Symmetric dimethylarginine correlates with the urea, creatinine, potassium, and clinical scores in feline urethral obstructions.

BACKGROUND: A urethral obstruction (UO) is an emergency commonly observed in male cats, which can result in significant clinical and laboratory alterations, leading to complications and death. OBJECTIVES: This study aimed to correlate symmetric dimethylarginine (SDMA) with the urea, creatinine, potassium, and bicarbonate levels in cats with UO. In addition, the correlation between clinical score and time of obstruction was evaluated. METHODS: Thirty male cats were selected and allocated into a control group (CG, n = 13) and an obstruction group (OG, n = 17). The laboratory analyses were conducted before treatment (M0) and at different times after treatment (12 h [M12], 24 h [M24], and 48 h [M48]). Correlations were established between SDMA and creatinine, urea, bicarbonate, potassium, time of obstruction, and the clinical score. RESULTS: A strong correlation (r > 0.6) was observed between SDMA and creatinine, urea, and potassium in the OG. Furthermore, there was substantial agreement (kappa value) between SDMA and creatinine at M24. A higher clinical score was associated with a longer time of obstruction. In the OG, at M48, the SDMA and creatinine levels were 50% and 41.2% higher, respectively. CONCLUSIONS: A correlation was observed between SDMA and creatinine in obstructed cats, and significant agreement between these values was observed 24 h after the unblocking treatment. A correlation among SDMA, urea, and potassium was observed. Approximately 9% more cats continued to have elevated SDMA levels after 48 h of treatment compared to creatinine. This suggests a slightly lower sensitivity of the latter biomarker but does not exclude the possibility of congruent and normalized values after a longer evaluation period.

Renal Magnesium Handling: A Comparison Between Dogs With Chronic Kidney Disease and Healthy Elderly Dogs.

Chronic kidney disease (CKD) and aging are known to possibly cause a progressive reduction in glomerular filtration rate, which may be associated with an increase in fractional excretion of electrolytes due to an adaptive response of the remaining functioning nephrons. However, the behavior of magnesium excretion has not been studied in CKD and healthy elderly dogs. The objective was to evaluate the fractional excretion of magnesium (FEMg) in dogs with (CKD) compared to healthy elderly dogs. Sixteen healthy elderly dogs and 43 dogs with CKD were divided into 3 groups (CKD 2 [n = 14], CKD 3 [n = 17], CKD 4 [n = 12]), in accordance with the current International Renal Interest Society (IRIS) criteria that were used in this study. Blood samples were obtained by jugular venipuncture and urine samples were obtained by cystocentesis. The FEMg was evaluated at a single time point in both urine and blood samples. FEMg was significantly higher in dogs with CKD compared to healthy elderly dogs, especially in advanced stages. This preliminary study demonstrates that FEMg may be altered in dogs with CKD. Further research is warranted to elucidate magnesium's potential role in cardiovascular and arterial calcification in dogs with CKD as observed in humans with CKD.

Glomerulotubular pathology in dogs with subclinical ehrlichiosis.

Subclinical stage of ehrlichiosis is characterized by absence of clinical or laboratory alterations; however, it could lead to silent glomerular/tubular changes and contribute significantly to renal failure in humans and animals. The aim of this study was to evaluate glomerular and tubular alterations in dogs with subclinical ehrlichiosis. We evaluated renal biopsies of 14 bitches with subclinical ehrlichiosis and 11 control dogs. Samples were obtained from the left kidney, and the tissue obtained was divided for light microscopy, immunofluorescence, and transmission electron microscopy. Abnormalities were identified by light microscopy in 92.9% of dogs with ehrlichiosis, but not in any of the dogs of the control group. Mesangial cell proliferation and synechiae (46.1%) were the most common findings, but focal segmental glomerulosclerosis and ischemic glomeruli (38.4%), focal glomerular mesangial matrix expansion (30.7%), mild to moderate interstitial fibrosis and tubular atrophy (23%), and glomerular basement membrane spikes (23%) were also frequent in dogs with ehrlichiosis. All animals with ehrlichiosis exhibited positive immunofluorescence staining for immunoglobulins. Transmission electron microscopy from dogs with ehrlichiosis revealed slight changes such as sparse surface projections and basement membrane double contour. The subclinical phase of ehrlichiosis poses a higher risk of development of kidney damage due to the deposition of immune complexes.

Learning curve for the laparoscopy-guided kidney biopsy procedure in small corpses of dogs and pigs.

The use of renal biopsy through laparoscopy is increasingly present both in human and veterinary medicine. However, both techniques require skill and training to make the operator capable to do it. The learning curve allows the quantitative and qualitative assessment of the number of attempts and minimum time for the surgical procedure. The objective included establish the learning curve for laparoscopy-guided kidney biopsy procedures in dog and pig corpses. Six dogs and six pigs corpses weighing less than 10 kg were used for this study. All corpses underwent kidney biopsy performed through laparoscopy. Twenty-four operators, two per animal, performed 20 renal biopsies each (10 for each kidney), with 480 collection-procedures in total. Duration and difficulty of the procedure and the biopsy sample quality were evaluated and statistical analysis was performed using a mixed regression model with a random effect of individuals and multivariate analysis of data. There were 91.5% of the samples that were adequate for evaluation. There was no significant difference in the number of glomeruli or cortex percentage considering the attempts in either species, demonstrating the operator's ability since first collection. Swine samples showed higher amounts of renal cortex than canine samples. The procedure duration was shorter as more attempts were performed in dogs and pigs. From the fourth repetition, the professional reached a plateau for the variable related to 'collection', and from the second, the professional presented uniform duration for 'sample storage'. Operators of the swine model acquired more agility than the dog ones. The variable 'difficulty' decreased as more repetitions were performed, reaching a plateau in the sixth attempt. Seven renal biopsies laparoscopy-guided are required for an operator to be considered 'capable' to perform the procedure in the referred species included. The learning curve for image-guided kidney biopsy procedures improves the implementation of this technique and benefits patients that undergo this procedure.

Future strategies to improve short- and long-term outcomes of renal transplantation in dogs / Estratégias futuras para melhorar os resultados de transplante renal em cães a curto e longo prazo

ABSTRACT: Transplants for cats with naturally occurring renal disease have been introduced into clinical practice, but canine renal transplantation represents a greater challenge because of the lack of a balanced immunosuppressive protocol, difficulty in selecting compatible canine kidney donors, and absence of transplantation monitoring protocols. This and other important factors will be discussed in this review to help improve short- and long-term outcomes for renal transplantation in dogs.

RESUMO: O transplante renal em gatos com doença renal naturalmente adquirida está cada vez mais sendo introduzido na prática clínica. O transplante renal em cães, por sua vez, representa um desafio maior devido a falta da definição de um protocolo imunossupressor equilibrado, dificuldade na seleção de doadores compatíveis e ausência de protocolos de monitoramento de transplantes. Esses e outros fatores serão abordados nesta revisão afim de melhorar os resultados, tanto a curto quanto a longo prazo do transplante renal em cães.