The father called 911, The Associated Press reported, and authorities later euthanized the violent dogs.
"Christian still asks where the pony is and why he was killed," Raul Vasquez, Christian's father, told ABCNEWS.com. "He liked having a pony -- it was [therapeutic]."
Anniversary, said Vasquez, was Christian's best friend.
Because of a Make-a-Wish Foundation policy that prohibits granting more than one wish to any one child, the organization could not replace Anniversary. But when word spread about Christian's loss, people from around the country -- and even a few in Canada -- donated money to help fund a replacement horse for the young boy.
Tombstone, who also goes by the nickname Buckshot, is a miniature gelding leopard Appaloosa, and will arrive at Christian's home as early as this week, said Jelaine Workman, the executive director of the Texas Plains Make-a-Wish Foundation. While the organization couldn't donate the second pony itself, it helped organize the outpouring of donations.
Vasquez told ABCNEWS.com his son is "very excited" for his new horse to arrive.
Crystal Brown Cries for Chevy
Crystal Brown confided in Chevy, her 4-year-old Australian shepherd mix, more than any person in her life.
"Chevy was Crystal's absolute best friend," Shirley Brown, Crystal's grandmother, told ABCNEWS.com. "She used to talk to the dog and tell him her secrets because she was a mixed-up kid and had a mixed-up life. Wherever she went, he went."
Chevy acted as Crystal's therapy dog, said Brown, and helped her deal with her depression and emotional troubles that stemmed from a difficult family life. Crystal's father is estranged and her mother struggles with bipolar depression and drug addiction.
On Feb. 7, when Brown let Chevy outside to go to relieve himself, the dog took off, and she was unable to catch him.
"I felt empty," Crystal told The Associated Press. "I couldn't talk to anyone. He was my dog. It was just me and him … I told him everything, and he never shared any of my secrets."
Crystal and her grandmother got a terrible surprise several weeks after canvassing the neighborhood for Chevy with no luck.
A package was delivered to the Brown's, addressed to Crystal, and upon opening it, the 17-year-old was met with a horrific surprise: Inside the package was Chevy's head, along with Valentine's Day candy.
"She was hysterical," Brown told the Minnesota Star Tribune. "She was screaming. She said, 'Grandma, it's my dog's head.'"
One of Crystal's friends, 24-year-old Anthony Gomez, later admitted in court to watching another man shoot the dog in the head, according to the Tribune. Gomez, who pleaded guilty to "terroristic threats," will be sentenced in late November. He is expected to serve at least 14 months in jail.
Pauline and Hennessey the Chihuahua
Three-and-a-half-year-old Pauline Veloz found a best friend in her little Chihuahua named Hennessey.
The dog, according to the San Jose Mercury News, was able to predict when Pauline -- who was born blind and suffers from cerebral palsy -- was going to have a seizure.
But Pauline and Hennessey's friendship was cut tragically short when the Chihuahua was fatally attacked by a neighborhood pit bull.
"She really bonded with him," Pauline's grandmother, Jennifer Miller, told the Mercury News. "The little dog was always by her side or on her lap. He was her world."
Despite being rushed to the vet by family members, Hennessey suffered a severed spinal cord and a punctured liver, kidney, lung and abdominal wall, the paper reported.
Like many disabled children who experience the loss of a service animal, Pauline's progress has regressed, her grandmother said.
"She doesn't sleep well. She's very fussy, and she wants to bang her head again," said Miller, who told the paper that her granddaughter's fist has reclenched since Hennessey's death.
The pit bull that attacked Hennessey was euthanized after the incident, Greg Van Wassenhove, Santa Clara County's director of agriculture and environmental management, told ABCNEWS.com.