Symmetric dimethylarginine concentrations in dogs with International Renal Interest Society stage 4 chronic kidney disease undergoing intermittent hemodialysis

Outcome of Acquired Fanconi Syndrome Associated with Ingestion of Jerky Treats in 30 Dogs

Acquired canine proximal renal tubulopathy (Fanconi syndrome) related to excessive ingestion of jerky treats has been recognized since 2007. This study aimed to improve knowledge about the syndrome’s characteristics, especially long-term outcome. By reaching out to veterinarians and dog owners, dogs suspected of jerky induced Fanconi syndrome were identified. The dog’s medical records were reviewed, and owners interviewed. Data was analyzed using linear mixed models (p < 0.05 was considered statistically significant) and descriptive statistics are reported. Thirty dogs, median body weight 6.8 (range 1.2−59) kg and age 6.5 (0.5−14) years, were enrolled as suspected cases based on history of jerkey ingestion and confirmed normoglycemic/hypoglycemic glycosuria. Clinical signs included polydipsia (23/30), polyuria (21/30), lethargy (19/30), weight loss (15/30), hyporexia (11/30), vomiting (7/30), diarrhea (7/30) and no clinical signs (2/30). Para-clinical findings included azotemia (6/28), hypophosphatemia (9/25), metabolic acidosis (3/8), hypokalemia (6/20), proteinuria (13/26), aminoaciduria (4/4), hematuria (22/29) and ketonuria (7/27). Clinical signs resolved in 22/28 within 11 (0.3−52) weeks and glycosuria resolved in 28/30 within 6.5 (1−31) weeks. There were no associations between serum creatinine and urea and the amount/duration of jerky ingestion. Serum symmetric dimethylarginine concentrations were only available for a few dogs, therefore no conclusion was achieved on a possible association with duration of jerky ingestion. Apart from a larger percentage of dogs achieving complete recovery, the current findings are in agreement with previous reports.

A Review of Specific Biomarkers of Chronic Renal Injury and Their Potential Application in Nonclinical Safety Assessment Studies

A host of novel renal biomarkers have been developed over the past few decades which have enhanced monitoring of renal disease and drug-induced kidney injury in both preclinical studies and in humans. Since chronic kidney disease (CKD) and acute kidney injury (AKI) share similar underlying mechanisms and the tubulointerstitial compartment has a functional role in the progression of CKD, urinary biomarkers of AKI may provide predictive information in chronic renal disease. Numerous studies have explored whether the recent AKI biomarkers could improve upon the standard clinical biomarkers, estimated glomerular filtration rate (eGFR), and urinary albumin to creatinine ratio, for predicting outcomes in CKD patients. This review is an introduction to alternative assays that can be utilized in chronic (>3 months duration) nonclinical safety studies to provide information on renal dysfunction and to demonstrate specific situations where these assays could be utilized in nonclinical drug development. Novel biomarkers such as symmetrical dimethyl arginine, dickkopf homolog 3, and cystatin C predict chronic renal injury in animals, act as surrogates for GFR, and may predict changes in GFR in patients over time, ultimately providing a bridge from preclinical to clinical renal monitoring.

Macronutrient status and indicators of acid-alkaline blood balance in cats with chronic renal failure

Chronic renal failure is a common pathology among cats. According to various literary sources, this pathology is found in 0.5–14.0% of cats. Pathology in cats in our studies is a consequence of glomerulonephritis. The diagnosis of chronic renal failure established on the basis of clinical, instrumental, and laboratory methods of blood and urine testing. Studies have found that chronic renal failure in cats is clinically characterized by apathy, anorexia, dry skin, odor of urea, vomiting, thirst, occurrence in the mouth of uremic ulcers (9.5% of patients), tachycardia (up to 177 beats per minute) tachypnoea (up to 45 respiratory movements per minute), hypertension. In the urine – hypostenuria, erythrocyturia, leukocyturia, kidney epithelium, hyaline and granular cylinders. According to echosonography – increase in echogenicity of the parenchyma, brain substance echone negative, cortico-brain differentiation erased. In the blood test – normochromic macrocytic anemia, thrombocytopenia, hyperazotemia (up to 27.9 mmol/L), hypercreatininemia (324 μmol/L), hyperuricemia (615 μmol/L), 4.6-fold increase in SDMA (symmetric dimethylargin). In chronic renal failure, cats have a significant change in the elemental composition of the blood. In particular, the Na+ content was increased by 3%, Ca2+ 1.6 times, P 2.1 times. Instead, the K+ level was reduced 1.9 times. Changes in acid-base equilibrium (ABE) were also detected: the pH decreased to 7.22; HCO3– by 34%, total CO2 by 32.3%, while anionic difference (AG) and buffer bases (BE) increased by 1.8 and 3.5 times, respectively. Such changes are characteristic of the development of lactic acidosis. The obtained experimental data on changes in mineral metabolism and acid-base equilibrium in the serum of cats in chronic renal failure supplement and clarify information on the pathogenic pathology of the kidneys in cats aged 5–10 years. Blood biochemical data can be used to improve early-stage diagnostics without clinical manifestations of chronic renal failure, their prevention and treatment, and to solve applied scientific problems in the field of nephrology and urology of small animals.

Symmetric dimethylarginine concentrations in dogs with International Renal Interest Society stage 4 chronic kidney disease undergoing intermittent hemodialysis

BACKGROUND

Symmetric dimethylarginine (SDMA) is a methylated arginine derived from intranuclear methylation of l-arginine by protein-arginine methyltransferase and released into circulation after proteolysis. It is primarily eliminated by renal excretion, and its concentration is highly correlated with glomerular filtration rate (GFR) in animals and humans and is an earlier indicator of kidney dysfunction than serum creatinine concentration (sCr).

OBJECTIVES

To evaluate and quantify the effects of IV fluid therapy (IF) or intermittent hemodialysis (IH) on renal function in a randomized group of dogs previously diagnosed with International Renal Interest Society (IRIS) stage 4 chronic kidney disease (CKD).

ANIMALS

Twenty-four client-owned dogs with naturally occurring CKD.

METHODS

Serum from 14 dogs treated by IH and 10 dogs treated with IF was submitted for measurement of sCr and SDMA. Dogs in each treatment group received up to 5 treatment sessions, administered 48 hours apart.

RESULTS

Significant differences (P ≤ .05) were seen between treatment groups, but dogs from the IH group were the most affected based on SDMA (P < .001), sCr (P < .001), and blood urea (P < .001) concentrations. Furthermore, for each 10% increase in urea reduction ratio, there was a 6.2 μg/dL decrease in SDMA (P = .002).

CONCLUSIONS AND CLINICAL IMPORTANCE

Although SDMA is dialyzable biomarker and despite its removal by IH, SDMA correlates better with renal function than does sCr in dogs with CKD undergoing IF and IH.