Renal pelvic rupture,intrapelvic haematoma and retroperitoneal haemorrhage associated with obstructive ureterolithiasis in a cat

A neutered female cat presented with a 9-day history of hyporexia and depression. The referring veterinarian had identified moderate non-regenerative anaemia, haematuria and suspected unilateral obstructive ureterolithiasis. Subsequent ultrasonography revealed moderate distension of the left renal pelvis with echogenic material, ureteral distension and ureterolithiasis. A partial ureteral obstruction was suspected. After 4 days of medical management, there was further distension of the renal pelvis with well-delineated echogenic material and an accumulation of perinephric fluid. A left nephroureterectomy was performed. Renal pelvic rupture with intrapelvic haematoma and retroperitoneal haemorrhage was confirmed by histopathology. Eighteen months following surgery, the cat remained clinically well with normal renal values.     

Tubulointerstitial nephritis causes decreased renal expression and urinary excretion of cauxin, a major urinary protein of the domestic cat

Cauxin, a member of mammalian carboxylesterases (EC 3.1.1.1), is excreted as a major urinary protein in the domestic cat. Urinary cauxin is derived from the kidney proximal straight tubules. Here, we report changes in the renal expression and urinary excretion of cauxin in cats with tubulointerstitial nephritis (TIN). Immunohistochemistry using anti-cauxin antibody showed fewer cauxin-positive tubules in 15 TIN cases than in normal animals. In areas with tubulointerstitial damage, fibroblasts and inflammatory cells replaced renal tubules, and cauxin-positive tubules consequently disappeared. Urine was analysed in six of the 15 cases. In the two cases with mild tubulointerstitial changes, urinary cauxin was detected using SDS-PAGE with Coomassie staining. In the four cases with severe tubulointerstitial changes, urinary cauxin was below the detection limit using Western blotting. These results indicate that the renal expression and urinary excretion of cauxin decrease with the progression of TIN in cats.     

Early detection of renal damage and disease in dogs and cats.

Renal damage and disease can be caused by acute or chronic insults to the kidney. Acute renal damage often results from ischemic or toxic insults and usually affects the tubular portion of the nephron. In contrast, chronic renal disease can be caused by diseases and/or disorders that affect any portion of the nephron, including its blood supply and supporting interstitium.Early detection of acute renal disease facilitates appropriate intervention that can arrest or at least attenuate tubular cell damage and the development of established acute renal failure. Similarly,early detection of chronic renal disease, before the onset of renal azotemia and chronic renal failure, should facilitate appropriate intervention that stabilizes renal function or at least slows its progressive decline.     

Nephropathy in young lambs

Renal disorders in lambs may be congenital, infectious, toxic, immunologically mediated or secondary to urethral obstruction. Congenital abnormalities are uncommon. Kidney infections often are only one aspect of more widespread diseases, for example, tick pyaemia or salmonellosis. Toxic diseases, which affect mainly the renal tubules, may be caused by bacterial, chemical or plant toxins, although in lamb nephrosis the cause is unknown. Immunecomplex glomerulonephritis is uncommon, and one form, mesangiocapillary glomerulonephritis of Finnish landrace lambs, is under genetic control. Urolithiasis may have secondary effects on the kidneys.     

Kidney pathology in non-obstructive urolithiasis in cattle

The objectives of the present study were to investigate the gross and histopathological findings in non-obstructive urolithiasis. Pathological examinations were carried out on 102 cattle kidneys with non-obstructive urolithiasis. The common gross lesions were cyst formations in the kidney lobes, hyperaemia and haemorrhage. The weight of the stones differed from 0.02 to 237.44 g and the colour changed brown to white. The calculi had different shapes. At histopathological examination of the kidneys slight to severe mononuclear cell infiltrations were commonly observed. Haemorrhage and connective tissue proliferations were also seen. Neutrophil leucocyte infiltrations caused by pyelonephritis were observed in some cases and multiple stone formations were found in these cases. Widening of the Bowman's space was a common histopathological finding especially when the stones were big or the inflammatory reaction was severe. Calcium deposits and eosinophylic material were found in the medullary tubules and pelvis renalis lumens in some kidneys. Giant cell formations around the stone reactions were rarely observed. Hyperplasia of the pelvis renalis and tubulus epithelium was another finding which occurred seldom. Whereas sand-like material accumulation seen in urinary bladders in some cases, no obstruction was observed in the urinary canal in this study.     

