Device for washing pets using a single hand having: - a Subassembly main body in fluid communication with a feeding pipe connected to a water hose for conveying and directing water through two lateral holes (1b, 1c) provided in the main body; said feeding pipe being also used as a handle and being provided with a valve for closing, dosing and opening a water supply; said Subassembly main body containing a shampoo supply container formed at its top, allowing admission of shampoo into the main body via a small hole in the lower part of said shampoo supply container, to allow the shampoo to be mixed into the water wherein said subassembly main body is a compact body which forms together with said feeding pipe a single cast main body and wherein the device further comprises - a Subassembly consisting of two detachable hose-type arms closed at their deployable ends, in fluid communication with the Subassembly main body via said two lateral holes, said arms being made of a flexible material and wrapped in a flat spiral, that extend in size depending on the force of the water introduced therein through the main body, having an adjustable semi-elliptical shape resulting from the unrolling at the same time with an arched steel strip normally wrapped and fastened to the inside of the winding direction all over the detachable hose-type arms' length, said arched steel strip allowing self-winding of the arms after closing the water supply and said arms being provided on the inner side of the winding direction with water and shampoo sprinkling holes. - a Subassembly main body in fluid communication with a feeding pipe connected to a water hose for conveying and directing water through two lateral holes (1b, 1c) provided in the main body; said feeding pipe being also used as a handle and being provided with a valve for closing, dosing and opening a water supply; said Subassembly main body containing a shampoo supply container formed at its top, allowing admission of shampoo into the main body via a small hole in the lower part of said shampoo supply container, to allow the shampoo to be mixed into the water wherein said subassembly main body is a compact body which forms together with said feeding pipe a single cast main body and wherein the device further comprises - a Subassembly consisting of two detachable hose-type arms closed at their deployable ends, in fluid communication with the Subassembly main body via said two lateral holes, said arms being made of a flexible material and wrapped in a flat spiral, that extend in size depending on the force of the water introduced therein through the main body, having an adjustable semi-elliptical shape resulting from the unrolling at the same time with an arched steel strip normally wrapped and fastened to the inside of the winding direction all over the detachable hose-type arms' length, said arched steel strip allowing self-winding of the arms after closing the water supply and said arms being provided on the inner side of the winding direction with water and shampoo sprinkling holes. said Subassembly main body containing a shampoo supply container formed at its top, allowing admission of shampoo into the main body via a small hole in the lower part of said shampoo supply container, to allow the shampoo to be mixed into the water wherein said subassembly main body is a compact body which forms together with said feeding pipe a single cast main body and wherein the device further comprises - a Subassembly consisting of two detachable hose-type arms closed at their deployable ends, in fluid communication with the Subassembly main body via said two lateral holes, said arms being made of a flexible material and wrapped in a flat spiral, that extend in size depending on the force of the water introduced therein through the main body, having an adjustable semi-elliptical shape resulting from the unrolling at the same time with an arched steel strip normally wrapped and fastened to the inside of the winding direction all over the detachable hose-type arms' length, said arched steel strip allowing self-winding of the arms after closing the water supply and said arms being provided on the inner side of the winding direction with water and shampoo sprinkling holes. - a Subassembly consisting of two detachable hose-type arms closed at their deployable ends, in fluid communication with the Subassembly main body via said two lateral holes, said arms being made of a flexible material and wrapped in a flat spiral, that extend in size depending on the force of the water introduced therein through the main body, having an adjustable semi-elliptical shape resulting from the unrolling at the same time with an arched steel strip normally wrapped and fastened to the inside of the winding direction all over the detachable hose-type arms' length, said arched steel strip allowing self-winding of the arms after closing the water supply and said arms being provided on the inner side of the winding direction with water and shampoo sprinkling holes.