Two dogs in each treatment group developed moderate to severe cervical esophageal paresis. This did not occur in control dogs. We found no evidence to support our hypothesis that muscle-sparing laryngoplasty results in less severe changes in swallowing function compared to a standard technique. The cervical esophageal paresis identified in both treatment groups could increase the risk of postoperative aspiration pneumonia in dogs treated for laryngeal paralysis via a lateral approach to the larynx. Further study to determine the frequency, cause, and duration of esophageal dysfunction is warranted.

Serial evaluation of thoracic radiographs and acute phase proteins in dogs with pneumonia.

BackgroundAcute phase proteins (APP) may guide treatment of pneumonia in dogs but correlations with radiographic abnormalities are poorly characterized.ObjectivesDevelop a thoracic radiographic severity scoring system (TRSS), assess correlation of radiographic changes with APP concentrations, and compare time to APP and radiograph normalization with duration of antimicrobials treatment.AnimalsSixteen client‐owned dogs, 12 with aspiration pneumonia, and 4 with community‐acquired pneumonia.MethodsConcentrations of C‐reactive protein (CRP), serum amyloid A (SAA), and haptoglobin were measured on days 1, 3, 7, 14, 28, and 60 and orthogonal 2‐view thoracic radiographs were obtained on days 1, 7, 14, 28, and 60. Treatment was clinician‐guided and blinded to APP concentrations. Radiographic severity scores were assigned by blinded, randomized retrospective review by 2 board‐certified radiologists with arbitration by a third radiologist.ResultsMedian (interquartile range [IQR]) time to normalization of CRP (7 days [7‐14]) and SAA concentrations (7 days [7‐14]) were shorter than antimicrobial treatment duration (17.5 days [14.5‐33.5]; P = .001 and .002, respectively) and TRSS normalization (14 days [8.8‐52], P = .02 and .02, respectively). The CRP and SAA concentrations were positively correlated with TRSS (CRP r s , 0.643; SAA r s , 0.634; both P < .0001). Both CRP and SAA identified normal thoracic radiographs area under the curve (AUC) 0.873 and 0.817, respectively, both P < .0001. Interobserver agreement for TRSS assignment was moderate (κ, .499; P < .0001).Conclusion and Clinical ImportanceConcentrations of CRP and SAA normalized before radiographic resolution and before clinicians discontinued antimicrobial treatment. The CRP and SAA concentrations may guide duration of antimicrobial treatment for dogs with pneumonia.

Anatomic characterization of the location of the esophageal ostium relative to the rima glottidis on CT in adult Labrador Retrievers.

To characterize the anatomic location of the esophageal ostium relative to the rima glottidis in adult Labrador Retrievers with the use of CT. 98 CT scans of 75 adult Labrador Retrievers. A search of the medical records database identified records of Labrador Retrievers that underwent CT of the head and neck between January 1, 2015, and December 31, 2018. Evaluators, blinded to each other's results, reviewed CT images and measured esophageal area at the level of the rima glottidis. For each dog, the left esophageal percentage (LEP) was calculated as the esophageal area left of the rima glottidis midline divided by the overall esophageal area at that level. Variables (age, sex, patient position, intubation status, and maxillary support during CT) were evaluated for association with LEP. The CT images of dogs that had multiple scans were assessed for within-patient variance. Mean LEP was 56.2 ± 18.1% for all dogs. Only right lateral recumbency was significantly associated with LEP, with a lower LEP for dogs positioned in right lateral recumbency (42.4 ± 12.7%), compared with left lateral (63.0 ± 7.4%) or sternal (57.3 ± 18.8%) recumbency. No association was detected between LEP and other variables assessed. Eleven dogs had multiple CT scans; within-patient variance for LEP was ± 26.6%. Results indicated that, although most dogs had an LEP > 50%, the esophageal ostium was fairly centrally located in most dogs and may be more mobile than previously thought. Additional research is warranted to assess this mobility and whether the esophageal ostium location, relative to the larynx, affects the incidence of aspiration pneumonia in dogs undergoing surgical treatment for geriatric-onset laryngeal paralysis and polyneuropathy.

Comparison of Short- versus Long-Course Antimicrobial Therapy of Uncomplicated Bacterial Pneumonia in Dogs: A Double-Blinded, Placebo-Controlled Pilot Study.

