Many factors can influence the normal development of our pets. But genetics are something that we cannot influence and have to treat post-partum.
Cleft palate is among the genetically determined and inherited diseases. It is a result of embryonic non-closure of the root of the mouth and results in several consequences.
To learn more about this congenital disease, dig into the following article.
What is Cleft Palate in Dogs?
Orofacial clefts can appear during embryonic or fetal development due to incomplete fusion of craniofacial anatomical structures.
These defects are most common in dogs between days 25 and 33 of prenatal development, while the primary palate is made up of the upper lip and the incisive bone.
On the other side, the secondary palate comprises the hard palate (the palatine processus of the upper jaw and the palatine bone) and the soft palate.
The cleft palate is thus defined as a congenital oro-nasal fistula caused by improper fusion of the structures dividing the oral and nasal cavities, including the soft, hard palate, incisive bone, and lips.
A cleft palate can occur alone or in conjunction with other organ developmental abnormalities. Approximately 8% of dogs with cleft lip/palate are often affected by disorders in other parts of the body.
Tumors and other birth defects may accompany cleft palate in dogs of various breeds (including the Dachshund, Yorkshire Terrier, Chihuahua, Toy Poodle, Cocker Spaniel, and others) as well as mixed-breed dogs.
Ventricular septal defect of the heart, hydrocephalus, epidermoid cyst, distichiasis0, microphthalmia, entropion, or rear limb deformity are all conditions seen in Shih-Tzu dogs.
Pierre Robin sequence may be associated with cleft palate and respiratory failure caused by retroglossoptosis caused by micrognathism.
Risk Factors and Etiology
Genetic Background
A cleft palate is caused by various factors and can also be a non-syndromic cleft lip or a congenital defect.
The occurrence and expression of the abnormality are influenced by both genetic (recessive or dominant with incomplete penetrance) and external conditions (feeding, chemical, toxicological, or infectious).
Congenital soft- and hard-palate disorders may be acquired with incomplete penetrance in Shih-Tzu Dogs, as well as possibly in Pointers, Bulldogs, and Swiss Shepherd Dogs.
The cleft palate is inherited in an autosomal pattern (monogenic autosomal recessive transmission) in the British Spaniel population, and cleft palate is rarely associated with cleft lip (CL).
Risk Factors
As proved by an oral administration of BW to Beagle bitches at 17-22 days in gestation, hypervitaminosis A may also be a causal factor of CP in puppies.
High dietary vitamin A content may be a pathophysiologic factor in approximately 50% of cleft palate cases. Cortisol and hydroxyurea may cause CP in the developing fetus.
The use of corticosteroids and exposure to tobacco smoking is linked to the risk of CP in dogs.
Cytostatic drugs, antifungal agents, and impaired cholesterol metabolism in females, as well as certain viral diseases, traumas, stress, and hormonal influences, may also contribute to the cleft palate in offspring (25–28 days of pregnancy in dogs).
Hormones engaged in metabolism regulation, like insulin and corticosteroids, are one type of factor. That is why teratogenic substances such as primidone, griseofulvin, sulfonamides, and drugs such as metronidazole and corticosteroids should not be given to pregnant females.
Certain toxins, such as those found in some lupines, can cause congenital defects in cattle (“crooked calf disease”), with symptoms including cleft palate.
Causes and Symptoms of Cleft Palates
Cleft lip and palate are examples of congenital palatine defects. Primary CP is diagnosed as soon as the puppy is born. Secondary CP, though more common and severe, is rarely revealed and may initially be missed by an external visual inspection.
The oral cavity defects disrupt the independent procedure of the gastrointestinal and respiratory systems, which is especially important in the neonatal period.
As a result, the first symptoms observed are more or less severe difficulties in normal feed intake (suction), although some symptoms, such as dysphagia (swallowing difficulties), may also appear.
The puppy isn’t able to hold the nipple of the mother due to the large cleft. The condition can result in food deposition and nasal cavity contamination.
Palatal defects can also occur due to a physical head injury, which can be caused by an impact or by other forces such as electrical burns, foreign object penetration, a necrotic component, or a gunshot wound.
Malnutrition, growth slowed or stopped, and even death from starvation are the results of milk intake problems.
Numerous respiratory tract infections, nasal mucosal inflammation, coughing, sneezing, choking, pharyngitis, or reflux are all common.
Cleft palates can also result in dental issues (e.g., hypodontia, malocclusion, tooth gaps and misalignment, deformations) or laryngological deformities.
Other cleft palate consequences include symptomless middle ear illness, which can lead to deafness.
Aside from recurring infections, secondary CP frequently results in aspiration pneumonia and animal death in the most serious forms (approximately one in every three cases).
Cleft palate also hampered maxillofacial growth and resulted in nasomaxillary hypoplasia in a group of Spanish Pointers, according to one research.
