LUNG INJURY LEADING TO RESPIRATORY-DISTRESS SYNDROME IN YOUNG DALMATIAN DOGS

A progressive pulmonary disease resulting in severe respiratory failur e and death in an average of 3 weeks was diagnosed in 11 young Dalmati an dogs. The dogs were from 4 litters, all genetically related by a co mmon ancestor. The initial clinical signs were tachypnea and noisy res piration. Respiratory distress developed shortly before death and was characterized by strenuous and rapid respirations, along with cyanosis and vomiting, On blood gas analysis, there were severe arterial hypox emia, hypercapnia, and marked alveolar-arterial oxygen difference, Rad iographically, a diffuse pattern of alveolar, interstitial, and peribr onchial densities was observed in the lungs. Most dogs developed pneum omediastinum and gastroesophageal intussusception in the terminal phas e of the disease. There was no response to treatment with antibiotics, corticosteroids, diuretics, or oxygen. At necropsy, the lungs were we t. heavy, and relatively airless. Absence of 1 kidney in 2 dogs and se vere internal hydrocephalus in 2 dogs were additional necropsy finding s, Pulmonary histopathology included metaplasia and atypia of the alve olar and bronchiolar epithelium, a nonpurulent inflammatory reaction c haracterized mainly by mononuclear cells and macrophages. eosinophilic hyaline membrane formation, and focal pulmonary fibrosis, The histolo gical manifestations were typical of acute lung injury. Clinically, th e findings were consistent with adult respiratory distress syndrome (A RDS), except for the relatively long course. No known risk factors for ARDS, such as trauma, toxin exposure, infection, or endotoxemia could be identified. The relationship of the other abnormalities (ie, renal aplasia, hydrocephalus) to the pulmonary disease also remains obscure , An inherited defect is suspected, because segregation analysis of th e 4 litters suggests autosomal recessive inheritance. Copyright (C) 19 95 by the American College of Veterinary Internal Medicine.