Billy the elephant, who has been at the LA Zoo for 23 of his 27 years, is overweight, depressed and sexually frustrated, according to a lawsuit put forth by real estate agent Aaron Leider.

The animal rights community is closely watching the long-running lawsuit, which will be heard in court this week and began Monday in downtown Los Angeles, the Daily News reports.

The suit alleges that the LA Zoo exhibit's ground is too hard -- causing Billy to suffer from cracked toes and weary joints -- and the space is too small. Leider said during the trial Monday that Billy is in a heightened state of sexual arousal -- known as musth -- for much of the year and cannot follow his instincts to travel long distances in search of mates. Instead, Billy bobs his head for hours and walks in circles, which some experts say is a sign of emotional turmoil and sexual frustration.

City attorneys, however, dismissed the accusations, saying that the zoo pampers its elephants with a two-story barn with radiant-heated floors, carrot-tossing games, daily "elephant pedicures" and an animal psychiatrist on hand, the Los Angeles Times reports. "If only people were treated so well," Deputy City Atty. John Carvalho said.

Regarding the accusation of sexual frustration, Carvalho brought up the two elephants that joined Billy in Nov. 2012, "He [Billy] can vocalize with Tina and Jewel, he can see Tina and Jewel and he can touch Tina and Jewel."

Leider is calling for the exhibit to close and the elephants to be sent to a sanctuary. However, the defense is pointing to santuaries' shortcomings. Brenda Scott Royce, director of publications for the Greater Los Angeles Zoo Association, who has worked for both zoos and sanctuaries, says that sanctuaries often have to rely on donations and have lower standards for accreditation. She wrote about the LA Zoo in a 2008 blog for The Huffington Post:

Animals at the Los Angeles Zoo lack for nothing. They have five full-time staff veterinarians, leaders in their field, on site not only to care for them in emergencies, but to provide routine preventive care using the latest digital diagnostic equipment. They receive fresh produce daily and their diets are determined by professionals trained in the field of animal nutrition, not dictated by what donations were able to be scrounged up that day.

Much to the chagrin of animal activists, Billy was the only elephant at the LA Zoo from 2007 to 2010. In 2010, despite a strong campaign from animal activists calling for the exhibit to be closed and Billy to be sent to a sanctuary, the LA City Council voted in favor of a $42-million expansion of the elephant exhibit. The new exhibit, The Elephants of Asia, opened in Nov. 2010 and stretches across 3.8 acres that include mud holes, sand, grassy hills, swimming pools and a waterfall. At that time, two female elephants, Tina and Jewel, were transferred to the exhibit from the San Diego Zoo. See all three elephants and the new exhibit in the video above.

Leading up to the controversial City Council vote, several celebrities spoke out on the issue. Actress-singer Cher, retired "Price is Right" host Bob Barker, actor Robert Culp, actress Lily Tomlin and comedian Kevin Nealon all called for the exhibit to close. On the other side, an unlikely duo -- rocker Slash (Guns N' Roses, Velvet Revolver) and "Golden Girl" Betty White -- joined forces to advocate for the new expansion.

Click through photos below of Billy and the LA Zoo's Elephants of Asia exhibit:

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  • Billy, a 25-year-old male Asian elephant

    Billy, a 25-year-old male Asian elephant walks in the newly constructed 6-acre, 42 million USD Pachyderm Forest habitat at the gala opening of the new Elephants of Asia exhibit at the Los Angeles Zoo, December 15, 2010 in Los Angeles, California. The exhibit features Billy and new additions Tina and Jewel. AFP PHOTO / ROBYN BECK (Photo credit should read ROBYN BECK/AFP/Getty Images)

  • City Council To Vote On Fate Of Controversial Elephant Exhibit at L.A. Zoo

    LOS ANGELES, CA - JANUARY 28: Billy, the only elephant currently at the Los Angeles Zoo, is seen in his temporary exhibit after the Los Angeles City Council voted today to keep Billy at the zoo and continue construction of the $42 million Pachyderm Forest elephant exhibit on January 28, 2009 in Los Angeles, California. A parade of celebrities who oppose elephants in zoos fought to shut down the project and send Billy to a sanctuary facility, including Bob Barker, Cher, Lily Tomlin and Kevin Nealon. After the Pachyderm Forest was approved by the City Council in 2006, actor Robert Culp and real estate agent Aaron Leider sued the city to stop the project alleging that zoo officials abuse elephants but the lawsuit was thrown out by the Los Angeles Superior Court. When completed, the 3 1/2-acre Pachyderm Forest will house up to five Asian elephants and three of their offspring in an enclosure with a waterfall and two pools. (Photo by David McNew/Getty Images)

