TUNIS, June 29 -- Nemcha, Zina and Zouina, three North African Sloughi hounds, play on the beach in Tunisia where their ancestors have long roamed desert plains, seemingly unaware of the existential threat to their dwindling breed.

The Sloughis, known for their speed and slender physique, have for many centuries accompanied nomadic societies across North Africa, and have been featured in art and lore dating back at least to the Roman era.

But nowadays breeders and advocates say that unregulated crossbreeding, the decline of nomadic lifestyles and habitat shifts due to urbanisation mean that they might soon disappear.

Olfa Abid, who was walking Nemcha, Zina and Zouina along the coast in northern Tunisia's Ras Angela, said the age-old br...