Experimental evaluation of urinary bladder marsupialization in male goats

OBJECTIVE: To evaluate the outcome of urinary bladder marsupialization in male goats. STUDY DESIGN: Prospective, experimental study. ANIMALS: Six healthy mixed-breed male goats. METHODS: After experimentally induced urethral obstruction, 6 male goats had urinary bladder marsupialization. Renal ultrasonography, complete blood count, and serum biochemical analysis were evaluated preoperatively (day 0), at 7 postoperative days, and then at 30-day intervals until 180 days. Stomal diameter was recorded immediately postoperatively and at each postoperative interval. Necropsy examination was performed on day 180 or when stomal stricture or death occurred. RESULTS: Stomal stricture occurred in 1 goat at 120 days. Another goat was found dead at 150 days; severe, suppurative cystitis was identified on necropsy. All goats had mild urine scald dermatitis. Serum biochemical values remained within normal limits, but significant decreases in white blood cell count, serum creatinine concentration, and stomal diameter occurred. At necropsy, all bladders were tubular in shape. Histological evidence of chronic suppurative cystitis and chronic, mild lymphoplasmacytic pyelitis occurred in all goats. Bacterial culture of renal tissue yielded growth in 3 goats, and bladder mucosal swabs yielded bacterial growth in all goats. CONCLUSIONS: Although clinical signs of ascending urinary tract infection were not observed in goats with patent stomata, urinary bladder marsupialization may result in ascending urinary tract inflammation or infection. CLINICAL RELEVANCE: Based on our results, urinary bladder marsupialization should be recommended with caution as the primary method for management of urinary tract obstruction in clinical cases.     

LESIONS OF THE RENAL PELVIS AND PROXIMAL URETER IN VARIOUS NEPHRO-UROLOGICAL CONDITIONS: AN ULTRASONOGRAPHIC STUDY

The applicability of ultrasonography was studied in the diagnosis of lesions of the renal pelvis and ureter in 10 dogs. Ultrasonographic findings of processes associated with dilatation and concretion formation in the renal pelvis were described and the differential diagnosis of the lesions was discussed. The authors propose a new classification system for judging processes characterized by dilatation of the renal pelvis. Experience suggests that ultrasonography is an effective procedure in the diagnosis of certain diseases of the upper urinary tract in dogs.     

Clinical evaluation of urinary liver-type fatty acid-binding protein for the diagnosis of renal diseases in dogs

Liver-type fatty acid-binding protein (L-FABP) is a biomarker for the early detection of renal diseases in humans. L-FABP is a cytotoxic oxidation product secreted from the proximal tubules under ischemic and oxidative stress conditions. First, L-FABP gene expression in the kidney and liver was evaluated. Next, the urinary L-FABP concentrations in dogs with or without renal diseases were measured using a novel enzyme-linked immunosorbent assay kit. Urinary L-FABP was normalized relative to urinary creatinine (uCre) concentrations (µg/g uCre). Finally, the relationships between urinary L-FABP and renal biomarkers used in canine medicine or serum alanine transaminase (ALT) as an indicator of liver damage were examined. Serum and urine samples from 94 client-owned dogs including 23 dogs with renal diseases and 71 dogs without renal diseases were used for analysis. Relative L-FABP gene expression was confirmed both in the liver and kidney. Dogs with renal diseases had a significantly higher urinary L-FABP than those without, and its predictive cutoff value was 26 µg/g uCre. Urinary L-FABP was significantly correlated with serum creatinine (r=0.4674, P<0.01), urea nitrogen (r=0.4907, P<0.01), urine specific gravity (r=−0.5100, P<0.01), and urine protein/creatinine ratio (r=0.7216, P<0.01), but not with serum ALT. Hence, dogs with a high urinary L-FABP value were more likely to have renal diseases.     

Guarded long-term prognosis in male cats with urethral obstruction

The aim of this study was to evaluate the course of urethral obstruction in cats. Forty-five male cats with urethral obstruction or lower urinary tract signs referable to urethral obstruction were included in the study. Follow-up information was gained by telephone interview in most cases and was available in 39 cats. Of the 22 cats with idiopathic urethral obstruction, eight (36%) re-obstructed after 3-728 days (median 17 days). Of 10 cats with urolithiasis, three (30%) re-obstructed after 10, 13 and 472 days, respectively. Of the seven cats with urethral plugs, three (43%) re-obstructed after 4, 34 and 211 days, respectively. Recurrent signs of lower urinary tract disease including obstruction were common in cats with urethral obstruction (20/39; 51%) and occurred in the same frequency irrespective of the primary cause of the obstruction. Recurrent obstruction (14/39; 36%) was the most common reason for euthanasia and was performed in 8/39 (21%) cats.     

