- Email: [email protected]
Behavioral Problems of Geriatric Dogs and Cats
Symposium on Internal Medicine and the Geriatric Patient
Behavioral Problems of Geriatric Dogs and Cats Katherine A. Houpt, V.M.D., Ph.D.,* and Bonnie Beaver, D.V.M., M.S. t
With the increase in both medical proficiency and psychological attachment of the owner for pets, the care provided to pets has greatly extended their life span. As a result, the veterinary profession must now deal with an increasing list of behavioral changes and problems principally associated with the geriatric pet. Although detailed studies on specific behaviors of old age are just beginning, a number of behavioral trends are already known, and these will be described. There are critical periods during the development of cats and dogs. 3• 5 They are mirrored by critical periods in the pet-human relationship. There are three periods in which the animal's behavior is most likely to disturb its relationship with its owner. The first of these periods for the dog is from the third to sixth month, when problems of housebreaking and chewing arise. The second period is during the second year when dogs, especially male dogs, mature socially and are most apt to become aggressive. The final period is during old age when some of the problems discussed below may occur. Cats generally have fewer behavioral problems, but one critical period can occur when a male cat reaches sexual maturity and begins to scent mark or urinate in the house. The other critical period, which is unrelated to age, occurs whenever there is a change in the cat' s environment. This change may be a move from one house to another or the addition of another cat to the household. Old cats may also have behavioral problems. Critical periods in the pet-human relationship are analogous to the developmental critical periods of dogs and cats in that small amounts of the proper experience can influence the animal's behavior and, therefore, the pet-human bond for many years to come.
*Assistant Professor, D-epartment of Physiology, New York State College ofVeterinary Medicine, Cornell University, Ithaca, New York tAssociate Professor, Department of Veterinary Anatomy, Texas A & M University College of Veterinary Medicine, College Station, Texas Veterinary Clinics of North America: Small Animal Practice-Vol. 11, No.4, November 1981
643
644
KATHERINE
A.
HOUPT AND BONNIE BEAVER
The most common behavioral problems that occur in old cats and dogs are those related to or secondary to degenerative disease and other geriatric changes. Behavioral problems secondary to arthritis, cardiovascular disease, renal disease, diabetes, deafness and blindness fall in this category. In addition there are social problems that occur in geriatric animals, due either to the death of another pet or to the addition of a new pet. Pain-Induced Aggression
Dogs suffering from arthritis or from any musculoskeletal degenerative disease may also be suffering chronic pain. These are the animals most likely to become increasingly irritable, particularly when touched. Typical examples are German Shepherd Dogs suffering from hip dysplasia or Beagles with cervical intervertebral disk protrusion. The owner is most likely to be bitten if the hindquarters of the former or the head of the latter are petted. The dog may be presented to the veterinarian for either the physical problem, the behavioral problem, or both. If the dog is presented primarily because of aggression, history and physical examination will often reveal the underlying cause of the aggression. Despite the physical basis of the aggression in these patients, the dogs should be taught not to express aggression by biting. Analgesic drugs may be prescribed to alleviate the pain. However, if the dog has learned to be aggressive whenever it is touched, or, perhaps, whenever it is simply approached, it will continue to be aggressive despite a relief from the pain that induced the aggression originally. The dog should be sharply reprimanded verbally whenever it growls or snaps. The owner should look the dog in the eye when reprimanding it. If possible, the dog should then be given a command such as "Sit" (if it is able to do that without pain), then rewarded with verbal praise. This technique of teaching the animal that aggression is going to be punished and obedient behavior rewarded is very effective in teaching the dog the difference between right and wrong behavior. Conditions other than those affecting the musculoskeletal system can be painful and can, therefore, result in pain-induced aggression. The following case illustrates iritis with accompanying aggression. A dog was presented with a history of gradually increasing aggression. The aggressive behavior was directed at other dogs for the most part. The dog lived in a household with three other dogs. It began to isolate itself from the others and to growl at them whenever they approached. Finally, it severely bit a small dog belonging to a neighboring family, although the two dogs had played peacefully on many previous occasions. The dog had growled and nipped at the owners as well. A detailed history revealed that the dog had previously been aggressive. The occasion was the period immediately following ovariohysterectomy. Apparently, this dog had a low tolerance for pain and a low threshold for aggression. The aggressive tendencies were not suppressed by the owners, who did not discipline any of the dogs consistently.
