Progesterone Concentrations in the Peripheral Plasma of the Blue Fox (Alopex Lagopus) During Pregnancy and the Oestrous Cycle

Abstract

A competitive protein-binding assay was evaluated and employed in the measurement of progesterone in serial plasma samples obtained from pregnant, non-pregnant and non-receptive blue-fox vixens.At the beginning of the period of pro-oestrous vulval swelling, the plasma progesterone concentration was always found to be below 2 ng/ml. Towards the end of pro-oestrus and during the period of oestrus (sexual receptivity) the concentration increased rather quickly. On the 3rd and the 4th days of oestrus, i.e. when most of the vixens were mated, the plasma progesterone concentrations were about 30 ng/ml (range: 18\p=n-\36 n g / ml ) . During gestation (53 or 54 days) the plasma progesterone level rose very steeply and attained a maximum plateau (> 80 ng/ml) between days 5 and 8 post coitum, remained high until about day 20, but thereafter fell rather quickly to below 30 ng/ml between days 35 and 40. Later on the progesterone level fell gradually to below 5 ng/ml at the day of parturition, and, 4 days post partum and later, the levels were below the limit of the sensitivity of the assay used (< 2 ng/ml).The progesterone values and profiles obtained from the non-pregnant vixens (mated vixens which failed to whelp) corresponded clearly to those obtained in the pregnant vixens. Indeed, even in two non-receptive vixens (unwilling to mate during the mating season) typical progesterone profiles were obtained during a period of about 70 days.

Fecal progesterone and estradiol changes during the breeding season in captive female wolf

“…This pattern of fecal steroids excretion is similar to the results of previous reports of wolves (Seal et al 1979) which were based on serum steroid analyses and also similar to the findings in bitch (Gudermuth et al 1998) and blue fox (Sanson et al 2005). This means that ovarian progesterone is necessary to maintain pregnancy of wolves as it is in other canine species (Moller 1973).…”

“…There are some reports about these effects in canine animals also, such as the domestic dogs, wolves (Canis lupus), arctic foxes (Alopex lagopus) and coyotes (Canis latrans). Most data on relevant researches were obtained through studies of blood samples (Moller 1973;Smith et al 1974;Concannon et al 1975;Wildt et al 1978;Seal et al 1979;Wildt et al 1979;Stellflug et al 1981). However, because the blood samples of wild animals are difficult to obtain, and the collection process may affect the normal life of wild animals or even cause damage to them, more and more researchers turn to develop ORIGINAL PAPER non-invasive techniques to evaluate the animal conditions today, including biochemical analysis of urinary samples and fecal samples (Gudermuth et al 1998;Sands and Creel 2004;Queyras and Carosi 2004;Ziegler and Wittwer 2005;Shimizu 2005;Walker et al 2005).…”

Plasma Progesterone Levels in Pregnant and Pseudopregnant Ferrets

“…The pattern of plasma progesterone levels in the ferret is similar to that in the dog (Christie, Bell, Horth & Palmer, 1971;Parkes, Bell & Christie, 1972), the mink, Mustela vison (Moller, 1973a), and the blue fox, Alopex lagopus (Moller, 1973b) …”

Physiological Constraints and Latitudinal Breeding Season in the Canidae

“…However, most studies supporting this pattern have been done on temperate zone species such as the Andean fox (Pseudalopex culpaeus, Crespo 1975), the Arctic fox (Alopex lagopus, Moller 1973), the coyote (Canis latrans, Gier 1975), the gray wolf (Canis lupus, Seal et al 1979), the kit fox (Vulpes macrotis, Egoscue 1956), the pampas fox (Pseudalopex gymnocercus, Crespo 1975), the red fox (Vulpes vulpes, Rowlands and Parkes 1935), and the swift fox (Vulpes velox, Kilgore 1969). A limited number of studies have reported monestrous cycles for tropical canids (African wild dog, Lycaon pictus, Monfort et al 1997;bushdog, Speothos venaticus, DeMatteo et al 2006;maned wolf, Chrysocyon brachyurus, Velloso et al 1998; fennec fox, Vulpes zerda, Valdespino et al 2002), but these studies were all conducted with captive animals in temperate regions.…”