Lucy is a Cavalier King Charles spaniel. Ancestors of this breed were probably developed in 16th century Europe by crossing small spaniels with “Oriental” toy breeds such as the Japanese Chin, pug, or Tibetan spaniel. The resulting toy spaniels became popular with royalty, particularly King Charles II of England, hence they were known as “King Charles spaniels.” He loved these dogs so much he issued a Royal Proclamation, commanding all toy spaniels be allowed everywhere in the British Empire, including Parliament. Paintings from the 16th, 17th, and 18th century by renowned artists including Titian, Van Dyck, and Gainsborough depict little spaniels fairly similar to today’s breed. They were popular among the aristocracy as “comforter spaniels,” because of their ability to provide warmth while sitting on one’s feet or lap, and to attract fleas that might otherwise bite the owner. Over the centuries, as various breeds went in and out of fashion, the “Charlies” seen in these famous paintings became less common, except one particular strain of red and white favored by various Dukes of Marlborough. This coat color, known as Blenheim after the dukes’ estate, Blenheim Palace, is still the most popular today.
By the mid-19th century, “Charlies” had gone through major changes. They were smaller, with dome-shaped heads, lower-set ears, and shorter noses. Then in the 1920s there was a revival of interest in breeding dogs truer to the ones portrayed in those 16th century works of art, with flat heads, high-set ears, almond eyes, and rather pointed noses. A breed club established in 1928 officially chose the name “Cavalier King Charles Spaniel,” adding the word “cavalier” to separate this new breed from older pug-faced varieties.
Now our girl Lucy would have been right at home in the lap of royalty, posing for her portrait, except for one thing. Lucy’s lip was drooping on one side. Her owner had noticed her dropping food when eating, and drooling. The asymmetry was subtle, until she started to pant. Then it was immediately obvious that one whole side of her face was affected. One eye did not open as wide as the other, the eyelids drooping slightly. I poked my finger at her eye, looking for a reaction called a “menace response.” When something threatens to poke you in the eye, you blink. It’s a reflex. You can’t control it. But Lucy didn’t blink. She wasn’t blind. She just couldn’t blink. Lucy had facial nerve paralysis, a dysfunction of the seventh cranial nerve resulting in weakness of the muscles of the ear, eyelids, lips, and nostril. It typically occurs unilaterally, i.e., on only one side. Sometimes it can be a symptom of middle- or inner-ear infection, tumor, trauma, or other serious underlying disease, but most unilateral cases are idiopathic, meaning there is no identifiable cause. Lucy had a minor ear infection, but otherwise seemed completely healthy. “It’s probably idiopathic,” I explained. “It may take weeks or months to improve, if it ever does.” Most animals with unilateral idiopathic facial paralysis tolerate the deficit well, although the affected eye may need regular lubrication to prevent damage from drying and excessive exposure. A similar condition called Bell’s palsy in people is occasionally associated with Lyme disease, so we tested and ruled out Lyme. I sent her home with ear and eye medications and plans to recheck in a month.
The next week another client brought in a Cavalier King Charles puppy for a pre-purchase exam. “One of the littermates has a heart murmur,” he reported. “Purebred dogs do have a higher risk for genetic disorders,” I said. “They’re drawing from a smaller gene pool.” I went on to list some of the inherited disorders Cavaliers are prone to — mitral valve disease of the heart, hip dysplasia, keratoconjunctivitis sicca (commonly known as “dry eye”), luxating patellas, deafness, macrothrombocytopenia (a blood cell abnormality), and syringomyelia (a central nervous system disorder), to name a few. I decided to print out information for the client about some of these diseases. As I clicked the Client Education Handout link, up popped an article with a photograph of a Cavalier smiling lopsidedly at the camera, looking exactly like Lucy!
I read the article, and learned that facial nerve paralysis is very common in this breed. Previously thought to be primarily idiopathic, it is now suspected that in Cavaliers, facial nerve paralysis may sometimes be a symptom of either of two underlying problems to which they have a genetic predisposition. First is primary secretory otitis media (PSOM), a condition in which thick mucus accumulates in the middle ear. Treatment involves periodically lancing the eardrum and flushing out the discharge. Second is syringomyelia, a condition in which a congenital malformation impedes the normal flow of cerebral spinal fluid, leading to creation of fluid pockets inside the central nervous system just at the back of the neck. Usually diagnosed at between six months and three years of age, affected dogs exhibit neck pain and frequent unilateral scratching on the neck, chest, and shoulder. But what jumped out at me was that facial nerve paralysis has been associated with both PSOM and syringomyelia.
I had Lucy come in for a recheck to discuss what I had learned. On otoscopic examination, her eardrums looked normal, making PSOM unlikely. Bouts of mild neck pain in her past were suggestive of syringomyelia, but definitive diagnosis would require MRI. And it was still possible the facial nerve paralysis was idiopathic. If she did have syringomyelia, she would not necessarily require treatment, as long as she was comfortable. If painful, anti-inflammatories and/or analgesics may help, and in severe cases, surgery. Since Lucy is not currently experiencing any discomfort, her owner is holding off on having an MRI. Perhaps the facial nerve paralysis will resolve with time. Perhaps not. As long as she is not in pain. In the meantime, should Lucy visit London: King Charles II’s edict still stands, and as a Cavalier King Charles spaniel, she would be welcome anywhere she wants to go … even the Houses of Parliament.