BEHAVIORAL PROBLEMS OF GERIATRIC
Docs AND CATS
645
Aggression due to Central Nervous System Disease Not all aggression in older animals is in response to pain. In some animals, the aggression may be due to tumors or infiuctions in the brain. Classically, aggression would be expected to result from lesions in the limbic system. An increase in aggression in a formerly docile pet or a decrease in aggression in a working guard dog might each be indicative of a lesion in the forebrain. Cerebral infarction as described by de Lahunta may be the cause of an increase in aggressive behavior of cats. 2 Deafness There are congenital forms of deafness, especially in white dogs and cats, 4 but deafness is also a condition that accompanies old age. The greatest threat to the life of a deaf dog is the automobile. Dogs that are accustomed to cars and have successfully avoided them for years may fail to do so when they are deaf. Apparently dogs use the sound of the automobile as much as or more than the sight of it to gauge its distance. It is particularly unfortunate that it is the family car that most often strikes and kills the deaf dog as it stands in the driveway. The behavior problem that arises in deaf dogs is one of control and discipline. The dog may have to be retrained with hand signals rather than voice commands. Many obedience trainers teach hand signals at the same time as verbal commands. It is easiest to teach young dogs, and it is recommended to all owners who intend to keep a dog for its lifetime that hand signals be taught at an early age. It is possible, however, to teach an old dog to sit when one points at its rump; to lie down when one pats the floor; and to come when one slaps one's knees. The last command is difficult because one may wish the dog to come when it has turned to leave. Unless the dog can see the hand signal it will not obey. One can teach sit by pushing on the rump. Gradually point rather than push, and finally point while inches and then feet from the dog. "Down" is trained in the same way by pulling the dog down gently with downward tension on the collar with the leash. The hand should rest on the floor. Eventually less pulling will be needed and the hand can gradually be withdrawn from under the dog's chin and patted on the floor. To reteach "come," several people should sit in a circle surrounding the dog. The dog should wear a co·llar with a long rope attached. The free end of the rope should be attached to a weight so that it can be tossed from person to person. Each person should "call" the dog by slapping his or her own knees. If the dog does not approach, it should be gently pulled in by the rope. As soon as any of the commands are obeyed, the dog should be rewarded with enthusiastic petting. Verbal praise won't be perceived, of course. Gentleness is necessary in handling old dogs, but the principles are the same as those governing the training of young dogs. A more serious behavioral side effect of deafness is exaggerated
646
KATHERINE
A.
HOUPT AND BONNIE BEAVER
barking. The original cause of the barking is unknown. The dog may bark in anticipation of the noise. If the noise doesn't occur (it isn't heard), the dog barks repeatedly. This behavior should extinguish since the reward of hearing the noise has been removed, but only after many barking episodes of hundreds of barks each. By the time the dog has stopped barking, the owner, in desperation, may have substituted some other reward to distract it from barking. The usual reward is food. The dog may stop barking in order to eat, but the food reward has been substituted for the noise reward. To decrease barking, the owner should grab the barking dog by the scruff of the neck, lift it so that its forelimbs aren't touching the ground, and stare angrily into its eyes. As soon as the dog stops barking it should be given another command such as "down" and rewarded for that. An alternative approach is to confine a dog in a small room alone when it barks. It should not be let out until it stops barking or pauses. At first, the pause may be as short as a few seconds, but at each session the length of time without barking necessary to secure release and reunion with others can be increased until the dog will learn to be quiet for minutes at a time. One dog that was presented with this behavioral problem had never been trained and had been allowed to bark at visitors. Most problems of the old dog are simply exaggerations of the relationship with the owner that have always existed. Blindness
Many old dogs become blind as a result of cataracts, glaucoma, or other diseases. Often the owner may be aware of the physical changes in an old dog's eyes but may not be aware that the dog is blind. A typical example is a Pomeranian with cataracts. This dog showed no abnormal behavior in its own home. The owners, who had noticed the cataracts, were not concerned until they took the dog to another state for a visit. The dog had visited there before, but on emerging from the car ran into a step and then a wall. The ability of animals to navigate in a familiar environment without visual cues is excellent. Therefore, blindness often is not noticed until the dog is in a strange place. At home, the Pomeranian's only deficit is that it cannot catch table scraps thrown to it from the table as well as it once did. It is interesting that this dog also became deaf but barked less than it had when it could hear doorbells and other stimuli to territorial barking. Pathologic Mourning
One of the strongest arguments for the sentience of animals is the observation that they appear to mourn when a human or when other pets disappear from their lives. Many owners have observed that a dog seemed depressed after the cat was killed, for example. This reaction usually lasts for a few days or weeks. A behavioral response to the loss of the owner has also been noted. The story of Greyfriar's Bobby, the dog that refused to leave his master's grave,
BEHAVIORAL PROBLEMS OF GERIATRIC
Docs AND CATS
647