Simple SummaryDogs diagnosed with bacterial pneumonia are often treated with long courses of antibiotics (3–6 weeks) and chest X-rays are used to help guide the duration of treatment. This is in stark contrast with humans with the same disease who are often treated for 5–10 days, and chest X-rays are not considered to be useful for monitoring response to treatment. The main goal of this study was to determine whether a shorter course of antibiotics (10 days) would be sufficient to treat dogs with bacterial pneumonia. Eight dogs with pneumonia were randomly assigned to receive 10 or 21 days of antibiotics. They were evaluated at 10, 30 and 60 days after diagnosis. At 10 days, 6/8 dogs had resolution of both clinical signs and evidence of inflammation on bloodwork and 5/8 dogs showed improvement in the chest X-rays. After 60 days, none of the dogs had clinical signs or evidence of inflammation on bloodwork regardless of antibiotic therapy duration. However, 3/8 dogs showed changes in the chest X-rays. This study suggests that a 10-day course of antibiotics may be sufficient to treat dogs with bacterial pneumonia, and chest X-rays may not be a reliable marker to monitor response to therapy.Current treatment for canine bacterial pneumonia relies on protracted courses of antimicrobials (3–6 weeks or more) with recommendations to continue for 1–2 weeks past resolution of all clinical and thoracic radiographic abnormalities. However, in humans, bacterial pneumonia is often treated with 5–10-day courses of antimicrobials, and thoracic radiographs are not considered useful to guide therapeutic duration. The primary study objective was to determine whether a short course of antimicrobials would be sufficient to treat canine bacterial pneumonia. Eight dogs with uncomplicated bacterial pneumonia were enrolled in this randomized, double-blinded, placebo-controlled study comparing clinical and radiographic resolution with differing durations of antimicrobial therapy. Dogs received a course of antimicrobials lasting 10 (A10) or 21 (A21) days. Dogs randomized to the A10 group received placebo for 11 days following antimicrobial therapy. Patients were evaluated at presentation and 10, 30 and 60 days after the initiation of antimicrobials. At 10 days, 6/8 dogs had resolution of both clinical signs and inflammatory leukogram, and 5/8 dogs had improved global radiographic scores. After 60 days, clinical and hematologic resolution of pneumonia was noted in all dogs regardless of antimicrobial therapy duration; however, 3/8 dogs had persistent radiographic lesions. Thoracic radiographs do not appear to be a reliable marker to guide antimicrobial therapy in canine bacterial pneumonia as radiographic lesions may lag or persist despite clinical cure. This pilot study suggests a 10-day course of antimicrobials may be sufficient to treat uncomplicated canine bacterial pneumonia.

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

To describe clinical cases of aspiration pneumonitis and pneumonia in dogs, which were successfully managed without antimicrobials. 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. 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. 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.

Identification of ventilator‐associated pneumonia in dogs and evaluation of empiric antimicrobial therapy: 13 cases (2012–2016)

AbstractObjectiveTo evaluate criteria used for diagnosis of ventilator‐associated pneumonia (VAP) in dogs and to determine whether appropriate empiric antimicrobial therapy affects outcome.DesignRetrospective observational study from 2012 to 2016.SettingPrivate small animal emergency and specialty center.AnimalsThirteen client‐owned dogs requiring positive‐pressure ventilation for over 48 hours.Measurements and main resultsMedical records of dogs requiring mechanical ventilation (MV) were reviewed. Dogs receiving MV for over 48 hours that had endotracheal lavages (ETL) and thoracic radiographs performed both at initiation of MV and at 48 hours were included. Signalment, body weight, temperature, reason for MV, WBC count, cytology, and semiquantitative aerobic cultures obtained via ETL were recorded. Outcome was defined as survival to discharge or nonsurvival (euthanasia). Six patients (46.2%) were diagnosed with VAP based on the presence of a new bacterial isolate identified on ETL culture at 48 hours. All patients with VAP had new pulmonary infiltrates present on radiographs. The majority of patients with VAP had a leukocytosis (4/6; 66.7%). Six patients (46.2%) survived to discharge. Of the survivors, 3 of 6 (50%) had VAP.ConclusionsBacterial cultures should be obtained at initiation of MV and at 48 hours. A diagnosis of VAP should be suspected in patients that have a new bacterial isolate identified by ETL culture at 48 hours. Radiographic changes and an increase in WBC count may help support a diagnosis of VAP, while culture results are pending. Further studies are needed to evaluate the effect of appropriate antimicrobial therapy on patient outcome.

