Table 1.
Summary statistics for diabetic dogs (n = 32) included in the study group.
Table 2.
Summary statistics for dogs stratified by serum glucose concentration.
Fig 1.
Classification of dogs by serum osmolarity or serum tonicity.
Classification of diabetic dogs as having normal tonicity (< 305 mmol/kg), mild hypertonicity (305–319 mmol/kg), moderate hypertonicity (320–329 mmol/kg), and severe hypertonicity (≥ 330 mmol/kg) using serum total measured osmolality (blue bars) or calculated tonicity (red bars). The effect of urea and other ineffective osmoles on total osmolality results in overestimation of the prevalence of severe hypertonicity in diabetic dogs.
Fig 2.
Contribution of measured effective osmoles to serum tonicity in insulin-treated diabetic dogs.
Glucose (green bar) contributed 5% of effective osmoles to serum tonicity in insulin-treated diabetic dogs. Sodium (blue bar) provided the majority of effective osmoles and with potassium (red bar) contributed a combined 95% of effective osmoles to serum tonicity. For simplicity, osmoles contributed by sodium and its corresponding anions and by potassium and its corresponding anions are represented, respectively, as ‘sodium’ and ‘potassium’ in the figure.
Table 3.
Serum tonicity and serum osmolarity in dogs stratified by serum glucose concentration ≥ 13.9 mmol/L (n = 17) or serum glucose concentration < 13.9 mmol/L (n = 15).
Fig 3.
Comparisons between OsMT and OsMC and OsMT and ST.
Panel A–Serum OsMT (open circles) and serum OsMC (open triangles) of individual dogs (n = 32) are shown. The mean osmolal gap (difference between measured and calculated total osmolality) was normal (< 10 mmol/kg). Mean OsMT and mean OsMC were not significantly different (p = 0.93). Panel B—OsMT (open circles) and calculated ST (crosses) of individual dogs (n = 32) are shown. The mean tonicity gap (difference between OsMT and calculated ST) was <10 mmol/kg. OsMT and calculated ST were significantly different (p = 0.0004).
Fig 4.
Relationships between dMCV and glucose, ST, and OsMT.
Panel A–The relationship between the dMCV and serum glucose in dogs with serum glucose concentration ≥ 13.9 mmol/L (blue diamonds) or < 13.9 mmol/L (red squares) is shown. The blue shaded area indicates dMCV values above the 3 μm3 cut-off used to classify dogs with serum hypertonicity. Panel B–Relationships between dMCV and ST (top) and OsMT (bottom) in dogs classified as described in Panel A. The blue shaded area indicates dMCV values above the 3 μm3 cut-off used to classify dogs with serum hypertonicity. The black dotted line indicates the cut-off (320 mmol/kg) that represents clinically relevant elevations in ST and OsMT.