Cricopharyngeal achalasia is a swallowing disorder that prevents food from passing normally from the pharynx into the esophagus. This condition is rare in dogs and the exact cause is unknown, but it is probably a neurological anomaly. It appears to be more common in the Cocker Spaniel and Springer Spaniel breeds.
Signs of a swallowing disorder are usually seen initially in the puppy at the time of weaning. When the puppy eats solid food it manifests repeated attempts to swallow the same bite until the latter is swallowed, regurgitated or sucked into the airways.
The most affected puppies have a voracious appetite but a low body weight due to the inability to take adequate nutrition. This disorder puts puppies at risk of inhalation pneumonia, or pneumonia caused by inhalation of food particles in the lungs.
There are many other swallowing disorders, some of which are caused by neuromuscular pathologies which, unlike cricopharyngeal achalasia, cannot be corrected surgically. For example, the difficulty in swallowing can originate in the mouth and not in the pharynx
- In young dogs, defects affecting the hard palate and soft palate can cause the passage of food and liquids from the mouth and nose during the meal due to an anomaly in the communication between the oral and nasal passages. These defects can usually be identified during a puppy’s oral examination.
- In young puppies, foreign bodies (such as ties, sticks or small chicken bones) can get stuck in the mouth, pharynx or esophagus causing hypersalivation and difficulty swallowing. These can be difficult to locate and it may be necessary to subject the puppy to sedation or general anesthesia in order to proceed with a thorough evaluation of the oral cavity and pharynx. X-rays of the neck or chest may also be needed.
- Some dental problems in young puppies during growth can cause difficulty in swallowing, but generally these problems arise after weaning and not at the time of weaning.
- The megaesophagus is a disease in which the esophagus loses the ability to contract by becoming dilated and flabby. The disease can be acquired or congenital. The megaesophagus is associated with regurgitation of food rather than difficulty swallowing. The ingested food accumulates in the dilated esophagus and passively slides in and out of the mouth, often assuming a tubular or “sausage” shape. Differentiation from cricopharyngeal achalasia can occur through radiographic study of the chest, but to define this disorder, the use of a contrast medium (such as barium) may be necessary.
- The recently weaned puppy is struggling to swallow food and eat properly
- The puppy is thin despite a healthy appetite
- The veterinarian will collect thecomplete anamnesis from the direct voice of the owner focusing on the nature of swallowing (passive regurgitation or He retched active).
- Before proceeding with the oral examination, the veterinarian will carry out a general physical exam to evaluate the general health of the dog, focusing his attention on body weight, auscultation of the chest and palpation of the throat and neck.
- The dog will be observed drinking water and eating a small meal in an attempt to determine if the problem is really pharyngeal in nature and not oral or related to the esophagus.
Pharyngeal disorders usually cause a difficult bolus propulsion from the back of the throat into the esophagus. Cricopharyngeal achalasia usually causes greater difficulty in swallowing food rather than liquids. Other pharyngeal disorders tend to present greater difficulty in swallowing fluids.
- Thoracic radiographs for the evaluation of the lungs (for pneumonia) and the size of the esophagus.
- The definitive diagnosis takes place by fluoroscopyor a moving radiographic image that monitors the transit of barium-coated food (contrast medium) once ingested. To understand the difference between cricopharyngeal achalasia and other forms of pharyngeal dysphagia, the intervention of an expert and qualified radiologist is necessary. The study can be recorded on videotape and subjected to the attention of other specialists in radiodiagnostics before reaching a final decision.
- The study should show that the pharynx is strong enough to push a bolus of food through the esophagus but that the opening, formed by the cricopharyngeal muscle ring, remains closed or opens at the wrong time. Other pharyngeal disorders often show that the pharynx is not strong enough to allow food to pass from the back of the throat and into the esophagus. The passage of food along the esophagus can be monitored to make sure it is normal.
- If the problem of swallowing is purely due to cricopharyngeal achalasia, surgery (crotopharyngeal muscle myotomy) is the treatment of choice and is usually decisive. It is important that the dog’s health is good before proceeding with the operation. This may mean the use of antibiotics to treat any pneumonia, the administration of fluids intravenously to compensate for any dehydration or even the use of a gastric tube for a few days before surgery to ensure that the dog is adequately fed.
- The dog will be shaved on the lower part of the neck and an incision will be applied on the junction of the pharynx and larynx in order to access the abnormal cricopharyngeal muscle group. The muscle group will be sectioned on both sides or a portion of each muscle group will be sectioned.
There is no medical option for treatment, as the problem is caused by the dysfunction of this muscle group.
What to do at home and prevention
The dog will initially be given easy-to-swallow food (e.g. a mixture of dry or wet food and water). After a few days, it will be possible to switch to a normal diet (food with a normal consistency).
In the event of pneumonia, the dog will undergo a course of antibiotics which must be administered for the entire duration recommended by the veterinarian. Follow-up radiographs will be needed to check the resolution of pneumonia.
It is not possible to prevent this disease since it is a congenital defect. However, early recognition of a swallowing problem offers the animal the possibility of timely diagnosis before the onset of malnutrition and pneumonia.