Respiratory Dysbiosis in Canine Bacterial Pneumonia: Standard Culture vs. Microbiome Sequencing.

It is unknown how the respiratory microbiome influences and is influenced by bacterial pneumonia in dogs, as culture of lung samples and not microbial sequencing guides clinical practice. While accurate identification of pathogens are essential for treatment, not all bacteria are cultivable and the impact of respiratory dysbiosis on development of pneumonia is unclear. The study purposes were to (1) characterize the lung microbiome in canine bacterial pneumonia and compare deviations in dominant microbial populations with historical healthy controls, (2) compare bacteria identified by culture vs. 16S rDNA sequencing from bronchoalveolar lavage fluid (BALF) culture-, and (3) evaluate similarities in lung and oropharyngeal (OP) microbial communities in community-acquired and secondary bacterial pneumonia. Twenty BALF samples from 15 client-owned dogs diagnosed with bacterial pneumonia were enrolled. From a subset of dogs, OP swabs were collected. Extracted DNA underwent PCR of the 16S rRNA gene. Relative abundance of operational taxonomic units (OTUs) were determined. The relative abundance of bacterial community members found in health was decreased in dogs with pneumonia. Taxa identified via culture were not always the dominant phylotype identified with sequencing. Dogs with community-acquired pneumonia were more likely to have overgrowth of a single organism suggesting loss of dominant species associated with health. Dogs with secondary bacterial pneumonia had a greater regional continuity between the upper and lower airways. Collectively, these data suggest that dysbiosis occurs in canine bacterial pneumonia, and culture-independent techniques may provide greater depth of understanding of the changes in bacterial community composition that occur in disease.

Long-term outcome and risk factors associated with death or the need for revision surgery in dogs with permanent tracheostomies.

To evaluate long-term outcomes and identify factors associated with death or the need for revision surgery in dogs with permanent tracheostomies (PTs). Retrospective cohort study. 69 client-owned dogs that received a PT between January 2002 and June 2016 at 1 of 4 veterinary teaching hospitals. Medical records were reviewed, and data extracted included signalment, history, clinical signs, radiographic and laryngeal examination findings, presence of esophageal abnormalities, date and reason for receiving a PT, postoperative complications, cause of death, and survival time. Dogs surviving < 2 weeks after receiving a PT were excluded. Major complications occurred in 42 of 69 (61%) dogs, with aspiration pneumonia (13 [19%]), skinfold occlusion (13 [19%]), and stoma stenosis (12 [17%]) being most common. Revision surgery was performed in 24 of 69 (35%) dogs, most commonly because of stoma stenosis or skinfold occlusion (9/24 [38%] each). Brachycephalic dogs were more likely (OR, 3.5; 95% confidence interval, 1.2 to 10.2) to require revision surgery than were nonbrachycephalic dogs. The overall median survival time was 1,825 days, and dogs that received corticosteroids before receiving a PT, had tracheal collapse, or were older had shorter survival times. Results of the present study indicated that creation of a PT was a viable treatment option for obstructive upper airway diseases in dogs and that long-term survival after receiving a PT was possible; however, a PT may not reduce the risk of aspiration pneumonia in dogs.

Effects of preoperative cisapride on postoperative aspiration pneumonia in dogs with laryngeal paralysis.

Retrospective evaluation of a preoperative prokinetic protocol using a constant-rate infusion of a serotonin 5-HT4 receptor agonist, cisapride, and its association with frequency of postoperative aspiration pneumonia in dogs undergoing unilateral arytenoid lateralisation as compared to a historical population at the same institution. Medical records of dogs undergoing unilateral arytenoid lateralisation for laryngeal paralysis were reviewed for historical findings, imaging findings, anaesthesia and surgery durations, perioperative medications and if surgery was performed as an emergency. Aspiration pneumonia events in the first 72 hours after surgery were recorded. The study group received a preoperative cisapride constant-rate infusion; historical 'controls' did not receive the cisapride protocol. One of 50 dogs in the cisapride group and six of 52 dogs in the historical group developed aspiration pneumonia within the immediate postoperative period. The cisapride protocol was largely well tolerated. A markedly lower rate of aspiration pneumonia in patients administered butorphanol with acepromazine preoperatively and buprenorphine postoperatively was noted, but the overall low frequency of aspiration pneumonia and variation in case management protocols precluded definitive conclusions with respect to optimal perioperative drug choices. Laryngeal paralysis is commonly treated by unilateral arytenoid lateralisation, and aspiration pneumonia is one of the most serious potential complications of this procedure. This study suggests that further investigation of a cisapride constant-rate infusion to prevent this complication is warranted.

