Lips of Ox
The lips are two in number in case of ox- upper and lower. these are thick, wide and comparatively immobile musculo- membranous folds, which surround the rima oris.
The angles of union of the lips- the commissures are situated 5cm behind the level of the corner incisor tooth. Each lip presents two surfaces and two borders.
The middle part of the external surface of the upper lip and the surface between the nostrils is bare and is termed the muzzle.
Lips is kept cool and moist by a fluid secreted by the nasolabial glands resent under the skin.
The muzzle is smooth and shows irregular lines mapping out small polygonal areas on which the duct of the naso-labial glands open. the rest of the surface presents long tactile hairs in addition to the ordinary fine hairs.
The external surface of the lower lip has rounded prominence, the chin and it presents the short and long hairs and internal surface is covered with mucous membrane. Small folds of mucous membrane the frenula labii pass from the lips to the gums
The attached border of each lip is continuous with the surrounding structures and free border of each lip is bare and presents on its free edge a number of short and blunt horny papillae
Lips become larger, longer and pointed towards the angles
Lips of Sheep and Goat
The lips are mobile and thin and are the organ of prehension in sheep and Goat. upper one lip is marked by a very distinct philtrum and otherwise is not bare.
Lips of Horse
The lips are thinner, narrower and more mobile in case of horse. the lips are also the organs of prehension in horse. the upper lip on its external surface has a shallow median furrow the philtrum.
Mucous membrane of lips may be pigmented, Horny papillae are absent and angle of union of lips is about the level of the first cheek tooth.
Lips of Pig
The upper lip is thick and short and is blended with snout and lower lip is small and pointed in Pig. labial glands are few and small.
Lips of Dog
Lips of dog are thin and mobile presenting numerous tactile hairs. The upper lip projects over the lower lip and covers it more or less at the sides.
The muzzle presents a deep groove or cleft, the philtrum giving the appearance of harelip. the commissures are about the level of the third or the fourth cheek tooth. Mucous membrane may be pigmented. Horny papillae are absent in dog.
Lips of Rabbit
The upper lip is fleshy and divided into two halves, which are placed on either side of the incisors below nasal flap. Muzzle is absent in rabbit. Plenty of tactile hairs spring from the skin covering upper lip.
Lips of Fowl
The lips in fowl are absent.
