Pathological and Blood Biochemical Findings on Uric Acid Lithiasis of the Urinary Tract in Newborn Piglets

Abstract

With the objective of elucidating the etiology of uric acid calculi of the urinary tract in newborn piglets, 28 healthy newborn piglets and 21 weak newborn piglets, which were born in the winter months, were investigated.Clinically, yellow diarrhea was observed in 10 of the weak newborn piglets. Autopsy of these piglets revealed pale pink, fine granular calculi in the renal pyramids and papillae in 8 piglets, and abnormalities, such as petechial hemorrhage and edema in the kidneys, as well as discoloration of the liver, in 5 piglets. histopathological studies were conducted on the liver, kidney, sternal bone marrow, and spleen. Calculi were present in the tubular lumina without obstructing the tubules, and were identified as uric acid calculi by a staining of Saint-Hilaire method. However, the relationship between the calculi and the histopathological abnormalities could not be determined.A blood biochemical study on the weak piglets revealed a low value of serum albumin and high values of GOT, GPT, creatinine, BUN, uric acid, lactic acid, and inorganic phosphorus.In addition, one week after delivery, the serum total protein level and the hepatic uricase level were lower than normal levels.On the basis of the above findings, uric acid calculi of the urinary tract in weak newborn piglets which were born in the winter months is surmised to be induced by the combined action of 1) factors peculiar to newborn piglets, such as hepatic hypofunction, a low uricase level in the liver, acidosis, renal hypofunction, and increased catabolism of protein accompanying hypoalimentation, and 2) bad conditions for health, such as diarrhea and cold.

Purine Metabolism of Uric Acid Urolithiasis Induced in Newborn Piglets.

“…These diseases are ascribed to extraordinary activities of the enzymes, and they are manifested as uricemia, uricosuria and uric acid stones. There are a few studies dealing with xanthine oxidase and uricase in newborn piglets [7,8]. In swine, hypoxanthine and xanthine are metabolized to uric acid by xanthine oxidase, and the uric acid is metabolized to allantoin by uricase [2,5].…”

“…There have been several clinical investigations of this disease [6,8,17] since Madsen et al [11] made the first report of clinical cases in 1944. Although these studies have suggested, as predisposing factors for this disease, viral infection [6], a low level of uricase activity in the liver [7,11], colds [7], starvation [11] and an excess of purine metabolism [8], the determinable etiology has not been demonstrated. We previously investigated the incidence of the uric acid stones in the kidneys of the newborn piglets at necropsy [9], and found that 108 of 1,338 piglets died within 18 days of age and uric acid stones were present in 13.0% of the dead piglets mostly with low body weight.…”

Über die postnatale Entwicklung des porcinen Purinkatabolismus und den Einfluß der Umgebungstemperatur auf den Turnover*

“…Nach neueren Berichten starben 230 von 1100 lebend geborenen Ferkeln in den ersten 2-19 Tagen (MAHANTA u. CHAUDHURY, 1988), 60 davon wiesen Harnsauresedimente in den Harnwegen auf, das sind 26,08 % aller Todesfalle. Nach anderen Beobachtungen (KAKINO et al, 1991) waren bei 8 von 21 an allgemeiner Schwache gestorbenen Ferkeln Harnsaureabscheidungen in den Nierentubuli festzustellen.…”