Which Pets Are Cool With Your Period, According to Vets

Sylvie, who lives in Brooklyn, is convinced that her boyfriend's dog is out to get her when she's menstruating. "When I'm on my period, he purposely sneaks into our room to sniff out my dirty underwear. He'll circle the bathroom door after I've thrown away a tampon," she said. While some animals react to periods more obviously, Broadly sought to investigate exactly how intuitive household pets are when it comes to menstruation. We learned which pets know when you're on your period but don't really care, and which ones will try to attack and mate with you.

Mikel Delgado, a certified cat behavior consultant and PhD candidate at UC Berkeley, explained to Broadly that while no scientific literature exists about cats and menstruation, she believes they'll likely sense a period because of their highly acute sense of smell. "They would detect menstruation because of the hormonal changes and because the actual menses has an odor," she said.

"Whether or not that change in smell will be a big deal to them? Probably not," said Delgado. "They have other ways they can identify us, like our voice and their sight. And for the most part, we still smell the same so our cat won't be like who is this strange new person?"

Some people are insistent that when they are menstruating, their cat knows what's up. Anna, who owns two kitties, told Broadly, "My cats know when I'm on my period because they come up and snuggle with me on the couch when I'm cramping and want to die."

In response, Delgado said, "I don't think that they have any awareness that Mom is on her period and might be crabby. They don't know what a period is and what it means, but if you have cramps and are on the couch all the time, the cat might want to cuddle. But not because she thinks you're on your period. She just wants to cuddle." So while cats can smell whether you're on your period, they don't necessarily understand what that means, and in true cat fashion, don't care to.

It's well known that dogs are exceptionally sensitive to smell. A canine's wet nose has around 220 million sensors compared to a human's measly 5 million sensors. This sense is so sensitive that dogs have been used to detect early stage cancer by smell alone. So it would make sense to assume that they know when we're on our periods.

Julie Hecht, a PhD student in animal behavior at CUNY and the writer of Scientific American's "Dog Spies" column told the animal website Cuteness that "[dogs] know something is different down there from usual." However, like cats, recognizing the different smell doesn't translate to recognizing menstruation. "It doesn't have a meaning to them, but they can certainly detect we would smell different," Hecht said. So while they don't know why you smell differently, they'll still notice that you do, resulting in increased crotch-sniffing and hounding after your used pads and tampons.

Like dogs, rodents are more sensitive to their sense of smell than sight. Dr. Beth Breitweiser, a veterinarian at All Wild Things Exotic Hospital, told Broadly that rodents might be able to pick up on their owner's period because of this, but aren't likely to care. "If they do sense menstruation, it would be possible they change behavior, but there has been no research into the subject," said Dr. Breitweiser. "Granted, rodents as pets usually aren't the most responsive to their owners, so it wouldn't seem like much of a change in behavior would occur."

It seems that the topic of menstruation in relation to household pets is a highly niche topic. Lorelei Tibbetts, a licensed veterinary technician and practice manager of The Center for Avian and Exotic Medicine in New York City, explained to Broadly that there has never been formal research about the intersection of birds and human periods. This dearth of research did not stop Tibbetts from being certain that birds are oblivious to periods. Simply put, "birds do not have a highly developed sense of smell, like how a dog would," said Tibbetts. "While dogs are hunters with keen noses, birds would not be aware of any change in their owner."

"We recommend you don't handle male iguanas during menstruation," warned Breitweiser. While iguanas are usually very calm pets, they have been known to attack their owners that are menstruating. Breitweiser attributes these attacks to their owner's changed pheromonal odor and the iguana's characteristic stoicism that makes the reptiles hard to read. "Because they're stoic, you can't really tell if iguanas love their owners. I have anecdotal evidence that they love their owners, such as when they change colors or recognize their owners," Breitweiser explained. "But some get males aggressive for whatever reason with these different pheromone levels. Especially if you're at eye level."

In "Male Iguanas in Breeding Season and Human Females" by Melissa Kaplan, author of Iguanas for Dummies, we learn that not only do iguanas attack menstruating women, but they also attempt to mate with them. Kaplan explains that some iguanas have special organs that can detect a menstruating woman's hormones, and that these abilities might lead them to feel they've detected a mate: their unsuspecting female owners.

Kaplan goes on to describe her personal experience with her iguanas, Elvys and Freddy. While "Elvys never tried to actively mate with [Kaplan] although, during [her] menstrual periods, he became more clingy that during the rest of the month" while "Freddy, on the other hand, tried to mate with [her]." Freddy's attempt to mate with Kaplan included him lunging at her neck first and her hands later, resulting in her hands "being severely torn and infected for a couple of months."

But not all reptiles are a threat while menstruating. While it has been proven that snakes can detect menstruation, Breitweiser explained that overall, a reptile's ability to sense menstruation depends on their sense of smell. But consider yourself warned: do not pick up an iguana while you are on your period.