Acute on chronic kidney disease in dogs: Etiology, clinical and clinicopathologic findings, prognostic markers, and survival

Mesenchymal stem cell transplantation: Systematic review, meta-analysis and clinical applications for acute kidney injury and chronic kidney disease in dogs and cats

Chronic kidney disease (CKD) and acute kidney injury (AKI) are diseases which affect the urinary tract characterized by the loss of renal function. Their therapy requires different therapeutic goals. Mesenchymal stem cells (MSC) transplantation has spread over the years as a treatment for many diseases. In the urinary tract, studies report anti-inflammatory, antiapoptotic, antifibrotic, antioxidant and angiogenic effects. This work reports the results of a meta-analysis about the effects of the MSC application in serum levels of creatinine in dogs and cats with AKI and CKD. The work followed PRISMA guidelines. Data were screened, selected, and extracted with characteristics about the studies. The kinds of injury were classified according to their identification and the risk of bias was calculated by the system SYRCLE. The results of each group were combined by the inverse variance method. The heterogeneity was evaluated by the I2 test. For the mean of creatinine, a meta-analysis was performed according to the study group and number of applications and separately for the control and treatment groups according to the kind of injury, dose, application route, and moment. At all, 4742 articles were found. Of these, 40 were selected for eligibility, 16 underwent qualitative analysis and 9 to the quantitative. The results denote advantage to the group treated with MSC over placebo. A statistical difference was observed both in combined analysis and in the subgroups division. However, a high heterogeneity was found, which indicates considerable variation between the studies, which indicates caution in generalize the results.

Mobility, functionality and functional mobility: A review and application for canine veterinary patients

Mobility is an essential aspect of a dog's daily life. It is defined as the ability to move freely and easily and deviations from an animals' normal mobility capabilities are often an indicator of disease, injury or pain. When a dog's mobility is compromised, often functionality (ability to perform activities of daily living [ADL]), is also impeded, which can diminish an animal's quality of life. Given this, it is necessary to understand the extent to which conditions impact a dog's physiological ability to move around their environment to carry out ADL, a concept termed functional mobility. In contrast to human medicine, validated measures of canine functional mobility are currently limited. The aim of this review is to summarise the extent to which canine mobility and functionality are associated with various diseases and how mobility and functional mobility are currently assessed within veterinary medicine. Future work should focus on developing a standardised method of assessing functional mobility in dogs, which can contextualise how a wide range of conditions impact a dog's daily life. However, for a true functional mobility assessment to be developed, a greater understanding of what activities dogs do on a daily basis and movements underpinning these activities must first be established.

International Renal Interest Society best practice consensus guidelines for the diagnosis and management of acute kidney injury in cats and dogs

Acute kidney injury (AKI) is defined as an injury to the renal parenchyma, with or without a decrease in kidney function, as reflected by accumulation of uremic toxins or altered urine production (i.e., increased or decreased). AKI might result from any of several factors, including ischemia, inflammation, nephrotoxins, and infectious diseases. AKI can be community- or hospital-acquired. The latter was not previously considered a common cause for AKI in animals; however, recent evidence suggests that the prevalence of hospital-acquired AKI is increasing in veterinary medicine. This is likely due to a combination of increased recognition and awareness of AKI, as well as increased treatment intensity (e.g., ventilation and prolonged hospitalization) in some veterinary patients and increased management of geriatric veterinary patients with multiple comorbidities. Advancements in the management of AKI, including the increased availability of renal replacement therapies, have been made; however, the overall mortality of animals with AKI remains high. Despite the high prevalence of AKI and the high mortality rate, the body of evidence regarding the diagnosis and the management of AKI in veterinary medicine is very limited. Consequently, the International Renal Interest Society (IRIS) constructed a working group to provide guidelines for animals with AKI. Recommendations are based on the available literature and the clinical experience of the members of the working group and reflect consensus of opinion. Fifty statements were generated and were voted on in all aspects of AKI and explanatory text can be found either before or after each statement.

A comprehensive analysis of albuminuria in canine chronic kidney disease

BACKGROUND

Albuminuria, an important marker of decreased kidney function in chronic kidney disease (CKD), is not routinely used for CKD detection or proteinuria appearance. Its relationships with biochemical parameters and blood pressure in dogs are poorly understood.

OBJECTIVES

This study aimed to evaluate the relationship of albuminuria with various CKD markers, its correlation with the urinary protein to creatinine ratio (UPC), and hypertension in dogs with early stages of CKD. It also sought to determine the usability of the urinary albumin to creatinine ratio (UAC) for CKD screening.