PERIRENAL EFFUSION IN DOGS AND CATS WITH ACUTE RENAL FAILURE

Perirenal fluid accumulation has been described as an ultrasonographic feature of urine leakage, hemorrhage, abscessation, or neoplasia. The purpose of this retrospective study was to report perirenal effusion as an additional ultrasonographic finding in canine and feline patients with acute renal failure. The causes of acute renal failure in 18 patients included nephrotoxicity (4), leptospirosis (3), ureteral obstruction (2), renal lymphoma (2), ureteronephrolithiasis (2), prostatic urethral obstruction (1) and interstitial nephritis and ureteritis (1). An underlying cause was not identified in three patients. The sonographic finding of perirenal fluid was bilateral in 15 patients. Unilateral perirenal fluid was identified ipsilateral to the site of ureteric obstruction in two patients. Large effusions extended into the caudal retroperitoneal space. Additional sonographic findings suggestive of renal parenchymal disease included mild (5), moderate (5) or severe (2) pyelectasia, increased renal echogenicity (11), increased (9) or decreased renal size (2) and ureteral and/or renal calculi (3). There did not appear to be an association between the volume of perirenal fluid and the severity of renal dysfunction. All patients with large effusions underwent euthanasia. Perirenal fluid developing in acute renal failure is thought to be an ultrafiltrate associated with tubular back-leak into the renal interstitium that overwhelms lymphatic drainage within the perirenal and retroperitoneal connective tissues although obstruction to urine flow may also play a role. Localized perirenal retroperitoneal free fluid may be a useful ultrasonographic feature to assist with the characterization of, and determination of prognosis in, patients with suspected renal disease.     

Renal fibrosis in feline chronic kidney disease: Known mediators and mechanisms of injury

Chronic kidney disease (CKD) is a common medical condition of ageing cats. In most cases the underlying aetiology is unknown, but the most frequently reported pathological diagnosis is renal tubulointerstitial fibrosis. Renal fibrosis, characterised by extensive accumulation of extra-cellular matrix within the interstitium, is thought to be the final common pathway for all kidney diseases and is the pathological lesion best correlated with function in both humans and cats. As a convergent pathway, renal fibrosis provides an ideal target for the treatment of CKD and knowledge of the underlying fibrotic process is essential for the future development of novel therapies. There are many mediators and mechanisms of renal fibrosis reported in the literature, of which only a few have been investigated in the cat. This article reviews the process of renal fibrosis and discusses the most commonly cited mediators and mechanisms of progressive renal injury, with particular focus on the potential significance to feline CKD.     

Renal Cryptosporidiosis (Cryptosporidium baileyi) in specific-pathogen-free chickens experimentally coinfected with Marek's disease virus

Renal Cryptosporidiosis was experimentally induced during a study to investigate the pathogenicity of Cryptosporidium baileyi in specific-pathogen-free (SPF) chickens coinfected with Marek's disease virus (MDV). Cryptosporidium baileyi was administered orally at 4 days of age to chickens previously infected at hatching (day 0) with the HPRS 16 strain of oncogenic MDV. Three control groups received MDV at hatching, C. baileyi on day 4, or placebo consisting of distilled water. Renal cryptosporidiosis lesions were induced in the group coinfected with MDV and C. baileyi. The kidneys were markedly swollen and pale, with visible urate crystals in the ureters and surface tubules. Oocysts of C. baileyi were demonstrated in six of seven cases tested by a scoring method with modified Sheather's sugar solution on renal tissue scrapings and were confirmed in three cases by histologic examination of paraffin-embedded kidney sections. Histologic study also revealed subacute interstitial nephritis, acute ureteritis, and attachment of cryptosporidia on the epithelial cell surface of the ureters and collecting ducts, collecting tubules, and distal convoluted tubules. Various developmental stages of the parasite were present in the kidney sections. To our knowledge, this is the first report of experimentally induced renal cryptosporidiosis in SPF chickens coinfected with MDV.     

