The protest comes four days before parliament is due to vote on the new animal rights bill proposed by the ruling Socialist part. But the draft law exposed divisions in its support base, with rural voters arguing that sections of the bill would effectively legislate hunting out of existence.
The party submitted a last-minute amendment to exclude hunting dogs and other animals involved in traditional rural activities.
Protesters, many of whom brought their dogs along, held signs including "Killing is not a sport" chanted "Stop hunting".
"Animals should not be exploited, exploitation is mistreatment," dog shelter worker Lara Mena, who attended Sunday's protest, told Reuters.
In Spain, dogs are used to track or catch animals such as deer, wild boar and rabbits. The hunting industry generates more than 5 billion euros ($5.42 billion) a year in economic activity, figures from Deloitte show.
(Reporting by Elena Rodriguez and Marco Trujillo, Writing by Jessica Jones, Editing by Raissa Kasolowsky)
