Pregnancy diagnosis in urine of Iberian lynx (Lynx pardinus)

Pregnancy diagnosis and sex identification with urinary glycopatterns of two mammal species

Glycome in urine could be promising biomarkers for detecting pregnancy diagnosis and sex noninvasively for animals, especially for rare species. We explore the applicability of grouping golden snub-nosed monkeys by sex or diagnosing pregnancy based on their urinary glycopatterns, which are determined via lectin microarray combining mass spectrometry analysis. Sprague-Dawley rats are used to verify whether this approach and whether the glycomic biomarkers can be generalized to other mammalian species. The results show that, for both species, lectin microarray combining mass spectrometry can distinguish individuals' pregnancy status and sex; significant differences are found in the types, amounts, and terminal modification of glycans between pregnant and non-pregnant females and between females and males. This indicates the approach could be generalized to other mammalian species to group sex and detect pregnancy, yet the glycopatterns appear to be species-specific and markers developed from one species may not be directly applicable to another.

Monitoring ovarian function and detecting pregnancy in felids: A review

Reliable detection and monitoring of estrus and pregnancy is essential to the effective ex situ conservation of endangered felids. Here, we review the current methods used to detect estrus and pregnancy in felids and describe the advantages and limitations of each. A total of 194 felid-focused publications were reviewed. The methods used included behavioral assessments (61 publications across 24 species), hormone monitoring (124 studies across 28 species), fecal protein monitoring (two studies in cheetah), ultrasonography (31 publications across seven species), vaginal cytology (22 publications across nine species), and laparoscopy (70 publications across 19 species). Behavior-based assessments of reproductive state are often inconsistent and unreliable in felids; thus hormone measurement is the most frequently used method for monitoring estrous cycles (66% of studies). In non-domestic felids, non-invasive fecal- or urine-based hormone metabolite analyses are preferred to blood assessments (66% of endocrine-based publications). While the measurement of fecal estrogen and progestin metabolites are useful for the retrospective assessment of ovarian activity, their use for real-time detection of estrus is limited. Vaginal cytology, laparoscopy and ultrasonography provide an acute and immediate determination of reproductive state but usually require anesthesia or sedation, which can prevent ovulation and cause abortions; thus, their use for pregnancy diagnosis is limited. Fecal progesterone or prostaglandin F_2α metabolites can be used to detect pregnancy in most felids (the exception being fecal progestins for Lynx spp.), but only during mid-to-late gestation. Urinary relaxin measurement is a promising method for earlier pregnancy diagnosis (30-40% duration of gestation) but is presently limited by poor assay sensitivity due to the lack of a feline-specific relaxin antibody. Elevated levels of fecal immunoglobulin J chain have been investigated as a tool to detect pregnancy in cheetah (>80% accuracy), but research is lacking on other species. We conclude that there is no single 'best method' for monitoring ovarian activity and detecting pregnancy in felids, and current best practice would involve a combination of existing methods. Non-invasive methods for detecting estrus and pregnancy in felids (e.g., accelerometry and infrared thermography) should also be considered to augment existing methods.

Toxoplasma gondii in small exotic felids from zoos in Europe and the Middle East: serological prevalence and risk factors

BACKGROUND

Toxoplasma gondii infections and cases of clinical toxoplasmosis have been recorded in zoo animals. Wild felids in human care can serve as definitive hosts that shed oocysts, but also as intermediate hosts for the parasite. Some felid species, such as the Pallas's cat (Otocolobus manul) or sand cat (Felis margarita), may suffer from clinically apparent toxoplasmosis. In the present study, our main aim was to assess risk factors for T. gondii infections in small exotic felids.

METHODS

A seroepidemiological study was conducted using the reduviid bug Dipetalogaster maxima for blood sample collection, a method previously evaluated on domestic cats. A total of 336 samples from 17 felid species were collected in 51 institutions, 48 of which were within Europe and the remaining three in the Middle East (United Arabic Emirates and Qatar). These samples were analyzed for T. gondii antibodies by immunoblotting and an immunofluorescent antibody test. Potential risk factors in zoos for seropositivity regarding T. gondii among members of the European Association of Zoos and Aquaria (EAZA) were evaluated using a questionnaire and individual data from the Zoological Information Management System (ZIMS).

