Tu mejor amigo, el perro (Your best friend, the dog) was released in 1971 by Ondina S.A., a former beverage company in Catalonia, Spain. The 50-card collector album features colorful illustrations of canine breeds from around the world. The collection includes a subset of famous dogs that features television and film stars Rin-Tin-Tin and Lassie; as well as historical dogs Becerrillo, Barry, and Laika.

One card was included with each carton of Ondina Cola soft drinks. A softcover collector album was sold separately. The card text and album descriptions were authored by F. M. Sesen. Tu mejor amigo, el perro was printed by T.G. Ruiromer in Barcelona. The album was published by Publicidad Solmak, S.L. of Les Valls.

The series was distributed in Mexico with Relle Dona snack cakes from Wonder. The Relle Dona variants contain numbering on the front of each card.

Laika (Лайка, "Curly") was a mixed-breed stray dog found on the streets of Moscow, Russia. On November 3, 1957, Laika became the first animal to orbit the Earth, travelling aboard the Sputnik 2 spacecraft. Laika died from overheating after the third orbit, about 5–7 hours into the mission. The card and album text incorrectly state that Laika was euthanized. The Sputnik 2 spacecraft reentered the atmosphere on April 14, 1958.