has such appeal that it was made into a movie. As heartwarming as these stories of pets' mourning are, the extreme cases of mourning can be most disturbing to the owner. The cases given below exemplify the pathologic responses of cats to the death of another cat. The first cat was a Siamese owned by an elderly woman. She had had many cats; at one time she had owned 17. Eventually all but two died. One cat was blind and was cared for by the remaining sighted cat. Apparently the blind cat was led about by the other. They groomed each other and slept together. When the blind cat died, the remaining cat began to yowl. Yowling is frequently a problem in Siamese, but this cat had previously been very quiet. At first, the owner would offer the cat food or take her outside whenever she yowled. This, of course, served to reinforce the cat' s vocal response. Soon the cat was yowling night and day. The yowling decreased when the cat was isolated for vocalizing and only allowed out of the basement when it had been quiet. The yowling stopped completely when another cat was obtained. The second case was that of a 12 year old domestic long hair that began to yowl after the death of its littermate, which had lived in the same house for l l years. The cat also began to withdraw hom the owners and spent more and more time on top of the refrigerator. It also became anorexic and would eat only if the owners were petting it. The owners did not want to get another cat so isolation of the cat away from the kitchen area when the owners were at work was advised and a palatable diet prescribed. Replacing an Animal before its Death When an animal, particularly an aging dog, begins to show signs of deterioration such as heart disease or arthritis, some owners feel that the eventual death of the animal will be less of an emotional blow to them if they obtain another dog prior to the death of the first. The aging dog may respond to the new dog in at least four ways. (l) Sometimes the addition of a new puppy is ignored by the aged dog. (2) In other cases, the puppy gives the aged dog companionship and the opportunity to play. (3) Unfortunately, in some situations, the aged dog does not accept the new one and may exhibit aggression, begin to house-soil, or misbehave in some other way. It is not clear what the owner should do to ·prevent unpleasant relationships between the old and the new animals. (4) Finally, even though an old and young dog get along well, they may begin to misbehave even if the aged dog never demonstrated a behavior problem in the past. There is apparently social facilitation of the unwanted behavior. In general, dogs in single-dog households are better behaved than those in multidog households. Whether this is simply a reflection of the owners or is an indication that one animal exacerbates the tendencies of the others is unknown. The following two cases illustrate some of the problems that may arise when a dog is replaced before its death. The owner of an old Welsh Corgi bitch obtained a second Corgi
648
KATHERINE
A. HouPT AND BoNNIE BEAVER
bitch to replace the first. Then, by chance, she had to keep a third dog, a male. These three dogs became a highly vocal triumverate. Tied to a tree while the owner was in class, they barked aggressively and dashed at anyone who approached them. The original and the replacement dog were well trained and docile dogs alone, but in a group they initiated the aggression. The third dog was not well trained, but once instigated by the females, he would bark loudly and for prolonged periods. The presence of the two intact females probably aggravated the male's aggressive tendencies. Finally the neighbors complained about the barking. The owner kept them in individual cages during the day and that eliminated the problem of their barking in the owner's absence when indoors, but they continued to bark aggressively when together. The second case involved a mongrel and a Collie owned by the same family. The Collie disappeared and the mongrel became depressed. The family bought a second Collie to replace the missing one, partly in response to the mongrel's apparent distress. Nearly a year later when the original Collie was found and returned, the mongrel attacked and the Collie, in retaliation, injured the mongrel severely. Subsequent attempts to reintroduce the dogs resulted in additional signs of aggression. The diagnosis was a change in the dominance status of the mongrel, who had been subordinate to the original Collie but was now dominant over the new Collie. The reappearance of the old Collie was a challenge to his position as "alpha" male. Obedience training and then gradual reintroduction when the dogs had been trained well enough to be under voice control was advocated. In both cases, castration would have attenuated the behavioral problem. In the second case, the owners would not agree to the surgery; in the first case, the male Welsh Corgi had a form of hemophilia and was, therefore, not a good surgical risk. Changes in Social Structure There may be aggressive episodes between dogs even when new animals have not entered the household. For example, in a family where the oldest resident dog has lived for a period of time with a younger male dog, there may come a time when the younger dog attempts to take over dominance of the group. In these cases, the younger dog will usually continue the chall~mge until he is soundly defeated or is successful. If the latter is true, the older dog generally becomes less outgoing and more submissive in personality. In other households, where dogs are approximately the same age, fights between the resident pets are not uncommon. These fights are frequently associated with changes in the environment such as the death of a family member or the visit of a friend or relative. In these cases, the dogs probably had been sharing dominance and possibly even had separate masters. The sudden change in the familiar routine is very upsetting, and the delicate balance under which the dogs exist has been thrown off. Not knowing how else to respond because
BEHAVIORAL PROBLEMS OF GERIATRIC DOGS AND CATS
649
of shared dominance, the dogs must come to terms at each new situation. In most cases the dogs had lived together since puppyhood, but during the last few years have started fighting. The fights may begin when someone comes to visit and stop when the person leaves. Commonly, the aggression becomes more serious and more frequent. The situation described here may reflect the desire of each animal to get attention from the visitor, but an unclear dominance has led to the fighting instead. Care must be taken to not reinforce this fighting by giving sought after attention. In other cases, two family dogs start fighting when a member of the family, often the husband, dies. The widow has a difficult time separating the dogs when they do fight and certainly is not able to reestablish a stable routine rapidly within the household. The husband in these situations probably represented the pack leader of the people-pet family and his absence made it necessary to establish a new leader. The two dogs apparently ranked higher than the woman and are now deciding which will take over the group leadership. In geriatric Beagle colonies, relationships between penmates have been known to drastically change, although the mechanism for it is not understood. Individual dogs have been found killed or badly wounded within the pens. As yet we are uncertain whether the individual was distressed and the others ganged up on it, or whether a single individual