METHODS

The study reviewed records of 102 dogs, categorising them into four groups based on disease status. UAC and UPC ratio, biochemistry and haematology variables, age, and systolic blood pressure were determined.

RESULTS

The Pearson's correlation coefficient between log-transformed values of UPC and UAC was r = 0.902 (95% CI: 0.87 to 0.93). Median UAC ratio values were 2.1 mg/g for the Healthy control group (n = 17), 54.2 mg/g for early stages CKD (n = 42), 5.8 mg/g for Acute sick control (n = 30), and 104 mg/g for Chronic sick control (n = 13). Thresholding UAC ratio as an indicator for impaired kidney function with the threshold of 10 mg/g (established based on the receiver operating characteristic curve) had a sensitivity 81.8%, specificity of 89.4%, positive predictive value (PPV) 90%, and negative predictive value (NPV) 80.1%. The correlation of UAC with biochemistry and haematology variables was statistically significant; for SDMA (μg/L), it was r = 0.566 and for other variables, it was weak to moderate. UAC was markedly elevated in cases of severe hypertension.

CONCLUSIONS

UAC ratio was significantly different among dogs with impaired and not impaired kidney function. The correlation strength for the UAC and UPC ratios was high. UAC ratio may be a promising marker for proteinuria analysis in dogs with CKD or other kidney function alterations.

Diagnostic utility of two-dimensional shear wave elastography in nephropathic dogs and its correlation with renal contrast-enhanced ultrasound in course of acute kidney injury

Aims of our study were to evaluate the feasibility and diagnostic value of two-dimensional shear wave elastography in dogs with acute kidney injury, chronic kidney disease, and acute on chronic kidney disease, its correlation with renal functional (creatinine, urea), and prognostic parameters (serum calcium-phosphorus product, urinary output), and with contrast-enhanced ultrasound (qualitative and quantitative evaluation). The study was prospective. A group of healthy (Group A) and a group of nephropathic dogs (Group B) were included. Shear wave elastography was performed on the left kidney of the subjects of both groups; contrast-enhanced ultrasound was performed only in dogs with acute kidney injury and acute on chronic kidney disease. Sixty-four dogs were included (Group A, n=24; Group B, n=40). The renal stiffness values were significantly higher in Group B than Group A; optimal cut-off stiffness values for detection of renal pathology were: ≥1.51 m/sec (area under the curve, 0.84; 95% confidence interval 0.74-0.94) and ≥6.75 kPa (area under the curve, 0.84; 95% confidence interval 0.73-0.94). For contrast-enhanced ultrasound, a significant positive correlation was found between renal stiffness, area under the curve, and wash-out area under the curve values of cortex quantitative analysis. No correlations were found between renal stiffness and renal functional and prognostic parameters. Shear wave elastography showed diagnostic utility to detect renal abnormalities in dogs with acute kidney injury, chronic kidney disease and acute on chronic kidney disease, however, it could not differentiate between these different nephropathies.

Diagnostic assessment of two-dimensional shear wave elastography in relation to dimethyl arginine levels in dogs with chronic kidney disease

BACKGROUND

In veterinary medicine, previous studies regarding the diagnostic performance of shear wave elastography (SWE) in chronic kidney disease (CKD) are not consistent with each other. Moreover, there has been no study evaluating the relationship between symmetric dimethyl arginine (SDMA) concentration and renal shear wave velocity (SWV) using two-dimensional SWE (2D SWE) in dogs with CKD.

OBJECTIVES

This study aimed to evaluate the diagnostic capability of 2D SWE in dogs with CKD and to assess the relationship between renal SWV and SDMA concentration.

METHODS

Dogs with healthy kidneys and dogs with CKD underwent 2D SWE and SDMA assay. Renal stiffness was estimated as renal SWV in m/s.

RESULTS

SDMA concentration had a weak positive correlation with the left (r = 0.338, p = 0.022) and right renal SWV (r = 0.337, p = 0.044). Renal SWV was not significantly different between healthy kidney and CKD groups in the left (p = 0.085) and right (p = 0.171) kidneys.

CONCLUSIONS

2D SWE may could not distinguish between dogs with healthy kidney and dogs with early stage of CKD, but it would be useful for assessing the serial change of renal function in dogs.

A pilot study of alterations of the gut microbiome in canine chronic kidney disease

Introduction

Gut dysbiosis has been noted in humans and animals with chronic kidney disease (CKD). However, little is known about the gut microbiome in canine patients with CKD. This study aimed to analyze and compare the gut microbiome profiles of healthy and CKD dogs, including differences in the gut microbiome between each CKD stage.

