HISTORY
A 42-day-old female Poodle dog was presented for anorexia and lethargy. The abdomen appeared painful and was distended. The owner had related that the animal was unable to nurse. Dyspnea, hypothermia and moderate dehydration were present. The percussion revealed a massive sound. Sonographic examination of the abdomen revealed many hypoechoic lesions with well-circumscribed irregular margins in the right caudoventral portion of the liver. There was a mild to severe presence of hypoechoic fluid free in the abdominal cavity. The signs were so severe that the dog died just after the exam, probably by sepsis.
At necropsy, the liver was slightly enlarged, with many abscess on both serosal and cut serosal found at the right lobes. Histologic findings included multiple focal abscesses in the liver. The material from the hepatic lesions was submitted for bacteriologic culture, and Edwardsiella ictaluri was isolated.
DISCUSSION
Hepatic abscesses from bacterial infection of the liver occur rarely in dogs and cats. When pre-sent, they occur most frequently in puppies as a sequela to omphalophlebitis. Hepatic abscess in a adult dogs are usually associated with extrahepatic infection or hepatic parenchymal damage due to trauma or neoplasia. Clinical signs in these dogs were nonspecific and similar to signs in dogs with other hepatic diseases. X-ray and ultrasonography are valuable diagnostic method. Laboratory tests usually indicate neutrophilia and a left shift, but with overwhelming sepsis, as occurs with rupture, a neutropenia and degenerative left shift might be found. Alanine aminotransferase activity is significantly increased. Staphylococci are the most common organisms associated with hepatic abscesses, although other bacterial species including E. coli, Salmonella sp., Nocardia asteroides, Clostridium sp. and Bacteroides fragilis have been isolated. Dogs immunocompromise secondary to diabetes may have been a predisposing factor. It has been postulated that a hyperglycemic state may precipitate infection with Listeria monocytogenes in domestic mammals.
Edwardsiella ictaluri was isolated by HAWKE from river catfish which had developed a septicemic disease, which he termed ESC (enteric septicaemia of catfish). E. ictaluri can be isolated from water. Other bacteria of genus Edwardsiella has been implicated in infection in birds, cattle and swine. In humans, E. tarda has been associated with gastroenteritis, abscesses and meningitis.
Countless bacteria are isolated from food products or pet food due to failure on food-processing steps and storage of commercial products that utilize, for example, fishmeal and fresh fish. It can to characterize contamination vehicle to the animals, as human can to become fomite of infection during pet feeding. This hypothesis suggests that the infection has alimentary origin, and the organism reached to the liver via the portal vein.
Treatment of liver abscess involves surgical drainage combined with appropriated antibiotic therapy. Antimicrobial treatment for liver abscesses should be broad spectrum and bactericidal.