initiated an attack on an innocent bystander. Continued research would answer many of the questions still associated with this situation. Social aggressive changes also occur between geriatric cats. Dominance orders are poorly defined in domestic cat populations. A territorial male may assume a top role and, if the population is large enough, a few may assume low ranks, called pariahs. The majority of individuals comprise a socially equal middle class. In a household where cats have shared a middle position relationship for a number of years, one cat may start to assume a pariah position, displaying the pariah threat toward others with which it used to associate on an . equal basis. This low-ranking individual may now prefer social isolation, responding to other family cats with aggression instead of friendliness. House-Soiling Urinary problems, so common to geriatric dogs, are also reflected in behavioral changes. By old age, most animals are very ingrained in acceptable house-training routines. When these dogs suddenly find themselves no longer able to control urination, owners often describe a "shameful attitude." There are obvious behavioral changes in attitude that do occur, and they must be met with understanding by the owner. There is a tendency to start isolating the dog in areas where "accidents" will not harm the rug; however, the coincidental social isolation is usually a serious problem. Changes in the dog's elimination routines occur in later years. In part, the noc-
650
KATHERINE
A.
HOUPT AND BONNIE BEAVER
turnal patterns reflect biologic needs, but for others it provides an opportunity to get human social contact and thus involves a learned component. Two of the side effects of chronic renal disease and some forms of cardiovascular disease are polydipsia and polyuria. It is not surprising that these signs may lead to urination in the house. In most cases, the urination is involuntary because of the fullness of the bladder. In these cases, the owner must simply take the dog outside more often or provide papers for the dog that is paper-trained. So many dogs are now left for nine or more hours a day while owners work that leaving papers in one spot so that the dog can urinate or defecate with impunity would seem a humane thing to do. This should be advised especially in the cast~ of the old dog in congestive heart failure. A dog that has been accustomed to going outdoors for a decade may also require paper-training. There are other cases in which there seem to be both pathologic and behavioral causes for urination in the house. A Dachshund with chronic renal disease began to urinate in the house. There was a definite pattern to its urination, however, in that it always took place in one part of the house. In addition, the dog, a male, did not squat, but rather lifted its limb and scent-marked vertical objects such as table legs. The predisposing cause appeared to be the granddaughter of the owners. The child, a toddler, had recently moved into the grandparents' home. She was given the job of feeding the dog, a job that had previously been performed by the grandmother. The dog urinated only in the section of the house where the child slept. In this case the owners did not wish to attempt treatment and the dog was euthanatized. Defecation in the house may also be a problem. This is particularly true of breeds predisposed to psychogenic diarrhea. German Shepherd Dogs appear to be a predisposed breed. A young widow purchased a German Shepherd for protection and companionship for herself and her young children shortly after her husband died. The dog was very successful in its role and became very sensitive to the woman's feelings. It would vocalize in response to her as some dogs vocalize to one another. Eventually, however, the woman remarried and moved to
BEHAVIORAL PROBLEMS OF GERIATRIC
DoGS AND CATS
651
several days they moved the game farther and farther into the house. This was successful in encouraging the dog to enter the new house. Diabetes Obesity predisposes dogs to diabetes, 1 although the exact causal relationship is unknown. Once diabetes is diagnosed, weight reduction is usually advised. Management of a diabetic dog is difficult at best, and a behavioral problem often complicates the medical one. Diabetic dogs are usually ravenous unless exogenous insulin completely compensates for the lack of endogenous insulin. The dog is ravenous because its brain is deprived of glucose. This is true despite the high plasma glucose levels of the diabetic dog because insulin is necessary for glucose to enter those parts of the brain that are involved in the control of ingestive behavior. Although the rest of the brain is relatively independent of insulin this is not the case for the hypothalamic areas believed to integrate signals from the periphery to regulate body weight. The diabetic dog acts as if it were starved because, in fact, its cells are starved for glucose. It is difficult to resist feeding a diabetic dog that cries and begs so urgently for food. The owners should be made aware of the physiologic cause of this paradoxical hunger so that they can understand it and be able to limit the dog's food intake as necessary. Resistance to Change Probably the most noticeable change exhibited by the geriatric pet is its resistance to changes in routine. As already described, new ventures can be met with aggression. However, a number of other pets react to the changes with increased social demands, changes in eating or eliminating patterns, or self-induced isolation. Cats are particularly prone to demonstrate these changes when their environment is altered. Visiting grandchildren, newly introduced cats, or family moves can be particularly upsetting. By providing a dark, quiet hiding place such as an isolated room or even a box in an outof-the-way corner, the owner can do much to ease the cat' s tension. When new cats are to be introduced, it is best to isolate the new individual in a separate room for a week or so to allow the resident to become accustomed to the odors. Gradual introduction is generally much more successful, although a number of resident cats will never accept new introductions. Dogs are also susceptible to changes in routine especially if they decrease the normal amount of human contact. In any situation, owners must be particularly careful to maintain interactions with the dog on as much of a schedule as possible. Hospitalization of any geriatric patient can be particularly difficult for the animal, and serious attempts should be made to provide the closed-in security desired by the cat and the human reassurance needed by the dog. Other geriatric animals are faced with moves by their owners and the establishment of new routines and territories. With a few
652
K>..THERINE
A.