Methods

The study was conducted on 29 client-owned dogs who underwent physical examination, complete blood count (CBC), serum biochemistry, and urinalysis. The gut microbiome profile of healthy dogs (n = 10) and dogs with CKD (n = 19) was analyzed employing 16S rRNA sequencing.

Results

Significant differences were seen in the composition of the gut microbiome, with increased operational taxonomic units from the phylum Proteobacteria (p = 0.035), family Enterobacteriaceae (p < 0.001), and genus Enterococcus (p = 0.002) in dogs with CKD, and a decrease in the genus Ruminococcus (p = 0.007). Furthermore, an increase in both the progression of CKD and abundance of genus Klebsiella (Jonckheere-Terpstra test statistic value (JT) = 2.852, p = 0.004) and Clostridium (JT = 2.018, p = 0.044) was observed.

Discussion

Our study demonstrated that in dogs with CKD, the composition of the gut microbiome varied depending on the stage of CKD. Alterations in gut microbiome composition observed in CKD patients are characterized by an increase in proteolytic bacteria and a decrease in saccharolytic bacteria. These findings suggest specific gut microbiota could be targeted for clinical management of uremic dogs with CKD.

Serum Bicarbonate Deficiency in Dogs with Acute and Chronic Kidney Disease

Serum bicarbonate deficiency is a disorder frequently found in human patients with acute (AKI) and chronic (CKD) kidney disease, due to abnormalities in kidney generation and reabsorption of bicarbonate. Although alkali supplementation is usually performed in both humans and veterinary CKD patients, data regarding the frequency of bicarbonate disorders in AKI and CKD dogs are scarce. The aim of the present study is to assess the frequency and the severity of bicarbonate deficiency of dogs affected by AKI, acute chronic kidney disease (ACKD), and CKD, and to investigate its possible association with the IRIS grade/stage as well as with disorders of calcium phosphate metabolism. A retrospective evaluation of the serum biochemical panels of all dogs with diagnoses of AKI, ACKD, and CKD referred to the nephrology and urology service of the Veterinary Teaching Hospital of the University of Pisa, between January 2014 and January 2022, was performed. Bicarbonate deficiency was defined as serum bicarbonate < 22 mmol/L and classified as moderate (between 18 and 22 mmol/L) or severe (<18 mmol/L). Serum bicarbonate deficiency was found in 397/521 dogs (76%), of which 142/397 (36%) showed moderate deficiency, and 255/397 (64%) severe deficiency. Dogs with AKI and ACKD showed a significantly higher frequency of bicarbonate deficiency (p = 0.004) and severe forms compared to CKD dogs (p = 0.02). In AKI and ACKD dogs, a negative linear correlation was found between serum bicarbonate and serum creatinine, urea, and phosphate. The frequency of bicarbonate deficiency was higher in the later stages of the disease in both AKI (p = 0.01), ACKD (p = 0.0003), and CKD dogs (p = 0.009). Dogs with serum CaxP ≥ 70 mg²/dL² showed a higher frequency of bicarbonate deficiency (p = 0.01) and showed severe forms (p = 0.01) compared to dogs with CaxP < 70 mg²/dL². Serum bicarbonate deficiency seems to be a very frequent disorder in both AKI, ACKD, and CKD dogs, with an increasing frequency and severity in more advanced stages of kidney disease. The higher frequency and severity of bicarbonate deficiency in AKI and ACKD may be caused by a more severe and sudden loss of kidney function, or extra-renal factors. Finally, the association between frequency and severity of bicarbonate deficiency and abnormal CaxP may suggest a potential connection between metabolic acidosis and bone mineral disorders.

Euthanasia and Pain in Canine Patients with Terminal and Chronic-Degenerative Diseases: Ethical and Legal Aspects

Euthanasia is commonly performed in veterinary medicine to humanely induce the death of an animal when its quality of life is affected by pain or chronic degenerative diseases. The choice of euthanasia is a bilateral decision that represents a challenge for both the veterinarian and the owner of the animal due to the close emotional human-animal bond. Currently, there is legislation that can orient veterinarians concerning euthanasia and the causes that would justify this resolution. However, it is still controversial, and deciding it as the last available resort requires considering it from a medical, legal, and moral perspective. Therefore, this review aims to explore the ethical and legal implications of euthanasia in canine patients. It will analyze the reason that can justify euthanasia in animals with pain or terminal and chronic degenerative diseases, highlighting the importance of effective communication, ethical knowledge, and consideration of euthanasia as a multimodal resolution.

