Overview of Cricopharyngeal Achalasia in Dogs
Cricopharyngeal achalasia is a swallowing disorder in dogs that prevents food from passing normally from the pharynx into the esophagus. The condition is rare in dogs and the exact cause is unknown, but is probably a neurological abnormality. It is reported to be more common in cocker spaniels and springer spaniels.
Signs of a swallowing disorder are usually seen initially in the puppy at the time of weaning. When eating solid food the puppy shows repeated attempts to swallow the same mouthful, until eventually it is swallowed, regurgitated or aspirated into the airway.
Most affected puppies have a voracious appetite but are thin from the inability to get adequate nutrition. The disorder puts them at high risk for aspiration pneumonia, which is pneumonia caused by inhaling food particles into the lungs.
The disease is important because it is one of the few swallowing disorders that can be cured with surgery.
What to Watch For
A recently weaned puppy who struggles to swallow food and eat properly
A puppy that is thin despite a healthy appetite
Diagnosis of Cricopharyngeal Achalasia in Dogs
Your veterinarian will want to investigate for cricopharyngeal achalasia in any puppy with difficulty swallowing and will observe the pup while eating and drinking to determine if the problem truly originates in the back of the throat, the pharynx. In addition, your veterinarian will probably recommend the following:
Chest X-rays to evaluate for aspiration pneumonia
Fluoroscopy. Moving X-ray images of the pharynx and esophagus while swallowing a barium coated meal provides a definitive diagnosis of cricopharyngeal achalasia.
Bloodwork is usually normal unless the animal has developed a significant pneumonia.
Treatment of Cricopharyngeal Achalasia in Dogs
Surgery offers an excellent possibility of curing the problem. A muscle that is not functioning properly at the junction of the pharynx and esophagus is cut, so that it no longer impedes movement of food from the throat down to the stomach.
Home Care and Prevention
Dogs will initially be fed a gruel, a mixture or dry or canned food and water that is easier to swallow. Over a period of several days this can be changed over to a normal food consistency.
If pneumonia has developed, your pet will be discharged on a course of antibiotics, and these should be administered for the full time, even if your pet appears to be well. Follow-up X-rays will be necessary to ensure that the pneumonia is resolving.
It is not possible to prevent this disease as it is a congenital defect, a disorder the animal is born with. Early recognition of a swallowing problem offers your pet the best chance for a prompt diagnosis before malnutrition and pneumonia set in.
Information In-depth for Cricopharyngeal Achalasia in Dogs
Cricopharyngeal achalasia is only one type of pharyngeal swallowing disorder. There are many others, some of which are caused by neuromuscular diseases that cannot be corrected by surgery. The difficulty in swallowing may originate in the mouth and not the pharynx.
In young dogs, defects of the hard and soft palate can cause food and liquids to fall from the mouth and nose during eating due to an abnormal communication between the oral and nasal passages. These defects can usually be recognized during an examination of your puppy‘s mouth.
In young puppies, foreign bodies such as string, sticks or small chicken bones can get lodged in the mouth, pharynx or esophagus, causing drooling and difficulty swallowing. These can be difficult to detect and your puppy may require sedation or general anesthesia to ensure a thorough evaluation of the oral cavity and pharynx. Follow up X-rays of the neck or chest may also be required.
Some dental disorders in young growing puppies may lead to difficulty swallowing, but usually these problems occur after weaning, not at the time of weaning.
Megaesophagus is a disease in which the esophagus, the tube conveying food from the mouth to the stomach, loses its ability to contract and becomes baggy and flaccid. The disease can be acquired or congenital. Megaesophagus is associated with regurgitation of food rather than difficulty in swallowing. Swallowed food accumulates in the distended esophagus and will passively slide forward and out of the mouth, often in a tubular or “sausage” form. Differentiation from cricopharyngeal achalasia may be possible with plain chest x-rays, but swallowing a barium coated meal may be necessary to define this disorder.
Diagnosis In-depth of Canine Cricopharyngeal Achalasia
Your veterinarian will take a detailed history, focusing on the nature of swallowing, whether there is passive regurgitation or active vomiting.
A general physical examination will assess your dog’s general health, focusing on body weight, listening to the chest and palpating the throat and neck, before looking inside the mouth itself.