  • City Council To Vote On Fate Of Controversial Elephant Exhibit at L.A. Zoo

    LOS ANGELES, CA - JANUARY 28: Billy, the only elephant currently at the Los Angeles Zoo, is seen in his temporary exhibit after the Los Angeles City Council voted today to keep Billy at the zoo and continue construction of the $42 million Pachyderm Forest elephant exhibit on January 28, 2009 in Los Angeles, California. A parade of celebrities who oppose elephants in zoos fought to shut down the project and send Billy to a sanctuary facility, including Bob Barker, Cher, Lily Tomlin and Kevin Nealon. After the Pachyderm Forest was approved by the City Council in 2006, actor Robert Culp and real estate agent Aaron Leider sued the city to stop the project alleging that zoo officials abuse elephants but the lawsuit was thrown out by the Los Angeles Superior Court. When completed, the 3 1/2-acre Pachyderm Forest will house up to five Asian elephants and three of their offspring in an enclosure with a waterfall and two pools. (Photo by David McNew/Getty Images)

  • City Council To Vote On Fate Of Controversial Elephant Exhibit at L.A. Zoo

    LOS ANGELES, CA - JANUARY 28: Children watch Billy, the only elephant currently at the Los Angeles Zoo, in his temporary exhibit after the Los Angeles City Council voted today to keep Billy at the zoo and continue construction of the $42 million Pachyderm Forest elephant exhibit on January 28, 2009 in Los Angeles, California. A parade of celebrities who oppose elephants in zoos fought to shut down the project and send Billy to a sanctuary facility, including Bob Barker, Cher, Lily Tomlin and Kevin Nealon. After the Pachyderm Forest was approved by the City Council in 2006, actor Robert Culp and real estate agent Aaron Leider sued the city to stop the project alleging that zoo officials abuse elephants but the lawsuit was thrown out by the Los Angeles Superior Court. When completed, the 3 1/2-acre Pachyderm Forest will house up to five Asian elephants and three of their offspring in an enclosure with a waterfall and two pools. (Photo by David McNew/Getty Images)

  • Animal Activists Try To Remove Elephant From Los Angeles Zoo

    LOS ANGELES, CA - DECEMBER 13: Art student Mayuka Thais, who supports sending Ruby, a 45-year-old African elephant at the Los Angeles Zoo, to a sanctuary, sits next to her painting at a town hall meeting to discuss the conditions of elephants in captivity on December 13, 2006 in Los Angeles, California. The push to move Ruby to the PAWS sanctuary in San Andreas, California would be contingent upon the zoo's willingness to release the elephant that activists say has been kept in isolation since the controversial death of her longtime companion, Gita, in June. If moved, Ruby would have 500 times the space of her current enclosure at the zoo. Of the three elephants that the zoo had earlier this year, only the Indian elephant Billy is still on public display. Animal rights activists have been vocal opponents of the zoo's elephant exhibit and would like to see the exhibit closed and both elephants removed to a larger space. (Photo by David McNew/Getty Images)

  • Animal Activists Try To Remove Elephant From Los Angeles Zoo

    LOS ANGELES, CA - DECEMBER 13: Activists who support sending Ruby, a 45-year-old African elephant at the Los Angeles Zoo, to a sanctuary place their placards against a wall at a town hall meeting to discuss the conditions of elephants in captivity on December 13, 2006 in Los Angeles, California. The push to move Ruby to the PAWS sanctuary in San Andreas, California would be contingent upon the zoo's willingness to release the elephant that activists say has been kept in isolation since the controversial death of her longtime companion, Gita, in June. If moved, Ruby would have 500 times the space of her current enclosure at the zoo. Of the three elephants that the zoo had earlier this year, only the Indian elephant Billy is still on public display. Animal rights activists have been vocal opponents of the zoo's elephant exhibit and would like to see the exhibit closed and both elephants removed to a larger space. (Photo by David McNew/Getty Images)