Utility of 1,2-o-dilauryl-rac-glycero glutaric acid-(6'-methylresorufin)-ester-lipase for monitoring dogs with chronic pancreatitis

BACKGROUND

The utility of 1,2-o-dilauryl-rac-glycero glutaric acid-(6'-methylresorufin)-ester-(DGGR)-lipase activity (DLA) in monitoring clinical progression of chronic pancreatitis (CP) in dogs is unknown.

OBJECTIVE

To examine the association of DLA with clinical signs of CP, as assessed by a CP clinical severity score (CPCSS).

ANIMALS

Twenty-four dogs.

METHODS

This is a retrospective study. Chronic pancreatitis was diagnosed based on clinical signs and DLA > 250 U/L and monitored using CPCSS and DLA.

RESULTS

The study included 134 visits (median, 10 visits/dog; range, 2-11). Mild-moderate (CPCSS, 0-3) and severe (CPCSS, ≥4) disease were documented in 94 (70%) and 40 (30%) visits, respectively. In emergency visits (n = 44; 33%) CPCSS (median, 5; range, 0-15) and DLA (median, 534 U/L; range, 63-7133) were higher (P < .001 and P = .003, respectively) than in scheduled ones (n = 90; 67%; median, 1; range, 0-6 and median, 384 U/L; range, 49-3747, respectively). DGGR-lipase activity was associated (P = .009) with the CPCSS, with a lower activity documented in mild-moderate CPCSS (median 391 U/L; range, 49-3747), compared to severe score (median, 558 U/L; range, 63-7133). DGGR-lipase activity was significantly, but weakly, correlated with CPSS (r = 0.233, P = .007). DGGR-lipase activity inefficiently discriminated mild-moderate vs severe CP (area under the receiver operator characteristics curve, 0.64; 95% confidence interval, 0.53-0.75; P = .012), with DLA cutoff of 428 U/L corresponding to sensitivity of 65% and specificity of 63%.

CONCLUSIONS AND CLINICAL IMPORTANCE

Increased DLA is associated with emergency revisits in dogs with CP, possibly reflecting acute flare-ups. DGGR-lipase activity was associated with the CPCSS over the follow-ups but could not differentiate disease severity.

Ultrasonographic quantitative evaluation of acute and chronic renal disease using the renal cortical thickness to aorta ratio in dogs

The renal cortical thickness (RCT) has been correlated with renal function. Previous studies have also reported that the RCT:Abdominal aorta(Ao) ratio is constant in normal dogs with various physical factors. This multi-center, retrospective, analytical study aimed to determine if there are differences between actual RCT and predicted value of RCT considering physical factors in dogs with acute or chronic renal disease. We also aimed to demonstrate whether the RCT and Ao ratio index would be useful for evaluating renal pathology. A total of 54 dogs with acute or chronic renal disease and 30 normal healthy dogs were included in this study. The RCT was measured at the center of the renal pyramid as the shortest distance perpendicular to the renal capsule from the base of the renal medullary pyramid at three points. The diameter of the Ao was measured just caudal to the branch of the left renal artery in the sagittal plane in systole. The RCT:Ao ratio of chronic kidney disease (CKD) patients was 0.50 ± 0.11 (mean ± standard deviation). The RCT:Ao ratio in normal dogs was 0.67 ± 0.07. The RCT:Ao ratio in patients with acute kidney injury (AKI) was 0.83 ± 0.05. There was a statistically significant difference between normal dogs and dogs with CKD (P < 0.001) and between normal dogs and dogs with AKI (P < 0.001). In conclusion, findings from the current study supported using the RCT:Ao ratio as a non-invasive quantitative method for characterizing kidney pathology in dogs with acute or chronic renal disease.

Fibrous osteodystrophy due to secondary renal hyperparathyroidism in a senile dog

ABSTRACT Renal hyperparathyroidism stands out among the complications of kidney disease in dogs due to phosphorus retention with a predisposition to hypocalcemia, parathyroid hormone stimulation with mobilization of calcium from the bones, characterizing fibrous osteodystrophy, unusual in the elderly. The objective was to report it in 12-year-old Labrador with polyuria, polydipsia, and emesis for five months due to maxillary and mandibular volume increase, followed by loosely fixed teeth, and facial deformity. Blood tests showed anemia, thrombocytosis, azotemia, hypoalbuminemia and hyperphosphatemia and urinalysis showed low density, glycosuria, proteinuria, and moderate caudate and transitional epithelial cells. Oral x-rays showed loss of dental bone support and decreased bone radiopacity. Chest radiographs showed decreased density in the ribs and costochondral junction; on the other hand, organs of the cardiorespiratory system showed no changes. The electrocardiogram and echocardiogram did not show impairment. Abdominal ultrasound revealed kidneys with asymmetry, increased echogenicity of the cortical and poorly preserved cortico-medullary definition. Oral histopathology showed intense fibroplasia associated with bone reabsorption. Support therapy was instituted, but the patient died ten days after consultation. Thus, although uncommon in the elderly, fibrous osteodystrophy should be investigated in dogs with advanced-stage chronic kidney disease and, even with conservative therapies, the prognosis is unfavorable.