Symptom heterogeneity and diagnosed variability are significant enough to produce a different spectrum even within the same litter.
Animals with severe acquired palatine deficiencies may exhibit clinical symptoms similar to those with congenital secondary palate oddities.
As a result of the previous, it must be emphasized that veterinary treatment must be provided in such cases, as it will help the puppy survive and ensure a good life quality in the future.
Given the high risk of anomalies coexisting in other anatomical structures, it is suggested that a comprehensive examination should be performed to rule out possible birth defects.
Early detection is critical because it may avoid secondary complications.
Diagnosis of Cleft Palates
All clinical actions and procedures conforming to the adopted criteria are essential to the diagnostic process. They aim to gather comprehensive information to obtain a complete clinical picture of the case.
These procedures include:
- Case history
- Pedigree
- Physical and specialistic evaluations for external and internal deficiencies
- Follow up tests
This, in turn, is required to precisely identify the illness and possibly select an appropriate therapy.
Affected animals that did not survive should have detailed post-mortem assessments, which could lead to a correct diagnosis and the development of new procedure strategies in the future.
In veterinary practice, the diagnosis is typically made through a postnatal clinical examination without genetic tests.
In addition to palpation, veterinarians may arrange additional tests, such as imaging diagnostics.
Diagnostics of Cleft Palate
Clinical examination
In veterinary practice, a postnatal clinical examination is typically used to make the diagnosis rather than genetic testing.
Veterinarians may request further tests, like imaging diagnostics, in addition to palpation.
Thorough physical tests and thorough studies can occasionally detect concurrent congenital disorders with congenital palate abnormalities.
These disorders include:
- Anotia
- Bifid tongue
- Otitis media
- Cranioschisis
- Atresias
- Polydactyly
- Microphthalmia
- Omphalocele
- Hydrocephalus
- Kyphosis
- Limb deformities
Within a breed, the observable phenotypic may vary. The type of abnormality can change and can appear in various combinations.
Nova Scotia Duck Tolling Retriever Dog (NSDTR) puppies have two copies of the mutant CLPS gene. This means that multiple variations are possible. From cleft lip to cleft palate with cleft lip, the puppies may have syndactyly in each condition.
Although cleft palate can occur during embryonic development, the defect may not be discovered in the puppy at birth.
As a result, to accurately diagnose CP, the veterinarian must thoroughly examine all possible symptoms.
A case history should be completed before a physical examination to determine the clinical features.
Cleft lip detection is simpler, whereas the diagnosis of partial fusion of the incisive bone, hard palate, or soft palate may necessitate a thorough examination of the oral cavity or the use of general anesthesia.
Cleft palate symptoms include difficulty eating, choking, sneezing, coughing, or nasal discharge. The results of peripheral blood cell counts and urinalysis may also be abnormal.
An initial complete blood count can help identify infection if aspiration pneumonia develops as a result of cleft palate.
Imaging techniques
Imaging diagnostics and laboratory tests have previously been recommended in some situations (for example, in the case of aspiration pneumonia), presenting a possible practical application of imaging diagnostics.
Because standard tests (such as X-ray radiography) only provide a partial picture of the abnormality and there are numerous associated health risks, a comprehensive diagnosis is required.
Multislice computed tomography (MCT) allows detection of structural dysfunctions that would otherwise go undetected during a clinical examination.
In the case of cancer, identification of craniofacial disorders caused by foreign bodies necessitates both imaging diagnostics and rhinoscopy (endoscopy of the nasal passages), as well as chest radiography and biopsy.
The extent, severity, and occurrence of other defects or complications (e.g., pneumonia) of a prospective CP treatment are important prognostic determinants.
Nonetheless, the best way to definitively diagnose cleft palate in puppies is to thoroughly inspect the mouth while the puppy is under general anesthesia.
This procedure allows the veterinarian to carefully examine the hard and soft palate and analyze the nature and extent of the defect.
We should emphasize the possibility camouflaged in implementing computed tomography in diagnosing defect severity and possible comorbid disorders.
Early imaging diagnostics may aid in the decision to treat affected puppies surgically or, in the case of a poor prognosis, euthanasia.
If your dog has a primary cleft, also known as a harelip, the diagnosis is simply based on the appearance of your pet’s nose and mouth, with teeth or an unusually shaped nostril.
Your veterinarian will evaluate your dog’s palate throughout the examination. A split of the hard palate will be visible because the presence of a hole is evident.
Your dog will be sedated for the veterinarian to look deep into the oral cavity and adequately observe the soft palate.
Thoracic x-rays may also be taken to look for symptoms of pneumonia caused by food aspiration.
Treatment Options
Prevention
Before beginning the reconstructive method and treatment for cleft palates, the source of the issue must be identified.
In the secondary cleft palate, dogs can develop aspiration pneumonia. Difficulty breathing in an affected puppy could be treated with liquids, oxygen, bronchodilators, and sometimes corticosteroids.