Fungal pneumonia in dogs and cats with pulmonary clinical signs in southern Brazil

ABSTRACT: Fungal pneumonia has been a differential diagnosis in dogs and cats with pulmonary clinical signs, posting also a public health risk to respective owners. Since a common-source environmental exposure may result in infection, dogs and cats may also act as sentinels for both animal and human disease. Accordingly, the present study has aimed to evaluate the occurrence of fungal pneumonia in dogs and cats with pulmonary clinical signs from May 2013 to February 2015 in southern Brazil. Thoracic radiographs, blood work and non-bronchoscopic Bronchoalveolar Lavage (BAL), followed by cytology and microbiologic analysis were performed in all animals. One dog was positive in the BAL fluid culture for a pathogenic fungus (Cryptococcus neoformans) and another dog to an opportunistic fungus (Candida parapsilosis). Both dogs have presented cough as the prior clinical sign and showed thoracic radiographic changes. In conclusion, the occurrence of fungal pneumonia in southern Brazil in dogs and cats through of this study was relatively low. The BAL fluid culture may allow diagnosis of fungal pneumonia caused by opportunistic or pathogenic fungi and this diagnosis should be a concern in dogs and cats with pulmonary clinical signs.

Molecular diagnosis of Pneumocystis pneumonia in dogs.

Pneumocystis pneumonia (PCP) is a life-threatening fungal disease that can occur in dogs. The aim of this study was to provide a preliminary genetic characterisation of Pneumocystis carinii f.sp.'canis' (P. canis) in dogs and thereby develop a reliable molecular protocol to definitively diagnose canine PCP. We investigated P. canis in a variety of lung specimens from dogs with confirmed or strongly suspected PCP (Group 1, n = 16), dogs with non-PCP lower respiratory tract problems (Group 2, n = 65) and dogs not suspected of having PCP or other lower respiratory diseases (Group 3, n = 11). Presence of Pneumocystis DNA was determined by nested PCR of the large and small mitochondrial subunit rRNA loci and by a real-time quantitative polymerase chain reaction (qPCR) assay developed using a new set of primers. Molecular results were correlated with the presence of Pneumocystis morphotypes detected in cytological/histological preparations. Pneumocystis DNA was amplified from 13/16 PCP-suspected dogs (Group 1) and from 4/76 dogs of control Groups 2 and 3 (combined). The latter four dogs were thought to have been colonized by P. canis. Comparison of CT values in 'infected' versus 'colonized' dogs was consistent with this notion, with a distinct difference in molecular burden between groups (CT ≤ 26 versus CT range (26 <CT < 35), respectively). Phylogenetic analyses showed that P. canis is specifically 'canine' associated, being separated from other mammalian Pneumocystis species, thereby confirming the accuracy of qPCR amplicon for Pneumocystis in dogs. Using qPCR, Pneumocystis DNA can be detected in specimens from the respiratory tract and a CT value can be interpreted to distinguish infection versus colonization.

Effect of Metoclopramide on the Incidence of Early Postoperative Aspiration Pneumonia in Dogs with Acquired Idiopathic Laryngeal Paralysis.

Evaluate the effect of a perioperative intravenous continuous rate infusion (CRI) of metoclopramide on the incidence of aspiration pneumonia in the short term postoperative period in dogs undergoing unilateral arytenoid lateralization. Prospective, randomized, multi-center clinical trial. 61 client-owned dogs with idiopathic laryngeal paralysis and normal preoperative thoracic radiographs. All dogs underwent unilateral arytenoid lateralization with a uniform anesthetic, analgesic, and management protocol. Dogs in the treatment group received an intravenous CRI of metoclopramide for 24 hours perioperative. All dogs were assessed for clinical signs of aspiration pneumonia based on the results of physical examination and owner interview up to the point of suture removal (10-14 days postoperative). Any dog with suspected aspiration pneumonia had thoracic radiographs performed. Six dogs developed aspiration pneumonia in the short term postoperative period (2/28 control dogs and 4/33 treated dogs), accounting for an overall frequency of 10% with no significant difference between control and treated dogs. No variables measured in the study were significantly different between control and treated dogs. Perioperative metoclopramide, at the doses used in this study, did not affect the incidence of aspiration pneumonia in the short term postoperative period in dogs with idiopathic laryngeal paralysis undergoing unilateral arytenoid lateralization.