Continuous renal replacement therapy is a safe and effective modality for the initial management of dogs with acute kidney injury

OBJECTIVE

To describe the management of dogs with acute kidney injury (AKI) by continuous renal replacement therapy (CRRT), and to investigate the relationship between a prescribed CRRT dose, the hourly urea reduction ratio (URR), and the overall efficacy.

ANIMALS

45 client-owned dogs diagnosed with severe AKI, receiving 48 CRRT treatments at a veterinary teaching hospital.

PROCEDURES

Retrospective study. Search of medical records of dogs with AKI managed by CRRT.

RESULTS

Median serum urea and creatinine at CRRT initiation were 252 mg/dL [Inter quartile range (IQR), 148 mg/dL; range, 64 to 603 mg/dL] and 9.0 mg/dL (IQR, 7 mg/dL; range, 4.3 to 42.2 mg/dL), respectively. Median treatment duration was 21 hours (IQR, 8.8 hours; range, 3 to 32 hours). Systemic heparinization and regional citrate anticoagulation were used in 24 treatments each (50%). The prescribed median CRRT dose for the entire treatment was 1 mL/kg/min (IQR, 0.4 mL/kg/min; range, 0.3 to 2.5 mL/kg/min). The median hourly URR was 4% (IQR, 1%; range, 2% to 12%), overall URR was 76% (IQR, 30%; range, 11% to 92%) and median Kt/V was 2.34 (IQR, 1.9; range, 0.24 to 7.02). The CRRT dose was increased gradually from 0.9 mL/kg/min to 1.4 mL/kg/min (P < .001) and the hourly URR decreased from 6.5% to 5.5% (P = .05). The main complication was clotting of the extra-corporeal circuit, occurring in 6/48 treatments (13%). Twenty-four dogs (53%) survived to discharge.

CLINICAL RELEVANCE

CRRT is safe when the prescription is based on the current veterinary guidelines for gradual urea reduction. Treatment efficacy can be maximized by gradually increasing the dose according to the actual URR.

Urinary interleukin-6 is a potentially useful diagnostic and prognostic marker of acute kidney injury in dogs

BACKGROUND

Interleukin-6 (IL6) is a pro-inflammatory cytokine implicated in the pathophysiology of urinary tract diseases. The objective of this study was to evaluate the diagnostic and prognostic utilities of urinary IL6 (uIL6) in dogs with acute kidney injury (AKI) and other urinary tract diseases.

METHODS

Eighty client-owned dogs were included and divided into four groups: AKI, chronic kidney disease (CKD), urinary tract infection and healthy controls. Urine samples were analysed for uIL6 and normalised to urinary creatinine (uIL6/uCr).

RESULTS

Dogs in the AKI group had higher uIL6/uCr compared with the control and CKD groups (p < 0.001 and 0.012, respectively). Receiver operator characteristic (ROC) curve analysis of uIL6/uCr as a diagnostic marker for AKI had an area under the curve (AUC) of 0.91 (95% confidence interval [CI], 0.81-1.0) with 82% sensitivity and 90% specificity (cutoff point 4.5 pg/mg) when including the AKI and control groups. ROC analysis including AKI compared with all other groups had an AUC of 0.77 (95% CI, 0.67-0.87) for the diagnosis of AKI with sensitivity and specificity of 71% and 78%, respectively (cutoff point 10.4 pg/mg). The 30-day mortality of the AKI group was 34%, and there was no difference in uIL6/uCr between survivors and non-survivors of AKI.

CONCLUSIONS

uIL6/uCr is a potentially sensitive and specific diagnostic marker for AKI in dogs.

Evaluation of symmetric dimethylarginine in cats with acute kidney injury and chronic kidney disease

Background

Serum symmetric dimethylarginine (SDMA) concentrations are considered a biomarker for renal dysfunction in dogs and humans with acute kidney injury (AKI). No studies have assessed SDMA in cats with AKI.

Hypothesis/Objectives

SDMA correctly identifies cats with azotemic AKI.

Animals

Fifteen control cats, 22 with novel AKI, 13 with acute on chronic‐AKI (AoC) and 19 with chronic kidney disease (CKD).

