Vascular Ring Anomalies in Cats

Vascular ring anomalies in cats can be difficult for the typical pet owner to diagnose, but not to detect. This condition can lead to compression of the esophagus, a condition commonly referred to as megaesophagus, which causes your cat to regurgitate food. Regurgitation is not the same as vomiting. In cats with vascular ring anomalies, food never makes it to the stomach and is stopped at a narrowing, or obstructed area in the esophagus. Vascular ring anomalies are dangerous as they not only prevent your cat from receiving the correct nutrition, they can also result in secondary conditions brought about by regurgitation.

The primary symptom of vascular ring anomalies in cats is the regurgitation of food shortly after eating. The owner can differentiate between vomit from the stomach and regurgitation by the lack of bile in the end product. Additionally, regurgitation will occur quickly after eating and on a more regular than sporadic basis. There are a few additional ancillary conditions that may occur as a result of the regurgitation.

• Pneumonia: Aspiration pneumonia can often result from regurgitation. This occurs when a piece of food becomes trapped in the lungs during the violent process of regurgitation or when food is sucked into the lungs during breath intake after regurgitation.
• Malnutrition: Malnutrition can occur when your cat is regularly regurgitating their food instead of properly digesting the nutrients.
• Weight loss: Weight loss is also a side effect of regurgitation due to inability to process nutrients.

Vascular ring anomalies in cats are typically inherited defects that occur during development while still in utero. This congenital condition, also referred to as persistent right aortic arch, is caused by improper growth in the arteries that abut the esophagus. As a result of the deformation, the esophagus is compressed near the area of the defect, often narrowing to such an extent that solid food cannot pass through in large quantities. 

In addition to causing megaesophagus, in some cases this congenital defect may lead to congestive heart failure if left untreated. 

Physical Exam and Blood Work

As with many conditions, the first step your veterinarian will take is a thorough physical examination. Your veterinarian may also draw blood for a full blood analysis to rule out any underlying infection as the cause of the regurgitation. Your veterinarian will also look for signs of malnutrition such as dulling of coat, lethargy or discoloration of gums.

X-rays

X-rays are the diagnostic method of choice for the detection of vascular ring anomalies; the oesophagus cranial to the heart is dilated with the oesophagus portion dorsal to the heart is constricted, this is more evident during contrast media (barium) studies.

Endoscopy

In cases where x-rays are unclear, or if the underlying cause of regurgitation is not immediately suspected to be a vascular ring anomaly, your vet may want to conduct an endoscopy. In an endoscopy procedure, your cat will be sedated and a tube with a small camera will be placed down the oesophagus. This will allow your vet to locate any obstruction or narrowing and pinpoint the exact location of the blockage.

Ultrasound

Your Veterinarian may choose to perform an ultrasound to check for other congenital heart disorders like septal or valve defects.

Computer Tomography

Due to a suspected correlation between vascular ring anomalies and axial skeletal malformations, CT scans are recommended for ruling out this condition.

Surgery is the recommended course of treatment for vascular ring anomalies in cats. While these type of surgeries have become more routine over time, there is still the possibility for infection or negative outcomes. Your pet will also need to be anesthetized in order to undergo surgery. Without surgical correction, your cat may face congenital heart issues that may lead to a shortened lifespan.

While surgery will resolve the underlying vascular ring anomaly, it may or may not cure the narrowing or blockage of the esophagus. In cases where the megaesophagus condition is permanent, modification of your cat’s eating habits and dietary choices may still allow effective management of the condition.

In cats with megaesophagus brought on by vascular ring anomalies, raised food dishes can be especially helpful. Feeding while your cat is sitting or is forced to extend their neck, will allow the esophagus to open as widely as possible during meals. Additionally, a wet food diet, or dry food that has been pureed, may also be fed since the lack of solid consistency will allow easier access past the obstruction and into the stomach.

Lastly, if your cat has potential for nutritional deficiencies, they may need to take an oral vitamin supplement. With surgery and proper feeding regiments, your cat has a good prognosis for long term recovery and management from vascular ring anomalies.