RESULTS

The sampled felids showed an overall seroprevalence for T. gondii of 63%. The risk factor study including data of 311 small exotic cats of 10 species resulted in a final generalized linear mixed model comprised of five variables: the likelihood of seropositivity increased statistically significantly with "Age", while feeding "Cattle: frozen" relative to "Cattle: fresh", "Outdoor housing fenced in on all sides", "Mesh size 2-5 cm" relative to "Mesh size > 5 cm" and "Wearing gloves: yes" had statistically significant protective effects.

CONCLUSIONS

Wild felids, including endangered species, kept in human care in European and Middle Eastern institutions, are widely exposed to T. gondii. Risk factor analysis revealed that feeding previously frozen tissues, keeping animals in enclosures that are fenced on all sides using fences with small mesh sizes, and wearing gloves when working inside enclosures seem to be the most relevant protective measures to prevent T. gondii infections in these animals .

Steroidogenic enzymes, their products and sex steroid receptors during testis development and spermatogenesis in the domestic cat (Felis catus)

In the present study we comprehensively characterize intratesticular sex steroid production, metabolism and receptors in the domestic cat to elucidate the role of testosterone, estradiol and progesterone in testis development, steroid synthesis and spermatogenesis. There is a great demand for new concepts of fertility control in domestic (feral) cats and wild felids. The acquired knowledge will help to understand the regulation of spermatogenesis in felids, and may reveal new target points for male contraception. Progesterone and androgens are produced throughout all stages of testicular development; their synthesizing enzymes are mainly expressed in Leydig cells, and to a much lesser extent also in tubular cells. Aromatase (CYP19A1), the estrogen synthesizing enzyme, is only present in the tubuli and is first detectable in spermatocytes and round spermatids at puberty. As shown by elevated expression of the enzymes steroid 5-α-reductase type 1 (SRD5A) and aldo-keto-reductase family 1 member C3 (AKR1C3), the capacity to metabolize particular steroids increases during testis development. Apparently, this refers to a decreasing intra-testicular testosterone concentration per mg tissue with increasing testis weight during postpuberty. The increasing potential of sulfation of E2 by estrogen sulfotransferase (SULT1E1) with ongoing development might be responsible for the low level of unconjugated intratesticular estradiol in all stages of development probably due to facilitated excretion of conjugated estrogens. For the first time, expression of the progesterone membrane receptor components 1 and 2 (PGRMC1, PGRMC2) was studied in mammalian testis tissue. Both of these and also the progesterone receptor (PGR) are expressed depending on the developmental stage and cell type, suggesting an important regulatory role of progesterone in the testis. Androgen receptor (AR) is present in almost all cell types except for some spermatogenic cells. The co-localization of aromatase with estrogen receptor alpha (ESR1) in spermatocytes and round spermatids of domestic cat testis indicates an auto-/paracrine function of estrogen in spermatogenesis. In summary, the testis of the domestic cat is an important source of sex steroids. All of them could act within the testis but additionally, at least androgens and estrogens are likely secreted by the testis, partly as conjugated steroids.

Non-Invasive Pregnancy Diagnosis in Big Cats using the PGFM (13,14-dihydro-15-keto-PGF2α) Assay

Non-invasive monitoring of hormones using feces has become a vital tool for reproductive management and reliable pregnancy diagnosis in big cats. Previous studies described the PGF_2α metabolite (PGFM) as an indicator of pregnancy in various feline species. The present study aimed to standardize pregnancy detection in big cats like the tiger (Panthera tigris), jaguar (Panthera onca) and lion (Panthera leo) using fecal samples. High-performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LCMS) were performed to identify PGFM in feces. An EIA developed against 9α,11α-dihydroxy-15-oxo-prost-5-en-1-oic acid-BSA was used to assay PGFM in fecal samples of the Bengal tiger, Asiatic lion and jaguar. The PGFM levels increased after 9 weeks of pregnancy and remained elevated until parturition. All animals showed elevated levels of PGFM in the last trimester of pregnancy, thus making PGFM a reliable tool for pregnancy diagnosis during this period that can be useful in captive breeding programs in these species.

