Handheld point-of-care blood analyzers deliver rapid results for biochemical and hematologic parameters, making them very useful in veterinary clinics and in fieldwork applications. This study compared the biochemical and hematologic parameters generated by the novel point-of-care analyzer i-STAT® Alinity V CHEM8+ cartridge between human-managed and free ranging populations of southern white rhinoceros (Ceratotherium simum simum). In addition, a novel reference interval for ionized calcium (iCa), a parameter of diagnostic and prognostic importance, was established for southern white rhinoceros. Blood samples were obtained from 10 managed (6 at NC Zoo and 4 at Busch Gardens Tampa Bay in 2019) and 30 free ranging white rhinoceros (collected in South Africa between 2018 and 2019) and analyzed using the i-STAT. Multiple parameters were higher ( ) in free ranging versus managed animals including potassium, blood urea nitrogen, creatinine, glucose, hematocrit, and hemoglobin. Conversely, iCa concentrations were higher ( ) in the managed populations of white rhinoceros. The RI determined for iCa was 1.36–1.56 mmol/L, with a mean of 1.46 mmol/L, and was determined using the guidelines from the American Society for Veterinary Clinical Pathology. There was no difference in anion gap, chlorine, total carbon dioxide, or sodium between the populations. Seasonality and locality of sampling as well as diet may be contributing factors to the higher iCa concentrations in managed rhinoceros. The six elevated parameters in free ranging rhinoceros are likely attributable to dehydration compounded by capture stress. This data provides insight into the state of several biochemical and hematologic parameters in southern white rhinoceros and will allow veterinarians to better assess the health of both managed and free ranging populations.

Fatty acids, especially omega-3 and omega-6 fatty acids, are important for reproductive and cardiovascular health in animals. While monitoring fatty acids is traditionally conducted using frozen blood fractions such as serum and plasma, advancements in analytical technology have developed a method of collecting microsamples of dried whole blood on Ahlstrom 226 grade filter paper that can provide information on long-term fatty acid status of animals. Blood samples were collected from five male pigs in both the traditional frozen method and on dried blood spot cards (DBS). The DBS samples were collected with untreated syringes and tubes, and approximately 320μL of blood was placed on each card with approximately 80μL per spot (4 spots). Statistical analysis was performed to compare the two sample groups to each other using the MannWhitney U-test and determine if DBS samples were similar to traditional whole blood samples. Of the 30 fatty acids and fatty acid groups with measurable concentrations, only four individual fatty acids, behenic acid, omega-3 docosapentaenoic acid, nervonic acid, and adrenic acid, had statistical differences. Most of these differences were minor and could be due to analytical errors or contamination. Comparisons between sample types found similar concentrations of key omega fatty acids and PUFAs and support the use of DBS collection as a less invasive method of blood collection and fatty acid analysis.

Southern white rhinoceroses (Ceratotherium simum simum) are African megaherbivores that are considered near threatened by the International Union for the Conservation of Nature. The fatty acid circulating values of these animals have not been thoroughly investigated. Fatty acids are critical for immune, heart, skin, and reproductive health, and may have a significant impact on the management and conservation of this species. Published data on fatty acids in this species is limited to incomplete profiles with very few animals in managed environments. The objectives of this research were to provide novel fatty acid percentage profiles for managed healthy southern white rhinoceroses, as well as to provide comparisons between two zoological institutions with differences in diet and climate during two distinct pasture growth periods. Whole blood samples were collected as dried blood spots from six rhinoceroses at the North Carolina Zoo (NC Zoo) and five rhinoceroses at Busch Gardens Tampa (BGT) in the low growth period (February to April) of 2019 and during the high growth period (July to September) of 2020. Fatty acid results indicated numerous differences when comparing the institutions within the same growth period and when comparing the same institution between its two growth periods. Most noteworthy were the higher levels of α-linolenic acid (18:3w3) and total omega-3 fatty acids and the lower linoleic acid (18:2w6), total omega-6 fatty acids, and omega-6 to omega-3 ratio found in the BGT population in both growth periods. This study provides novel percentages of fatty acids in managed southern white rhinoceroses and data on how fatty acid profiles may be altered between two housing locations via dietary differences in hay type and quantity, pasture availability via season, and pellet inclusion levels.

We used nuclear magnetic spectroscopy (NMR) to evaluate the metabolomics of heparinized whole blood drawn from six African savanna elephants (Loxodonta africana) maintained on a well characterized diet. Whole blood samples obtained under behavioral restraint, then quickly frozen in liquid nitrogen, were stored at −80 °C until analysis. Frozen samples were thawed under controlled conditions and extracted with methanol and chloroform to separate the polar and non-polar metabolites. We identified 18 polar metabolites and 14 non-polar lipids using one-dimensional (1D) and two-dimensional (2D) NMR spectra. Despite unexpected rouleaux formation in the thawed frozen samples, spectra were consistent among animals and did not vary dramatically with age or the sex of the animal.