Seasonal weight changes in laboratory ferrets

Abstract

Ferrets (Mustela putorius furo) are a valuable animal model used in biomedical research. Like many animals, ferrets undergo significant variation in body weight seasonally, affected by photoperiod, and these variations complicate the use weight as an indicator of health status. To overcome this requires a better understanding of these seasonal weight changes. We provide a normative weight data set for the female ferret accounting for seasonal changes, and also investigate the effect of fluid regulation on weight change. Female ferrets (n = 39) underwent behavioural testing from May 2017 to August 2019 and were weighed daily, while housed in an animal care facility with controlled light exposure. In the winter (October to March), animals experienced 10 hours of light and 14 hours of dark, while in summer (March to October), this contingency was reversed. Individual animals varied in their body weight from approximately 700 to 1200 g. However, weights fluctuated with light cycle, with animals losing weight in summer, and gaining weight in winter such that they fluctuated between approximately 80% and 120% of their long-term average. Ferrets were weighed as part of their health assessment while experiencing water regulation for behavioural training. Water regulation superimposed additional weight changes on these seasonal fluctuations, with weight loss during the 5-day water regulation period being greater in summer than winter. Analysing the data with a Generalised Linear Model confirmed that the percentage decrease in weight per week was relatively constant throughout the summer months, while the percentage increase in body weight per week in winter decreased through the season. Finally, we noted that the timing of oestrus was reliably triggered by the increase in day length in spring. These data establish a normative benchmark for seasonal weight variation in female ferrets that can be incorporated into the health assessment of an animal's condition.

DNA-Vaccine-Induced Immune Response Correlates with Lower Viral SARS-CoV-2 Titers in a Ferret Model

“…The low temperature recorded for all groups on study day 1 is likely to be a result of temperatures being taken following sedation, and not an effect of SARS-CoV-2 challenge. Following the viral challenge, some animals showed a slight body weight reduction in the vaccination phase; however, ferrets housed in single-sex groups show fluctuations in body weight related to seasonal physiology [ 14 ]. For this reason, weight loss in the absence of other clinical signs is not a cause for concern.…”

Melatonin Promotes the Development of Secondary Hair Follicles in Adult Cashmere Goats by Activating the Keap1-Nrf2 Signaling Pathway and Inhibiting the Inflammatory Transcription Factors NFκB and AP-1

“…MT is involved in the regulation of seasonal rhythms as well as having anti-aging, skin protective, anti-oxidative, and anti-tumor properties [ 14 , 15 , 16 , 17 ]. MT has been administered to fur-bearing animals such as mink, blue fox, and rex rabbit to promote hair follicle activity [ 18 , 19 , 20 , 21 ]. Our laboratory has conducted studies on goats with implantation of MT during the non-growing cashmere period showing that MT can promote the growth of secondary hair follicles, increase their numbers, and improve the quality of cashmere fibers [ 2 , 22 ].…”