Italy is home to several populations of native dogs that reside only in certain demographic regions. Such dog populations have not been under tight selection by humans and, as such, have never been officially recognised as breeds. One such population is the ‘Cane Fonnese’ or Fonni’s Dog, which features uniform morphologic and behavioural traits that reproduce across generations, thus qualifying Fonni’s Dog as a true breed eligible for recognition by national or international breed registries. The Fonni’s Dog population examined in the present work is native to Sardinia, where they are used as property or livestock guardian dogs. As such, they are greatly appreciated by the local populace. We have carried out morphological evaluations on 200 Fonni’s Dogs with the aim of developing a standard breed definition upon which the foun- dation of the Fonni’s Dog breed can be based. We have also reported genetic data of the Fonni’s Dog compared to four other established breeds sampled from the same geographic area.