  • Animal Activists Try To Remove Elephant From Los Angeles Zoo

    LOS ANGELES, CA - DECEMBER 13: An exhibit explains the social structure of elephants near the enclosure of the Indian elephant Billy which lives alone as the sole remaining elephant on public display at the Los Angeles Zoo while Ruby, a 45-year-old African elephant that activists want to send to a sanctuary, also resides alone and remains out of public view on December 13, 2006 in Los Angeles, California. The push to move Ruby to the PAWS sanctuary in San Andreas, California would be contingent upon the zoo's willingness to release the elephant that activists say has been kept in isolation since the controversial death of her longtime companion, Gita, in June. If moved, Ruby would have 500 times the space of her current enclosure at the zoo. Animal rights activists, including Assemblyman Lloyd Levine, D-Van Nuys, California, and 'The Price is Right' television host, Bob Barker, have been vocal opponents of the zoo's elephant exhibit and would like to see the exhibit closed and both elephants removed to a larger space. (Photo by David McNew/Getty Images)

  • Animal Activists Try To Remove Elephant From Los Angeles Zoo

    LOS ANGELES, CA - DECEMBER 13: The feet of Indian elephant Billy, sole remaining elephant on public display at the Los Angeles Zoo, are seen as Ruby, a 45-year-old African elephant that activists want to send to a sanctuary, remains out of public view on December 13, 2006 in Los Angeles, California. Captive elephants often develop foot problems that can be fatal. The push to move Ruby to the PAWS sanctuary in San Andreas, California would be contingent upon the zoo's willingness to release the elephant that activists say has been kept in isolation since the controversial death of her longtime companion, Gita, in June. If moved, Ruby would have 500 times the space of her current enclosure at the zoo. Animal rights activists, including Assemblyman Lloyd Levine, D-Van Nuys, California, and 'The Price is Right' television host, Bob Barker, have been vocal opponents of the zoo's elephant exhibit and would like to see the exhibit closed and both elephants removed to a larger space. (Photo by David McNew/Getty Images)

  • City Council To Vote On Fate Of Controversial Elephant Exhibit at L.A. Zoo

    LOS ANGELES, CA - JANUARY 28: Billy, the only elephant currently at the Los Angeles Zoo, is seen in his temporary exhibit after the Los Angeles City Council voted today to keep Billy at the zoo and continue construction of the $42 million Pachyderm Forest elephant exhibit on January 28, 2009 in Los Angeles, California. A parade of celebrities who oppose elephants in zoos fought to shut down the project and send Billy to a sanctuary facility, including Bob Barker, Cher, Lily Tomlin and Kevin Nealon. After the Pachyderm Forest was approved by the City Council in 2006, actor Robert Culp and real estate agent Aaron Leider sued the city to stop the project alleging that zoo officials abuse elephants but the lawsuit was thrown out by the Los Angeles Superior Court. When completed, the 3 1/2-acre Pachyderm Forest will house up to five Asian elephants and three of their offspring in an enclosure with a waterfall and two pools. (Photo by David McNew/Getty Images)

  • City Council To Vote On Fate Of Controversial Elephant Exhibit at L.A. Zoo

    LOS ANGELES, CA - JANUARY 28: Billy, the only elephant currently at the Los Angeles Zoo, is seen in his temporary exhibit after the Los Angeles City Council voted today to keep Billy at the zoo and continue construction of the $42 million Pachyderm Forest elephant exhibit on January 28, 2009 in Los Angeles, California. A parade of celebrities who oppose elephants in zoos fought to shut down the project and send Billy to a sanctuary facility, including Bob Barker, Cher, Lily Tomlin and Kevin Nealon. After the Pachyderm Forest was approved by the City Council in 2006, actor Robert Culp and real estate agent Aaron Leider sued the city to stop the project alleging that zoo officials abuse elephants but the lawsuit was thrown out by the Los Angeles Superior Court. When completed, the 3 1/2-acre Pachyderm Forest will house up to five Asian elephants and three of their offspring in an enclosure with a waterfall and two pools. (Photo by David McNew/Getty Images)

