The 6-year-old rescued pooch tested positive for Ehrlichiosis, a bacterial infection caused by the common brown dog tick, which can result in kidney disease and anemia, and can be fatal.

"I thought she was going to die," said Young, a writer, from Carroll Gardens, Brooklyn, who is happy that Elie is back to her old feisty self these days.

As the weather begins to heat up, however, so do the number of fleas, ticks and mosquitoes.

The itchiness and scratching brought on by these pests is enough to drive any sane animal - or human - mad. But the real problems lie in the diseases they carry.

"Ecto-parasites are potential sources of severe disease," said Dr. Ann Hohenhaus, medical director of the Animal Medical Center in Manhattan.

Other diseases that ticks can transmit to pets include Lyme disease, Rocky Mountain spotted fever and Babesiosis, a blood disorder.

Fleas can cause reactions in cats and dogs varying from a mild skin irritation to a severe allergic reaction. Because the tiny pests feed on blood, an extreme infestation can cause anemia or even death in animals. And a flea's three- to four-week life cycle means it will take at least that long to get rid of the enemy.

Meanwhile, heartworm, which requires a mosquito to transmit it from an infected animal to a healthy animal, is usually found in more wet and humid climates than New York City. This year, however, some local veterinarians said it could be more of a concern right here at home. That's because an estimated 60 percent of the dogs and some of the cats evacuated from Hurricanes Katrina and Rita were heartworm-positive.

Two Katrina dogs rescued by the Bide-A-Wee shelter in Wantagh, L.I., were infected with heartworm, said the shelter's spokesperson Dana Covey. Magnolia, a hound-mix and Shiba Inu mix, Bella, were both treated over a four-month period and then successfully adopted out. But some infected Katrina dogs may not have been treated.

"If Katrina dogs are floating around with heartworm, there maybe a higher number of dogs getting heartworm this year," Hohenhaus said.

Dr. Tom Nelson, president of the American Heartworm Society, said all animals, including cats, should be tested. If not detected and left untreated, heartworm can lead to congestive heart failure and death.

Heartworm prevention medications are usually administered once a month. Depending on the brand used, many also protect against intestinal parasites such as roundworms and hookworms.

Most traditional veterinarians recommend products like Frontline for flea and tick prevention and Heartguard to prevent heartworm.

Prevention methods, however, should be customized to a pet's lifestyle. Hohenhaus suggests discussing with your vet whether your cat or dog will be spending the summer indoors, in the city, or traveling to the mountains, or at the Hamptons. Still, holistic veterinarian, Marcie Fallek says a healthy animal may need a little protection. "The key is to have a healthy animal," she said, and suggests staying away from toxins.