Common Names or Abbreviations:
 | Cleft Lip |
| Cleft Palate |
| Harelip |
Description or definition:
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Cleft palate is a skeletal disorder occasionally seen at birth in puppies of all breeds. The palate is made of two parts: the soft palate at the rear of the mouth, which is made mostly of muscles, and the hard palate at the front of the mouth, which is made of two bony plates. Normally the plates fuse at their middle juncture during fetal growth. A cleft palate results when the bones forming the roof of the mouth do not grow normally. This results in an opening in the roof of the mouth that communicates with the nasal cavity. The slit can vary in both length and width from a very small hole to a cleft that involves nearly the entire roof of the mouth.
Cleft palates can occur with or without cleft lip, also know as 'harelip'. Cleft lip occurs when the tissues that form the upper lip do not join in the middle. |
Symptoms:
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The defect is present at birth. Since the palate separates the nasal and oral cavities, puppies as young as one day old will often have milk come out their noses as they nurse. Other visible signs are: |
| Fluids e.g. milk coming out the nose during feeding |
| Sneezing |
| Coughing/gagging |
| Snuffling |
| Rhinitis |
| Pneumonia (due aspiration of foods) |
| Poor weight gain |
| Stunted growth |
| Inability to feed properly |
Diagnosis:
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Cleft palate is suspected when milk is seen dripping from a puppy's nostrils during nursing. The diagnosis is made by visual examination of the roof of the mouth. When the cleft is very small, x-rays might be necessary. |
Treatment:
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Mild problems may not require any treatment. The only possible treatment of severe cleft palate is to surgically close the hole by using surrounding tissues (bone and mucus membrane). |
Prevention:
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Environmental Conditions: |
Dr. Lowell Ackerman DVM, The Genetic Connection, says that cleft palate and
cleft lip can result from either hereditary or environmental causes. The
environmental causes include administration of drugs such as corticosteroids,
metronidazole, or griseofulvin during pregnancy, among other possibilities.
Wide Smiles, the human cleft palate organization, also cautions about exposure
to pesticides, herbicides, and other chemicals during pregnancy. Fever and
illness have also been known to cause clefting.
Most of what is known about prevention of clefts is inferred from human studies. It is know that excessive amounts of Vitamin A early in pregnancy, can cause serious birth defects. As Vitamin A is found especially in liver, it would be wise to give only very small amounts of liver to bitches during pregnancy pending more complete investigation of the effects in dogs. In human babies, supplementation with folic acid has been shown to be effective in reduction of birth defects including cleft palate.
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The Genetics of Clefts: |
Since the condition is normally inherited, affected dogs should be sterilized.
Dogs that pass on this defect or are definite carriers should not be used for
breeding unless there is known exposure of the dam to disease or toxins during
the critical period for this particular litter.
Cleft lip and palate is thought to be an inherited trait in many breeds, but the exact mode of inheritance is only known in a few breeds. In Brittany Spaniels it is said to be autosomal recessive trait; in Westies it has been shown to be polygenic and does not have a single gene mode of inheritance. In the English and French bulldog, pointer, and Shih Tzu, the trait may be autosomal dominant with incomplete penetrance. In a 2000 survey, Boston terrier breeders reported 15% of their puppies have either a cleft lip or palate. Other breeds affected are cocker spaniel, dachshund, German shepherd, Labrador retriever, miniature schnauzer, and Pekingese.
George A. Padgett, DVM, of Michigan State University says there are twenty-two compounds known to cause cleft palate in dogs. He notes that the palate normally closes on the 18th through the 21st day of a bitch's pregnancy. He feels that only drugs given prior or during this time could be responsible for causing clefts. He makes the point that the drugs that cause problems with clefts are not generally available in the environment and they have to be prescribed and given to the bitch. He says that the end result is that most cleft palates in dogs are inherited rather than caused by things in the environment.
Links to sites about this disease:
This summary provided by:
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Ellen F. Lennen |
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Southern Highlands Shilohs |