Bess

Bess (ベス) is the pet dog of the Yamane family who live near to the Tendo Dojo.

Biography
Suspicious that Ryoga has acquired a Jusenkyo curse, Ranma chases after him after he drops his umbrella in the middle of a rain storm. Shortly after losing sight of Ryoga, Ranma finds Bess near a pile of Ryoga's clothes and assumes that this must be his cursed form. Ranma then takes Bess back to the Tendo Dojo where she decides to keep Ryoga's secret as part of the "warrior's code" before Akane walks in and recognizes Bess as the Yamane's dog. Making sure Akane isn't looking, Ranma pours some hot water over Bess and observes that it doesn't change form and thus can't be Ryoga's cursed form.