  • City Council To Vote On Fate Of Controversial Elephant Exhibit at L.A. Zoo

    LOS ANGELES, CA - JANUARY 28: Billy, the only elephant currently at the Los Angeles Zoo, is seen in his temporary exhibit after the Los Angeles City Council voted today to keep Billy at the zoo and continue construction of the $42 million Pachyderm Forest elephant exhibit on January 28, 2009 in Los Angeles, California. A parade of celebrities who oppose elephants in zoos fought to shut down the project and send Billy to a sanctuary facility, including Bob Barker, Cher, Lily Tomlin and Kevin Nealon. After the Pachyderm Forest was approved by the City Council in 2006, actor Robert Culp and real estate agent Aaron Leider sued the city to stop the project alleging that zoo officials abuse elephants but the lawsuit was thrown out by the Los Angeles Superior Court. When completed, the 3 1/2-acre Pachyderm Forest will house up to five Asian elephants and three of their offspring in an enclosure with a waterfall and two pools. (Photo by David McNew/Getty Images)

  • City Council To Vote On Fate Of Controversial Elephant Exhibit at L.A. Zoo

    LOS ANGELES, CA - JANUARY 28: Billy, the only elephant currently at the Los Angeles Zoo, is seen in his temporary exhibit after the Los Angeles City Council voted today to keep Billy at the zoo and continue construction of the $42 million Pachyderm Forest elephant exhibit on January 28, 2009 in Los Angeles, California. A parade of celebrities who oppose elephants in zoos fought to shut down the project and send Billy to a sanctuary facility, including Bob Barker, Cher, Lily Tomlin and Kevin Nealon. After the Pachyderm Forest was approved by the City Council in 2006, actor Robert Culp and real estate agent Aaron Leider sued the city to stop the project alleging that zoo officials abuse elephants but the lawsuit was thrown out by the Los Angeles Superior Court. When completed, the 3 1/2-acre Pachyderm Forest will house up to five Asian elephants and three of their offspring in an enclosure with a waterfall and two pools. (Photo by David McNew/Getty Images)

  • City Council To Vote On Fate Of Controversial Elephant Exhibit at L.A. Zoo

    LOS ANGELES, CA - JANUARY 28: Billy, the only elephant currently at the Los Angeles Zoo, is seen in his temporary exhibit after the Los Angeles City Council voted today to keep Billy at the zoo and continue construction of the $42 million Pachyderm Forest elephant exhibit on January 28, 2009 in Los Angeles, California. A parade of celebrities who oppose elephants in zoos fought to shut down the project and send Billy to a sanctuary facility, including Bob Barker, Cher, Lily Tomlin and Kevin Nealon. After the Pachyderm Forest was approved by the City Council in 2006, actor Robert Culp and real estate agent Aaron Leider sued the city to stop the project alleging that zoo officials abuse elephants but the lawsuit was thrown out by the Los Angeles Superior Court. When completed, the 3 1/2-acre Pachyderm Forest will house up to five Asian elephants and three of their offspring in an enclosure with a waterfall and two pools. (Photo by David McNew/Getty Images)

  • City Council To Vote On Fate Of Controversial Elephant Exhibit at L.A. Zoo

    LOS ANGELES, CA - JANUARY 28: Billy, the only elephant currently at the Los Angeles Zoo, is seen in his temporary exhibit after the Los Angeles City Council voted today to keep Billy at the zoo and continue construction of the $42 million Pachyderm Forest elephant exhibit on January 28, 2009 in Los Angeles, California. A parade of celebrities who oppose elephants in zoos fought to shut down the project and send Billy to a sanctuary facility, including Bob Barker, Cher, Lily Tomlin and Kevin Nealon. After the Pachyderm Forest was approved by the City Council in 2006, actor Robert Culp and real estate agent Aaron Leider sued the city to stop the project alleging that zoo officials abuse elephants but the lawsuit was thrown out by the Los Angeles Superior Court. When completed, the 3 1/2-acre Pachyderm Forest will house up to five Asian elephants and three of their offspring in an enclosure with a waterfall and two pools. (Photo by David McNew/Getty Images)