Antibiotics are advised in situations of pneumonia and rhinitis. It is also critical to avoid airway infections and to consume adequate nutrition and energy.
On the other hand, pregnant bitch folic acid supplementation is one of the prophylactic treatments against cleft lip/palate in the progeny. Folic acid has the same impact on dogs as it has on people.
Because cleft palate is a polyetiological defect, folic acid supplementation will not eliminate all instances.
Congenital cleft palate in dogs includes clefts of the hard palate, lips, soft palate, alveolar process, and soft palate hypoplasia, which can be corrected surgically using a variety of procedures.
Although cleft lip correction is mainly undertaken for cosmetic reasons, surgical intervention of secondary CP is also required to prevent persistent respiratory infections and to enhance food intake for optimal animal nutrition.
Primary cleft palate in dogs in the front and posterior regions of the palate are effectively operated on using a variety of procedures.
Furthermore, dogs require adequate pre- and post- cleft palate surgery handling, which includes preparing the animal for the treatment as well as caring for and convalescing afterward.
The proper execution of the procedure is critical, albeit problems may emerge, especially if the fissures are significant for the health of oral and nasal cavities.
All treatments are normally performed on animals once they have reached a certain stage of development, especially for secondary cleft palates.
During that time, dog owners should treat their dogs with extreme caution, utilizing a special diet consisting of creamy feeds, either commercial or homemade, administered through tube or stoma.
Feeding in an upright position and methodical cleaning of food debris is essential for improving the quality of life after cleft palate in dogs repair and allowing them to reach the suitable age (about 3-4 months) to be eligible for reconstructive surgery.
Veterinary surgeons advocate for specialized care that is given for an extended length of time, warn breeders about the risk of passing on the defect to offspring, as well as prescribe sterilization of affected animals.
The proprietors must demonstrate a high level of devotion, including reading and sticking to specific specified rules, which requires tolerance and meticulousness.
The recommendations also give thorough advice on caring for the pregnant bitch and handling CP-affected puppies from the first day to eight weeks of age.
Surgical Corrections – Cleft Palate Repair
According to the literature, when the dog reaches the age of 6 months, minor cracks may resolve spontaneously within a short period. In contrast, larger ones, though diminished in size, never completely heal.
After the emergence of permanent teeth and at ages greater than 6 to 8 weeks, possible surgical treatment is advised.
Scientists advocated 4-5 months as the minimum age appropriate for reconstructive surgery.
Additionally, they recommended the third month of life as the ideal age because earlier, the tissues are too fragile, and later the deformity can get excessively huge.
Palate plastic surgery is typically performed between the ages of 8 and 12 weeks for congenital palatal defects. The bottom wall of the nasal cavity is intended to be rebuilt during CP correction.
If the cleft affects both the hard and soft palates, the hard palate must be closed first and cannot be done immediately in a newborn puppy suffering birth defect.
A better option is to close the clefts sequentially, first the cleft lip and then the cleft palate.
This reduces the risk of incidents during the development of the maxillary complex in the future, and any disturbances are likely to be less severe than with a repair done simultaneously or in the opposite order.
If the patient has extensive lesions, it may take more than one surgery to close the cleft successfully.
According to surgeons, following a surgical procedure typically necessitates surgical correction and restoration in a non-syndromic cleft lip, and the animals should then be sterilized.
Post-Surgical Therapy
Opioids and non-steroidal anti-inflammatory drugs (NSAIDs) are suggested as treatments for post-surgical pain.
The maxillofacial region may occasionally experience aberrant growth and development, which can result in maxilla deformation and, as a result, occlusion issues.
Animals with CP are typically put to euthanasia, often for financial (due to expensive surgeries) or other practical reasons, and scientists are here to change that practice.
Each case of CP that has been identified is unique, and while the defect presents difficulties for the breeder or the dog’s owner, it is in no way fatal.
The appropriate wound healing affects the recovery and treatment because cleft palate surgery frequently necessitates the suturing of mucosa from the tooth cavity.
It will be required to follow up with your veterinarian to monitor the process of healing, which includes looking for the proper fusion of mucosa over the palate.
If your pet had an infection or a case of pneumonia before the surgery, antibiotics will be provided.
In some circumstances, your pet will require tube feeding for seven days following the procedure.
The optimum course of action will then be discussed by your veterinarian; the typical routine is a soft diet for the following minimum of six weeks.
FAQ
To sum up
One of the dogs’ most common congenital defects is the cleft palate, which is connected with unusual craniofacial development.
Brachycephalic breeds appear to be the most susceptible. The presence of the fissure linking the oral and nasal cavities characterizes this anatomical and functional disorder.
Despite advances in diagnostic and therapeutic methods, physical diagnosis and surgery remain the foundation for this malformations’ diagnosis and treatment.
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*photo by zhagunov – depositphotos