The Beagle with ADHD
Behavioral Problems with Medical Roots
I have been told I have ADHD but I don’t think I—hey, look, a squirrel!
The owner of a nine-year-old spayed female beagle named Emma described her as “hyperexcitable” and “hyperactive.” Emma also showed some signs of thunderstorm phobia and was obsessed with food. I was not very concerned about this last aspect of the dog’s behavior. Beagles are notorious food-oriented “chowhounds.” Additionally, Emma also exhibited signs of separation anxiety. She would become anxious whenever she noticed the owner was leaving. Emma would howl as her owner headed off down the front walk. She destroyed things or had accidents in the house when alone, and delivered the classic squat-and-pee greeting response upon the owner’s return.
As my primary diagnosis, I jotted down “separation anxiety.” Also on the list was generalized anxiety and, somewhat dubiously, possible obsessive-compulsive disorder involving food. But in the back of my mind I considered the remote possibility of attention deficit hyperactivity disorder, better known under the rubric of ADHD.
I decided to treat the separation anxiety first, using a training program that fostered independence, environmental enrichment and medication with an antidepressant, Clomicalm. The typical time scale for improvement with such medication is two months. At that point, Emma’s owner reported that her dog was considerably better. The beagle still displayed some signs of separation anxiety, however, was still excitable, particularly in the car, and was still obsessed with food.
But we had made some progress. I was moderately happy with this report. I allowed the situation to drift for a few more months before inviting the owner to bring Emma back for a follow-up appointment.
“How much better is Emma’s separation anxiety?” I asked. “Give me a percentage of improvement.”
“I’d say Emma is about thirty percent better,” she replied cheerfully.
I swallowed hard, disappointed. “Thirty percent, is that all?”
“Well, maybe fifty percent.” I saw that the woman was simply hoping to make me feel better by quoting a higher percentage.
Even stretching the improvement to 50 percent, Emma’s progress was unsatisfactory. The conversation turned once again to her unruly behavior. The owner reported that Emma was positively “ballistic” in the house, tearing around the place and practically ricocheting off the walls. In addition, she was still totally unmanageable in the car.
The owner kept invoking the word “hyperactive” to describe Emma’s behavior. She was doing my work for me. After all, what does H in ADHD stand for?
“Okay,” I finally said. “Let’s do a trial to rule out ADHD.”
I arranged for the beagle to do a Ritalin trial at home. The results were jaw-dropping. Emma’s owner reported that a ten milligram dose of Ritalin totally calmed the dog down. This was not a 30 or 50 percent change. This was a 90–100 percent improvement. The owner added that Emma did not appear sedated, but was acting “just like a normal dog.” To her, the result was nothing short of a miracle.
Armed with this new information and a putative diagnosis of ADHD, I had the owner give Emma Ritalin twice daily to see if we could achieve sustained improvement. A week or so later she called back to say that Emma now tolerated thunderstorms, was calm in the car and her food obsession was gone. You might argue that Ritalin cured her food obsession because it reduced her appetite, but the other responses were difficult to explain unless Emma had ADHD.
The only remaining issue was some desultory hound-style howling when Emma was left alone. Everyone was happy with this result, including Emma. My conclusion was that ADHD was contributing to Emma’s clinical signs and that most of her behavior problems were secondary to ADHD. A medical condition, in other words, caused the behavioral condition.
Over the years I’ve seen many dogs like Emma with an assortment of behavior problems that owners describe as overactivity or hyperactivity. Some have responded to treatment with stimulants such as Ritalin and methamphetamine. I’ve had my share of failures, too, in the response to test-dosing dogs with a stimulant.
Not every apparently hyperactive pet necessarily has ADHD. Some of these subjects may have been simply overactive. Being overactive is a behavioral state resulting from lack of exercise, an improper diet and a boring lifestyle. That is all too often the case with pets in modern suburban households with no outlet for their pent-up energies. I almost always address underlying lifestyle issues before prescribing Ritalin. In my experience, ADHD is uncommon and is something of a curveball diagnosis.
Many behavior issues have medical underpinnings. A listless cat might have developed thyroid problems. Nocturnal anxiety could have its roots in a serious illness such as cancer. Anatomical irregularities in certain breeds can lead to sleep apnea. Determining if a behavioral issue has a medical cause is often a vital step in my practice when presented with problem pets.
