Cleft palate

From Dog
A cleft palate in a Miniature Schnauzer located on the midline, from the incisal papilla (black arrow) to the posterior border of the soft palate (white arrow)[1]

Cleft palate is a relatively common congenital defect of dogs characterized by non-closure or partial closure of the bilateral maxillary bones which form the hard-palate during pre-natal development.

A cleft palate results in communication between the oral and nasal cavities, affecting proper swallowing of milk post-natally. Secondary cleft palate may also occur later in development and involves a hard palate and/or a soft palate[2]. The lip may also be affected (cleft lip; hare lip).

The disease is autosomal-recessive in the Pyrenean Mountain Dog[3] and Boxer[4].

Polygenic disorders causing cleft palate have been reported in the Australian Shepherd with lumbar scoliosis, short malformed tibias and fibulas, polydactyly, brachygnathism and cleft lip[5]. It has also been described in a litter of St. Bernards with cleft palate, anotia, incomplete bifid tongue, preaxial hind paw polydactyly, and an extra thoracic vertebra and rib[6].

In some dogs, nongenetic causes have been identified, such as nutritional, hormonal, mechanical, and toxic factors[7][8]. Excess dietary intake of vitamin A during pregnancy has been reported as causing this condition[9].

Dogs affected by palatine defects also have a greater risk of concurrent defects in the tympani bullae[10].

In bitches with cleft palate, 15 - 20% of their offspring may spontaneously develop cleft palate[11].

Affected pups usually have prehension difficulties and special teats are usually required to maintain adequate milk intake. On physical examination, coughing, sneezing, presence of nasal discharge from the external nares due to rhinitis and poor growth are often found.

Although blood tests are usually normal, chest radiographs frequently show anterior lung lobe consolidation consistent with aspiration pneumonia.

Surgical correction can be attempted with small defects, but tissue shortage is a major complication with cleft palate anomalies[12]. Cleft palate surgery has been reported to be associated with a high rate of surgical failure, with two to three attempts commonly reported[13].

Where the defect is relatively minor, surgical correction is usually indicated. Surgical repair requires a mucoperiosteal and overlapping flap technique[14]. The mucoperiosteum of the hard palate is incised and the mucosa of the soft palate is used to create the mucosal flaps. The oral mucosal flap is then sutured into the defect created by raising the nasal mucosal flap with a simple interrupted pattern[1]. In cases with large defects, a cortico-cancellous bone graft harvested from the ilium may be used[15] or the application of a palatine prosthesis using a dental resin.

In severely affected pups, euthanasia is often recommended.

Due to the possible underlying genetic predisposition, affected pups which are surgically corrected are not recommended as breeding dogs and early desexing is recommended.

References

  1. 1.0 1.1 Lee J et al (2006) Application of a temporary palatal prosthesis in a puppy suffering from cleft palate. J Vet Sci 7(1):93-95
  2. Hawkins BJ (2001) Dental disease and care. In: Hoskins JD, editor. Veterinary Pediatrics. 3rd ed. Philadelphia: Saunders. pp:135–146
  3. Kemp C et al (2009) Cleft lip and/or palate with monogenic autosomal recessive transmission in Pyrenees shepherd dogs. Cleft Palate Craniofac J 46(1):81-88
  4. Moura E et al (2012) Nonsyndromic cleft lip and palate in boxer dogs: evidence of monogenic autosomal recessive inheritance. Cleft Palate Craniofac J 49(6):759-760
  5. Senders CW et al (1986) Observations about the normal and abnormal embryogenesis of the canine lip and palate. J Craniofac Genet Dev Biol Suppl 2:241-248
  6. Villagómez DA & Alonso RA (1998) A distinct Mendelian autosomal recessive syndrome involving the association of anotia, palate agenesis, bifid tongue, and polydactyly in the dog. Can Vet J 39(10):642-643
  7. Howard DR et al (1974) Mucoperiosteal flap technique for cleft palate repair in dogs. J Am Vet Med Assoc 165:352–354
  8. Sinibaldi KR (1979) Cleft palate. Vet Clin North Am 9:245–257
  9. Davies M (2011) Excess vitamin A intake during pregnancy as a possible cause of congenital cleft palate in puppies and kittens. Vet Rec 169(4):107
  10. White RN et al (2009) Soft palate hypoplasia and concurrent middle ear pathology in six dogs. J Small Anim Pract 50(7):364-372
  11. Martínez-Sanz E et al (2011) A new technique for feeding dogs with a congenital cleft palate for surgical research. Lab Anim 45(2):70-80
  12. Ophof R et al (2008) Implantation of tissue-engineered mucosal substitutes in the dog palate. Eur J Orthod 30(1):1-9
  13. Griffiths LG & Sullivan M (2001) Bilateral overlapping mucosal single-pedicle flaps for correction of soft palate defects. J Am Anim Hosp Assoc 37:183–186
  14. Nelson AW (2002) Cleft Palate. In: Slatter D, editor. Textbook of Small Animal Surgery. 3rd ed. Philadelphia: Saunders. pp:814–823
  15. Ishikawa Y et al (1994) Use of a corticocancellous bone graft in the repair of a cleft palate in a dog. Vet Surg 23:201–205