Smelaya and Malyshka
Smelaya (Смелая, “Brave” or “Courageous”) was due to make a flight in September but ran away the day before the launch. She was found the next day and went on to make a successful flight with a dog named Malyshka(Малышка, “Little One”).
Bolik and ZIB
Bolik (Болик) ran away just days before her flight in September 1951. A replacement named ZIB (a Russian acronym for “Substitute for Missing Bolik”, “Замена исчезнувшему Болику” Zamena ischeznuvshemu Boliku), who was an untrained street dog found running around the barracks, was quickly located and made a successful flight.
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Albina and Tsyganka
Albina (Альбина, a real female name) and Tsyganka (Цыганка, “Gypsy girl”) were both ejected out of their capsule at an altitude of 85 km and landed safely. Albina was one of the dogs shortlisted for Sputnik 2, but never flew in orbit.
Damka and Krasavka
Damka (Дамка, “Queen of checkers”) and Krasavka (Красавка, “Little Beauty”) were to make an orbital flight on December 22, 1960 as a part of the Vostok programme, but their mission was marked by a string of equipment failures. The upper stage rocket failed and the craft re-entered the atmosphere after reaching a sub-orbital apogee of 214 km. In the event of unscheduled return to the surface, the craft was to eject the dogs and self-destruct, but the ejection seat failed and the primary destruct mechanism shorted out. The animals were thus still in the intact capsule when it returned to the surface. The backup self-destruct mechanism was set to a 60 hour timer, so a team was quickly sent out to locate and recover the capsule. Although the capsule was reached in deep snow on the first day, there was insufficient remaining daylight to disarm the self-destruct mechanism and open the capsule. The team could only report that the window was frosted over in the −45 degree temperatures and no signs of life were detected. On the second day, however, the dogs were heard barking as the capsule was opened. The dogs were wrapped in sheepskin coats and flown to Moscow alive.[7] Damka was also known as Shutka (Шутка, “Joke”) or Zhemchuzhnaya (Жемчужная, “Pearly”) and Krasavka was also known as Kometka (Кометка, “Little Comet”) or Zhulka (Жулька, “Cheater”).
(source: wikipedia)