Cortisol levels in cats' hair in presence or absence of Microsporum canis infection

Evaluation of hair and nail cortisol concentrations and associations with behavioral, physical, and environmental indicators of chronic stress in cats

Background

Chronic stress is implicated in behavioral and health issues in cats, but methods for recognition, evaluation, and measurement of stress are lacking. Cortisol concentration is typically used as an indicator of stress.

Objectives

To evaluate use of an enzyme immunoassay to quantitate hair and nail cortisol concentrations (HCC and NCC) in cats and evaluate associations between HCC and NCC and behavioral, physical, and environmental correlates of chronic stress in cats.

Animals

Forty‐eight adult, owned or community cats.

Methods

Cross‐sectional study. Nail clippings and hair were collected from cats. Medical history and cat daily lifestyle questionnaires were completed by owners or caretakers. A commercial laboratory performed cortisol extraction and quantification using a validated enzyme immunoassay kit. Correlational and regression analyses were used to evaluate associations between HCC and NCC and behavioral, environmental, and medical factors.

Results

Hair and nail cortisol concentrations were significantly associated (r_s = 0.70; P < .001), but HCCs varied widely within and among cats. Cats with litterbox issues had significantly increased HCC (P = .02) and NCC (P = .001) as compared to cats without litterbox issues. Cats with groomed coats had lower HCCs (P = .02) as compared to cats without groomed coats, whereas cats with dander and mats had higher NCCs (P = .01) as compared to cats without dander and mats.

Conclusions and Clinical Importance

The quantification of NCCs might improve identification and evaluation of chronic stress in cats. The variability of HCCs in individual cats warrants caution using this measurement in chronic stress studies.

Comparison of AlphaLISA and RIA assays for measurement of wool cortisol concentrations

Radioimmunoassay (RIA) methods have always represented a technique of choice for the determination of steroids in biological samples. The Amplified Luminescent Proximity Homogenous Assay-Linked Immunosorbent Assay (AlphaLISA) is now emerging as the new-generation immunoassay technology that does not require washing/separation steps. The aim of this study was to adapt the Perkin-Elmer's AlphaLISA kit for wool cortisol and compare it with a RIA wool cortisol assay. Wool from lambs, 35 at birth (A0) and 54 at two months old (A2), was collected and each extract was evaluated for wool cortisol concentrations (HCC) both by RIA and AlphaLISA immunoassay. The two methods showed good precision, sensitivity and specificity for determining HCC. Both methods were able to detect significant differences between the high and the low HCC assessed in lambs at A0 and A2 (P < 0.01). The HCC assessed with RIA were significantly higher than those assessed with AlphaLISA (P < 0.01). Moreover, the correlation between HCC measured using the AlphaLISA and RIA methods was strong (r = 0.878). The regression analyses show a constant and not proportional error. This could be due to the diversity in the dosage steps and to the diversity of the molecules used in the two methods. Results support the validity of using AlphaLISA as an alternative method to RIA for the quantification of cortisol in sheep wool and considering the performances showed it has a great potential to be further applied as an excellent tool to evaluate HCC in samples derived from animal species.

Dermatophytosis in companion animals: A review

Dermatophytosis, a zoonotic disease, is caused by fungi of three main genera, namely, Micropsorum, Trichophyton, and Epidermophyton. Specific lesions of dermatophyte infections are localized in the face, legs, and/or tail. Skin lesions in infected animals demonstrate localized alopecia, erythema, and crust, which are more commonly known as ringworm. Factors that affect dermatophytosis include the dermatophyte species; virulence factors of the agent; and the immune status, age, and sex of the host. High levels of cortisol and pro-inflammatory cytokines have also been reported to play an important role in dermatophyte infection. This review aims to explore and understand factors that affect dermatophyte infection with an emphasis on the prevalence, clinical signs, pathogenesis, immune response, and the roles of cortisol and cytokines in companion animals infected by a dermatophyte.

Assessment of Cortisol and DHEA Concentrations in Griffon Vulture (Gyps fulvus) Feathers to Evaluate its Allostatic Load

