Wry nose is a congenital condition in foals where the nose appears twisted or crooked due to malformations that develop during gestation. This condition involves significant changes in the shape and direction of the upper jaw, nasal bones, and other features of the skull.

While wry nose can vary in severity, it often affects the horse’s ability to eat and breathe properly. In some cases, the nasal bones are deviated enough to obstruct the nasal canal, which interferes with normal breathing.

Twisted bones in the roof of the mouth can misalign the upper incisors, complicating the horse’s ability to suckle and eventually grasp and chew food. Misaligned jaws can also interfere with chewing and swallowing.

Although the exact cause of wry nose remains unclear, it likely involves a combination genetic and environmental factors. Diagnosing this condition involves physical examination and imaging techniques, while treatment ranges from minor surgical interventions to major reconstructive surgeries.

By understanding wry nose, recognizing its symptoms, and learning how to assess its impact on quality of life, horse owners and caretakers can make informed decisions about treatment options for affected foals in their herd.

Wry Nose in Horses

Wry nose (also known as campylorrhinus lateralis, facial deviation, or deviated nose) in horses is a noticeable malformation of the face that develops during gestation. Affected foals are born with a crooked or twisted nose.

Wry nose is characterized by mild to severe changes in the shape and direction of the upper jaw, incisive bones, nasal septum, and nasal bones. [1][2][3][4][5][6][7]

In some cases, wry nose results from the upper jaw being shorter than the lower jaw. In others, the nasal bones and hard palate are more severely arched than normal. [1]

This condition is not only a cosmetic concern for horse owners, but also has ramifications for the health and wellbeing of the horse. [8][9] Depending on severity, wry nose can interfere with affected horses’ ability to nurse, eat or breathe properly. [1][3]

Equine Nasal Anatomy

To understand wry nose, it is useful for owners and caretakers to familiarize themselves with the normal anatomy of the horse’s nose.

Nasal Bones

The nasal bones form the upper part of the nasal cavity and are important in shaping the horse’s nose.

In horses with wry nose, these bones are twisted, fused, or deviated. [4] This leads to a significant alteration in the expected straight alignment of the nasal cavity. This particular deviation is the primary contributor to the crooked appearance of the nose from the outside.

If the nasal bones deviate too much into the nasal canal, the horse’s airway can become obstructed leading to difficulty breathing and increased respiratory sounds. [3][7][8]

Nasal Septum

The nasal septum is a partition comprised of bone and cartilage. This structure divides the nasal cavity into two halves.

In horses with wry nose, the nasal septum is often deviated or misshapen. This can result in obstruction of the airway that can cause difficulty breathing. [3][4][8] In addition, severe deviations in the soft palate can open a communication between the mouth and sinuses, which can interfere with swallowing.

Incisive Bones

The incisive bones (also known as premaxillary bones) are located at the front of the upper jaw. They form the structure that supports the upper incisor teeth. These bones are essential to the proper alignment and function of the front teeth.

In horses with wry nose, the incisive bones are often twisted or rotated. This causes misalignment of the upper incisors, which makes it difficult to eat because the horse cannot effectively grasp and chew food. [4]

Equine teeth continue to grow over the course of the lifetime. Even with routine dental care, the teeth can grow long enough to damage the surrounding soft tissues if they are not opposed by other teeth due to malformation of the oral bones. [3]

Maxillary Bones

The maxillary bones form most of the upper jaw. This is the structure that houses the upper grinding teeth known as the premolars and molars.

In horses with wry nose, these bones are twisted or misaligned. [8] This impacts the structure and function of the upper jaw. Maxillary deformities not only affect the horse’s appearance, but can also contribute to dental issues that can negatively impact the horse’s ability to chew and digest food. [3]

Mandible

Although the mandible (also known as the lower jaw) is not primarily affected by wry nose, it can become misaligned due to deviation in the upper jaw. If the upper and lower jaw do not meet evenly, it can impact the wear pattern that helps keep the tooth height even and effective at chewing.

Misaligned teeth left to grow without intervention can result in pain and inflammation in the soft tissues of the mouth. Ongoing issues with chewing can also result in poor nutrition, which has the potential to cause more severe, long-term health effects. [3]

Musculature and Soft Tissues

There are numerous muscles and soft tissues that are involved in the function of the horse’s mouth. In horses with wry nose, these tissues may adapt to the altered bone structure. Depending on the nature of the deformity, these changes can impact the horse’s ability to move its jaw normally. [3][4]

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Causes

The cause of wry nose is not fully understood at this time. Since affected foals are often born with the condition, a genetic component is suspected. [1] However, some researchers state there is no evidence for this theory. [3]

Another theory is that wry nose develops due to a failure of the uterus to expand properly with the growth of the fetus. [1][7]

This accounts for cases where both the upper and lower jaws are malformed, but does not explain the more common case where only the upper jaw is affected. [1] For this reason, some researchers believe this is highly unlikely to be a cause. [8]

There is some evidence that abnormal fusing of the incisive bone to the nasal bone on one side of the nose is another possible explanation, although the cause of this abnormality is also unknown. [8]

Cases of wry nose may be multifactorial, resulting from multiple developmental deformities happening at the same time. More research into this condition is necessary for a cause to be determined.