Comparative analysis of intraluteal steroidogenic enzymes emphasises the functionality of fresh and persistent corpora lutea during pro--and metoestrus in the lynx

European lynx species demonstrate an atypical ovarian cycle compared to other felids. The physiological persistence of corpora lutea (CLs), reflected in constantly elevated progesterone (P4) concentrations in serum, is thought to ensure a seasonal monooestrus. Moreover, the coexistence of CLs from a recent ovulation (freshCLs) and persistent CLs from previous years (perCLs) on the same ovary has been proven. We assume that perCLs in lynxes occur due to fundamentally different mechanisms of luteal regression. Our study presents a detailed analysis of steroidogenic enzymes and steroids in fresh and perCLs obtained from Iberian lynxes during metoestrus, and in perCLs obtained from Eurasian lynxes during prooestrus. By quantitative PCR we measured relative mRNA amounts of steroidogenic acute regulatory protein (STAR), cytochrome P450 oxidases (CYPs), hydroxysteroid dehydrogenases (HSDs) and a steroid reductase (SRD). Protein expression in CLs was investigated for CYP11A1, CYP17A1, CYP19A1 and HSD3B. Additionally, the intraluteal and serum steroid content was determined. During metoestrus, mRNA amounts of STAR, CYP11A1, CYP19A1, HSD17B7 and SRD5A1 were significantly higher in perCLs compared to freshCLs. Protein of CYP11A1 was detected independently of the CL age in metoestrus, but expression was less evident in prooestrous perCLs. The protein signal of CYP17A1 was strong in freshCLs and perCLs of metoestrus, but weak at prooestrus. The presence of CYP19A1 protein was confirmed in each stage of the CL. These findings contribute to the hypothesis that CLs from previous years might support freshly developed CLs for pregnancy maintenance. However, initiation of ovulation might require a functional down-regulation of perCLs prior to breeding. It is noteworthy that the HSD3B1 mRNA amount was significantly elevated in fresh compared to perCLs (metoestrus). Accordingly, HSD3B protein was substantially present in freshCLs, whereas signals were literally absent in all perCLs. Elevated expression of HSD3B coincided with high intraluteal oestrogen concentrations in freshCLs; however, the enzyme pattern was less concordant with intraluteal P4 and androgen concentrations. Serum P4 concentrations of Iberian lynxes were constant between prooestrus and prolonged dioestrus. Moreover, constantly high serum oestrogen concentrations were measured during pro-, met- and prolonged dioestrus. The physiology of exceptionally high serum oestrogen concentrations outside the breeding season of lynxes merits further investigation. In conclusion our study supports the concept that the unique reproductive strategy of lynxes is directly linked to sustained intraluteal steroid biogenesis in persistent CLs.

Relaxin: a hormonal aid to diagnose pregnancy status in wild mammalian species

In the beginning of 1960s, seminal studies characterizing circulating concentrations of immunoreactive relaxin in companion dogs and evaluating the differences in concentrations among pregnant, nonpregnant, and pseudopregnant bitches indicated the potential for relaxin to be applied clinically as a diagnostic aid to detect pregnancy status in wild animal species. A brief historical overview of the nature of relaxin and early work to develop and validate immunologic methods to analyze relaxin in the blood of rodents and pigs is initially discussed, which is followed by a summary of the development and validation of relaxin immunoassays to diagnose pregnancy in companion dogs and cats. Thereafter, observation of the pregnancy-specific increase in circulating concentrations of relaxin in laboratory, companion, and farm animal species leads to discussion on the application of radioimmunoassays, enzyme immunoassays, and a rapid immunomigration assay to diagnose pregnancy in wild terrestrial (e.g., wolves, lions, elephants, rhinoceros, panda) and marine (e.g., seals, dolphins) mammal species. A reference table is included with a comprehensive list of numerous species and essential reagents that have been used in various in-house and commercial immunoassays to successfully analyze relaxin quantitatively and qualitatively in blood (serum or plasma) and to some extent in urine. Although the detection of relaxin concentrations has the potential to aid in the diagnosis of pregnancy in many wild animal species, there are challenges in other species. Future efforts should focus on validation of nonradiolabeled relaxin immunoassays for broader application among species and improving techniques (e.g., extraction, purification) to analyze relaxin in samples other than blood (e.g., urine, feces, saliva, blow, skin, blubber) that can be collected in a less-invasive or -stressful manner and processed accordingly for basic and applied purposes, especially with application toward conservation of threatened or endangered species.

