Retrospective evaluation of the association between admission blood glucose and l‐lactate concentrations in ponies and horses with gastrointestinal disease (2008‐2016): 545 cases

Abstract

Objectives A recent study described increased l‐lactate concentrations in ponies with gastrointestinal disease compared to horses, but blood glucose (BG) concentrations were not considered. The study tested the hypothesis that BG and l‐lactate concentrations are correlated in horses and ponies with gastrointestinal disease and that BG concentrations, not equid type (pony vs horse), are an independent predictor of L‐lactate concentrations. It was further hypothesized that equid type was an independent predictor of BG concentrations. Design Retrospective study 2008–2016. Setting University teaching hospital. Animals Admission data from 545 animals (384 horses and 161 ponies) with gastrointestinal disease. Interventions None. Measurements and Main Results Data collected included signalment, clinicopathological findings on admission, and nature and location of the gastrointestinal lesion (strangulating vs non‐strangulating and large vs small intestinal lesion). The association between admission blood l‐lactate concentrations, equid type (pony or horse) and BG concentrations was investigated in a multivariable model. Admission l‐lactate and BG concentrations were strongly correlated (n = 522; r = 0.63; P < 0.001). Ponies had significantly higher l‐lactate (2.7 mmol/L (0.5–18.0 mmol/L) vs 1.4 mmol/L (0.3–19 mmol/L); P < 0.001) and BG concentrations than horses (8.4 mmol/L (4.2–24.4 mmol/L); 151 mg/dL (76–439 mg/dL) vs 6.9 mmol/L (3.4–26.8 mmol/L); 124 mg/dL (61–482 mg/dL); P < 0.001). In the multivariable analysis, l‐lactate concentrations were significantly and positively associated with admission BG concentrations in all animals and also with equid type. For each millimole per liter (18 mg/dL) increase in BG, l‐lactate concentrations increased by 7.9% (5.9, 9.9); P < 0.001. In comparison to ponies, l‐lactate concentrations were decreased by 27.7% (37.4, 16.5); P < 0.001 in horses. Admission BG concentrations were significantly and positively associated with l‐lactate concentrations in all animals. For each millimole per liter increase in l‐lactate concentration, BG concentration increased by 6.2% (4.7, 7.6; P < 0.001). Admission BG concentrations were not associated with equid type. Conclusion Admission BG concentrations and equid type are independent predictors of blood l‐lactate concentrations in equids with gastrointestinal disease, but their relationship requires further investigation.

Correlation betweenl‐lactate and glucose concentrations and body condition score in healthy horses and ponies

“…Similar to previous studies, ponies compared to horses had higher average BCS and higher heart girth:height and lower neck length:heart girth ratios, indicating that adiposity was more widespread in ponies. Contrary to expectations and in contrast to previous studies in horses and ponies with gastrointestinal disease, healthy ponies had significantly lower blood l ‐lactate concentrations compared to horses. l ‐lactate concentrations were weakly, but significantly, associated with measures of adiposity.…”

“…In recent studies investigating ponies and horses with gastrointestinal disease, blood l ‐lactate and glucose concentrations on admission were higher in ponies compared to horses regardless of the primary lesion . The investigators speculated that ponies could have higher resting l ‐lactate concentrations either as a result of differences in body condition (BC), particularly obesity, or underlying metabolic differences such as a comparatively lower insulin sensitivity in ponies.…”

“…Lactate concentrations, therefore, reflect the state of cellular metabolism, and increased concentrations are thought to be an early signal of emerging insulin resistance . Ponies, particularly obese ponies, are less sensitive to insulin as compared to large breed horses, which could be a reason for the observed higher l ‐Lactate concentrations in ponies with gastrointestinal disease . Administration of exogenous corticosteroids to healthy horses decreases insulin sensitivity and increases l ‐Lactate concentrations, and increased free cortisol concentrations have been identified in overweight and obese equids .…”

Variations in haematological and biochemical parameters in healthy ponies

“…The differences between full-sized horses and ponies in glucose and insulin metabolism, oxidative capacity and response under sympathetic stimulation are widely reported in the literature [21-23, 35, 45]. Although higher glucose concentrations, re ecting metabolic differences have been clearly shown in ponies with gastrointestinal diseases [45], these differences are frequently not noticeable at rest but only during dynamic response testing [18,21].…”

Clinical Pathology in the Adult Sick Horse

“…12 This difference may be explained by carbohydrate metabolism via the Cori cycle, in which blood glucose (which also was found to be higher in the study ponies) leads to the generation of lactate. 13 Increased liver enzyme activities occasionally are observed in horses presented for acute gastrointestinal disorders and likely reflect anatomic proximity of the 2 organ systems and direct communication via the biliary system and portal circulation. A retrospective study examining horses with colic observed that increased g-glutamyltransferase (GGT) activity was observed in 49% of horses with right dorsal displacement but only 2% of horses with left dorsal displacement of the large colon, a finding attributed to extrahepatic biliary obstruction from bile duct compression by the displaced colon.…”