A retrospective study of 3866 dogs with hyperlactatemia at a university teaching hospital found that metabolic acidosis, whether primary or part of a mixed disorder, was present in only 37.5% of cases, and that most hyperlactatemic dogs had concurrent acidifying and alkalinizing processes that traditional acid-base panels don't capture.
What the study found
Of 3866 dogs with plasma lactate >2 mmol/L at any point during hospitalization, traditional acid-base analysis identified abnormalities in 2586 dogs (66.9%). The most common primary disorder was respiratory acidosis in 609 dogs (15.7%). Metabolic acidosis, either primary or as part of a mixed disorder, was present in 1452 patients (37.5%).
Among 1755 dogs with data available for semiquantitative acid-base evaluation, the approach identified concurrent acidifying and alkalinizing effects in 1241 dogs (70.7%) when excluding the lactate effect. Unmeasured anions were the most frequent acidifying effect in 775 dogs (44.1%).
The most common disease associated with hyperlactatemia was gastrointestinal disorders in 1232 dogs (29.3%), and the most common mechanism was circulatory shock in 741 dogs (19.1%).
Metabolic acidosis was associated with higher mortality: 682 of 1452 dogs with metabolic acidosis died (46.9%) compared with 479 of 2414 without metabolic acidosis (19.8%) (p < 0.001). Type A hyperlactatemia (tissue hypoperfusion) was associated with higher mortality (374/717, 52.5%) than type B (metabolic derangement without hypoperfusion) (227/746, 30.4%) (p < 0.001).
How the study was built
Retrospective study at a single university teaching hospital. The authors reviewed records of 3866 dogs with various diseases and plasma lactate >2 mmol/L at any timepoint during hospitalization. All 3866 underwent traditional acid-base analysis (pH, bicarbonate, base excess). Among these, 1755 had sufficient data for semiquantitative acid-base evaluation, which accounts for strong ion difference, albumin, phosphate, and unmeasured anions.
The abstract does not state exclusion criteria, inter-rater reliability for disease classification, or whether the mortality analysis adjusted for confounders. We don't have the full methods, so we can't assess those design elements.
The number, and its error bars
This is observational data from one institution. The mortality difference between dogs with and without metabolic acidosis was statistically significant (p < 0.001), as was the difference between type A and type B hyperlactatemia (p < 0.001), but the study reports no confidence intervals or effect-size measures. It can show associations between acid-base status and outcomes, but it cannot prove that treating the acidosis differently would change survival. The population is dogs sick enough to be hospitalized at a referral center with lactate measured, so the findings may not generalize to outpatient or primary-care presentations.
What the authors say it cannot tell you
The abstract states that the semiquantitative approach "might be a valuable tool" to understand underlying mechanisms, which is conditional language acknowledging that the study does not prove the approach changes clinical decisions or outcomes.
The abstract does not list other limitations.
Who paid for it
The abstract does not state funding source or conflicts of interest.
What this means for your practice
VeterinaryPracticeNow's read, not the study's. Everything in this section is our editorial interpretation for practice owners. The study does not claim any of it.
If your ER protocol is lactate-based but you're not running a full acid-base panel with electrolytes and albumin, you're likely missing the compensatory mechanisms that determine case severity and prognosis. The study found that most hyperlactatemic dogs had concurrent acidifying and alkalinizing processes, a dog with elevated lactate from vomiting-induced metabolic alkalosis is a different clinical picture than one with lactic acidosis from septic shock, and a traditional pH-bicarb panel won't always tell you which you're looking at.
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The semiquantitative approach requires a blood gas analyzer that measures strong ion difference, albumin, and phosphate. If you're running lactate point-of-care but not a broader metabolic panel, the study's finding that concurrent processes were common suggests you're missing information that matters for case assessment. The mortality difference between type A and type B hyperlactatemia matters for prognosis conversations with clients, though the study doesn't give you a protocol for distinguishing the two in real time.