HOUPT AND BONNIE BEAVER
days of quiet, most cats will adjust without many problems. Dogs that are faced with different surfaces to eliminate on may try not to urinate or defecate as they normally would. If used to a backyard and then confined to an apartment, the dog may have difficulty changing to walks on a leash, to concrete, or to asphalt. It may take a gradual change with a generous amount of owner praise to accomplish the transition. Summary Dogs and cats that have been perfectly acceptable pets for many years may develop behavioral problems with old age. Most often these problems develop in animals that have never been very well behaved but have been tolerated by the owners until the problem has somehow exacerbated secondary to some other geriatric problem. The behavioral problems of old dogs most likely to be encountered by the practitioner are those of deaf dogs, dogs that house-soil because of renal, cardiovascular or gastrointestinal problems, and dogs that are aggressive because of a change in the number of animals or humans in the household or that are aggressive secondary to a chronic painful condition such as arthritis. Common feline problems may concern changes in the eat's environment. The treatment of behavioral problems of old animals is similar to the treatment of the problems of young animals, except that the physical limitations and disabilities of the old, usually ill, animal must be considered. Owners should be advised of the behavioral problems that may occur secondary to degenerative diseases and also be persuaded to keep social and environmental changes to a minimum in an old animal's life. REFERENCES l. Andersen, G. L., and Lewis, L. D.: Obesity. In Kirk, R. W. (ed.): Current Veterinary Therapy VII. Philadelphia, W. B. Saunders Co., 1980. 2. de Lahunta, A.: Veterinary Neuroanatomy and Clinical Neurology. Philadelphia, W. B. Saunders Co., 1977. 3. Fox, M. W., and Bekoff, M.: The behaviour of dogs. In Hafez, E. S. E. (ed.): The Behaviour of Domestic Animals, Edition 3. Baltimore, Williams and Wilkins Co., 1975. 4. Innes, J. R. M., and Saunders, L. Z.: Comparative Neuropathology. New York, Academic Press, 1962, pages 316-317. 5. Scott, J. P., and Fuller, J. L.: Dog Behavior: The Genetic Basis. Chicago, The University of Chicago Press, 1965.
Department of Physiology New York State College of Veterinary Medicine Cornell University Ithaca, New York 14853
Behavioral Problems of Geriatric Dogs and Cats Katherine A. Houpt, V.M.D., Ph.D.,* and Bonnie Beaver, D.V.M., M.S. t
With the increase in both medical proficiency and psychological attachment of the owner for pets, the care provided to pets has greatly extended their life span. As a result, the veterinary profession must now deal with an increasing list of behavioral changes and problems principally associated with the geriatric pet. Although detailed studies on specific behaviors of old age are just beginning, a number of behavioral trends are already known, and these will be described. There are critical periods during the development of cats and dogs. 3• 5 They are mirrored by critical periods in the pet-human relationship. There are three periods in which the animal's behavior is most likely to disturb its relationship with its owner. The first of these periods for the dog is from the third to sixth month, when problems of housebreaking and chewing arise. The second period is during the second year when dogs, especially male dogs, mature socially and are most apt to become aggressive. The final period is during old age when some of the problems discussed below may occur. Cats generally have fewer behavioral problems, but one critical period can occur when a male cat reaches sexual maturity and begins to scent mark or urinate in the house. The other critical period, which is unrelated to age, occurs whenever there is a change in the cat' s environment. This change may be a move from one house to another or the addition of another cat to the household. Old cats may also have behavioral problems. Critical periods in the pet-human relationship are analogous to the developmental critical periods of dogs and cats in that small amounts of the proper experience can influence the animal's behavior and, therefore, the pet-human bond for many years to come.
