Size Matters: Zoo Data Analysis Shows that the White Blood Cell Ratio Differs between Large and Small Felids

Abstract

<jats:p>The total number of white blood cells (WBCs) is related the immune system. In mammals, it is affected by the body mass, but it is unclear how the numbers of different WBC types correlate with this parameter. We analyzed the effect of body mass on WBC number and ratio in felids, where species are similar in diet (warm-blood vertebrates) and reproductive strategy (promiscuity). Based on zoo veterinary data (ZIMS database) we analyzed the effect of body mass on WBC number and neutrophils/lymphocytes ratio in 26 species of felids. The number of WBCs correlated with the body masses of animals: large cats had more WBC, which may be due to greater risks of infection associated with larger body surface, lifespan and home range size. For the first time we found obvious differences in the number of WBC types. Large cats also had more neutrophils and monocytes but fewer lymphocytes than smaller cats. The ratio of neutrophils to lymphocytes is greater in large felids. This phenomenon may be related to diet (relative prey size and kill utilization time), which suggests regular contact of large cats with bacterial and protozoal pathogens in contrast to the small cats.</jats:p>

Hematological and Biochemical Reference Values in Healthy Captive Tigers (Panthera tigris)

“…Furthermore, the results of blood tests conducted in wild animals provide baseline values for future studies and may help to support conservation strategies [ 13 ]. Hematological analysis provides information on potential oxygen transportation, blood coagulation and immunity [ 14 ]. These parameters together with blood chemistry are used in both human and veterinary medicine to help diagnose diseases, to establish disease processes and to monitor the progression of disease.…”

“…There are few literature descriptions of hematological and serum biochemical values in wild felids. A large amount of data is available on the international database International Species Information System (ISIS) and the ZIMS database [ 20 ], which collates the results of hematological and biochemical measurements from zoos around the world [ 14 ]. Unfortunately, information about sex, age and health status of individual subjects (which may influence hematological and biochemical parameters) is not always available on this database.…”

Leukocytes count and profile during early postnatal ontogenesis in domestic cats: Effect of litter size and multiple paternity

“…The limits of normal hematological parameters for farm animals have long been known (Meyer & Harvey, 2007). The last three decades, many studies have been conducted to find out the influence of various factors on leukocyte profiles and identify their normal values for many mammalian species (Gabunshchina, 2012; Novozhilov, 2009; Obanda et al, 2014; Rietkerk et al, 1994; Seltmann et al, 2017), including carnivores (Naidenko & Alshinetskiy, 2020; Pavlova et al, 2018; Royer & Anderson, 2014; Thoresen et al, 2009) to interpret hematological parameters correctly (Davis & Maney, 2018). Hematological profiles may differ significantly even in taxonomically closely related species (Naidenko & Alshinetskiy, 2020), depending, for example, on their habitats (Hellgren et al, 1993; Lacey et al, 2000).…”

“…Most often, the obtained hematological data from in situ populations are compared to the reference values adopted for domestic cats, which are well known (Earle et al, 1990;Tvedten, 1981;Weiss & Wardrop, 2010;Harvey et al 2012). At the same time, significant changes in the number and ratio of various forms of leukocytes associated with the body mass of the species have been observed in different cat species (Naidenko & Alshinetskiy, 2020). However, a number of other factors can have a significant effect on blood parameters, in particular the number of leukocytes: population density (Lazutkin et al, 2016;, pregnancy (Roy et al, 2010), lactation (Alekseeva et al, 2020), diseases (Kocan et al, 1985;Osbaldiston, 1978) or age.…”

“…The data on hematology of wild cats are very limited and mainly restricted by the description of species-specific parameters (Shanmugam et al, 2017;Shrivastav & Singh, 2012) or interspecies comparisons (Naidenko & Alshinetskiy, 2020;Naidenko et al, 2019). Significant progress in the study of the feline family is achieved mainly by researching the domestic cat as a model species (Pope, 2000;Shatz & Palme, 2001;Tsutsui, 2006), subsequently the data and developed methods are used to preserve wild felines (Jewgenow et al, 2006;Naidenko et al, 2011;Painer et al, 2014;Pribbenow et al, 2014;Veraguas et al, 2017).…”