Should I keep hairy pets when my wife is going to give birth?

Question

cats, hamsters. Should I still keep them when my wife is going to give birth?

My concern is about whether the hair from my hairy pets affect my wife and the baby in term of allergy (The hair might attract dust)?

Answer 1

Short Version: It isn't necessary to get rid of your pets as a precaution. If you find after your baby is born that it is a problem, you can consider isolating or even removing them.

In terms of allergies, there are two different main allergens referenced in your question: dust and pet hair (more specifically, pet dander, which is a combination of hair and dead skin flakes, and which is the trigger for most pet-related allergies).

Speaking from personal experience (I have fairly severe dust and dust mite allergies), there isn't much of a direct relationship between the two.

Dust in the home is best handled by ventilation (which increases the exposure to pollens, so choose your allergens carefully!) and cleaning.

Pet dander is best handled, generally speaking, by either ventilation and cleaning, or limiting exposure to the pets. In many cases, someone with mild-to-moderate pet allergies can live with pets without significant discomfort, simply by ensuring that the house is regularly cleaned, and the pets are well groomed.

For infants, however, the story is a little bit different.

In 1989, scientist David P. Strachan published an article in the British Medical Journal introducing his "hygiene hypothesis".

In his hypothesis, Strachan suggests that the general increase in incidences of allergies we're seeing may be due to a concomitant increase in our general hygiene, as reduced exposures to infectious agents, microorganisms, and parasites could increase our susceptibility to allergic diseases by suppressing natural development of our immune system.

There are studies that apparently support this theory, although there are also alternative theories that include the possibility that overexposure to allergens triggers the allergic diseases.

Pet ownership does seem to be associated with decreased risk of allergies in some, but not all, communities:

According to Perzanowski, pet ownership appears to be associated with a decreased risk of developing allergies in some, but not all, communities. For example, in countries with lots of cats, like the suburban U.S. and Australia, a pet cat appears to provide a protective effect. But in countries with few cats, he says, ownership actually increases the risk for allergic sensitization, the immune reaction that often precedes allergy symptoms. And don't even try to understand countries with moderate cat ownership—studies have been inconclusive. As for why these differences exist, no one really knows.

However, that same article cautions that the studies show correlation, but not causation:

Such studies don't prove causation, says Carl-Gustaf Bornehag, a public health scientist at Karlstad University in Sweden. Often, people who are allergic to pets—or, because allergies are at least partially hereditary, people who are at risk of becoming allergic because someone in their family is—simply aren't going to own them, he says.

This skews study results, making it appear that pets protect against allergies when they actually don't. Although some studies have tried to circumvent this potential bias by stratifying results based on hereditary risk, "until there is a 'randomized distribution of cats trial,'" says Columbia's Perzanowski, "there will always be some chance of confounding by who chooses to own a cat,"—or a dog, for that matter."

The article then finishes with what I think is a pretty good summary:

So should parents get a pet if they want to minimize their child's risk of developing allergies? "That's the million dollar question," says Litonjua, and the short answer, he says, is no. "If you want to get to get a pet to try and prevent allergies, that's probably not a good reason," he explains. But "if the kids really want the pet—if you want the pet—then go ahead, as long as you're not having any symptoms when you get exposed." Flea bites and poop aversion, of course, don't count.

Slightly off the original topic, but of possibly relevant interest: According to a fairly recent study, dog ownership has been tied to general increases in overall health of children:

Babies in homes with dogs have fewer colds, fewer ear infections, and need fewer antibiotics in their first year of life than babies raised in pet-free homes, Finnish researchers find.

Homes with cats saw similar benefits, but not as pronounced as with dogs.

Its not clear why this would be true, but the hygiene hypothesis, and the newer 'microbiome or microflora hypothesis" are both cited as possible contributing factors.

Answer 2

I recall reading a study from the mid nineties that found growing up with one furry pet decreased allergies, growing up with two furry pets was better, but that the third furry pet did not give any benefits with regard to allergies.