*Assistant Professor, D-epartment of Physiology, New York State College ofVeterinary Medicine, Cornell University, Ithaca, New York tAssociate Professor, Department of Veterinary Anatomy, Texas A & M University College of Veterinary Medicine, College Station, Texas Veterinary Clinics of North America: Small Animal Practice-Vol. 11, No.4, November 1981
643
644
KATHERINE
A.
HOUPT AND BONNIE BEAVER
The most common behavioral problems that occur in old cats and dogs are those related to or secondary to degenerative disease and other geriatric changes. Behavioral problems secondary to arthritis, cardiovascular disease, renal disease, diabetes, deafness and blindness fall in this category. In addition there are social problems that occur in geriatric animals, due either to the death of another pet or to the addition of a new pet. Pain-Induced Aggression
Dogs suffering from arthritis or from any musculoskeletal degenerative disease may also be suffering chronic pain. These are the animals most likely to become increasingly irritable, particularly when touched. Typical examples are German Shepherd Dogs suffering from hip dysplasia or Beagles with cervical intervertebral disk protrusion. The owner is most likely to be bitten if the hindquarters of the former or the head of the latter are petted. The dog may be presented to the veterinarian for either the physical problem, the behavioral problem, or both. If the dog is presented primarily because of aggression, history and physical examination will often reveal the underlying cause of the aggression. Despite the physical basis of the aggression in these patients, the dogs should be taught not to express aggression by biting. Analgesic drugs may be prescribed to alleviate the pain. However, if the dog has learned to be aggressive whenever it is touched, or, perhaps, whenever it is simply approached, it will continue to be aggressive despite a relief from the pain that induced the aggression originally. The dog should be sharply reprimanded verbally whenever it growls or snaps. The owner should look the dog in the eye when reprimanding it. If possible, the dog should then be given a command such as "Sit" (if it is able to do that without pain), then rewarded with verbal praise. This technique of teaching the animal that aggression is going to be punished and obedient behavior rewarded is very effective in teaching the dog the difference between right and wrong behavior. Conditions other than those affecting the musculoskeletal system can be painful and can, therefore, result in pain-induced aggression. The following case illustrates iritis with accompanying aggression. A dog was presented with a history of gradually increasing aggression. The aggressive behavior was directed at other dogs for the most part. The dog lived in a household with three other dogs. It began to isolate itself from the others and to growl at them whenever they approached. Finally, it severely bit a small dog belonging to a neighboring family, although the two dogs had played peacefully on many previous occasions. The dog had growled and nipped at the owners as well. A detailed history revealed that the dog had previously been aggressive. The occasion was the period immediately following ovariohysterectomy. Apparently, this dog had a low tolerance for pain and a low threshold for aggression. The aggressive tendencies were not suppressed by the owners, who did not discipline any of the dogs consistently.
BEHAVIORAL PROBLEMS OF GERIATRIC
Docs AND CATS
645
Aggression due to Central Nervous System Disease Not all aggression in older animals is in response to pain. In some animals, the aggression may be due to tumors or infiuctions in the brain. Classically, aggression would be expected to result from lesions in the limbic system. An increase in aggression in a formerly docile pet or a decrease in aggression in a working guard dog might each be indicative of a lesion in the forebrain. Cerebral infarction as described by de Lahunta may be the cause of an increase in aggressive behavior of cats. 2 Deafness There are congenital forms of deafness, especially in white dogs and cats, 4 but deafness is also a condition that accompanies old age. The greatest threat to the life of a deaf dog is the automobile. Dogs that are accustomed to cars and have successfully avoided them for years may fail to do so when they are deaf. Apparently dogs use the sound of the automobile as much as or more than the sight of it to gauge its distance. It is particularly unfortunate that it is the family car that most often strikes and kills the deaf dog as it stands in the driveway. The behavior problem that arises in deaf dogs is one of control and discipline. The dog may have to be retrained with hand signals rather than voice commands. Many obedience trainers teach hand signals at the same time as verbal commands. It is easiest to teach young dogs, and it is recommended to all owners who intend to keep a dog for its lifetime that hand signals be taught at an early age. It is possible, however, to teach an old dog to sit when one points at its rump; to lie down when one pats the floor; and to come when one slaps one's knees. The last command is difficult because one may wish the dog to come when it has turned to leave. Unless the dog can see the hand signal it will not obey. One can teach sit by pushing on the rump. Gradually point rather than push, and finally point while inches and then feet from the dog. "Down" is trained in the same way by pulling the dog down gently with downward tension on the collar with the leash. The hand should rest on the floor. Eventually less pulling will be needed and the hand can gradually be withdrawn from under the dog's chin and patted on the floor. To reteach "come," several people should sit in a circle surrounding the dog. The dog should wear a co·llar with a long rope attached. The free end of the rope should be attached to a weight so that it can be tossed from person to person. Each person should "call" the dog by slapping his or her own knees. If the dog does not approach, it should be gently pulled in by the rope. As soon as any of the commands are obeyed, the dog should be rewarded with enthusiastic petting. Verbal praise won't be perceived, of course. Gentleness is necessary in handling old dogs, but the principles are the same as those governing the training of young dogs. A more serious behavioral side effect of deafness is exaggerated
646
KATHERINE
A.