Dr. Samuel Corson at Ohio State University in the 1960s established the validity of a diagnosis of canine ADHD. His team’s research on the effects of stress in dogs found that laboratory dogs exposed to random, mild electric shocks through the floor of their cages developed a hyperkinetic syndrome. Yet these dogs, including a dog called Jackson, who became aggressive as well as hyperactive, responded wonderfully to treatment with stimulants. The paradoxical calming effect of a stimulant drug was analogous to the response of hyperactive children to such treatment. A groundbreaking model for study of human hyperactivity had been created, out of which flowed the present-day treatments for ADHD.
In Pavlovian conditioning trials, dogs that had difficulty paying attention responded positively to treatment with stimulants. At about the same time, other researchers found hyperactivity in rodents and cats. It seemed that all animals, including humans, could suffer from this troublesome condition.
The veterinary behaviorist Dr. Andrew Luescher encountered ADHD quite frequently in certain breeds of dog, including working German shepherds. To confirm the diagnosis, if a dog appeared clinically hyperactive, Luescher would bring him to the veterinary hospital to make baseline measurements of behavior, heart rate, and respiratory rate. Then he administered a stimulant, such as amphetamine, and continued taking measurements over four hours.
In a normal dog, the expectation would be that the dog’s activity level, heart rate, and respiratory rate would increase. Logically, the dog would be stimulated by a stimulant. In a dog with ADHD, by contrast, a paradoxical calming response would occur. The administration of the drug was accompanied by reductions in heart rate and respiratory rate. The latter response, Luescher argued, supported a diagnosis of ADHD. The logic was somewhat switched around. If subjects responded to the treatment, Luescher theorized, then they must suffer from the syndrome.
Another veterinary behaviorist, Dr. Walter Burghardt, was so convinced by the concept of canine ADHD that he once said he diagnosed it in over 30 percent of his patients and treated it with Elavil, a tricyclic antidepressant with stimulant properties. In Burghardt’s view, owners do not usually come to behavior clinics stating that their dog has ADHD, but have various other complaints about their dog’s behavior. It is up to the clinician to determine ADHD as the root cause.
One added note regarding Dr. Corson: today, he is most remembered for pioneering the use of therapy dogs to help alleviate certain mental conditions in humans. One famous case involved a nineteen-year-old psychotic man who stayed in bed all day and did not respond to normal treatments. When a dog was brought into his room, however, the young man totally opened up. The mere presence of the pet was therapeutic. It’s remarkable that a researcher who focused on a canine model for ADHD established that pets can serve as a calming influence for agitated people. Once again, it highlights the fact that the benefits of medical research can flow both ways, from humans to pets and from pets to humans.
Other medical problems that can generate behavioral changes are such dire conditions as liver failure, rabies, cancer, and a rare disorder called lissencephaly, or “smooth brain.” The danger here, quite apart from those presented by the conditions themselves, is that a veterinarian might miss the underlying reasons for a pet’s strange behavior.
When the liver fails to do its job for any reason, toxic substances accumulate, such as ammonia and fatty acids. Because of this, the brain is also affected and neurotransmissions get out of whack. The processes that occur in liver failure in humans and animals are similar, as are the behaviors and neurological signs that this dysfunction produces. Behavioral changes in dogs associated with this condition include loss of appetite, depression, and lethargy, as well such bizarre quirks as aimless wandering, head pressing, circling, pacing, and even compulsive eating and drinking. Some animals appear blind. Others develop partial or full-blown seizures, sometimes progressing to coma and death.
In extreme liver failure in an old dog, no veterinarian would confuse this serious medical condition with a behavioral one. In the early stages of liver failure, however, particularly in a youngster, the behavioral signs may not lead a veterinarian to suspect liver failure and immediately check for it.
A typical scenario might be a young dog who has a congenital condition, in which blood that would normally traverse from intestines to the liver goes directly into the circulation system instead, bypassing the liver’s filtering and purification processes. This is called a portosystemic shunt and is quite common in some small breeds of dogs, particularly in Maltese terriers. Various behaviors, including unpredictable bouts of aggression, pacing and circling, and partial seizures may occur, all due to the underlying physical condition. In some affected dogs, behavioral issues are more pronounced after a high-protein meal. These behavioral signs form grounds for suspicion of a liver disorder.
