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CLEFT PALATE
Overview of the Condition:
A cleft palate is an opening between the mouth (oral cavity) and the nose (nasal cavity) that occurs when the tissues separating these two cavities do not grow together properly. This birth defect can occur in the lip (“primary cleft palate”, “cleft lip”, or “harelip”) or along the roof of the mouth (“secondary cleft palate”). Within the mouth, the cleft can extend along the bony portion (hard palate), the flexible portion that is used in swallowing (soft palate), or both.
Signs/Clinical Presentation:
Animals with primary cleft palates are obvious (Figure1). Because the lips and nostrils did not fuse, the teeth and gums of the upper jaw may be exposed and one nostril may be distorted or incomplete. Animals with secondary cleft palates (Figure 2) within the mouth will sneeze and snort because food and saliva will pass through the gap into the nose. Nasal discharge from the food may occur during or after nursing or eating and may become continuous if infection is present. Animals may cough and gag when they drink water, particularly if the soft palate is affected. Because eating is difficult, the animals may not grow well, and they are at risk for pneumonia because of accidental inhalation of food and liquids. Affected animals may also have trouble breathing and exercising because of fluid or infection in their noses.
Figure 1. Primary cleft palate or “harelip” in a ten year old Cocker spaniel. The dog only sneezed occasionally and its owners were not bothered by its appearance, so they never had it corrected.
Figure 2. Secondary cleft palate in a dog. The yellow arrows point to the cleft in the hard palate, and the green arrows point to the cleft in the soft palate.
Risk Factors:
Purebred dogs and cats have a higher incidence of cleft palate, and brachycephalic breeds, with their short stubby faces, are most commonly affected (Figure 3). Cleft palates may occur more commonly in Boston terriers, Pekingese, bulldogs, miniature schnauzers, beagles, cocker spaniels, dachshunds, and Siamese cats. Although heredity is considered the primary cause of this problem, nutritional deficiencies, viruses, and poisons that affect the mother during pregnancy may also increase the risk of cleft palates in developing puppies and kittens.
Figure 3. French bulldog puppy with secondary cleft palate and nasal discharge.
Diagnostic Tests:
Cleft palate of the lip and the hard palate are easily seen during a veterinary examination. Most animals must be anesthetized, however, to see the soft palate because it is so far back in the mouth. Your veterinarian may want to take chest x-rays to see if there is any evidence of pneumonia.
Differential Diagnoses:
Viral infections can cause puppies and kittens to sneeze and cough, and animals with foreign bodies (stick or grass seeds) in their nose will also sneeze a lot. Anything blocking the esophagus (the tube that carries food from the mouth to the stomach) can cause food to come up unexpectedly and make the animals gag. Animals with esophagus problems, however, do not tend to sneeze or have drainage from the nose unless they also have pneumonia. Cleft palates can also occur from trauma (falling from great heights or electrical cord burns).
Treatment Options:
Small primary clefts of the lip and nostril rarely cause clinical problems, but they are unsightly and most owners prefer to have them corrected (Figures 4, 5, 6, 7).
Figure 4. Primary cleft palate or “harelip” in a springer spaniel. The defect in this dog extended through the lip and edge of the nostril only.
Figure 5. When the cleft is pushed together, the lip and nostril look relatively normal.
Figure 6. The cleft in the nostril and lip have been repaired.
Figure 7. A small cleft within the mouth below the nostril was also closed. The narrow
gap (green arrow) between the upper teeth was not repaired because it did not extend into the nose.
Secondary cleft palates require surgical treatment to prevent chronic nasal and lung infections and to help the animal receive adequate nutrition. The thick soft tissue (“mucosa”) covering the remainder of the hard palate can be rotated or rolled inward and sutured in place to cover the hole (Figures 8, 9, 10, 11, 12). Alternatively, flaps from the inner surface of the lip or from skin on the cheek or forehead can be used.
The surgery is difficult on very young animals and, with growth, the cleft in hard palates may become smaller, so puppies are kittens are often fed with feeding tubes until they reach 3-4 months of age. Owners can learn how to pass a stomach tube, or the veterinarian can place an “esophageal” feeding tube through the side of the neck so that blendarized diets can be fed easily.
Figure 8. The large gap (yellow arrows) in the soft palate is visible when the mouth is opened wide under anesthesia.
Figure 9. The cleft in the soft palate has been sutured closed.
Figure 10. A flap of tissue (green arrow) has been rolled inward to cover the hole.
Figure 11. The flaps have been sewn in place; within 2 weeks, the exposed bone on the roof of the mouth (green arrows) will be covered with a new lining of mucosa.
Figure 12. The cleft palate in this French bulldog puppy has been closed with two sliding flaps.
When to Seek Referral:
Animals with secondary cleft palates should be referred to an ACVS Veterinary Surgeon for repair. The greatest success rates are seen when the procedure is performed initially by an experienced surgeon. Find an ACVS Veterinary Surgeon.
Potential Complications of Surgery:
Because the surgery is performed in young, underweight animals with breathing problems, anesthesia and surgery recovery can be risky. Many animals have swelling of the soft palate after the surgery, which can cause snoring and difficulty eating, but this usually resolves. Soft palates that are still too short after surgery may result in continued coughing and gagging.
Puppies and kittens with cleft palates tend rub their surgical sites with their tongues and to pick up things with their mouths that put pressure on the repair. Therefore, it is not uncommon for small areas of the cleft to break open, resulting in more nasal discharge and sneezing. Pawing at the nose or mouth may also damage the surgery site. Also, growth of the upper jaw may cause the parts of the cleft repair to become thin and open up. These openings (“oronasal fistulae”) can be closed 4-6 weeks after the original surgery.
Aftercare:
Antibiotics are given to animals with pneumonia or nasal infections. Elizabethan collars are left on for 1-2 weeks to stop pets from rubbing their faces. Animals with cleft hard palates are fed soft, blendarized foods by mouth or through a feeding tube for 2-4 weeks after surgery, and should not be given hard food or toys for at least a month. Animals that have clefts limited to the soft palate are fed canned food for two weeks before their diets are changed.
Prevention and Prognosis:
Animals that are born with cleft palates should not be bred, and their parents should not be bred if they are one of the predisposed breeds. Prognosis is excellent for pets with small clefts. When more than half of the hard palate is affected, surgery is much more difficult and more complications are expected. Special dental appliances and tissue flaps have been used to close very large defects.
—Karen Tobias, DVM, MS
Diplomate ACVS
Posted 2/23/2006
Reviewed 10/1/2011 by Mitchell A. Robbins, DVM, Diplomate ACVS
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