HOUPT AND BONNIE BEAVER
barking. The original cause of the barking is unknown. The dog may bark in anticipation of the noise. If the noise doesn't occur (it isn't heard), the dog barks repeatedly. This behavior should extinguish since the reward of hearing the noise has been removed, but only after many barking episodes of hundreds of barks each. By the time the dog has stopped barking, the owner, in desperation, may have substituted some other reward to distract it from barking. The usual reward is food. The dog may stop barking in order to eat, but the food reward has been substituted for the noise reward. To decrease barking, the owner should grab the barking dog by the scruff of the neck, lift it so that its forelimbs aren't touching the ground, and stare angrily into its eyes. As soon as the dog stops barking it should be given another command such as "down" and rewarded for that. An alternative approach is to confine a dog in a small room alone when it barks. It should not be let out until it stops barking or pauses. At first, the pause may be as short as a few seconds, but at each session the length of time without barking necessary to secure release and reunion with others can be increased until the dog will learn to be quiet for minutes at a time. One dog that was presented with this behavioral problem had never been trained and had been allowed to bark at visitors. Most problems of the old dog are simply exaggerations of the relationship with the owner that have always existed. Blindness
Many old dogs become blind as a result of cataracts, glaucoma, or other diseases. Often the owner may be aware of the physical changes in an old dog's eyes but may not be aware that the dog is blind. A typical example is a Pomeranian with cataracts. This dog showed no abnormal behavior in its own home. The owners, who had noticed the cataracts, were not concerned until they took the dog to another state for a visit. The dog had visited there before, but on emerging from the car ran into a step and then a wall. The ability of animals to navigate in a familiar environment without visual cues is excellent. Therefore, blindness often is not noticed until the dog is in a strange place. At home, the Pomeranian's only deficit is that it cannot catch table scraps thrown to it from the table as well as it once did. It is interesting that this dog also became deaf but barked less than it had when it could hear doorbells and other stimuli to territorial barking. Pathologic Mourning
One of the strongest arguments for the sentience of animals is the observation that they appear to mourn when a human or when other pets disappear from their lives. Many owners have observed that a dog seemed depressed after the cat was killed, for example. This reaction usually lasts for a few days or weeks. A behavioral response to the loss of the owner has also been noted. The story of Greyfriar's Bobby, the dog that refused to leave his master's grave,
BEHAVIORAL PROBLEMS OF GERIATRIC
Docs AND CATS
647
has such appeal that it was made into a movie. As heartwarming as these stories of pets' mourning are, the extreme cases of mourning can be most disturbing to the owner. The cases given below exemplify the pathologic responses of cats to the death of another cat. The first cat was a Siamese owned by an elderly woman. She had had many cats; at one time she had owned 17. Eventually all but two died. One cat was blind and was cared for by the remaining sighted cat. Apparently the blind cat was led about by the other. They groomed each other and slept together. When the blind cat died, the remaining cat began to yowl. Yowling is frequently a problem in Siamese, but this cat had previously been very quiet. At first, the owner would offer the cat food or take her outside whenever she yowled. This, of course, served to reinforce the cat' s vocal response. Soon the cat was yowling night and day. The yowling decreased when the cat was isolated for vocalizing and only allowed out of the basement when it had been quiet. The yowling stopped completely when another cat was obtained. The second case was that of a 12 year old domestic long hair that began to yowl after the death of its littermate, which had lived in the same house for l l years. The cat also began to withdraw hom the owners and spent more and more time on top of the refrigerator. It also became anorexic and would eat only if the owners were petting it. The owners did not want to get another cat so isolation of the cat away from the kitchen area when the owners were at work was advised and a palatable diet prescribed. Replacing an Animal before its Death When an animal, particularly an aging dog, begins to show signs of deterioration such as heart disease or arthritis, some owners feel that the eventual death of the animal will be less of an emotional blow to them if they obtain another dog prior to the death of the first. The aging dog may respond to the new dog in at least four ways. (l) Sometimes the addition of a new puppy is ignored by the aged dog. (2) In other cases, the puppy gives the aged dog companionship and the opportunity to play. (3) Unfortunately, in some situations, the aged dog does not accept the new one and may exhibit aggression, begin to house-soil, or misbehave in some other way. It is not clear what the owner should do to ·prevent unpleasant relationships between the old and the new animals. (4) Finally, even though an old and young dog get along well, they may begin to misbehave even if the aged dog never demonstrated a behavior problem in the past. There is apparently social facilitation of the unwanted behavior. In general, dogs in single-dog households are better behaved than those in multidog households. Whether this is simply a reflection of the owners or is an indication that one animal exacerbates the tendencies of the others is unknown. The following two cases illustrate some of the problems that may arise when a dog is replaced before its death. The owner of an old Welsh Corgi bitch obtained a second Corgi
