Table 1.
Studbook numbers (SB #) were used to identify individuals and mates were based on Species Survival Program recommendations. Age was determined at the start of the study for each cat. Rearing is listed as either mother—raised by the dam or hand—raised by humans at any time prior to weaning. Breeding success was defined as copulations observed (Y) or no copulations observed (N). All individuals were sexually mature at the time of the study.
Table 2.
Immunoassays used to evaluate fecal samples from an adrenocorticotrophic hormone challenge (ACTH).
Results indicated a high correlation for both validation methods used; parallel displacement curves and recovery of the standards. Cross-reactivities of each assay with associated glucocorticoid metabolites are indicated as well as the optimal dilution used for samples on each assay.
Table 3.
Definitions and groupings for potential exogenous stressors (Events) and classification for housing (Social status) of fishing cats.
Fig 1.
Comparison of four immunoassays employed to characterize fecal glucocorticoid metabolites (FGM) in the feces of a single female fishing cat (SB# 633) during an adrenocorticotrophic challenge.
The cortisol RIA (Coat-A-Count, PITKCO-9, 2010-10-21, Siemens, Los Angeles, CA, USA) and corticosterone RIA (I125 kit ImmuChem, MP Biomedicals, LLC Diagnostics Division Orangeburg, NY, USA) also had measurable peaks above their pretreatment means (not shown here). The corticosterone EIA (R0006 supplied by C.J. Munro) did not.
Fig 2.
Representative fecal glucocorticoid metabolite profile of a fishing cat (SB# 721) that experienced an institutional transfer.
The red shading indicates the time the cat spent in quarantine. The outlined box indicates the return to baseline, defined as 30 consecutive days with ≤ 1 peak above 2.5 standard deviations of the individual’s overall baseline.
Fig 3.
Effect of time on fecal glucocorticoid metabolites (FGM).
A negative effect of time on mean FGM concentrations by transfer month was found using a regression analysis on transferred (y = -0.0897x + 2.5003; R2 = 0.38; P = 0.003), but not stationary cats (y = -0.0206x + 1.5868; R2 = 0.19; = 0.299). Particular note should be taken to the Quarantine period and the first 2 months post release from quarantine for the cats that were transferred, which corresponds to the mean time period calculated for fishing cats to return to baseline after institutional transfer.
Fig 4.
Elevations in fecal glucocorticoid metabolite (FGM) due to chronic illness.
Sustained periods of elevation in FGMconcentrations were observed during chronic illness in three fishing cats: (a) SB# 780 presented with elevated liver values during his exam for pre-shipment and was later diagnosed and treated for hepatitis with normal liver values reported 212 days post transfer; (b) SB# 657 treated for a bladder mass tumor, and although collection ended while values were still elevated, baseline values were confirmed several months later when collection resumed (days 313–330); and (c) SB# 440 presented with neurological symptoms and FGMs remained elevated until death.
Fig 5.
Exogenous stressors and social housing.
Effects of exogenous stressors (a) and social housing factors (b) on mean (±SE) fecal glucocorticoid metabolite (FGM) concentrations in fishing cats. Samples were collected from 26 fishing cats housed at AZA institutions in North America between 2010–2013.
Fig 6.
Mean (±SE) fecal glucocorticoid metabolite (FGM) concentrations are presented for fishing cats with observed copulations (successful) and those with no observed copulations (unsuccessful).
Results of binomial GLMM revealed that both Mean and Peak Mean FGM measures could predict breeding success in fishing cats.
Table 4.
Five fecal glucocorticoid metabolite (FGM) measures were calculated in fishing cats (n = 24) during institutional transfers and breeding introductions that took place between 2010–2013. Mean and Peak mean FGM were both significant predictors of individuals exhibiting successful copulations.