A Retrospective Study on Bacteriology, Clinicopathologic and Radiographic Features in 28 Cats Diagnosed with Pyothorax

Pathological findings and patterns of feline infectious peritonitis in the respiratory tract of cats

Feline infectious peritonitis (FIP) is an important cause of death in cats. Thoracic manifestations are less common than abdominal manifestations, and FIP-associated respiratory disease is poorly documented. This study aimed to investigate pathological findings in the respiratory tract of cats with FIP and the occurrence and distribution of feline coronavirus antigen in the respiratory tract using immunohistochemistry. A retrospective study was carried out on 112 cats with FIP, of which 66 had inflammatory histological lesions in the respiratory tract (58.9%) and were included in this study. Three major gross patterns were defined: marked fibrin deposition in the thoracic cavity with lung atelectasis; marked fibrin deposition in the thoracic cavity with lung pyogranulomas; and lung pyogranulomas without thoracic effusion. Histological analysis revealed primary lesions in the visceral pleura and lung parenchyma at a similar frequency, with multifocal to diffuse presentations. Marked lesions were commonly observed. Five major histological patterns were defined: pleuritis; pleuritis and vasculitis/perivascular injury in the lung parenchyma; pleuritis and pneumonia; perivascular injury in the parenchyma without pleuritis; and pneumonia without pleuritis. In the pleura and pulmonary parenchyma, FIP virus antigen was detected in perivascular and peribronchial macrophages and in macrophages within bronchial-associated lymphoid tissue and foci of necrosis and inflammation in the pleura and lung parenchyma. Co-infections with retroviruses were detected in 47 cats (71.2%), mainly with feline leukemia virus (62.2%). Although FIP is a systemic disease, some cats developed significant lesions in the thoracic cavity, including involvement of the upper respiratory tract and presenting respiratory signs, without other classic signs of FIP. This work advances our knowledge of FIP in the respiratory system, helping veterinarians to recognize the various presentations of this disease.

A Retrospective Comparative Evaluation of Selected Blood Cell Ratios, Acute Phase Proteins, and Leukocyte Changes Suggestive of Inflammation in Cats

Neutrophil-to-lymphocyte (NLR), monocyte-to-lymphocyte (MLR), and platelet-to-lymphocyte (PLR) ratios have been proposed as diagnostic and prognostic markers for neoplastic and inflammatory diseases in dogs and cats. The aim of this retrospective preliminary study was to evaluate the relationship between these ratios and markers of inflammation routinely measured in cats. A total of 275 cats were enrolled. Complete blood count, serum amyloid A (SAA), albumin, globulin, and albumin-to-globulin ratio (AGR) data were analyzed, as well as the presence of leukocyte alterations considered suggestive of inflammation (LAI: neutrophils left shift, toxic neutrophils, and reactive lymphocytes) evaluated in blood smears. The NLR and MLR correlated positively with SAA and globulins and negatively with albumin and AGR. Higher NLR and MLR were found in cats with increased SAA and globulins and decreased albumin and AGR. The PLR correlated negatively with albumin and AGR. A higher PLR was found in cats with hypoalbuminemia. Cats with LAI had higher NLR, MLR, and PLR. In cats with no changes in parameters indicative of inflammation, 11.25, 0.42, and 528.3 were identified as upper limits for NLR, MLR, and PLR, respectively. In conclusion, the NLR, MLR, and PLR act as good inflammatory markers easily evaluated by routine hematology.

Pyothorax caused by Nocardia sp. in a cat - Case report

Nocardiosis is an infection caused by ubiquitous opportunistic bacteria and is rare in felines. In retrospective studies of the infection in the species, pyothorax was found in only about 5% of the cases described, with the most frequent forms being cutaneous and subcutaneous. This report describes Nocardia spp. as an etiologic agent of pyothorax in a feline leukemia virus (FeLV)-positive female cat. A 10-year-old female mixed-breed cat, positive for FeLV, with chronic kidney disease IRIS stage 2, was examined with a severe dyspneic onset, suspected of pleural effusion. It also had skin lesions in the interscapular region. The patient underwent thoracentesis, and a dense, creamy, fetid, and flocculated liquid was collected. Radiography was performed after draining the pleural fluid, which showed images suggestive of atelectasis of the left lung lobes and pneumonia. The collected material was sent for analysis, which found that it was a septic exudate. In addition, it was referred for bacterial culture in a special medium due to suspicion of nocardiosis. Long-term treatment with amoxicillin + clavulanic acid resolved the clinical case.

Therapy of Pyothorax in Cats via Small-Bore Thoracostomy Tube in Terms of Efficacy, Complications and Outcomes

Simple Summary

With this study we present our therapeutic strategy for cats with purulent fluid accumulation in the thorax. In addition to the systemic administration of antibiotics, the aim of the therapy is always the drainage of the purulent fluid from the thorax. For this purpose, we use a particular small-bore chest drain. The first aim of our study is to assess the efficacy and complication rate of our drainage. The second objective is to evaluate two treatment groups regarding their disease outcomes. We were able to show that our small-bore chest drain is similarly effective to the traditionally used large-bore drains. At the same time, we had a very low drain-associated complication rate. We detected no difference between the treatment groups and, thus, no effect on survival by early placement of bilateral drains into the thoracic cavity or lavage of the thoracic cavity with a heparinised solution. Our study supports the theory that drainage of purulent fluid from the thoracic cavity in cats can be performed with small-bore drains with good results and minimal risk of complications.

Abstract

First-line therapy for cats with pyothorax consists of intravenous antibiotics, drainage of the septic pleural effusion and closed-chest lavage. Large-bore thoracostomy tubes are traditionally used for drainage, but case series indicate a comparable efficacy using small-bore tubes. In this retrospective study, we describe a new technique of sheath-guided small-bore (6 F) thoracostomy tubes in cats with pyothorax and evaluate their efficacy and complications. Additionally, we compare outcomes between two treatment groups. Placement and use of the small-bore thoracostomy tubes described here has a low complication rate of 4% (3/67 tubes), and 53% (24/45) of the cats could be treated with thoracostomy tubes and closed-chest lavage according to the protocol. The success rate is reduced by 18% (8/45) due to deaths caused mainly by sepsis, 16% (7/45) due to structural diseases requiring surgery and a further 14% (6/43) due to lavage failures that could only be cured after additive therapy (thoracotomy or fibrinolysis). The long-term prognosis was very good, with a survival rate one year after discharge of 94% (30/32). We detected no effect on survival by early placement of bilateral thoracostomy tubes or closed-chest lavage with a heparinised solution. In conclusion, therapy of pyothorax with small-bore thoracostomy tubes is as successful as therapy with large- or medium-bore tubes.