Miranda Cosgrove has felt the loss of her dog Pearl keenly.
"I never had anything die in my life before except a hamster," the 19-year-old actress tells PEOPLE, sharing that the past two weeks since her 14-year-old poodle died of kidney failure
have "definitely been hard."
"She was a part of our family and because I was an only child, she was a really big part of my life," Cosgrove says. "Every time I look back on a memory, she was there."
Cosgrove, whose Nickelodeon series iCarly
will end airing original episodes next month, is a freshman at the University of Southern Calfornia. While visiting with her parents, she noticed that Pearl's behavior changed from perky and playful to lethargic and listless.
"My mom and I took her to the vet and they examined her. They said her heartbeat was really strong and everything was fine, but she was acting tired and kind of funny," Cosgrove explains. "They took some blood and called us the next day and said she had kidney failure. She wasn't herself. She was so tired and kind of confused."
From the time Cosgrove was in kindergarten, Pearl has been a constant companion. The dark gray pooch often rode in the front basket of Cosgrove's bicycle. The pair enjoyed swimming at the beach and snuggling together under the blankets while watching movies.
Since saying goodbye to Pearl, Cosgrove has moved into her new Los Angeles home, which boasts a backyard pool.
"She loved swimming and I live in an area where everybody walks their dogs. I was so excited to have her move in with me," Cosgrove says. "I wish I would have been able to have her there with me because she would have enjoyed it."
While she continues to grieve, Cosgrove knows that she will have another dog again someday.
"I can't think about getting another dog right away. I don't want to feel like I'm trying to replace her. But I do love dogs," she says, noting that Pearl will always be in her heart. "Pearl made the whole house feel different. Every time I'd come home she'd greet me. She was the best. I miss her so much."