| Entropian |
There are numerous eyelid disorders in dogs. Entropian (rolling inwards), and ectropian (drooping or rolling
outward) are the most common and, although they are considered abnormal eyelid conformations, are
characteristics of many breeds. For example, droopy lower eyelids (ectropian) are usually present in Basset
hounds and other hound breeds. The breeding of Shar Peis and Chow Chows, in which breeding selection has been
made for numerous facial wrinkles, has led to turning in of the eyelids (both upper and lower in many cases).
Ectropian, unless very pronounced, does not lead to severe diseases of the eye itself. However, the droopy
eyelid may collect debris such as dust, pollen and plant material from the environment. This may cause ocular
irritation that leads to discharge and a red eye. This is particularly pronounced in hunting dogs or dogs that are
outdoors much of the time. Dogs that have ectropion must be watched carefully by their owners for possible
foreign bodies in their eyes, and the dogs' eyes must be cleaned and often medicated on a regular basis.
Entropion on the other hand frequently causes ocular pain and corneal disease. If the eyelid is rolled inward
sufficiently so that the hairs of the eyelid rub on the eye, much damage may be done. Dogs with entropian usually
squint and have watery eyes. If the entropian is not corrected and the rubbing continues, ulcers often develop on
the cornea and the cornea becomes pigmented. Vision may be lost. Dogs that have had entropian correction
surgery cannot be shown.
Although entropian and ectropian are hereditary disorders in many breeds, their mode of inheritance is complex.
No one gene controls the development of eyelid conformation. Instead, it is a combination of genes that control
eyelid size and shape, depth of the orbit (eye socket), size and shape of the eyes, head conformation and amount
of facial skin. All of these genes work in concert to determine the relationship of the eyelids to the eye.
Therefore if an eyelid conformation defect is to be eliminated, only those dogs without entropian or ectropian
must be bred. In many cases this may be difficult as "abnormal" eyelids may be a desirable breed standard.
The current recommendations for breeding dogs with ectropian is classified as a "breeder option". This is
because, although it is a hereditary problem, it is usually not sight threatening. Entropion is a painful and
potentially blinding disease and therefore affected dogs in breeds that have a high incidence of entropian (such
as Bloodhounds, Chow Chows, English Bulldog, Standard Poodle, Bull Mastiff, Chinese Shar Pei, Mastiff, Vizsla, and
Saint Bernards) are not denied certification. However, because exaggerated facial conformation with loose skin
and/or heavy facial folds often leads to eyelids that roll in or out predisposed the animal to irritation,
discomfort and possible vision loss, selecting away from these traits in all breeds is strongly encouraged.
outward) are the most common and, although they are considered abnormal eyelid conformations, are
characteristics of many breeds. For example, droopy lower eyelids (ectropian) are usually present in Basset
hounds and other hound breeds. The breeding of Shar Peis and Chow Chows, in which breeding selection has been
made for numerous facial wrinkles, has led to turning in of the eyelids (both upper and lower in many cases).
Ectropian, unless very pronounced, does not lead to severe diseases of the eye itself. However, the droopy
eyelid may collect debris such as dust, pollen and plant material from the environment. This may cause ocular
irritation that leads to discharge and a red eye. This is particularly pronounced in hunting dogs or dogs that are
outdoors much of the time. Dogs that have ectropion must be watched carefully by their owners for possible
foreign bodies in their eyes, and the dogs' eyes must be cleaned and often medicated on a regular basis.
Entropion on the other hand frequently causes ocular pain and corneal disease. If the eyelid is rolled inward
sufficiently so that the hairs of the eyelid rub on the eye, much damage may be done. Dogs with entropian usually
squint and have watery eyes. If the entropian is not corrected and the rubbing continues, ulcers often develop on
the cornea and the cornea becomes pigmented. Vision may be lost. Dogs that have had entropian correction
surgery cannot be shown.
Although entropian and ectropian are hereditary disorders in many breeds, their mode of inheritance is complex.
No one gene controls the development of eyelid conformation. Instead, it is a combination of genes that control
eyelid size and shape, depth of the orbit (eye socket), size and shape of the eyes, head conformation and amount
of facial skin. All of these genes work in concert to determine the relationship of the eyelids to the eye.
Therefore if an eyelid conformation defect is to be eliminated, only those dogs without entropian or ectropian
must be bred. In many cases this may be difficult as "abnormal" eyelids may be a desirable breed standard.
The current recommendations for breeding dogs with ectropian is classified as a "breeder option". This is
because, although it is a hereditary problem, it is usually not sight threatening. Entropion is a painful and
potentially blinding disease and therefore affected dogs in breeds that have a high incidence of entropian (such
as Bloodhounds, Chow Chows, English Bulldog, Standard Poodle, Bull Mastiff, Chinese Shar Pei, Mastiff, Vizsla, and
Saint Bernards) are not denied certification. However, because exaggerated facial conformation with loose skin
and/or heavy facial folds often leads to eyelids that roll in or out predisposed the animal to irritation,
discomfort and possible vision loss, selecting away from these traits in all breeds is strongly encouraged.
| This page was created by and is maintained by Belinda Winters for BFH Bassets. If you have any questions or comments email belindawinters@bfhbassets.com |