The Narcoleptic Horse
Night Terrors and Other Sleep Problems
To sleep, perchance to dream . . .
Working with an animal shelter, a caring, well-meaning family accepted a seven-month-old German shorthair pointer puppy named Jake for foster care. The new owners were duly warned that the dog had extreme sleepwalking episodes at least ten times per night, behavior that was probably the reason for his surrender. Sleepwalking didn’t sound like that much of a problem to Jake’s new interim family, but they soon learned otherwise.
Jake’s nighttime behavior also seemed to have no particular trigger. The dog gave little or no warning signs before having one of his “night terror” attacks. Some nights would go by without any, and on other nights they were alarmingly frequent. As each attack started, Jake would paddle furiously whine, cry, snarl, and bark. Spookily enough, at times during these episodes his eyes would be wide open, but he was clearly in some kind of somnambulant state and not fully conscious.
We’ve seen this kind of nighttime behavior before, in Comet, the Golden retriever brought to me for his inexplicable rages. As with Comet, Jake’s foster family also made a video of their dog’s strange behavior. But that footage wasn’t only utilized to enlighten an animal behaviorist such as myself. Instead, it turned up on YouTube (http://bit.ly/1JOIWXC).
The video got a lot of hits, and comments flooded in. Most of them treated the footage as some sort of amusing spectacle. “He is soooo cute!” read one. “Funny how he jumps up, runs around and plops back down on the pillow like nothing happened.” Finally, well down in the comment thread, came a dose of common sense: “This shouldn’t be an entertainment for you guys. RBD or REM Behavior Disorder is a serious condition for animals and human. This is pretty severe.”
His foster family had found it increasingly difficult to keep Jake for fear that he would hurt a person or another animal. The dog was completely unadoptable at this point. The local vet suspected canine distemper, which causes seizures and tried treating Jake with potassium bromide, an anticonvulsant and sedative. The measure had little success. Diagnosis of such problems in dogs is very difficult. Certainly partial seizures can cause such signs, but so can other sleep disorders. Often the final diagnosis is made retrospectively by positive response to a particular treatment.
Various conditions could have led to Jake’s bizarre behavior. One of them is indeed a condition the Internet commentator suggested, RBD (rapid eye movement behavior disorder). After my initial contact with the dog’s foster family, I suggested treatment with a Valium-type drug, clonazepam, which is often used for treatment of RBD but also has anticonvulsant properties. A double whammy or twofer deal, so to speak. Unfortunately, I was not able to monitor Jake’s future progress because I was not the vet on the spot. I trust that he would have fared well as long as appropriate doses of this medication were employed.
The responses to Jake’s video measure the gulf in common knowledge about pet behavior. No one can deny that animals are often comical. David Letterman’s “Stupid Pet Tricks” was hugely popular, even though some of the animals featured were actually psychologically disturbed. Observing pets’ oddities is one of the great enjoyments of life. At the same time, the ignorance of classic signs of a mental disorder and regarding viewing it as entertainment is troubling. It indicates the distance we have to go informing the public about something so ordinary, so unremarkable, as an interrupted nap.
Nighttime presents many faces, and not all of them are healing. As the all-too-true saying goes, “Four a.m. knows all my secrets.” Something about the night brings out our demons. It’s the most natural thing in the world, and in humans probably has its roots in our prehistoric ancestors spooking at things that went bump in the night, a survival trait that was good for the perpetuation of the species. In the existential algorithm, darkness so often equals death. It’s no wonder that we worry more at night.
In pets, many behavioral issues turn up in the wee hours, some of which have a medical basis, some of which do not. “Nocturnal anxiety” is the catchall term for this condition, which affects pets more commonly than one might think. In my experience with dogs and cats, there are four main causes of nocturnal anxiety: Alzheimer’s disease, PTSD, noise phobia, and underlying medical conditions that cause pain or discomfort. I have already discussed the first three conditions in earlier chapters.
The so-called Sundowner Syndrome is one of the first things to cross my mind when an older animal becomes distressed as night falls and darkness arrives. Canine and feline cognitive dysfunction often features changes in sleeping patterns and displays of nighttime anxiety. These are often heralded by the Sundowner Syndrome, which can include disorientation, such as becoming lost in familiar environments; altered interactions with family members; and barking aimed at nothing in particular.
By contrast, if the distress begins immediately after some traumatic event, PTSD is high on the list of potential causes. For noise phobia to be involved, the sound the pet is fearful of may be more clearly audible at night because of the lack of masking noise of daytime clamor. One dog I treated had nocturnal panic attacks, triggered by the screech of the metal snowplows across the road surface, setting the poor pooch’s nerves on edge. Another dog became fearful of the noise of the boiler turning on at night. More recently, I’ve seen a dog whose trigger was the sound of a pack of agitated coyotes howling nearby at night.
It is fairly easy to ascertain a diagnosis for such conditions in dogs or cats. What is more difficult to diagnose is the effect of some painful disease that causes an animal distress at night. We have to gradually exclude other causes in order to make a diagnosis.
