Wry Nose

Also known as: Campylorrhinus lateralis

Introduction

Wry nose is a congenital deviation and shortening of the premaxillae, nasal bones and nasal septum in foals. The deviation can be very mild to severe, and can result in severe nasal obstruction. There is usually malocclusion of the teeth but most foals can still nurse and are still bright and active.

It is thought that foetal malpositioning is the cause of this condition. However Arabian foals seem to be more commonly affected which may point to a genetic component.

Wry-nosed foals can also have other deformities of the neck and limbs, and a cleft palate may also be present.

Clinical Signs

The deviation can be mild to severe, up to 90° and may be accompanied by protrusion of one of the nasal bones.

There may be excessive arching of the nasal bones and hard palate. There is incisor malocclusion and some of the mandibular incisors may be visible. The tongue may protrude and feed may be retained in the oral cavity.

The foal may be unable to nurse due to the deviation, or it may have respiratory impairment, even when it is resting.

Diagnosis

The obvious facial deformities are visible on clinical examination.

Radiography may help confirm and further evaluate the degree and severity of the deviation.

Endoscopic evaluation permits evaluation of the hard and soft palate.

Treatment

Conservative management is possible in mild cases and some spontaneous improvement can be expected with time.

Severely affected foals require intensive nursing care, and euthanasia may be necessary in some cases.

If the foal is unable to nurse, administration of colostrum through a nasogastric tube should be performed. The foal's immunoglobulin levels should be assessed to check for adequate colostrum consumption.

Surgical correction is generally undertaken in at least 2 procedures and involves straightening the maxillae/premaxillae and nasal bones and removing the affected part of the nasal septum:

The premaxillae/maxillae are transected at their point of maximum curvature and an autogenous rib graft is inserted into the space created on the concave side of the deformity when the incisors are realigned. The bones are stabilised with pins or an external fixator.
After these osteotomies have healed, a portion of the deviated nasal septum is removed and the nasal bones are straightened.

Distraction osteogenesis is another method of surgical correction.

Prognosis

Mild cases have a good prognosis and conservative treatment is sufficient as deformities may resolve spontaneously with growth.

Cases requiring surgery have to undergo multiple interventions and the aftercare required is significant. The cosmetic results may be poor if the premaxillae/maxillae are abnormally short, or if the nasal bones collapse (which is more likely in foals less than 6 months of age).

Unfortunately neither the functional or the cosmetic outcome can be guaranteed.

Wry Nose Learning Resources
Flashcards Test your knowledge using flashcard type questions	Equine Reproduction and Stud Medicine Q&A 02

References

Rush, B. (2004) Equine Respiratory Diseases John Wiley and Sons

McAuliffe, S. (2008) Color Atlas of Disease and Disorders of the Foal Saunders

McGorum, B. (2007) Equine respiratory medicine and surgery Elsevier Health Sciences