  • Animal Activists Try To Remove Elephant From Los Angeles Zoo

    LOS ANGELES, CA - DECEMBER 13: The Indian elephant Billy, sole remaining elephant on public display at the Los Angeles Zoo, is seen as Ruby, a 45-year-old African elephant that activist want to send to a sanctuary, remains out of public view on December 13, 2006 in Los Angeles, California. The push to move Ruby to the PAWS sanctuary in San Andreas, California would be contingent upon the zoo's willingness to release the elephant that activists say has been kept in isolation since the controversial death of her longtime companion, Gita, in June. If moved, Ruby would have 500 times the space of her current enclosure at the zoo. Animal rights activists, including Assemblyman Lloyd Levine, D-Van Nuys, California, and 'The Price is Right' television host, Bob Barker, have been vocal opponents of the zoo's elephant exhibit and would like to see the exhibit closed and both elephants removed to a larger space. (Photo by David McNew/Getty Images)

  • Animal Activists Try To Remove Elephant From Los Angeles Zoo

    LOS ANGELES, CA - DECEMBER 13: The Indian elephant Billy, sole remaining elephant on public display at the Los Angeles Zoo, is seen as Ruby, a 45-year-old African elephant that activist want to send to a sanctuary, remains out of public view on December 13, 2006 in Los Angeles, California. The push to move Ruby to the PAWS sanctuary in San Andreas, California would be contingent upon the zoo's willingness to release the elephant that activists say has been kept in isolation since the controversial death of her longtime companion, Gita, in June. If moved, Ruby would have 500 times the space of her current enclosure at the zoo. Animal rights activists, including Assemblyman Lloyd Levine, D-Van Nuys, California, and 'The Price is Right' television host, Bob Barker, have been vocal opponents of the zoo's elephant exhibit and would like to see the exhibit closed and both elephants removed to a larger space. (Photo by David McNew/Getty Images)

  • Animal Activists Try To Remove Elephant From Los Angeles Zoo

    LOS ANGELES, CA - DECEMBER 13: The Indian elephant Billy, sole remaining elephant on public display at the Los Angeles Zoo, is seen surrounded by chains as Ruby, a 45-year-old African elephant that activist want to send to a sanctuary, remains out of public view on December 13, 2006 in Los Angeles, California. The push to move Ruby to the PAWS sanctuary in San Andreas, California would be contingent upon the zoo's willingness to release the elephant that activists say has been kept in isolation since the controversial death of her longtime companion, Gita, in June. If moved, Ruby would have 500 times the space of her current enclosure at the zoo. Animal rights activists, including Assemblyman Lloyd Levine, D-Van Nuys, California, and 'The Price is Right' television host, Bob Barker, have been vocal opponents of the zoo's elephant exhibit and would like to see the exhibit closed and both elephants removed to a larger space. (Photo by David McNew/Getty Images)

  • An Asian elephant drinks water at the Lo

    An Asian elephant drinks water at the Los Angeles Zoo and Botanical Garden in Los Angeles on April 04, 2012. AFP PHOTO /JOE KLAMAR (Photo credit should read JOE KLAMAR/AFP/Getty Images)

  • Animal Activists Try To Remove Elephant From Los Angeles Zoo

    LOS ANGELES, CA - DECEMBER 13: The Indian elephant Billy, sole remaining elephant on public display at the Los Angeles Zoo, is seen as Ruby, a 45-year-old African elephant that activist want to send to a sanctuary, remains out of public view on December 13, 2006 in Los Angeles, California. The push to move Ruby to the PAWS sanctuary in San Andreas, California would be contingent upon the zoo's willingness to release the elephant that activists say has been kept in isolation since the controversial death of her longtime companion, Gita, in June. If moved, Ruby would have 500 times the space of her current enclosure at the zoo. Animal rights activists, including Assemblyman Lloyd Levine, D-Van Nuys, California, and 'The Price is Right' television host, Bob Barker, have been vocal opponents of the zoo's elephant exhibit and would like to see the exhibit closed and both elephants removed to a larger space. (Photo by David McNew/Getty Images)