I discovered the ins and outs of this situation by accident many years ago while treating an aged Afghan hound for nocturnal anxiety. Our internal medicine vets at Tufts had gone over this dog with a proverbial fine-tooth comb. They could discover nothing to explain his sudden change of behavior.
The dog was turned over to me, in the hope that I might come up with some therapeutic cocktail that would make him more restful and less anxious at night. This I happily did, using a combination of a mild antianxiety drug, buspirone, combined with a morphine-like analgesic, butorphanol. The results of the treatment were good. Within days the dog and his owners were once again sleeping through the night.
A few months later, the dog had a spontaneous fracture of one of his legs. When he was admitted back to our hospital, his leg was X-rayed and then, because of suspicious findings, he was sent for a nuclear bone scan. This test, which also goes by the name scintigraphy, finds anomalies in bone. It’s sophisticated, expensive, and obviously not part of a routine examination.
Unfortunately, the scan turned up a serious problem. The hound was found to have multiple myeloma, a terminal condition. Like some malicious Pac-Man, the cancer was eating away at his bones.
From cases like these, I learned over the years that nocturnal anxiety can be an early sign of deeper medical problems, an insight that has helped me diagnose and treat dogs in similar predicaments. As I slowly accrued a number of cases of medically induced nocturnal anxiety I became more confident about the diagnosis. In the majority of cases, the medical cause of this condition turned out to be some form of cancer.
One older dog with this condition clearly did not have Alzheimer’s or PTSD. He was not sound sensitive. By eliminating these common causes of behavioral changes in the nighttime, I was able to zero in on medical issues. The dog turned out to have a retrobulbar tumor, a malignant growth behind his eye. At the time of the dog’s initial clinic appointment, I did not know what the medical basis of his problem was, but I felt confident enough to inform the owner that I was sure his pet had some medical issue causing his nighttime anxiety. That problem, I said, would become apparent in time. I treated the dog’s symptoms and waited.
Sure enough, some months later, his owners reported that his eye had started to bulge out of its socket. They contacted an eye specialist, who removed the retrobulbar tumor. The dog’s nighttime anxiety abated. The dog understood he was unwell long before we figured out what was wrong with him.
If nighttime anxiety at times occurs in a dog with a painful medical condition, it stands to reason that the same must also occur in people. I did not know this for certain at the time I was treating dogs, but could have predicted it by applying the principles of One Medicine. After years of diagnosing medically induced nocturnal anxiety in numerous canines, I encountered a client who clued me in.
“They give a handout to parents of children with cancer who are being treated at the Dana-Farber Hospital in Boston to warn them about nocturnal anxiety,” the client told me. “That’s when things seem to get so much worse.” Apparently, children with cancer are more likely to suffer distress at night than at any other time in the twenty-four-hour cycle.
The reason for this, I assume, is the same as in dogs with painful medical conditions. At night there is little else going on. There are few lights or sounds for distraction. As is said in The Who’s famous pop song “Pinball Wizard”:
Ain’t got no distractions,
Can’t hear no buzzers and bells.
Family members might be all asleep, the nursing staff is reduced to bare-bones level, so human interactions become more limited when compared to the daylight hours. The mind is free to focus on internal processes.
In pets as in humans, this situation causes insomnia, restlessness, and distress. Such conditions generally disturb the night, for the sufferer as well as the other members of the household. The ultimate solution is to surgically remove the offending tumor, if possible, or treat it with radiation or chemotherapy. In the meantime, as with the Afghan hound, anxiolytics and analgesics are helpful in treating symptoms.
Sleep apnea can occur in both people and dogs. Most affected dogs are short-nosed dogs such as English bulldogs, Pekes, boxers, and Boston terriers, who suffer from what is known as the brachycephalic airway syndrome (BAS), an unwelcome spin-off of selective breeding. Physical aspects of BAS include an elongated soft palate, an underdeveloped trachea, everted laryngeal saccules, and stenotic nares, which is the medical term for narrowed nostrils.
Though not all brachycephalic dogs have the full gamut of physical issues, even two or three of the symptoms can be compromising. Veterinarians with a special interest in bulldogs must learn to be proficient at corrective soft palate surgery, a procedure similar to the radical throat procedure performed in people who snore and have obstructive sleep apnea.
The brachycephalic syndrome can be problematic during the day also, especially in hot humid weather or when dogs with the condition are exercised hard. Some even collapse and have to be revived. Nighttime brings its own problems, as these dogs wheeze and struggle for breath. “Snore and you sleep alone,” is the old adage, and for this reason many short-nosed, snorty, and snuffly dogs wind up exiled from place of pride in the bedroom.
Signs of sleep apnea in dogs are the same as those in people. They include loud and chronic snoring, interrupted breathing with long pauses between breaths, choking or gasping during sleep, frequent waking during the night, daytime fatigue, irritability, aggression, and depressed mood. As with people, being overweight increases the severity of the condition.
So if you have a cranky old, overweight English bulldog—or a cranky old overweight husband—airway problems may be partly to blame. For husbands, nasal surgery may help to correct the problem, and for dogs such a procedure can be performed to correct genetic malformation of the nose cartilage.