The use of a non-invasive approach to collect biological samples from natural populations represents a great means of gathering information while avoiding handling animals. Even if corticosterone is the main glucocorticoid investigated in birds, there has been observed a proportional direct link between corticosterone and cortisol concentrations. Dehydroepiandrosterone (DHEA) can be produced by the adrenal cortex and should have prominent antiglucocorticoid properties also in birds. The aim of this study was to verify if there is any difference in the cortisol and DHEA feather concentrations between clinically normal and physiologically compromised Griffon vultures (Gyps fulvus) through the non-invasive approach of collecting moulted feathers without having to pluck them from the bird. The study was carried out using 8 physiologically compromised (PC) Griffons and 9 clinically normal Griffons considered as the control (CTRL) group that were necropsied or from the wildlife rehabilitation centre. Primary and secondary covert feathers were either collected directly from the birds’ cage floors, or, in the case of dead Griffons, they were plucked off the animals. The results, obtained by RIA, revealed that both cortisol (P<0.01) and DHEA (P<0.05) feather concentrations were higher in the PC than in the CTRL group. No difference was observed by comparing the cortisol/DHEA ratio between the two evaluated groups (P=0.15). Pearson’s correlation coefficients showed no correlation between feather hormone concentrations in the PC group (r=0.01, P=0.96) while a positive correlation in the CTRL group (r=0.65, P=0.006) was observed. In conclusion, our study reveals that moulted feathers can be a non-invasive and an interesting tool to evaluate the allostatic load of wild birds and they allowed better understanding the relationship between hormones of the hypothalamic–pituitary–adrenal axis and the physiological status of the birds.

Descriptive epidemiology and test characteristics of cats diagnosed with Microsporum canis dermatophytosis in a Northwestern US animal shelter

OBJECTIVES

The aims of this descriptive study were to identify risk factors for feline Microsporum canis infection at shelter intake, to describe screening test accuracy, and to refine confirmatory testing time frames.

METHODS

Database records for the general feline population and intake data, medical records and fungal culture logs for cats diagnosed with M canis at a limited admissions shelter were accessed retrospectively for a period of 2 years.

RESULTS

The feline population at the study shelter had a prevalence of M canis of 1.8% (95% confidence interval [CI] 1.6-2.0%). Kittens were eight (95% CI 4.8-13.5) times more likely to present with dermatophytosis than adults. Although more cats presented with M canis during summer and autumn, season was not significant when the model was controlled for age. Owner-surrendered cats were half as likely (95% CI 0.41-0.77) as transported cats to be diagnosed with M canis. Wood's lamp examinations had a sensitivity of 66.8% (95% CI 60.2-73.4) and a specificity of 74.8% (95% CI 64.2-85.1) compared with dermatophyte test medium (DTM) culture. In 78.8% (95% CI 61-91) of littermate or household groups with mixed Wood's lamp results, all cats were DTM culture positive. Under consistent incubation conditions, 202/202 diagnostic DTM plates for M canis-infected cats showed recognizable colony growth before 7 days (median 4 days), and 19/19 fomite carrier cat cultures showed growth before 12 days (median 5 days).

CONCLUSIONS AND RELEVANCE

Applying the results of this study to shelter protocols could optimize diagnostic approaches and shorten the length of stay for shelter cats and kittens, resulting in streamlined shelter operations and improved feline welfare.

The nexus of hair corticosterone level, immunocompetence, metabolic rates and overwinter survival in the root vole, Microtus oeconomus

Although corticosterone (CORT) regulates many physiological mechanisms, the associations between CORT levels, immunocompetence, energy expenditures and overwinter survival have not been examined. Here, we studied individual variation in CORT level extracted from hair, immunocompetence quantified as the neutrophil-to-lymphocyte (N/L) ratio, total white blood cells (WBC) and natural antibody levels (NAbs), along with the resting (RMR) and peak metabolic rates (PMR) and mortality during three consecutive winter seasons in a natural population of the root vole, Microtus oeconomus. In early winter, hair CORT level was strongly positively associated with body mass and inversely related to voles' ability to survive. We suggest that the observed association between hair CORT level and body mass may be the key component of the physiological nexus driving the survivorship of individual rodents. Additionally, hair CORT was a significant predictor of variation of the whole body RMR, which in turn enhanced overwinter survival in the studied population. On the other hand, hair CORT was not significantly associated with changes in the blood indices. Interestingly, the analysis carried out only during the first year of study (2008), which was characterized by a high population density and prevalence of infestation with a blood protozoan, Babesia spp., showed that the intensity of the infestation was negatively correlated with both the hair CORT level and the N/L ratio. Because CORT is often considered immunosuppressive, we expected a positive association between its level and the N/L ratio. However, hair CORT did not significantly correlate with the N/L ratio. We suggest that the lack of an association between hair CORT and the N/L ratio resulted from a small inter-individual variation in the N/L ratio in 2008, which was much higher and less variable than in the other years of our study.