Risk factors for the development of aspiration pneumonia after unilateral arytenoid lateralization in dogs with laryngeal paralysis: 232 cases (1987-2012).

To identify risk factors for the development of aspiration pneumonia after unilateral arytenoid lateralization in dogs with laryngeal paralysis. Retrospective case series. 232 client-owned dogs with a diagnosis of laryngeal paralysis treated with left-sided unilateral arytenoid lateralization. Medical records were reviewed. Signalment, medical history, surgical complications, and outcome data were collected. Follow-up was performed via review of medical records and by telephone interview with the owner, referring veterinarian, or both. At the 1-, 3-, and 4-year follow-up periods, aspiration pneumonia occurred in 18.6%, 31.8%, and 31.8% of dogs, respectively. The 1-, 3-, and 4-year survival rates for dogs with postoperative aspiration pneumonia were 83.1%, 51.5%, and 25.8%, respectively. None of the dogs with aspiration pneumonia before surgery developed clinical signs of aspiration pneumonia after surgery. Postoperative megaesophagus (hazard ratio [HR], 2.58; 95% confidence interval [CI], 1.56 to 3.93) and postoperative administration of opioid analgesics prior to discharge (HR, 1.69; 95% CI, 1.12 to 2.80) were significant risk factors for the long-term development of aspiration pneumonia in this study. Perioperative metoclopramide administration did not significantly decrease the risk for development of aspiration pneumonia (HR, 0.94; 95% CI, 0.67 to 1.37). In the present study, aspiration pneumonia was the most commonly reported postoperative complication of unilateral lateralization in dogs treated for laryngeal paralysis; however, preexisting aspiration pneumonia was not associated with an increased risk for development of aspiration pneumonia after surgery. Megaesophagus was identified as an important risk factor for eventual development of aspiration pneumonia. Administration of an opioid analgesic may increase the risk of aspiration pneumonia in dogs treated surgically for laryngeal paralysis.

Retrospective study of diseases and associated pneumonia type diagnosed in dogs at post-mortem at Veterinary Teaching Hospital, Ibadan, Nigeria

The causes and types of pneumonia in dogs have not been accorded due attention in Nigeria. It is imperative to investigate the incidence and type of pneumonia commonly observed during post-mortem at the Department of Veterinary Pathology arm of the Veterinary Teaching Hospital, Ibadan, Nigeria. This investigation was carried out on 397 archival canine samples for dogs presented for necropsy at the Department of Veterinary Pathology, University of Ibadan, during the periods of 2000 - 2012. The gross diagnosis was obtained from the postmortem records while the specific type of pneumonia was by histopathology of selected lungs tissues, using standard techniques. Descriptive statistics was employed to evaluate the effect of age, sex, breed and the type of pneumonia. Alsatian(29%) and Rottweiler(14.4%) breeds of dogs were the common breeds of dogs encountered at post-mortem, and the dogs above 3 year old (51.9%) were the most affected, with leptospirosis (38.5%) being the most prevalent disease diagnosed, followed by neoplasia (13.49%) while infectious canine hepatitis was the least prevalent (0.5%). The histopathological diagnosis revealed that the pneumonic patterns were that of suppurative bronchopneumonia (75%), fibrinous bronchopneumonia (10%) and interstitial pneumonia, (15%). The diseases associated with the different pneumonia seen during the histopathological examination were leptospirosis, canine distemper, and left sided heart failure. Findings has shown that pneumonia in dogs were commonly associated with leptospirosis. In the course of this study, the histopathological lesions and changes associated with the pneumonia seen in the leptospirosis cases include alveolar haemorrhages, edema, neutrophils and macrophages in the alveolar spaces and neutrophils in small pulmonary vessels. In lieu of this, pneumonia could be a major contributory factor to death associated with leptospirosis in the cases reviewed.Keywords: Archival necropcy samples, Dogs, Incidence, Leptospirosis, Pneumonia