Obstructive renal cyst in a dog: ultrasonography-guided treatment using puncture aspiration and injection with 95% ethanol

A 12-year-old, intact male, mixed-breed dog was evaluated after surgical removal of a mast cell tumor from the shoulder. Results of laboratory tests were within the reference ranges, but examination of urinary sediment identified epithelial cells of the upper urinary tract and microscopic hematuria. Abdominal ultrasound examination performed after a 12-hour fast identified a simple cyst in the left kidney. The cyst was approximately 26 mm in diameter, was anechoic, and had a thin, slightly hyperechoic wall with distal acoustic enhancement accompanied by dilatation of the caudal papillary duct and renal pelvis (Fig 1). Excretory urography with iopamidol^a contrast (800 mg/kg IV) confirmed the presence of dilatation of the left renal pelvis and collecting system (Fig 2).     

LAPAROSCOPIC SONOGRAPHY IN THE URINARY SYSTEM

This work reports the use of laparoscopic-transducer sonography for the examination of the urinary system in a swine model. Animals underwent a two-phase study. In the first phase, the urinary system was examined using laparoscopic sonography. In the second a partial ureteral obstruction was induced, and sonographic changes were recorded and evaluated. Sonography was used to evaluate kidneys, ureters, and bladder. Anatomic structures were evaluated and the following pathological findings were identified: renal cysts, one polycystic kidney, dilation of the renal pelvis, hydronephrosis, and one perirenal pseudocyst. Where necessary, contrast digital fluoroscopy (excretory urography and retrograde ureteropyelography) was also performed. Laparoscopic sonography mainly is used for evaluation prior to laparoscopic surgery to guide decisions relating to surgery. The quality of the images obtained laparoscopically is superior to that of percutaneous or transabdominal images, because artifacts are reduced and the contact surface of the transducer is placed directly over the study area. Laparoscopic sonography proved highly effective for studying renal and ureteral disorders prior to minimally invasive surgery.     

Duplex Doppler Estimation of Intrarenal Pourcelot Resistive Index in Dogs and Cats With Renal Disease

In human beings, intrarenal blood flow impedance, expressed as the resistive index (Rl) and obtained by duplex Doppler ultrasonography, has been used to aid in diagnosis and prognosis of renal failure. Higher than normal values for Rl were obtained in 3 of 4 dogs with acute tubular necrosis (ATN) and in 5 of 10 dogs with glomerulonephrosis (GN). Normalization of Rl was observed in 2 dogs with ATN evaluated serially during treatment. Increased Rl values were obtained in 9 of 10 cats with nonobstructive renal disease and in 2 of 5 cats with obstructive renal disease. Normalization of Rl was observed in 3 cats with renal failure in which treatment was effective (1 with obstruction; 2 with nonobstructive disease). The magnitude of increase in Rl did not correlate with the magnitude of concurrent renal dysfunction. These results suggest that duplex Doppler evaluation of intrarenal Rl is more useful as an ancillary diagnostic technique in azotemic dogs with ATN than in those with GN and in azotemic cats with nonobstructive than in those with obstructive disease.     

Urinary Biomarkers for Acute Kidney Injury in Dogs

Routinely, kidney dysfunction and decreased glomerular filtration rate (GFR) are diagnosed by the evaluation of changes in the serum creatinine (SCr) and blood urea nitrogen (BUN) concentrations. However, neither of these tests is sensitive or specific enough for the early diagnosis of impaired kidney function because they are both affected by other renal and nonrenal factors. Furthermore, kidney injury can be present in the absence of kidney dysfunction. Renal reserve enables normal GFR even when nephrons are damaged. Renal biomarkers, especially those present in urine, may be useful for the study of both acute and chronic nephropathies. The aim of this review is to describe the current status of urinary biomarkers as diagnostic tools for kidney injury in dogs with particular focus on acute kidney injury (AKI). The International Renal Interest Society (IRIS) canine AKI grading system and the implementation of urinary biomarkers in this system also are discussed. The discovery of novel urinary biomarkers has emerged from hypotheses about the pathophysiology of kidney injury, but few proteomic urine screening approaches have been described in dogs. Lack of standardization of biomarker assays further complicates the comparison of novel canine urinary biomarker validation results among studies. Future research should focus on novel biomarkers of renal origin and evaluate promising biomarkers in different clinical conditions. Validation of selected urinary biomarkers in the diagnosis of canine kidney diseases must include dogs with both renal and nonrenal diseases to evaluate their sensitivity, specificity as well as their negative and positive predictive values.     