The use of noninvasive and minimally invasive methods in endocrinology for threatened mammalian species conservation

Endocrinology is an indispensable tool in threatened species research. The study of endocrinology in threatened species not only advances knowledge of endocrine mechanism but also contributes to conservation efforts of studied species. To this end, endocrinology has been traditionally used to understand reproductive and adrenocortical endocrine axes by quantifying excreted steroid metabolites. From these studies a large body of knowledge was created that contributed to the field of endocrinology, aided conservation efforts, and created a template by which to validate and conduct this research for other species. In this regard noninvasive hormone monitoring has become a favored approach to study the basic endocrinology of wildlife species. Due to the increased understanding of endocrine physiology of threatened species, breeding rates of captive population have improved to levels allowing for reintroduction of species to restored natural ecosystems. Although these approaches are still employed, advances in biochemical, molecular, and genomic technologies are providing inroads to describe lesser known endocrine activity in threatened species. These new avenues of research will allow for growth of the field with greater depth and breadth. However, for all approaches to endocrinology, limitations on resources and access to animals will require innovation of current methodologies to permit broad application for use in threatened species research.

Comparative metabolism of PGFM (13,14-dihydro-15-keto-PGF2α) in feces of felids

Methods for monitoring endocrine activities are useful tools for reproduction management. In particular, captive breeding of endangered felid species is considered to be an important part of the species conservation efforts. Within breeding programs, reliable methods for pregnancy diagnosis are highly demanded to prevent peri- and postpartal losses, but pregnancy diagnosis based on gestagen metabolites in felids is hampered by pseudopregnancies. Recently, we described fecal PGFM as an indicator for pregnancy in several feline species, but peak levels of PGFM secretion differed dramatically between species. It is believed that prostaglandin composition and metabolism pathways may differ as well. Therefore, a study was devised to both compare various fecal immunoreactive PGFM metabolites and to identify prostaglandins in fecal extracts by liquid chromatography-mass spectrometry (LCMS). Our results confirmed that fecal metabolite patterns differ between feline species. The identity of PGFM was confirmed in six of eight felids. In Iberian lynx and the Sumatran tiger, PGFM did not exceed 5% of all immunoreactivities. The total number of immunoreactivities varied between two (e.g., domestic cat) and four (e.g., oncilla). Several prostaglandins were identified by LCMS; apart from PGFM, all LCMS-identified prostaglandins, including tetranor-PGFM, did not show any cross-reactivity with our PGFM-specific antibody. This indicates the existence of still unknown eicosanoids and further studies are needed to clarify the origin of the different metabolites. Although differing stages of pregnancy did not reveal significant differences in the composition of metabolites, we could not exclude the possibility that metabolites from other prostaglandins (e.g. PGE2) contributed to the fecal metabolite patterns.

