A multicenter retrospective study of 151 renal biopsies in horses

ECEIM consensus statement on equine kidney disease

The aim of this consensus statement is to summarize and appraise scientific evidence and combine this with the clinical experience of a panel of experts to optimize recommendations on how to recognize and manage kidney disease in horses.

Imaging of the Urinary Tract

This article provides a comprehensive review of imaging techniques used to evaluate the equine urinary tract. This overview includes officially recognized modalities and new applications reported in the most current literature. Technical aspects and indications for use of endoscopy and ultrasonography are highlighted. Normal endoscopic and ultrasonographic appearance of the upper and lower urinary tract is described, with characterization of common abnormalities found in patients with hematuria, stranguria, and renal failure. Visual examples of several pathologic conditions from clinical cases are provided. An outline of the main features, potentials, and limitations of radiography, nuclear scintigraphy, and computed tomography is provided.

Acute Kidney Injury and Renal Failure in Horses

Nephrotoxic and hemodynamically mediated disorders are the most common causes of acute renal failure (ARF) in horses and foals. Leptospira spp. is the most common infectious cause of ARF. Initial treatments for ARF include elimination of nephrotoxic drugs, correction of predisposing disorders, and fluid therapy to promote diuresis. Horses and foals with polyuric ARF often have a good prognosis, while those with oliguric or anuric ARF have a guarded to poor prognosis. When fluid therapy is unsuccessful in improving urine production, various drugs treatments have been used in an attempt to increase urine production, but none are consistently effective in converting oliguria to polyuria.

Evaluation of podocin in urine in horses using qualitative and quantitative methods

No sensitive method for diagnosing early kidney dysfunction in horses has been identified so far. Many studies carried out in humans and small animals show that podocin can be useful to diagnose various kidney diseases, mainly affecting the glomeruli. The aim of this study was to perform a qualitative and quantitative analysis of podocin in urine samples obtained from healthy horses, horses with clinical kidney dysfunction and horses at risk of acute kidney injury. The study objectives aimed to assess: (1) whether the selected podocin tryptic peptide for LC-MS-MRM allows for podocin detection in horse; and (2) whether the species-specific ELISA test makes this detection possible as well;, (3) whether the chosen methods are sensitive enough to detect kidney dysfunction and glomerular injury, (4) whether the results of the tests applying both methods correspond with one another, (5) whether the results correlate with the hematological and biochemical data. The signals that may indicate the presence of trypsin fragments of podocin were found in three healthy horses, all the horses diagnosed with kidney dysfunction and half of the animals at risk for acute kidney injury. The concentration of podocin, diagnosed with the ELISA test was as follows: from 0.19 to 1.2 ng/ml in healthy animals, from 0.19 to 20.0 ng/ml in AKI horses, from 0.29 to 5.71 ng/ml in horses at risk for acute kidney injury. The results of both methods corresponded significantly. Podocin may be a potential biomarker of clinical kidney disease in horses and may be used in the detection of glomerular injury. However, its use is limited by the possibility of physiological podocyturia. LC-MS-MRM seems to be a more sensitive method to evaluate the presence of podocin than the ELISA test, whilst selected tryptic peptides of podocin appear to apply to horses. The ELISA test showed greater effectiveness in excluding the disease than in confirming it.

Acute kidney injury due to Leptospira interrogans in 4 foals and use of renal replacement therapy with intermittent hemodiafiltration in 1 foal

Four 2‐month‐old foals were presented to an equine hospital with acute kidney injury caused by Leptospira interrogans infection. Clinical signs were nonspecific and included lethargy, fever, and unwillingness to nurse. The most important hematologic and clinicopathologic findings were azotemia, anemia, thrombocytopenia, hyponatremia, and hypochloremia. The diagnosis was based on urinary real‐time PCR, serology using a microscopic agglutination test, or both. The most important serovars involved were L. interrogans serogroup australis serovar Bratislava and Australis. Treatment consisted of IV fluid therapy and antimicrobial treatment. Renal replacement therapy with hemodiafiltration was performed in 1 of the foals. All foals survived to discharge. This report highlights the importance of early diagnosis and treatment in foals with acute kidney injury caused by L. interrogans infection.

Ultrasonographic Reference Values of Kidney Dimensions and Clinicopathological Findings Associating the Transcutaneous Ultrasound-Guided Renal Biopsy in Donkeys (Equus asinus)

This study aimed to establish normal ultrasonographic reference values of kidney dimensions in donkeys (Equus asinus) and to describe and evaluate the clinicopathological variations associated with ultrasound-guided renal biopsy. The ultrasonographic dimensions of the right and left kidneys were conducted on 16 donkeys, which were then divided into two groups; eight each for biopsy of the right kidney (RK) and left kidney (LK). Three ultrasonographic cineloops were obtained at 17th intercostal space daily for 3 consecutive days. Renal length, width, and dimensions of the cortex, medulla, and pelvis for both the kidneys in each donkey were recorded. Maximal dimensions were obtained for the RK (length 10 ± 8 cm, width 4.9 ± 1 cm, thickness 4.2 ± 0.4 cm) and LK (length 8.9 ± 0.9 cm, width 4.7 ± 0.8 cm, thickness 3.5 ± 0.7 cm) with good-to-excellent repeatability for all measurements. Follow-up ultrasonography revealed development of postbiopsy subcapsular hematomas, which were confirmed postmortem, of mild (volume < 20 mL), moderate (volume from 20 to 40 mL), and severe degrees (volume > 40 mL). Gross hematuria had been observed till 24 hours after biopsy, and then microscopic hematuria was noticed thereafter. Variable clinicopathological changes were noticed in blood and urine. All the biopsy specimens were adequate for histopathological assessment. Postmortem histopathological examination revealed various kidney changes. In conclusion, kidney dimensions can be used by veterinarians for accurate diagnosis and management of renal diseases. Ultrasound-guided renal biopsy is a relatively safe procedure; however, some complications may develop. Renal biopsy is commonly associated with clinicopathological variations; thus, caution should be taken during interpretation of these variables.

Renal neoplasia in horses - a retrospective study

OBJECTIVE

Being confronted with a case series of renal neoplasia in several horses which was in striking divergence to literature data, we recognized the need of a retrospective study to assess the presence of renal neoplasms in horses.

MATERIAL AND METHODS

Anamnestic animal data, necropsy findings and results of histological and immunohistochemical examinations from 2010 through 2015 were collected and evaluated regarding renal neoplasia.

RESULTS

Data from postmortem examinations of 1069 horses revealed 20 horses with renal tumors constituting a prevalence of 1.87 %. Primary renal neoplasms built the majority of cases (n = 15; 75 % of total renal neoplasms) and comprised nine renal carcinomas, four renal adenomas, one renal neuroendocrine tumor and a single nephroblastoma. Among the five secondary renal neoplasms lymphosarcoma was most common (3/5). Remaining metastatic tumors comprised one melanoma and one hemangiosarcoma. No breed or sex predilections were noticeable. Except for the case of nephroblastoma in a stillborn foal, all horses presenting with renal tumors were more than 10 years of age, often older than 20 years. Anamnestic data and clinical symptoms were inconclusive and not assigned to renal disease in most cases. Merely one horse with renal carcinoma presented with renal insufficiency and two horses showed signs of shock due to severe bleeding after tumor capsule rupture in renal carcinoma.

CONCLUSION AND CLINICAL RELEVANCE

Renal tumors occur more often than anticipated, especially in older horses. Contradictorily to the literature, primary renal tumors significantly outnumbered secondary neoplasms in this study.