Markers of iron metabolism in retired racing Greyhounds with and without osteosarcoma

Abstract

Background: Greyhounds have well-described clinicopathologic idiosyncrasies, including a high prevalence of osteosarcoma (OSA). Hematocrit, HGB, and HGB oxygen affinity are higher than in other dogs, while haptoglobin concentration is lower, so we hypothesized that Greyhounds have a different iron metabolism. To our knowledge, there are no reports on serum iron profiles in Greyhounds.

Objectives: To elucidate iron metabolism in Greyhounds, we wanted to compare serum iron concentration, total iron-binding capacity (TIBC), and percent transferrin saturation (%SAT) in healthy retired racing Greyhounds (RRGs) with OSA (RRGs - OSA), and also with non-Greyhounds (NGs), without and with OSA (NGs - OSA).

Methods: Serum iron concentration and unsaturated iron-binding capacity (UIBC) were measured by standard methods, and TIBC and %SAT were calculated in RRGs (n = 25), RRGs - OSA (n = 28), NGs (n = 30), and NGs - OSA (n = 32).

Results: TIBC was lower in RRGs than in NGs (P < .0001), and in RRGs - OSA than in NGs - OSA (P < .0001). NGs - OSA had lower TIBC than healthy NGs (P = .003). Percent SAT was higher in RRGs than in NGs (P < .0001) and in RRGs - OSA (P = .008), and %SAT was also lower in NGs than in NGs - OSA (P = .004). Percent SAT was also higher in RRGs - OSA than in NGs - OSA (P = .001). Both RRGs - OSA (P = .02) and NGs - OSA (P < .0001) had lower serum iron concentrations than their healthy counterparts.

Conclusion: Lower TIBC and higher %SAT may constitute another Greyhound idiosyncrasy compared with other dogs. In this study, all dogs with OSA had higher serum iron concentrations and %SAT than healthy dogs.

Keywords: Dihydroartemisinin; iron sequestration; percent transferrin saturation; serum iron concentration; total iron-binding capacity.

Figure 1

Box-and-whisker plot of serum iron concentration in healthy retired racing Greyhounds (RRGs), RRGs with osteosarcoma (RRG–OSA), healthy Non-Greyhounds (NGs), and NGs with OSA (NGs–OSA). The box represents 2.5–97.5 percentiles, the horizontal line in the middle of the box represents the median, and the whiskers indicate the standard error.

Figure 2

Box-and-whisker plot of total iron-binding capacity (TIBC) in healthy retired racing Greyhounds (RRGs), RRGs with osteosarcoma (RRG–OSA), healthy Non-Greyhounds (NGs) and NGs with OSA (NGs–OSA). The box represents 2.5–97.5 percentiles, the horizontal line in the middle of the box represents the median, and the whiskers indicate the standard error.

Figure 3

Box-and-whisker plots of percent transferrin saturation (%SAT) in healthy retired racing Greyhounds (RRGs), RRGs with osteosarcoma (RRG–OSA), healthy Non-Greyhounds (NGs), and NGs with OSA (NGs– OSA). The box represents 2.5–97.5 percentiles, the horizontal line in the middle of the box represents the median, and the whiskers indicate the standard error.