Progesterone and estradiol in cat placenta--biosynthesis and tissue concentration

Ovarian and placental steroids are essential for the maintenance of pregnancy. In some mammals it is evident that the placenta is responsible for the production of steroids. However, in the domestic cat, steroid secretion from the placenta has not yet been elucidated. Our study aimed to find out whether feline placentae are able to produce steroids. Placentae from different pregnancy stages were analyzed for mRNA expression of five steroidogenic enzymes (HSD3B1, CYP11A1, CYP17A1, HSD17B1 and CYP19A1) and for tissue concentrations of progesterone and estradiol. Steroidogenic enzymes responsible for the final steps of estradiol (CYP19A1) and progesterone synthesis (HSD3B) were expressed at very high levels and followed almost the same pattern over pregnancy as the intraplacental hormones themselves. By contrast, the other enzymes were found in very low quantities suggesting that biosynthesis occurs via extra-placental steroid precursors. The plasma steroid profiles measured by other groups differ from the placental hormone courses determined by us; therefore we conclude that the feline placenta can produce progesterone and estradiol.

Less invasive blood sampling in the animal laboratory: clinical chemistry and haematology of blood obtained by the Triatominae bug Dipetalogaster maximus

Dipetalogaster maximus (Dipmax), a blood-sucking bug belonging to the family Reduviidae, has been used to obtain blood samples, for example for clinical chemistry and haematology, in a variety of zoo animals and wildlife. Using this bug allows stress-free blood sampling as the bug is able to draw blood without the mammal noticing the bug. In laboratory animal science, the need for blood samples from unstressed animals may arise, especially in animal behaviour research. The use of Dipmax bugs may prove a valuable tool for this purpose. To validate the method, we compared an array of standard blood parameters sampled from New Zealand White rabbits, sampled either by the use of bugs or by the conventional method; puncture of vena auricularis caudalis. The overall hypothesis was that there was no significant difference in clinical chemistry and haematological parameters between the bug method and the conventional method. A total of 17 clinical parameters as well as 12 haematological parameters were measured and compared in New Zealand White rabbits. The results showed that for 13 of these 29 analysed parameters, the bug method and the conventional method did not give significantly different results, and the obtained results were thus directly comparable. For the remaining parameters the obtained results were significantly different. However, all parameters were measurable in the bug samples. The influences of the bug metabolism on these parameters are discussed.

Patterns of ovarian and luteal activity in captive and wild Canada lynx (Lynx canadensis)

Canada lynx face some unique breeding restrictions, which may have implications for population viability and captive management. The goal of this study was to improve our understanding of basic reproductive physiology in Canada lynx. Using fecal hormone metabolite analysis, we established normative patterns of fecal estrogen (fE) and progestagen (fP) expression in captive and wild female Canada lynx. Our results indicate that Canada lynx have persistent corpora lutea, which underlie their uncharacteristic fP profiles compared to other felids. Thus, fP are not useful for diagnosing pregnancy in Canada lynx. We also found that Canada lynx are capable of ovulating spontaneously. Captive females had higher concentrations of fE and fP than wild females. Both populations exhibit a seasonal increase in ovarian activity (as measured by fE) between February and April. Finally, there was evidence of ovarian suppression when females were housed together.

Validation of a less invasive blood sampling technique in rabies serology using reduviid bugs (Triatominae, Hemiptera)

During serologic rabies surveys, bleeding is often difficult or almost impossible in small or endangered mammals such as bats. Therefore, the usefulness of an alternative, less invasive technique--that is, the use of blood-sucking reduviid bugs (Dipetalogaster maximus and Rhodnius prolixus)--was investigated. Bugs were used in combination with a conventional method (retro-orbitale bleeding) to obtain blood samples from the same individual NMRI-mice (Mus musculus) vaccinated against rabies. Rabies virus-neutralizing antibody (VNA) titers between paired blood samples obtained from the same mice were compared. The accuracy (between-method comparison), precision (repeatability of results), and robustness (influence of digestion on blood parameter) of the bug method was evaluated. VNA titers in the blood sample obtained from the bugs' crops were equivalent to those from samples collected directly from the mice. No differences between samples taken from different bugs that had fed on the same mouse were noted. In addition, there were no changes in VNA titers in blood samples collected from the triatomine bugs for up to 4 hr after completion of the blood meal. This study demonstrates that the application of blood-sucking bugs offers a validated alternative for obtaining blood samples to determine rabies virus-neutralizing antibody titers and is highly suitable for animals with limited or no accessibility of veins by conventional sampling techniques.