Although portosystemic shunts are uncommon in human children, they do occur. In children, other liver diseases, such as failure of the bile duct development or hepatitis, produce similar signs, including personality and behavior changes, mood swings, impaired judgment, and seizures. Of course, a physical workup with blood testing and imaging can easily ascertain the liver failure in people and animals. So if you have a child who has bouts of “acting weird” at school, or a Maltese terrier who starts stargazing or acting aggressively after a meal, liver tests could be in order.
Rabies in humans and animals is caused by the same infectious agent, involves the same pathophysiologic processes, and results in similar signs in humans and animals. The virus travels up peripheral nerves to the brain and causes severely disruptive neurological symptoms. These include confusion, agitation, aggression, paranoia, terror, and hallucinations, usually progressing to death. Both people and animals may express the so-called furious form of rabies. Rage is the outward expression of the inner disruption of the brain. Paralysis occurs with or without hydrophobia. Basically, to know the disease in one species is to know it in another. Owing to the vaccination of dogs, cats, and people who work with animals, rabies in pets and people is extremely rare in the United States. Prophylactic treatment given immediately after a bite is also highly effective, and it is necessary since the untreated disease is 100 percent fatal.
Any cancer that causes abnormal growth of cells within the brain can affect its function. Since the growth occurs within what is an enclosed space, the skull, the expansion of the tumor causes an increase in pressure. The consequent disruption of normal brain activity is sometimes accompanied by partial or generalized seizures. Brain tumors are always something to watch out for in elderly pets when they start to behave oddly. They may display different-sized pupils or a pronounced head tilt. Or they might circle in one direction or exhibit seizures.
Some years ago, I missed a diagnosis of a brain tumor in a cat. The cat’s owner, an elderly woman and a resident of Cape Cod in Massachusetts, complained that her cat was biting her hands and forearms. Because of ongoing damage to her delicate, aging skin, the owner dearly wanted these attacks to stop.
Working on the assumption that common things occur commonly, I treated this six-year-old feline as if it was a case of what I call the alpha cat syndrome. I advised the owner on how to avoid aggressive attacks, how to repel an attack if necessary, and how to teach her cat to earn valued resources. She reported that this treatment had helped in the short-term. A couple of months later the local vet called to tell me that the cat had started circling in one direction. The diagnosis: a brain tumor.
I should have realized that a six-year-old cat does not suddenly start exhibiting an odd behavior problem. If the problem were purely behavioral, the cat would have been showing this pushy, assertive behavior at a much earlier age.
A thirteen-year-old beagle-sheltie mix called Buddie whom I saw relatively recently suffered from what appeared to be periodic panic attacks since the age of ten. The episodes began with him leaping up as if he had been bitten. Following that, he would spend days in a state of agitation and terror with his family helpless to make him feel better. His owner reported that he could not be verbally interrupted when the attacks occurred and stated that a bout usually lasted four to five days. Although I initially considered panic attacks or noise phobia as possible causes for his condition, it occurred to me that they might also be brought on by partial seizures. Seizures in a dog older than ten years are frequently the result of a brain tumor. In Buddie’s case, it would have had to be a slow-growing tumor because of his three-year history of “panic attacks.” But that was still possible and would have explained the geriatric onset of the behavior and the sudden change in behavior in a dog with a previously even temperament. An MRI would have settled the diagnosis, but an MRI costs up to $2,000, and quite likely there would have been nothing that could be done, even if one were discovered. Buddie had already lived past the life expectancy for a dog of his size and breed mix, so I decided to treat him symptomatically and to forgo pursuing a definitive diagnosis. His owner agreed—but a brain tumor causing partial seizures was high on the list of possible causes for his condition.
For humans, brain tumors present signs similar to the ones we see in animals. Behaviorally, there can be confusion and personality changes, leading to altered behavior and sometimes aggression. Depending on where the tumor is, the signs can be slightly different. In general terms, they are equivalent from species to species. Treatments are the same, too, including surgery, radiation therapy, and chemotherapy. If you were a radiation oncologist working with people, your skills would easily transfer to treating domestic animals, although you would have to be prepared to take a serious pay cut. The opposite would also hold true, that a veterinary radiation oncologist would have a flying start in an oncology clinic.