Renal dysfunction in dogs with pyometra

Renal function and pathologic changes in 27 dogs with pyometra were studied. Evaluation included CBC; serum biochemical evaluation; urinalysis; urine and uterine bacteriologic culture; uterine morphologic features; and light, electron, and immunofluorescent microscopic evaluation of renal tissues. Measurements of 24-hour creatinine clearance, protein excretion, Na excretion, and urine volume were made in 12 dogs without azotemia. Of 27 dogs, 26% were azotemic and 89% had a urine sp gr less than 1.035. Glomerular filtration rate was reduced in 75% of 12 dogs without azotemia. None of these 12 dogs was proteinuric. Examination of renal biopsy specimens revealed a high prevalence of mild tubulointerstitial nephritis, but few specific glomerular lesions. Minimal immunofluorescence was detected within the mesangium in 18% of the dogs. Immunofluorescence was not associated with the interstitium or tubules. Urinary tract infection was detected in 22% of the dogs. Escherichia coli and Klebsiella were recovered from the uterus in 59 and 15% of the dogs, respectively. Low urine specific gravity values were obtained from dogs without azotemia and from dogs with uterine cultures considered negative for E coli and other gram-negative bacteria. The reduction in glomerular filtration rate was a functional abnormality not correlated with structural damage in the glomerulus.     

Applications of ultrasonography in the diagnosis of parenchymal kidney disease in cats: 24 cases (1981-1986)

Renal sonograms from 24 cats with confirmed parenchymal kidney disease and from 1 cat with radiographic and palpable evidence of renal enlargement (but without identifiable histologic abnormalities) were evaluated to describe the ultrasonographic appearance of feline renal diseases and to determine the role of ultrasonographic examination in the clinical evaluation of these cases. In all cats with radiographic evidence of abnormal renal size or contour and when poor intraabdominal radiographic contrast precluded visualization of the kidneys, ultrasonography provided complementary information pertaining to location (cortical/medullary), extent, and distribution (focal/multifocal/diffuse) of disease. Ultrasonography also characterized these lesions as cystic (cavitating) or solid. The echo patterns were most specific for renal cysts. Infiltrative diseases did not have consistent patterns. Multifocal hypoechoic nodules, diffuse cortical hyper-echogenicity, and normal-appearing parenchyma were identified. In these instances, however, ultrasonography did define the extent of disease and narrowed the spectrum of differential considerations.     

Mammalian renal modifications in dry environments

The literature on the role of the kidney and renal morphological modifications in places of limited water supply is reviewed. The anatomical structures for urine concentration found in animals living in desert or arid environments, although not all occurring in one particular animal, are wide medullae, long loops of Henle, long proximal tubules, long collecting tubules, small renal corpuscles, extension of the renal pelvis, well developed elongated papillae, occurrence of giant vascular bundles, specialized ultrastructure of Henle's loops, epithelial changes in the collecting tubule, zonation of the vasa recta and peculiarity of the arterial supply to the kidney. The renal renin content is moderately high in these species. The renin-angiotensin-aldosterone system is very active, retaining Na⁺ with water. The urine is concentrated at the expense of other electrolytes. Both the renal blood and urinary flow rates are lower than in species with access to unlimited water supply. The juxtaglomerular apparatus components are topographically intimate for effective tubuloglomerular autoregulation of renal blood flow.     

Canine renal failure syndrome in three dogs

Three dead dogs were brought to the College of Veterinary Medicine, Kyungpook National University for study. Clinically, all the dogs showed emaciation, anorexia, depression, hemorrhagic vomiting and diarrhea for 7~10 days before death. All the clinical signs were first noted for about one month after feeding the dogs with commercial diets. At necropsy, all 3 dogs had severe renal damage with the same green-yellowish colored nephroliths in the renal pelvis. They also showed systemic hemorrhage and calcification of several organs, which might have been induced by uremia. Microscopically, necrosis, calcification and calculi were detected in the renal tubules, and especially in the proximal convoluted tubules and collecting ducts of the kidney. These findings were supportive of a mycotoxic effect, and especially on their kidneys. However, the precise cause of the toxic effect in these cases of canine renal failure could not be determined.