Methods

Retrospective study. Cats with azotemia (serum creatinine concentrations >1.7 mg/dL) were defined as having AKI or CKD based on history, clinical signs, clinicopathological findings and diagnostic imaging, and classified using the International Renal Interest Society (IRIS) grading/staging systems. Serum SDMA concentrations were compared between groups with nonparametric methods, and correlations assessed using Spearman's correlation coefficient. Data are presented as median [range].

Results

SDMA concentrations were 11 (8‐21) μg/dL, 36 (9‐170)μg/dL, 33 (22‐75) μg/dL and 25 (12‐69) μg/dL in control, novel AKI, AoC and CKD cats. SDMA concentrations were significantly higher in cats with novel AKI (P < .001), AoC (P < .001) and CKD (P < .01) compared to controls. SDMA concentrations were significantly higher in cats with more advanced AKI (IRIS grade IV‐V) compared to less severe AKI (IRIS grade II). Serum creatinine and SDMA concentrations had a significant correlation in cats with novel AKI (r_s = 0.826, n = 22; P < .001) and a significant correlation when all cats across all 4 groups were considered together (r_s = 0.837, n = 69; P < .001).

Conclusions and Clinical Importance

Serum SDMA concentrations are elevated in cats with established AKI (novel and AoC) and CKD, providing evidence for use of SDMA as a biomarker for AKI in cats.

Cystatin C assay validation using the immunoturbidimetric method to evaluate the renal function of healthy dogs and dogs with acute renal injury

Background and Aim: Acute kidney injury (AKI) is associated with a grave prognosis. A clinical assessment of kidney function can be performed based on the glomerular filtration rate (GFR). Cystatin C (CysC) can indicate the GFR or kidney function and its measurement is currently performed using immunological methods such as nephelometry, immunoturbidimetry, and enzyme-linked immunosorbent assays in human medicine. However, these techniques are not specific for use in veterinary medicine. This study aimed to validate an immunoturbidimetric assay for serum CysC (sCy) in dogs, determine the sCy reference intervals for healthy dogs, evaluate sCy stability in serum samples, and compare sCy with serum creatinine (sCr) in healthy dogs and dogs with AKI. Materials and Methods: Forty-three dogs were divided into a control group (n = 19) and an AKI group (n = 24). An immunoturbidimetric method including commercially available human CysC calibrated with canine CysC was used to evaluate canine serum samples. Results: An average recovery of 97% was observed for canine serum samples. The reference interval for CysC in healthy dogs was 0.57–1.29 mg/L. The sCy concentration in dogs with AKI was significantly higher (2.82 ± 1.46 mg/L) than in healthy dogs (0.93 ± 0.18 mg/L). Statistical analysis confirmed a strong correlation between sCy and sCr (r = 0.94; p < 0.05) in dogs with AKI. Conclusion: The immunoturbidimetric method of evaluating sCy yielded satisfactory results and can be used for canine samples when a species-specific calibrator is used. Furthermore, sCy is a reliable marker of renal dysfunction in dogs. It is best to store samples for sCy evaluation at temperatures between 4°C and 8°C.

Long-term outcome of dogs recovering from acute kidney injury: 132 cases

Background

Information regarding long‐term outcome of dogs recovering from acute kidney injury (AKI) is limited.

Objectives

Determine the long‐term outcome of dogs recovering from AKI and identify predictors for serum creatinine concentration (sCr) normalization and long‐term outcome.

Animals

One hundred thirty‐two dogs with AKI that survived ≥30 days postdischarge.

Methods

Retrospective study. Search of medical records of dogs diagnosed with AKI that survived to discharge. Follow‐up data were retrieved from medical records and by telephone interviews with the owners or primary care veterinarians or both.

Results

Estimated median survival time (MST) was 1322 days (95% confidence interval [CI], 1147‐1626), and 76% of the dogs were alive at last contact. Normalization of sCr was documented in 55% of the dogs at discharge and in additional 20% during the follow‐up period. The proportion of dogs with sCr normalization decreased with increase in AKI grade (P = .02). Long‐term survival was not associated with sCr normalization (P = .63). Etiology was associated with the long‐term outcome (P = .004).

Conclusion and Clinical Importance

Long‐term survival of dogs with AKI is longer than previously described. Normalization of sCr in 99 dogs (75%) occurred, either at discharge or within the follow‐up period. Normalization of sCr was not associated with long‐term survival. Estimated MST of dogs with sCr normalization was not different compared with dogs that developed azotemic chronic kidney disease (CKD), presumably because of slow CKD progression rate. Etiology is an important factor determining sCr normalization and long‐term survival, emphasizing the importance of the reversibility of renal injury rather than its severity.

