(CNN) -- It started with sinus congestion for Shawna Coronado. Then the splitting migraines came. Coronado soon discovered the furry causes: Harrington and Kalamazoo.
Shawna Coronado endures headaches and congestion to keep her 30-pound pug, Harrington.
Her 30-pound pug and orange tabby scattered dead skin flakes around the house, triggering Coronado's allergic reactions. Her two daughters are also allergic, but their reactions are less severe.
Like the 10 million American pet owners with allergies, the Coronados faced a dilemma: Can human and dog co-exist in the same house?
"We love them," said Coronado about her family's pets. "They're adorable. They're really our babies. They're part of the family. We could never live without them."
Allergies can cause itchy eyes, hives, sneezing, congestion or even asthma. To keep animals around, allergic pet owners get shots, pop antihistamines, squeeze eyedrops, squirt nasal spray, use inhalers or just deal with it. Others try to find a dog that won't trigger the symptoms.
President-elect Barack Obama's family has said his family is seeking a "hypoallergenic dog," because of his eldest daughter, Malia's, allergies.
Here are steps recommended to reduce allergens in homes with pets:
Unfortunately, there's no such thing.
The belief that certain breeds are hypoallergenic is "a complete misconception," said Dr. Robert Wood, chief of pediatric allergy and immunology at Johns Hopkins University School of Medicine. "You can't predict by type or breed, or length of hair."
Pet allergies are not caused by dog hair, the American Academy of Allergy, Asthma and Immunology noted in a recent statement.
"The allergen is produced in saliva, urine, dander-- it's not just hair," said Dr. Wanda Phipatanakul, an allergist at Children's Hospital in Boston, Massachusetts. "Even with a hairless dog, there are still allergens."
For their next pet, the Coronados are considering a poodle. Although poodles, bichon frises and Malteses are often touted as hypoallergenic dogs, these breeds all produce allergens. There hasn't been sufficient research to determine whether certain breeds are more allergy-friendly, said Dr. Clifford Bassett, an assistant clinical professor of medicine at The Long Island College Hospital in New York.
"There is not a lot of research in this area," he said. "There are differences between breeds, but we don't have research to definitively say. They all produce allergens."
The key factors are the animal's size and the volume of hair. The fur can collect pollens, mold spore and allergens and bring them indoors, triggering reactions. Even so, reactions vary widely, because everyone's body is different, doctors say.
Before committing to a pet, make an arrangement to bring the animal to the home for a trial period to see how the person with allergies fares.
"It's always going to be trial and error," Wood said. "Someone might be allergic to one breed, but the main dog allergen that people are allergic to is present in all dogs."
It is also possible for someone to develop dog allergies months or years after bringing the animal home.
If symptoms arise, doctors recommend getting tested to be certain that the allergy is coming from the animal. Allergic reactions could come from other irritants, such as pollen or dust.
A person's allergies can also inexplicably change over time. In the same way that some people outgrow food allergies, there is a rare possibility that pet owners could outgrow their allergies to animals, experts said.
Pills and medications are available to treat the symptoms, but the best remedy, said Philatanakul, is to not have pets.
"There's nothing that can be done except for avoidance," she said. "There's no cure. You're exposing yourself to high levels of allergens in your home. We generally recommend they should not have a pet. It's not recommended."
For many families, having a loving, furry companion outweighs the runny noses, wheezing and water eyes.
Coronado, who is also allergic to mold, dust and yeast, suspects it's not just the dog and cat causing her headaches. After cutting out beer, bread and cheese from her diet, she says she doesn't get as many allergic reactions. But she can't pick up the cat without getting congested. Sometimes Harrington and Kalamazoo trot into the house bringing all sorts of allergens with them and trigger her allergic reactions. Despite the discomforts, the Coronados aren't getting rid of their animals.
"Our lives are so enriched because we have dogs and cats," she said. "You can live in a positive way and live well with the pets or you can suffer every day and think it's miserable. It's really how you look at it. The reason we live with pets is because we live life in a positive way and we work it out."
Her two daughters have cat allergies, but they don't have asthma or breathing difficulties, so Kalamazoo is staying put in their Warrenville, Illinois, home.
"Pets are healing for we humans," Coronado said. "They are for my children. We adore them as part of the family. On a mental health level, children gain something from pets. Children gain a lot from being in nature and being outside. Dogs and cats as pets are part of that experience."
Pets do provide therapeutic value, said Bassett.
"Pets make people feel good," he said. "Pets reduce anxiety, blood pressure. Pets are here to stay."