Maternal and neonatal canine cortisol measurement in multiple matrices during the perinatal period: A pilot study

Abstract

Stress exposure during perinatal period may lead to maternal cortisol increase that negatively affects the offspring development. In recent years, the interest on non-invasive sampling methods to measure cortisol as a marker of stress is increasing in both humans and animals. Indeed, discomfort due to blood collection may compromise the diagnostic outcome, mainly in uncooperative patients. So far, some alternative matrices but not milk have been explored in adult dogs, while no data are available on the neonate and paediatric live pups. This study aimed to measure cortisol concentration in different biological substrates in both dams (blood, saliva, hair and milk) and pups (saliva and hair) at established times from proestrus up to two months after parturition. For this purpose, five female German shepherd bitches and their 22 pups were enrolled. Cortisol concentration was assessed using the enzyme immunoassay kit (Salivary Cortisol ELISA kit, Salimetrics) after matrices appropriate preparation if required. Cortisol was measurable in all the substrates, except some milk samples below the detection limit. Maternal cortisol concentrations differed among the matrices (P <0.0001) with the highest values recorded in plasma (median 0.596 μg/dL) compared to saliva (median 0.159 μg/dL), hair (median 0.083 μg/dL) and milk (median 0.045 μg/dL). Cortisol in dams did not vary within the same matrix over time. In pups, salivary (median 0.295 μg/dL) cortisol was always higher than hair (median 0.049 μg/dL; P <0.0001). At birth (P = 0.01) and two months later (P = 0.05), neonatal salivary cortisol was higher compared to other samplings. The present study demonstrates the suitability of these innovative substrates for cortisol measurement, suggesting them as potential diagnostic support in canine neonatology and welfare.

Utero-placental expression and functional implications of HSD11B1 and HSD11B2 in canine pregnancy

“…In humans, e.g., fetal glucocorticoids are 5-10 times lower than maternal circulatory levels [59]. Although several studies have attempted to measure fetal exposition to cortisol in the dog using, e.g., puppy hair and claws [60,61], a clear comparison with maternal levels is still not available. Nevertheless, it appears plausible that such a protective mechanism might be also present in the dog.…”

Dam (Canis familiaris) Welfare throughout the Peri-Parturient Period in Commercial Breeding Kennels

“…Although a different species, our finding is supported by a recent study in cats, which observed higher concentrations of serum cortisol at 4 weeks postpartum than before mating, 1–2 days after parturition and 8 weeks postpartum [ 36 ]. In contrast, more recent studies in dogs found no change in coat and claw cortisol between 4 and 8 weeks postpartum [ 29 ], or plasma and salivary cortisol between parturition, 21, and 60 days postpartum [ 28 ]. The difference in findings may be due to the larger sample size and representation of multiple breeds in the current study.…”

“…We collected data from a minimum of six dams per kennel to ensure adequate representation of within kennel variation. The total number of kennels included in the study ensured a representation of different environments and management practices and allowed us to reach a sample size larger than other similar research in different populations [ 28 , 29 , 36 ]. To maximize data collection time and travel, each kennel was required to have a minimum of three bitches that met selection criteria and were expected to whelp in the same week.…”

“…For example, multiple studies have measured changes in cortisol throughout various stages of the peri-parturient period, which is a product of hypothalamic-pituitary-adrenal (HPA) axis activation and can be used to capture changes in an individual’s stress response [ 24 , 25 ]. They found no significant changes in plasma, hair, or salivary cortisol [ 26 , 27 , 28 ]. However, a recent study identified a trend of increase in hair and claw cortisol from mating to 60 days postpartum [ 29 ].…”