Pneumocystis canis pneumonia in dogs

Pneumocystis canis is a potential cause of life-threatening interstitial fungal pneumonia in dogs. It is seen almost exclusively in two canine breeds, miniature Dachshunds and Cavalier King Charles Spaniels (CKCS). Historically, Australian veterinarianshadakey role in thedocumentation of this entity and its conspicuous breed associations. Affected Dachshunds and CKCS are likely to have an inherited immunodeficiency that predisposes them to infection with this commensal organism of the respiratory tract and pharynx. A high index of suspicion is required tomake a timely diagnosis and save affected patients, as these dogs copepoorlywith anaesthesia andothermeasures to procure the specimens required to make a definitive diagnosis. Possible co-infection with Bordetella bronchiseptica must be considered when determining antimicrobial strategies. Affected dogs occasionally have a previous or concurrent history of generalised demodicosis. With early intervention, affected dogs can be saved, although some require lifelong therapy to prevent recurrence. The future challenge is to develop fast molecular techniques to diagnose P. canis pneumonia (PCP) and to determine the underlying immune defect in over-represented breeds through the rapidly advancing field of canine genomics.

Characterization of Pneumonia Due to Streptococcus equi subsp. zooepidemicus in Dogs

Streptococcus equi subsp. zooepidemicus has been linked to cases of acute fatal pneumonia in dogs in several countries. Outbreaks can occur in kenneled dog populations and result in significant levels of morbidity and mortality. This highly contagious disease is characterized by the sudden onset of clinical signs, including pyrexia, dyspnea, and hemorrhagic nasal discharge. The pathogenesis of S. equi subsp. zooepidemicus infection in dogs is poorly understood. This study systematically characterized the histopathological changes in the lungs of 39 dogs from a large rehoming shelter in London, United Kingdom; the dogs were infected with S. equi subsp. zooepidemicus. An objective scoring system demonstrated that S. equi subsp. zooepidemicus caused pneumonia in 26/39 (66.7%) dogs, and most of these dogs (17/26 [65.4%]) were classified as severe fibrino-suppurative, necrotizing, and hemorrhagic. Three recently described superantigen genes (szeF, szeN, and szeP) were detected by PCR in 17/47 (36.2%) of the S. equi subsp. zooepidemicus isolates; however, there was no association between the presence of these genes and the histopathological score. The lungs of S. equi subsp. zooepidemicus-infected dogs with severe respiratory signs and lung pathology did however have significantly higher mRNA levels of the proinflammatory cytokines tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), and interleukin 8 (IL-8) than in uninfected controls, suggesting a role for an exuberant host immune response in the pathogenesis of this disease.

Streptococcus zooepidemicus: An emerging canine pathogen

Streptococcus equi subsp. zooepidemicus (S. zooepidemicus) has caused several outbreaks of haemorrhagic pneumonia in dogs in recent years. This highly contagious and often fatal disease is characterised by sudden onset of clinical signs including pyrexia, dyspnoea and haemorrhagic nasal discharge. Post mortem examination typically reveals pulmonary haemorrhage and pleural effusion. Histopathology demonstrates fibrino-suppurative, necrotising and haemorrhagic pneumonia in most cases. The pathogenesis of S. zooepidemicus infection in dogs is incompletely understood. Bacterial virulence factors as well as host factors may contribute to the severe outcome. S. zooepidemicus occasionally causes zoonotic infections with potentially serious consequences. Canine vaccines for S. zooepidemicus are currently not available and prevention of the disease therefore relies on limiting bacterial spread by implementing stringent control measures in kennels. Further research, particularly sequence analysis of canine strains, is required to gain insights into epidemiology and pathogenesis of this emerging disease.

Necrotizing Pneumonia and Pleuritis Associated with Extraintestinal Pathogenic Escherichia Coli in a Tiger (Panthera Tigris) Cub

Extraintestinal pathogenic Escherichia coli (ExPEC) cause diseases in humans and animals, affecting organs outside the alimentary canal. In recent years, ExPEC have been reported as a cause of fatal pneumonia in dogs, cats, and in a horse. In the current report, a fatal case of pneumonia and pleuritis is described in a 4-week-old tiger (Panthera tigris) cub associated with ExPEC. The cub was presented with a sudden-onset respiratory illness and died after a few hours. Postmortem examination of the cub revealed an acute necrotizing pneumonia. The alveolar spaces were filled with large numbers of inflammatory cells (predominantly macrophages), edema, fibrin strands, and short bacillary bacteria. Escherichia coli O6:H31 was isolated in pure culture from the affected lung. It carried virulence genes cnf-1, sfa, fim, hlyD, and papG allele III, which are known to be associated with ExPEC strains. No evidence of infection by any other agent was detected. This is the first report, to the authors' knowledge, in which ExPEC has been associated with pneumonia in tigers.