Introduction The study by Skinner et al. investigates the association between proteinuria and survival times in dogs diagnosed with lymphoma. The retrospective study aims to determine whether proteinuria at diagnosis impacts median survival times and whether lymphoma stage or type correlates with proteinuria prevalence. While the study provides valuable insights into a previously underexplored area, it has several methodological and interpretative limitations. Strengths Clinical Relevance – The study addresses an important question in veterinary medicine, as proteinuria is a common but often overlooked clinical finding in dogs with lymphoma. The findings could influence diagnostic and prognostic evaluations. Data Collection and Analysis – The study utilises a well-defined cohort of 86 dogs and employs appropriate statistical methods, including Kaplan-Meier survival analysis and log-rank testing, to assess differences in survival times. Exclusion Criteria – The study rigorously excludes dogs with potential confounders such as prior glucocorticoid treatment, renal lymphoma, or hypercortisolism, ensuring a more homogenous study population. Comparative Analysis – By classifying proteinuria using two different criteria (dipstick protein concentration and protein-to-urine specific gravity ratio), the study attempts to validate its findings through different methodological approaches. Limitations and Critique Retrospective Nature – The study is inherently limited by its retrospective design, which introduces selection biases and limits the ability to control for all confounding variables. A prospective study with standardised diagnostic protocols would provide stronger evidence. Lack of UPC Measurement – The study does not include urine protein-to-creatinine (UPC) ratios, the gold standard for quantifying proteinuria. Instead, it relies on urine dipstick tests and a protein-to-USG ratio, both of which have variable sensitivity and specificity. This may lead to misclassification of proteinuria status. Potential for False Positives – The use of urine dipstick tests is problematic, as dipsticks are prone to false-positive results due to factors such as alkaline urine (which was excluded but may still contribute to errors) or urinary tract infections that may have been undetected despite exclusion criteria. Limited Sample Size – While 86 dogs is a reasonable sample, stratification by lymphoma stage and type results in small subgroups, reducing statistical power. For example, only 12 dogs were classified with T-cell lymphoma, limiting meaningful comparisons between B-cell and T-cell groups. Uncontrolled Treatment Variability – The study acknowledges that treatment protocols varied widely, which could influence survival times independent of proteinuria status. The lack of standardisation in chemotherapy regimens, including variations in CHOP protocols, makes it difficult to isolate proteinuria as an independent prognostic factor. Lack of a Control Group – The absence of a control group of healthy dogs with proteinuria prevents conclusions about whether proteinuria in lymphoma cases is pathologically significant or merely incidental. Confounding by Age – Proteinuric dogs were significantly older than non-proteinuric dogs. Since age is an independent prognostic factor in lymphoma, it is unclear whether the observed reduction in survival is due to proteinuria itself or merely reflects an older population with concurrent comorbidities. Interpretation of Results The study finds a statistically significant difference in median survival times between proteinuric and non-proteinuric dogs, with shorter survival observed in proteinuric cases. While this suggests proteinuria may be a negative prognostic marker, causality cannot be established. Several alternative explanations exist: Proteinuria may simply be a marker of overall disease severity rather than a direct contributor to reduced survival. Older dogs, which were more likely to be proteinuric, may naturally have shorter survival regardless of lymphoma status. Proteinuria may indicate pre-existing renal dysfunction or other systemic conditions that impact prognosis independently of lymphoma. Conclusion and Future Directions Despite its limitations, this study highlights the potential prognostic importance of proteinuria in dogs with lymphoma. However, further research is needed to clarify the causal relationship. Prospective studies incorporating UPC measurements, standardised treatment protocols, and larger sample sizes would strengthen the findings. Additionally, investigating whether proteinuria resolves with lymphoma treatment or correlates with treatment response could provide further clinical insights. Until then, clinicians should interpret proteinuria in lymphoma cases cautiously, considering it alongside other prognostic indicators rather than as a standalone determinant of survival.