Air leak syndrome in animals: definition and pathogenesis.

Air leak syndrome (ALS) is described in human medicine as a constellation of clinical disorders including pneumomediastinum, pneumopericardium, pulmonary interstitial emphysema, pneumothorax, pneumoperitoneum, pneumoretroperitoneum and subcutaneous emphysema. The pathogenesis of ALS depends on the anatomy of the mediastinum and its associations with thoracic, abdominal and cervical connective tissues, as well as a physical phenomenon referred to as the Macklin effect. Various animal species develop diverse combinations of these lesions, although ALS has not been recognized in animals. However, this term aids pathologists in addressing this disease compilation. The aim of this retrospective study is to illustrate examples of ALS in animals by arbitrarily selecting 13 cases in dogs, cats, pinnipeds, sea otters and harbour porpoises. ALS can be classified into three groups based on aetiology: iatrogenic, secondary or spontaneous. Iatrogenic ALS was diagnosed in two cats with tracheal laceration following endotracheal intubation. Secondary ALS was identified in two dogs, one with acute respiratory distress syndrome and the other due to grass awn migration. Secondary ALS in pinnipeds was diagnosed following severe pulmonary parasitism, uraemic pneumonia and oesophageal perforation. The other marine mammals developed ALS following trauma. Spontaneous ALS was also diagnosed in one cat and one dog without any apparent predisposing causes.

Causes of cetacean stranding and death on the Catalonian coast (western Mediterranean Sea), 2012-2019.

The causes of cetacean stranding and death along the Catalan coast between 2012 and 2019 were systematically investigated. Necropsies and detailed pathological investigations were performed on 89 well-preserved stranded cetaceans, including 72 striped dolphins Stenella coeruleoalba, 9 Risso's dolphins Grampus griseus, 5 bottlenose dolphins Tursiops truncatus, 1 common dolphin Delphinus delphis, 1 Cuvier's beaked whale Ziphius cavirostris and 1 fin whale Balaenoptera physalus. The cause of death was determined for 89.9% of the stranded cetaceans. Fisheries interaction was the most frequent cause of death in striped dolphins (27.8%) and bottlenose dolphins (60%). Cetacean morbillivirus (CeMV) was detected on the Catalan coast from 2016 to 2017, causing systemic disease and death in 8 of the 72 (11.1%) striped dolphins. Chronic CeMV infection of the central nervous system was observed from 2018-2019 in a further 5 striped dolphins. Thus, acute and chronic CeMV disease caused mortality in 18% of striped dolphins and 14.6% of all 89 cetaceans. Brucella ceti was isolated in 6 striped dolphins and 1 bottlenose dolphin with typical brucellosis lesions and in 1 striped dolphin with systemic CeMV. Sinusitis due to severe infestation by the nematode parasite Crassicauda grampicola caused the death of 4 out of 6 adult Risso's dolphins. Maternal separation, in some cases complicated with septicemia, was a frequent cause of death in 13 of 14 calves. Other less common causes of death were encephalomalacia of unknown origin, septicemia, peritonitis due to gastric perforation by parasites and hepatitis caused by Sarcocystis spp.

Fatal Photobacterium damselae-induced enteritis in a leatherback turtle Dermochelys coriacea.

Stranded leatherback turtle Dermochelys coriacea complete pathology reports are rare, and the cause of mortality is difficult to determine in many cases. We conducted a complete pathological study of a stranded leatherback turtle from the western Mediterranean. The main finding was a fibrino-necrotizing enteritis with associated bacteria which were identified as Photobacterium damselae subsp. damselae according to biochemical and phenotypical characteristics. This report provides evidence of the pathogenic effect of this bacterium in wild sea turtles.

Hypercalcemia of Malignancy in a Dog Diagnosed With Cholangiocellular Carcinoma.

A 4-year-old, neutered male Golden Retriever was presented with a 1-week history of weight loss, polyuria, and polydipsia. The diagnostic workup showed an increased ionized calcium concentration, mild increase in serum creatinine and urea concentration, and severe hyperlipasemia. A complete abdominal ultrasound revealed multiple hepatic nodules. A cytological diagnosis of malignant epithelial neoplasia, highly suggestive of bile duct adenocarcinoma was made. In order to confirm the presumptive diagnosis of hypercalcemia of malignancy due to the presence of a hepatic neoplasia, serum parathormone-related peptide concentration was measured, and the result revealed an increased concentration. The dog was hospitalized and received supportive treatments consisting of intravenous furosemide and fluid therapy. After ruling out lymphoma and hypoadrenocorticism, oral prednisone was initiated and ionized calcium concentration decreased gradually down to normal concentration after 7 days of hospitalization. Chemotherapy with intravenous epirubicin was initiated based on the cytological diagnosis. One month after diagnosis and due to the worsening of its clinical condition, the dog was humanely euthanized. Postmortem examination confirmed a cholangiocellular carcinoma. To our knowledge, this is the first report of malignant hypercalcemia associated with cholangiocellular carcinoma in a dog.

Coinfection with Entamoeba polecki and Brachyspira hyodysenteriae in a pig with severe diarrhea.

Enteric disease in pigs is usually of multifactorial etiology, including infectious and non-infectious factors. In many cases of endemic diarrhea in weaner-to-finisher pigs, the combination of 2 or more microorganisms leads to aggravation of intestinal lesions and, consequently, clinical signs. We autopsied a 4-mo-old fattening pig with diarrhea and diagnosed severe fibrinonecrotizing typhlocolitis. Numerous spiral-shaped bacteria and amoeba-like PAS-positive protozoa were observed in the cecal and colonic mucosa and submucosa. Brachyspira hyodysenteriae was detected by PCR from colonic content. By in situ hybridization, large numbers of Entamoeba polecki were found within the lamina propria and submucosa; moderate numbers of Blastocystis sp. and scattered trichomonads were present in intestinal content. In addition, Entamoeba polecki, Balantidium spp., Blastocystis sp., and Trichomonas sp. were also detected by PCR.