Nephrin and podocin mRNA detection in urine sediment of dogs with chronic kidney disease: preliminary observations

Introduction

Dogs with chronic kidney disease (CKD) may have alterations in the glomerular filtration barrier, including podocyte loss. Detection of podocyte mRNA in urine could be useful for assessing podocyturia in dogs with kidney disease. The objective of this study was to evaluate the presence of nephrin mRNA (NPHS1) and podocin mRNA (NPHS2) in urine sediments of dogs with naturally occurring CKD and healthy dogs.

Material and Methods

Twenty-four dogs, 14 with CKD and 10 as healthy controls, underwent clinical evaluation. The dogs with CKD were divided into two groups, according to the International Renal Interest Society criteria: stage 1 or 2 CKD (n = 5) and stage 3 or 4 CKD (n = 9). Urine was collected by catheterisation or free catch and RNA isolation from the urine sediments was optimised using glycogen as a co-precipitant. Detection of NPHS1 and NPHS2 in the sediment samples was performed using quantitative real-time PCR.

Results

Both types of mRNA were detected in samples from all groups, but the percentages of detection were higher in the group of dogs with stage 1 or 2 CKD and lower in the group of dogs with stage 3 or 4 disease.

Conclusion

Physiological podocyturia was observed in healthy dogs, and the results suggest differential podocyturia in dogs with CKD, according to the stage of the disease, i.e. an increase in podocyturia in dogs at stage 1 or 2 and a reduction in podocyturia in dogs at stage 3 or 4.

Acute kidney injury in dogs: Etiology, clinical and clinicopathologic findings, prognostic markers, and outcome

BACKGROUND

Acute kidney injury (AKI) is a common, potentially fatal condition.

OBJECTIVES

To characterize the etiologies, clinical and clinicopathologic findings, hospitalization period, and outcome of dogs with AKI and to identify markers of negative prognosis.

ANIMALS

Two hundred forty-nine client-own dogs diagnosed with AKI and hospitalized at a veterinary teaching hospital.

METHODS

Retrospective study. Search of medical records for dogs with AKI.

RESULTS

Common clinical signs included lethargy (225/249, 90%), anorexia (206/249, 83%), and vomiting (168/249, 68%). Etiologies included ischemic/inflammatory (144/249, 58%), infectious (19/249, 8%), nephrotoxicosis (14/249, 6%), or other (13/249, 5%). Hospital-acquired AKI was diagnosed in 9% (23/249) of the dogs. Median presentation and peak serum creatinine (sCr) concentrations were 4 mg/dL (range, 1.1-37.9) and 4.6 mg/dL (range, 1.1-43.1), respectively. Dogs were classified to AKI grades as follows: Grade I, 6 (2%), Grade II, 38 (15%), Grade III, 89 (36%), Grade IV, 77 (31%), and Grade V, 39 (16%). One hundred and sixty-four (66%) dogs survived. There was a positive association between death and AKI grade (P = .009). The case fatality rate was higher among dogs with anuria compared with dogs without anuria (50% vs 28%, respectively; odds ratio [95% confidence interval]: 2.5 [1.39-4.6]; P = .002). Forty-seven (18.8%) dogs underwent hemodialysis, of which 60% survived.

CONCLUSION AND CLINICAL IMPORTANCE

Two-thirds of dogs with AKI survived. Hospital-acquired AKI was common. The severity of AKI, as reflected by presence of anuria, AKI grade, and other body organs involvement, was associated with the outcome.

Comparative quantitation of aquaporin-2 and arginine vasopressin receptor-2 localizations among chronic kidney disease and healthy kidney in dogs

BACKGROUND AND AIM

Aquaporin-2 (AQP2) and arginine vasopressin receptor-2 (AVPR2) are proteins that control water homeostasis in principal cells. Chronic kidney disease (CKD) is defined as the impairment and irreversible loss of kidney function and/or structure, which causes water imbalances and polyuria. The study aimed to know the expression of AQPs and AVPR2 in the kidneys of a canine with CKD.

MATERIALS AND METHODS

The kidneys were collected from two dog carcasses from Small Animal Teaching Hospital, Faculty of Veterinary Medicine, Chiang Mai University. The kidney tissue was prepared for immunohistochemistry and investigated the expression and localization of tissue's AQP2 and AVPR2. For statistical analysis, the Mann-Whitney U-test was applied to the data.