Hair cortisol and dehydroepiandrosterone concentrations in naturally Taenia solium infected pigs in Tanzania

The aim of this study was to measure hair cortisol and dehydroepiandrosterone (DHEA) concentrations in naturally Taenia solium infected and non-infected control pigs and assess the effect of an environmental change on the aforementioned parameters. Three hair patches were obtained from 13 T. solium infected and 15 non-infected controls sows, respectively corresponding to 3 time points (prior to, at and approximately two weeks after arrival at the research facility). Cortisol and DHEA were extracted using methanol and analysed by radio immune assay. Mean hair cortisol concentrations were significantly lower (p<0.001) in T. solium infected (4.7±3.0pg/mg) compared to control pigs (9.0±3.7pg/mg) prior to arrival at the research facility, however no significant difference was observed between the two groups at arrival and after approximately two weeks. Similar patterns were also observed for DHEA concentrations (infected pigs 253.9±82.3pg/mg, control pigs 387.7±116.4pg/mg) (p<0.001). Results showed that lean animals had significantly higher cortisol concentrations in both groups, infected and controls pigs, while DHEA was not significantly different between lean and normal animals. Results of this study have shown that an environmental change could have an effect on pigs' hormonal levels suggesting an undergoing adaptation process. After the pigs were kept under the same conditions, fed and watered ad libitum, no significant differences were observed between the groups, but a drop in DHEA concentrations was observed in all the pigs. Weight however had an effect on cortisol levels as lean animals had significantly higher cortisol concentrations in both groups, compared to normal pigs.

Hair cortisol and its potential value as a physiological measure of stress response in human and non-human animals

There is considerable interest in the potential for measuring cortisol in hair as a means of quantifying stress responses in human and non-human animals. This review updates the rapid advancement in our knowledge of hair cortisol, methods for its measurement, its relationship to acute and chronic stress, and its repeatability and heritability. The advantages of measuring cortisol in hair compared with other matrices such as blood, saliva and excreta and the current theories of the mechanisms of cortisol incorporation into the fibre are described. Hair cortisol as a measure of the physiological response to stress in a variety of species is presented, including correlations with other sample matrices, the relationship between hair cortisol and psychosocial stress and the repeatability and heritability of hair cortisol concentrations. Current standards for the quantification of hair cortisol are critically reviewed in detail for the first time and gaps in technical validation of these methods highlighted. The known effects of a variety of sources of hair cortisol variation are also reviewed, including hair sampling site, sex, age and adiposity. There is currently insufficient evidence to conclude that cortisol concentration in hair accurately reflects long-term blood cortisol concentrations. Similarly, there is a lack of information surrounding the mechanisms of cortisol incorporation into the hair. This review highlights several directions for future research to more fully validate the use of hair cortisol as an indicator of chronic stress.

Intrinsic factors, adrenal gland morphology, and disease burden in captive cheetahs (Acinonyx jubatus) in South Africa

Adrenal gland weight (AW) and corticomedullary ratio (ACMR) are used as indicators of stress in animals. Captive cheetahs (Acinonyx jubatus) have higher ACMRs than free-ranging ones and stress has been linked to gastritis, amyloidosis, glomerulosclerosis, and myocardial fibrosis. We reviewed age, sex, body weight (BW), kidney weight (KW), and left AW and ACMR with necropsy findings in 51 South African captive cheetahs. Eleven common histopathologic lesions were counted for each animal as measure of its disease burden. Adrenal corticomedullary hyperplasia was significantly correlated with left AW and ACMR. Males had significantly higher AWs than females; other parameters showed no difference between the sexes. Disease burden, gastritis, and myocardial fibrosis were moderately correlated with adrenal morphology supporting prior evidence that gastritis and myocardial fibrosis are linked to stress. Glomerulosclerosis was not correlated with adrenal morphology and neither kidney nor liver amyloidosis contributed significantly to variation in AW or ACMR on multivariate analyses. Interstitial nephritis showed much stronger correlations with kidney and liver amyloidosis than gastritis. All three adrenal parameters were correlated with age; age was the only significant variable affecting ACMR on the multivariate analyses; and disease burden as well as systemic amyloidosis and kidney disease (except for fibrosis) showed moderate correlations with age. Age may, therefore, be important in the pathogenesis of disease in captive cheetahs, particularly of amyloidosis and kidney disease. None of the intrinsic measurements or adrenal parameters were sufficiently closely linked to disease to be used as ante-mortem proxies for disease burden or specific diseases. Zoo Biol. 36:40-49, 2017. © 2016 Wiley Periodicals, Inc.

Relocation and Hair Cortisol Concentrations in New Zealand White Rabbits

To investigate how long relocation modified hair cortisol concentrations in New Zealand white rabbits, 19 rabbits were subjected to a change in their breeding facility at the beginning of the trial and then were kept under stable environmental conditions. Hair samples were collected at the time of arrival to the nonhuman animal facility and at 40-day intervals from the same skin area for up to 440 days after the animals' arrival to the facility. A period effect on the hair cortisol concentration was found (p < .01). The transfer of the rabbits to the new facility might have induced an increase in the hypothalamic-pituitary-adrenal axis activity (p < .01). A second increase in hair cortisol concentration (p < .01) occurred at 320 days, after a change of personnel at the facility that occurred at 280 days, which was the only environmental change. The relocation of rabbits to the facility resulted in a stress response leading to elevated cortisol levels. The effect of relocation on mean cortisol concentrations was exhausted within 120 days when all environmental factors were kept stable.