Risk Factors

Wry nose is a rare condition in horses. [3][5] It is noted more often in Arabian and miniature horse breeds, but detailed statistical research into breed prevalence is lacking. [1][3][5]

Some evidence suggests that horses born to first-time mothers are more likely to have wry nose than those born to mares that have previously given birth, but more research is needed. [1]

Symptoms

The characteristic symptom of wry nose is a twisted or deviated nose. [8] This condition is usually present at birth and is typically reported to the veterinarian within the first few weeks of life. [8]

Along with the facial deformity, symptoms include: [1][3][8][10]

  • Difficulty suckling
  • Eventual difficulty grasping and chewing food
  • Difficulty breathing and increased respiratory sounds
  • Eventual overgrowth of teeth
  • Asymmetrical nostrils

Severity

The severity of wry nose depends on the extent of the deviation, the impact on the surrounding structures, and the effect on the horse’s ability to suckle, eat, and breathe. [9]

Foals with mild cases of wry nose can suckle and eventually eat successfully. [1][7]

Foals with moderate cases of wry nose have some difficulty with suckling, eating and breathing. [4][9] They may need to take milk replacements from a bucket instead of nursing. [3][9]

In some cases, affected foals require the placement of a temporary or permanent tracheostomy tube. This type of intubation helps the foal breathe more effectively by bypassing narrowed or obstructed structures. [3][9]

Severely affected foals are unable to suckle effectively. [1] In these cases, they may survive by using a milk replacement. [1][9] If this is not possible, the horse may not survive.

Foals that survive to wean may have difficulty grasping grass and other food. [1][3] They also may develop dental problems as their teeth continue to grow without the necessary grinding action of proper chewing. [3]

In cases where the septum is severely deviated, the foal may have difficulty breathing and may wheeze even when at rest. [1]

In rare cases, this condition is accompanied by other birth defects such as cleft palate, umbilical hernia, and contracted tendon syndrome. Foals with wry nose tend to be more susceptible to aspiration pneumonia. [3]

Diagnosis and Treatment

Wry nose is self-evident and diagnosed based on physical examination. The characteristic malformation of the nose is clear to the naked eye. [1][3][8]

The degree of deviation is measured with: [1][3][4]

  • X-rays
  • CT scans
  • Dental impressions

Treatment

Mild cases of wry nose may require little to no intervention. [1][4][8]  In these cases, if the horse has trouble breathing, it may require a minor surgery to place a temporary tube that bypasses the upper airway. [1] If the foal is eventually able to eat and breathe normally, the tube may be removed and no further intervention is required.

Foals with moderate or severe wry nose, particularly those with difficulty eating or breathing require reconstructive surgery. [1][3][7][8][10] Surgery aims to reshape the face, realign the teeth, and open the airways.

The recommended age for reconstructive surgery varies and depends on the individual case and the treating veterinarian’s qualified opinion. The age for reconstructive surgery ranges from 2 to 7 months old. [3][8]

Prior to and after surgery the horse may require: [1][3]

Prognosis

The prognosis for foals with wry nose is good in mild or moderate cases. In mild cases, wry nose may be self-limiting and resolve itself as the horse matures. [1][7] In severe cases, the prognosis is guarded.

Surgical success is defined by the horse recovering and being able to eat and breathe normally. [3][9][10] The prognosis for a return to full athletic capacity remains guarded. [9]

In the most extreme cases and where surgery is unsuccessful in returning function, humane euthanasia may be the only option. [4][8][9]

Since the causes of wry nose are not fully understood, there are no specific preventative measures that can help a horse avoid developing wry nose. It may be beneficial to avoid breeding horses that have produced offspring with wry nose, as a genetic component is suggested, but this is not confirmed.

Ensuring breeding mares are in top health before, during, and after pregnancy creates the best chances of producing healthy offspring without conformation defects.

Summary

Wry nose in horses is a condition in which a foal is born with a noticeably crooked or twisted nose. Not only is there a cosmetic concern for these horses, but these malformations can also impact affected horses’ ability to suckle, eat, and breathe.

  • The causes of wry nose are not fully understood at this time, but it may have a genetic and environmental component
  • The characteristic symptom of the condition is a malformation of the structures that make up the nose
  • Secondary symptoms include dental issues, wheezing, and difficulty eating
  • Diagnosis is based on the presence of the malformation and the degree of deviation is measured with X-rays, CT scans and dental impressions
  • Mild cases may resolve on their own, most cases require some form of surgical correction
  • Prognosis for foals with mild to moderate wry nose is good; those with a severe deviation have a more guarded prognosis

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References

  1. Hawkins, J. Ed., Advances in Equine Upper Respiratory Surgery. ACVS Foundation. John Wiley & Sons, 2015.
  2. Mousquer, M. A. et al., Gestation in a Mare with Facial Deviation (Wry Nose). Acta Scientiae Veterinariae. 2019.
  3. Easley, J., Basic Equine Orthodontics. Equine Dentistry. Elsevier. 2005.
  4. Sapper, C. B. et al., Gingival Approach to Correct Wry Nose Using Locking Compression Plates in Two Foals. Equine Veterinary Education. 2022.
  5. Cousty, M. et al., Use of an External Fixator to Correct a Wry Nose in a Yearling. Equine Veterinary Education. 2010.
  6. Rangel, J. P. P. et al., Correcting Campylorrhinus Lateralis in a Foal by Bone Distraction: A Case Report. Journal of Equine Veterinary Science. 2020.
  7. Schumacher, J. et al., Surgical Correction of Wry Nose in Four Horses. Veterinary Surgery. 2008.
  8. Auer, J. A., Craniomaxillofacial Disorders. Equine Surgery. Elsevier. 2012.
  9. Robertson, J. T., Surgical Correction of Wry Nose in Newborn Foals. Equine Veterinary Education. 2010.
  10. Doyle, A. J. and Freeman, D. E., Extensive Nasal Septum Resection in Horses Using a 3‐Wire Method. Veterinary Surgery. 2005.