Soft Palate Disorders and beyond in Dogs

Congenital soft palate disorders in dogs involve abnormalities in the soft tissues in the back of the mouth which have occurred in the developmental and gestational processes.  These abnormalities can include the length and thickness of various parts of the soft palate which can affect the relationship between the hard and soft palate in your dog’s mouth.  These abnormalities and their associated effect on the relationship of the hard and soft palates can cause some physical problems with your animal companion.  Some of these problems are correctable while others are not and the possibility of death or the need for euthanasia exists.

The roof of the canine mouth consists of a hard palate and a soft palate. The hard palate is the bony tissue located in the anterior or front part of the roof of the mouth, while the soft palate is soft tissue located behind the hard palate in the back part of the mouth.  Disorders of the soft palate involve those resulting from genetic or inherited abnormalities of this soft tissue.

This article discusses medical conditions affecting the soft palate and other structures within the mouth and throat.

There are some symptoms that you will notice about your dog that will alert you to the need for medical assistance.  Some of these symptoms will be immediately noticeable while others may take a bit longer to present, depending on the age of the animal.  When they do present, however, it is vital to get medical assessment of the situation so that whatever treatment is deemed appropriate can be initiated. These are the most obvious and commonly observed symptoms:

• Noisy breathing, especially when inhaling
• Retching or gagging in some dogs, especially when swallowing 
• Cyanosis (blue tongue and gums) secondary to decreased levels of oxygen
• Occasional collapse especially after over activity, excitement or excessive heat and humidity
• Difficulty suckling, drinking or licking
• Milk coming from the nose or mouth after or during suckling
• Difficulty vocalizing

Types

Soft palate disorders are genetic or inherited and are present at birth.  They can be characteristic of the dog breed, (note the differences in the shape of the head, muzzle and throat of English Bulldogs, French Bulldogs, Boxers, Boston Terriers, Pekingese, Chinese Pugs, Lhasa Apsos, Shih Tzus and Bull Mastiffs).  The following list of types of disorders that have been found in dogs:

• Brachycephalic syndrome (a combination of anomalies that can include elongated soft palate, stenotic nares and everted laryngeal saccules)
• Congenital oronasal fistulas (cleft palate and cleft lip)
• Occlusal anomalies (these include abnormal lengths of upper jaw and lower jaw) 
• Ankyloglossia, a tongue anomaly sometimes referred to as tongue tie 
• Macroglossia, or large tongue 
• Microglossia, a tongue anomaly that presents with underdeveloped tongue tissue that can make nursing difficult as well as difficulty with swallowing
• Epitheliogenesis imperfecta, relates to skin structure 
• Tight-lip syndrome of Chinese Shar-Peis, small or missing lower lip portion
• Brachycephalic syndrome, includes a combination of elongated soft palate, stenotic nares and everted laryngeal saccules

Soft palate disorders in dogs are generally congenital (present at birth) and may be inherited (defect passed from parents in DNA).  The disorders are caused by anomalies or abnormalities which have a physical effect on basic vital functions. Those affected often have Brachycephalic Upper Airway Syndrome, some signs of which include:

• Abnormal shape of the head, muzzle and throat 
• Throat and breathing passages are often smaller than normal or are flattened by the shape of the head and muzzle
• May have narrowed windpipes 
• May experience collapse of the larynx (cartilages that open and close the upper airway)
• May have paralysis of the laryngeal cartilages that prevent the opening and closing of the airway
• Elongated soft palate, the soft palate is longer with the tip extending into the airway and can interfere with air movement into the animal’s lungs
• Stenotic nares, abnormal or misshapened nostrils which can narrow or even collapse inwardly when the dog inhales
• Everted laryngeal saccules, this is tissue in the airway, located just in front of the vocal cords that, due to the defect, gets sucked into the windpipe to cause at least partial obstruction to the air flow

Diagnosis of soft palate disorders in dogs can take several forms.  Once the defect or symptoms have been noted, your veterinarian will need to do a full physical examination.  The discovery of defects could come as a result of a normal, routine evaluation or as a result of an episode of respiratory distress or difficulty eating or drinking.  The examination by your veterinarian may require some anesthesia in order to be performed adequately.  Before this is attempted, your veterinary caregiver will likely do some blood work and get a chest x-ray to detect possible respiratory issues before general anesthesia is administered.  

CT scan of the head and throat area will reveal any soft tissue defects and this will give a better idea of what will be found upon anesthetized examination.  Knowing the possible defects in advance will allow decisions to be made prior to anesthesia as to what medicine and protocols should be used.  This will reduce additional administrations of anesthesia which will put the dog at risk for further respiratory issues.

The treatments for soft palate disorders of dogs varies depending on the type of defect causing the disorder as well as the degree to which it affects the dog’s ability to function normally.  Some treatment options may seem more extreme than others but these recommendations are made based on the animal’s overall ability to function within a normal environment. 

Surgical intervention is dependent upon the size and location of the defect.  Those animals having extensive soft palate involvement generally have a poor prognosis even after surgery.  Before surgical intervention is attempted, ethical questions should be addressed, as well as sterilization or exclusion from the breeding stock be decided.  If you are a breeder or have plans to breed your dog, prevention of reproducing defects in your dog’s offspring should be a high priority.

Occlusal anomalies will most likely require orthodontic or endodontic procedures to correct. Prognathia will require orthodontic repair or procedures or appliances. 

For tongue anomalies there exists a variety of surgical repairs to the soft tissue available that are dependent upon the size and location of the defect.  In the case of microglossia (bird tongue), there exists a poor prognosis even when supportive dietary steps are taken. Euthanasia could be a more viable treatment. In the case of tight-lip syndrome of Chinese Shar-Peis, surgical repair involving creating mucosal flaps is available.

In any of these cases, decisions to euthanize may be needed if the dog survives its early post-birth developmental stages but has severe congenital deformities.  Some extreme conditions will likely result in the early death of the dog regardless of medical or surgical intervention.  Your veterinarian will evaluate your dog thoroughly and will provide you with solid and ethical treatment options.  There may be significant changes in your lifestyle and home environment that will be needed to accommodate your pet’s physical limitations.  In some cases, surgery will be appropriate. For mild cases, no treatment will be required but the patient should be monitored closely.

In the event that your pet is diagnosed with any soft palate disorder and if the dog survives beyond infancy, it is vital that steps be taken to render the dog sterile so that the  risk of reproducing the defect in its offspring is eliminated.