Your dog will be observed drinking water and then eating a small meal to try to determine whether the problem is truly pharyngeal, and not oral or related to the esophagus. Oral disorders usually cause difficulty in getting food up into the mouth and rolled in a ball, or bolus, at the back of the throat ready for swallowing.
Pharyngeal disorders usually cause difficulty in the actual propulsion of the bolus from the back of the throat into the esophagus. Cricopharyngeal achalasia usually causes more difficulty in swallowing food than liquids. Other pharyngeal disorders tend to have more difficulty with swallowing liquids.
Chest x-rays will be taken to evaluate the lungs for pneumonia and the esophagus for size.
The definitive diagnosis of cricopharyngeal achalasia is made by fluoroscopy, a moving X-ray image that can monitor a barium coated meal as it is swallowed. To tell the difference between cricopharyngeal achalasia and other forms of pharyngeal dysphagia takes a skilled and experienced radiologist. The study may be recorded on videotape and reviewed by other radiographic specialists before a final decision is made.
The study should show that the pharynx is strong and pushes a bolus of food toward the esophagus, but the opening, formed by the cricopharyngeal muscle ring, stays shut, or opens at the wrong time. Other pharyngeal disorders often show that the pharynx lacks the strength to push the food from the back of the throat and into the esophagus. The passage of the food along the esophagus can be monitored to make sure it is normal.
Treatment In-depth for Canine Cricopharyngeal Achalasia
If the swallowing problem is purely due to cricopharyngeal achalasia, then surgery is the treatment of choice and is usually curative. It is important that the dog is in the best possible health going into surgery. This may mean using antibiotics to treat pneumonia, providing intravenous fluids to offset dehydration, or even placing a feeding tube into the stomach for a few days prior to surgery to make sure the patient is adequately nourished.
Your dog will be shaved on the underside of the neck and an incision made over the junction of the pharynx and the larynx, to gain access to the abnormal cricopharyngeal muscle group. The muscle group on both sides is either cut, or a portion of each muscle group cut out.
There is no medical option for treatment because the problem is produced by the constricting dysfunction of this muscle group.
Your dog may require hospitalization for several days, if a state of dehydration existed, or the need to give intravenous antibiotics.
The incision and either stitches or staples will lie on the underside of the neck. This area must be examined daily for signs of swelling, redness or discharge. Given the location of the incision, use of an Elizabethan collar is normally not recommended.
Initially, food should be given in a liquidized form. A soupy gruel should be fed for the first couple of days following surgery to make sure he is swallowing normally. If all goes well then the diet can gradually revert to normal food consistency, usually by the end of the first week.
Bones and chew toys should be avoided for the first couple of weeks following the procedure.
Oral antibiotics will continue at home, perhaps for an additional four to six weeks, depending on the severity of the pneumonia. In some cases your veterinarian may demonstrate the use of percussion, that is, patting the chest with a cupped hand over various lung fields to encourage mucus to be coughed up by your dog.
If the swallowing disorder fails to resolve this may be due to one of several complications:
The muscle was inadequately cut or removed, or the procedure only performed on one side, so the obstructive effect persists.
Scarring has occurred and restored some continuity to the constricting muscle band.
Other forms of pharyngeal dysphagia are present concurrent with the cricopharyngeal achalasia.
The first two problems can be corrected surgically. In the third case, the surgery will actually have made the problem worse, and there is usually no good treatment alternative.
Sutures or staples can be removed in 10 to 14 days following surgery.
Prevention In-depth for Cricopharyngeal Achalasia
This is not a disease that can be prevented because it is a rare congenital problem. In many cases, dogs with swallowing disorders will be noticed by the breeder at the time of weaning and not be available for sale as pets.
Because the exact cause of the disorder is unknown, it would be unwise to breed from a sire or dam whose offspring have developed cricopharyngeal achalasia.
Early and accurate diagnosis offers the best prognosis for your dog as malnutrition, dehydration and especially aspiration pneumonia, can significantly impact the risk for anesthesia and subsequent surgical success.
The diagnosis of cricopharyngeal achalasia requires fluoroscopy, not normally available outside of universities and larger veterinary institutions, and the study needs to be evaluated by an experienced radiologist.