Lissencephaly is a brain condition that occurs in both dogs and people. The brain surface, which normally is wrinkled like a walnut, is instead smooth like a billiard ball. Most affected dogs and people are seriously impaired in learning and behavior. Lissencephaly has been reported in breeds such as Lhasa apsos, Irish setters, samoyeds, and wirehaired fox terriers, which implies that faulty genetics may be involved. In humans, lissencephaly can be caused by viral infections during the first trimester of pregnancy, or insufficient blood supply to the fetal brain, also in early pregnancy. But genetic causes are known, including a mutation of the so-called relin gene.
Interestingly, the relin gene is named after a spontaneous mutation in the so-called relin mouse. Without this gene, mice have abnormal brain development and coordination problems. If the genetic causes of lissencephaly were studied in dogs, the same gene might be implicated.
Behavioral conditions with medical underpinnings can have heartbreaking repercussions in pets. Dogs that may simply be suffering from medical conditions are blamed for bad behavior, as if they were at fault. A cat that scratches its owner suddenly becomes less loved and is ultimately rejected. This blame game sometimes leads to euthanasia, when in reality a corrective operation or dose of medicine might solve the problem.
Pain, from any cause, will affect the behavior of animals and people. The receptors that sense pain are the same in animals and people, the nervous pathways that transmit pain signals are the same, and the brain centers involved in receiving pain signals are the same. It only makes sense that the outward expression of pain is pretty much the same.
Pain underlies many a behavior problem and animals respond to the same analgesic drugs that are employed in people for pain relief. We see reduction of both the outward and inward signs of pain. Specifically, opioids, aspirin, and other nonsteroidal painkillers all deliver relief in dogs, cats, and other animals. Topical and regional anesthetics when appropriate are also highly effective in controlling pain.
Pain can sometimes be subjective. Injured soldiers returning from war require less morphine to control their pain than soldiers with identical injuries on the way to the front. We humans increase the pain we feel by projecting what the injury will mean for us in the future. With dogs, there are probably no such projections. Pain for animals is appreciated in the moment.
Anxiety increases the sense of pain in people and animals. Drugs like nitrous oxide and morphine do not completely alleviate pain in people: they just make recipients care less about the pain so they can tolerate it better. Though I cannot prove it, I think the same dynamic might apply to animals.
I do know, however, that morphine works in dogs to control pain. At Tufts, we have done studies on pain relief in dogs using epidural morphine to control postsurgical pain. In another experiment, we used an opioid called butorphanol in dogs after limb amputation surgery. It worked well. After twenty years of experience as a veterinary anesthesiologist, I can say with confidence that animals experience pain, and they respond positively to appropriate analgesic and anesthetic techniques.
Pet animals that are in pain appear depressed and cranky. They can sometimes be more aggressive if handled in such a way that exacerbates the pain. Pain shuts down appetite. It stimulates the sympathetic nervous system, resulting in an increased heart rate, increased blood pressure, and sweating. Because that is where their sweat glands are located, dogs and cats sweat only on their paws. Horses sweat over their whole bodies. Humans evidence similar behavioral and physiological responses to pain. Despite minor species differences in expression, such as the precise location of sweat glands, there is little difference in how species respond to pain.
We can clearly see that animals suffer. Descartes should be relegated to the history books and philosophical discussions where he belongs. Animals are not pain-immune automatons. If it looks like pain, behaves like pain, and responds to treatment like pain, then it probably is pain.
The medical-behavioral relationship at times works the other way around, in that emotional and behavioral issues can lead to illness. Factors such as anxiety or stress can actually cause physical disease. Such conditions may be properly labeled psychosomatic. The term speaks to the relation between the psyche, the mind, and the somatic, meaning “of the body.”
The power of the mind, in particular one’s overall mental attitude, can have positive or negative effects on one’s well-being. Whether at the beginning of an ordinary day, or in the midst of chaos, or during an illness, if you believe good will happen, you will notice more good than bad. In terms of positive thinking, if you believe it, it will be more likely to happen. Conversely, negative thoughts and attitudes lead to a lack of resilience and worse outcomes. Specific conditions in humans that are thought to include a psychosomatic component include psoriasis, eczema, stomach ulcers, high blood pressure, and heart disease.
Can animals suffer from psychosomatic conditions, too? Do they have psyches that can be sufficiently distraught as to produce somatic illnesses?
The answer is a resounding yes. As with humans, certain skin conditions in animals appear to be worsened by stress. As we have seen, acral lick dermatitis, while appearing to be a skin disease, is actually an anxiety-driven compulsive disorder with fundamental origins in the brain. That is to say, it is psychosomatic. Other psychosomatic skin conditions include skin picking in monkeys and feather picking in birds.
