The WHOLE time?!
I would take reports of non-human animal females’ incapacity for enjoying sex / having orgasms with the traditional SDMB spoonful of NaCl – reports to that general effect have been floating for a long time on the basis of very little evidence and the support of very little research.
When I was an undergrad (in the dim dark days of the mid-1980s), it was often asserted that no creature other than homo sapiens has females who get physical pleasure from sex, that behaviors are all mechanical products of instincts and that sex is more often than not physically painful. The common house cat was often cited – the tom has barbs on his penis and the pussycat howls (in pain, they said, from the barbs). Some handful of years later I remember reading a contradictory essay by a researcher who used kitties in heat and smooth glass rods and reported that the pussycats yowl with or without those darn barbs.
For some reason there seems to be a tendency in cross-species studies that compare us to other animals to see in other animals what the researchers believe would validate what they believe to be “most natural” for our own species, and the marginal nature of the female orgasm is one of them.