A less invasive alternative to surgery is continuous positive airway pressure, or CPAP, via a nasal or full face mask. Currently only people will tolerate these appliances, and no genius inventor has come up with a viable CPAP rig for dogs. A last resort for dogs might be throat surgery. Some people become so worn down by their dog’s sleep apnea that an invasive surgical approach finally becomes the lesser of two evils.
The science fiction author Philip K. Dick posed a novel question as the title of one his books, Do Androids Dream of Electric Sheep? Like anxiety or post-traumatic stress, dreaming is one more facility that some people believe only sophisticated human brains have. A simple glance at a dog’s brain waves during sleep would disabuse such advocates of human exceptionalism.
Dogs do dream. Like our dreams, theirs come during a phase called rapid eye movement sleep. During this REM phase, the large antigravity muscles of the body are mostly paralyzed, but muscles that control fine motor movement remain active. In dogs, these include the muscles that control the movement of the eyeballs, eyelids, muzzle, ears, larynx, whiskers, and paws. Just as with people, a dog’s eyeballs move rapidly to and fro. Because of the muscle paralysis and the resulting relaxation, the REM phase is sometimes called the sleep of the body. But during REM, brain-wave activity remains decidedly active. Neural activity is similar to that seen in animals that are awake. It is in this phase of sleep that dreaming occurs.
Once in a while, for both people and dogs, the large muscles are not paralyzed in sleep. Though soundly asleep, the animal can physically act during his dreams. Like most dogs with REM behavior disorder, people with this affliction may exhibit mindless aggression. Dream-enacting behaviors in people include talking, yelling, punching, kicking, sitting, jumping from bed, arm flailing, and grabbing. Similarities between the human and canine condition abound.
Waking behavior during sleep is one thing. Sleep behavior during wakefulness is the flip side of the coin, and goes by the name of narcolepsy. Narcolepsy causes animals or people to fall asleep suddenly during the day, sometimes in the middle of an activity or meal. The sufferer feels excessive daytime sleepiness, punctuated by sudden bouts of REM sleep. The narcoleptic might also collapse into a conscious, paralytic state called cataplexy. Excitement caused by, for example, anticipation of food or other upcoming events is often the trigger for these so-called sleeping attacks.
Years ago I was consulted about a horse that was literally falling asleep on his feet. The quarter horse would buckle at the knees and almost collapse when his girth was cinched prior to going out on a ride. Because of this stumbling and falling behavior, the owner was quite rightfully concerned about possible danger to her daughter, who often rode the horse. She was considering putting the animal down.
Tufts veterinary school was this owner’s last resort and the horse’s last chance. Of course, more than one condition can cause a horse to collapse, so we brought the animal into our equine wards for a few days to have various specialists take a look at him and put him through a complete gamut of tests.
Internal medicine specialists found no diseases that would cause him to collapse. Neurologists declared there were no signs of brain conditions. Cardiologists checked the horse’s heart and employed a “Holter monitor” for continuous ECG monitoring, which ruled out intermittent cardiac rhythm disturbances. Since these investigations were all negative, the case was passed off to me, aka “End-of-the-Line Dodman.”
I suspected that the horse had narcolepsy, and I treated him with a tricyclic antidepressant, amitriptyline. We waited and watched. On this medication, the horse had no further attacks, not even when the girth was cinched. The horse went home on a daily dose of the medication. For as long as I followed up with this owner, the horse had no further attacks.
Studies of a pack of narcoleptic dogs at Stanford University in the 1970s led to discovery of a genetic glitch associated with the condition. A research team headed up by Emmanuel Mignot, a French pharmacologist and director of the Stanford Center for Sleep Sciences and Medicine, found a mutation of a gene responsible for proper formation of a brain chemical that regulates wakefulness and appetite.
Mignot and his wife, Servane Briand, adopted one of the dogs in the study, Bear, a male Belgian schipperke. The dog was brought to Mignot by a breeder, who told him the animal “fell down every time he got excited.” Bearichon, as he was affectionately called, lived to a ripe old age, a further indication that narcolepsy isn’t a life-threatening affliction—unless a person falls asleep in the middle of the street or while driving.
Enhanced emotions trigger narcoleptic episodes in dogs. Bear fell asleep whenever he got particularly animated. While he was eating he would collapse because he’d suddenly get excited about his meal. In other studies, laboratory dogs fell asleep when shown an escape route to the exterior. Free, free at last! Only just let me take a little nappy first. People may have narcoleptic attacks triggered by strong emotions, too. They often occur when people are laughing or crying.
Treatment of narcolepsy is the same for animals and people. One of the mainstays is a stimulant drug called Provigil, named from the Greek pro, for “vigil,” being watchful. Another treatment involves serotonin and norepinephrine-enhancing tricyclic antidepressants, such as the one we used in the narcoleptic horse case mentioned above.
Shakespeare calls sleep “nature’s soft nurse,” yet it proves problematic in such conditions as night terrors and narcolepsy, the two ends of the sleep disturbance spectrum.