Anxiety and stress are the driving force behind these behaviors. A condition called neurotic excoriation is a skin scratching disorder reported in humans. I once gave advice to the staff at the Mayo Clinic on how to treat a human sufferer of this condition, who had been refractory to all the treatments the doctors at the clinic had tried.
The patient, a vice president of a major US corporation, neurotically scratched one side of his face, which as a result became deeply ulcerated. He had actually damaged the nostril on that side. Despite the Mayo Clinic’s best efforts, his obsessive scratching had been going on for two years.
Within three days of Mayo implementing our recommendation to treat him with an opioid antagonist, naltrexone, the man improved greatly. After a month of treatment, his face had healed. I warrant the same treatment would work for skin-picking monkeys, but I haven’t tried that so far. After all, humans are primates, too—the naked ape.
The effects of stress and anxiety on appetite can be quite clear. Dogs eat less and thrive less well when stressed. In extreme cases, illness can follow.
Stress and anxiety can play the same kind of tricks on people, too. Worried humans tend to lose weight and in extreme cases can fail to thrive. Anorexia nervosa is an anxiety-driven compulsive disorder. Sufferers are extremely concerned about their appearance and keep thinking they are overweight.
Stress can affect cardiovascular function in people and animals. Stress causes the release of stress hormones—the very same stress hormones, in fact—causing elevation in blood pressure and heart rate. The long-term effect of these elevations is not good for heart health, particularly in individuals who have heart disease. People do vary a bit from dogs in this respect, however, as dogs tend not to get atherosclerosis. Rather, canines tend to be affected by either valvular heart disease or cardiomyopathy, a disease of the heart muscle.
Robert Sapolsky, a neuroscientist at Stanford University who has studied baboons, found that in-charge, dominant baboons had less stress than those of lower rank. Upon postmortem examination, the subordinate animals often displayed gastric ulcers and enlarged adrenal glands, clear evidence of a psychosomatic manifestation of stress. Years later, through a twist of fate, all the dominant males were wiped out by tuberculosis as a result of scavenging from human garbage dumps. The upshot: a much more peaceful regime, more friendly associations, and, of course, less stress. Let that be a lesson to us all.
So-called irritable bowel syndrome is a gastrointestinal disease of dogs that appears to be psychosomatic. Afflicted animals sometimes suffer explosive diarrhea in stressful situations. There may be other factors involved in this condition, but stress certainly seems to precipitate it, at least in some dogs. I’m sure you know what I’m going to say next. Yes, people get irritable bowel syndrome, which is also exacerbated by anxiety and stress.
Finally, there is type 2 diabetes. A large body of animal studies supports the idea that stress reliably causes a spike of glucose levels in the blood, or hyperglycemia, and aggravates the risk of type 2 diabetes. Hyperglycemia has detrimental effects on nerves. The condition is best controlled by the combination of diet, exercise, and stress reduction. We can be talking about either humans or animals, and the conversation about cause and treatment would be much the same.
Depression of the immune system from stress can lead to a plethora of physical disorders. If a person or animal is under constant stress, hormones such as cortisol will depress the immune function. A depressed immune system in turn leads to increased susceptibility to infections and impaired ability to regulate improper cell division. A healthy immune system, on the other hand, works to mop up aberrant cells that might otherwise multiply, leading to cancer. Cancer is one of the leading causes of human death. It is also the leading medical cause of death in dogs.
Thus psychosomatic conditions exist in both human and nonhuman animals. Many result from stress and anxiety. Severe ongoing anxiety can affect just about every organ system in the human body. Worry will shorten life span. Clearly, it is important to address the toxic effect of too much stress. Engaging in a healthy lifestyle helps, as does addressing any developing issues before it leads to serious detrimental effects.
Ask a smart aleck about anxiety, and he’ll tell you not to worry about it. It is true that stress oftentimes triggers more stress. It can be a self-perpetuating loop. It’s important to break the chain for both you and your pet. I once met a medical student at a health spa who was expounding about all the healthy things he was doing to stay in good physical shape. He exercised, did not smoke or drink, and ate only healthy food. But then he added that, unfortunately, he could not stop worrying about maintaining his health (and other things) and he knew that worry, or stress, was the biggest killer of all. Now there’s a catch-22 situation if ever I heard of one.