RESULTS

By immunohistochemistry, AQP2 was expressed strongly in the basolateral and apical membranes of the principal cells, whereas AVPR2 was localized in the principal cell's basolateral membrane in both renal cortex and renal medulla. In the normal kidney, the semi-quantitative immunohistochemistry for the percentage of protein expression of AQP2 and AVPR2 was 5.062±0.4587 and 4.306±0.7695, respectively. In contrast, protein expression of AQP2 and AVPR2 in CKD was found to be 1.218±0.1719 and 0.8536±0.1396, respectively. The data shows that the percentage of AQP2 and AVPR2 expression was decreased, corresponding to a 4-fold and 5-fold in CKD (p<0.001).

CONCLUSION

Our findings revealed that CKD was a marked decrease in AQP2 and AVPR2 expression. The central role of specific AQP2 and AVPR2 in regulating water homeostasis will provide correlations in case of CKD with polyuria.

Focused Ultrasound Examination of Canine and Feline Emergency Urinary Tract Disorders

This article discusses the usefulness of ultrasound examinations in the management of the patient with an emergency urinary tract disorder. It discusses the use of previously described point-of-care ultrasound protocols such as the abdominal focused assessment with sonography for trauma, triage, and tracking protocol in the unstable azotemic patient. Point-of-care ultrasound examination can help direct investigations and expedite the diagnosis of specific causes of azotemia. The limitations of point-of-care ultrasound assessment of the kidneys, ureter, bladder, and urethra are also addressed, emphasizing that point-of-care ultrasound examination should complement and not replace a complete urinary tract ultrasound examination.

Effect of alprostadil in the treatment of intensive care unit patients with acute renal injury

BACKGROUND

Acute kidney injury (AKI) is a sudden or rapid decline in the filtration function of the kidneys which is marked by increased serum creatinine or blood urea nitrogen.

AIM

To examine the value of alprostadil-assisted continuous venous-venous hemofiltration (CVVH) in the treatment of severe AKI in severely ill patients.

METHODS

This was a retrospective study and the inclusion criteria were as follows: (1) Age of patients (≥ 18 years); (2) Admission to intensive care unit due to non-renal primary disease, APACHE II score (≥ 18 points); (3) The diagnostic criteria of AKI guidelines were formulated with reference to the Global Organization for the Improvement of Prognosis in Kidney Diseases, with AKI grades of II-III; (4) All patients were treated with CVVH; and (5) Complete basic data were obtained for all patients.

RESULTS

The clinical effect of alprostadil administered in the treatment group was better than that observed in the control group (P < 0.05). The urine output of patients in the alprostadil group returned to normal time (9.1 ± 2.0 d) and was lower than that in the control group (10.6 ± 2.5 d), the difference was statistically significant (P < 0.05); adverse reactions occurred in the alprostadil group compared with the control group, but the difference was not statistically significant (P > 0.05).

CONCLUSION

Alprostadil-assisted CVVH in the treatment of severely ill patients with AKI can effectively improve the renal resistance index and partial pressure of urine oxygen, and has a positive effect on improving renal function.

Acute on chronic kidney disease in dogs: Etiology, clinical and clinicopathologic findings, prognostic markers, and survival

BACKGROUND

Chronic kidney disease (CKD) and acute exacerbation of CKD (ACKD) are common in dogs.

OBJECTIVE

To characterize the etiology, clinical and laboratory findings, and short- and long-term prognosis of dogs with ACKD.

ANIMALS

One hundred dogs with ACKD.

METHODS

Medical records of dogs diagnosed with ACKD admitted to a veterinary teaching hospital were retrospectively reviewed.

RESULTS

The most common clinical signs included anorexia (84%), lethargy (77%), vomiting (55%) and diarrhea (37%). Presumptive etiology included inflammatory causes (30%), pyelonephritis (15%), ischemic causes (7%), other (3%), or unknown (45%). Median hospitalization time was 5 days (range, 2-29 days) and was significantly longer in survivors (6 days; range, 2-29 days) compared with nonsurvivors (4 days; range, 2-20 days; P < .001). Mortality rate was 35%. International Renal Interest Society (IRIS) acute kidney injury (AKI) grade at presentation was associated (P = .009) with short-term survival, but presumptive etiology was not (P = .46). On multivariable analysis; respiratory rate (P = .01), creatine kinase (CK) activity (P = .005) and serum creatinine concentration (SCR; P = .04) at presentation were associated with short-term outcome. Median survival time of dogs discharged was 105 days (95% confidence interval [CI], 25-184), with 35 and 8 dogs surviving up to 6 and 12 months, respectively. Presumptive etiology (P = .16) and SCR (P = .59) at discharge were not predictors of long-term survival.

CONCLUSION AND CLINICAL IMPORTANCE

Short-term outcome of dogs with ACKD is comparable to those with AKI but long-term prognosis is guarded. The IRIS AKI grade at presentation is a prognostic indicator of short-term outcome.