648
KATHERINE
A. HouPT AND BoNNIE BEAVER
bitch to replace the first. Then, by chance, she had to keep a third dog, a male. These three dogs became a highly vocal triumverate. Tied to a tree while the owner was in class, they barked aggressively and dashed at anyone who approached them. The original and the replacement dog were well trained and docile dogs alone, but in a group they initiated the aggression. The third dog was not well trained, but once instigated by the females, he would bark loudly and for prolonged periods. The presence of the two intact females probably aggravated the male's aggressive tendencies. Finally the neighbors complained about the barking. The owner kept them in individual cages during the day and that eliminated the problem of their barking in the owner's absence when indoors, but they continued to bark aggressively when together. The second case involved a mongrel and a Collie owned by the same family. The Collie disappeared and the mongrel became depressed. The family bought a second Collie to replace the missing one, partly in response to the mongrel's apparent distress. Nearly a year later when the original Collie was found and returned, the mongrel attacked and the Collie, in retaliation, injured the mongrel severely. Subsequent attempts to reintroduce the dogs resulted in additional signs of aggression. The diagnosis was a change in the dominance status of the mongrel, who had been subordinate to the original Collie but was now dominant over the new Collie. The reappearance of the old Collie was a challenge to his position as "alpha" male. Obedience training and then gradual reintroduction when the dogs had been trained well enough to be under voice control was advocated. In both cases, castration would have attenuated the behavioral problem. In the second case, the owners would not agree to the surgery; in the first case, the male Welsh Corgi had a form of hemophilia and was, therefore, not a good surgical risk. Changes in Social Structure There may be aggressive episodes between dogs even when new animals have not entered the household. For example, in a family where the oldest resident dog has lived for a period of time with a younger male dog, there may come a time when the younger dog attempts to take over dominance of the group. In these cases, the younger dog will usually continue the chall~mge until he is soundly defeated or is successful. If the latter is true, the older dog generally becomes less outgoing and more submissive in personality. In other households, where dogs are approximately the same age, fights between the resident pets are not uncommon. These fights are frequently associated with changes in the environment such as the death of a family member or the visit of a friend or relative. In these cases, the dogs probably had been sharing dominance and possibly even had separate masters. The sudden change in the familiar routine is very upsetting, and the delicate balance under which the dogs exist has been thrown off. Not knowing how else to respond because
BEHAVIORAL PROBLEMS OF GERIATRIC DOGS AND CATS
649
of shared dominance, the dogs must come to terms at each new situation. In most cases the dogs had lived together since puppyhood, but during the last few years have started fighting. The fights may begin when someone comes to visit and stop when the person leaves. Commonly, the aggression becomes more serious and more frequent. The situation described here may reflect the desire of each animal to get attention from the visitor, but an unclear dominance has led to the fighting instead. Care must be taken to not reinforce this fighting by giving sought after attention. In other cases, two family dogs start fighting when a member of the family, often the husband, dies. The widow has a difficult time separating the dogs when they do fight and certainly is not able to reestablish a stable routine rapidly within the household. The husband in these situations probably represented the pack leader of the people-pet family and his absence made it necessary to establish a new leader. The two dogs apparently ranked higher than the woman and are now deciding which will take over the group leadership. In geriatric Beagle colonies, relationships between penmates have been known to drastically change, although the mechanism for it is not understood. Individual dogs have been found killed or badly wounded within the pens. As yet we are uncertain whether the individual was distressed and the others ganged up on it, or whether a single individual initiated an attack on an innocent bystander. Continued research would answer many of the questions still associated with this situation. Social aggressive changes also occur between geriatric cats. Dominance orders are poorly defined in domestic cat populations. A territorial male may assume a top role and, if the population is large enough, a few may assume low ranks, called pariahs. The majority of individuals comprise a socially equal middle class. In a household where cats have shared a middle position relationship for a number of years, one cat may start to assume a pariah position, displaying the pariah threat toward others with which it used to associate on an . equal basis. This low-ranking individual may now prefer social isolation, responding to other family cats with aggression instead of friendliness. House-Soiling Urinary problems, so common to geriatric dogs, are also reflected in behavioral changes. By old age, most animals are very ingrained in acceptable house-training routines. When these dogs suddenly find themselves no longer able to control urination, owners often describe a "shameful attitude." There are obvious behavioral changes in attitude that do occur, and they must be met with understanding by the owner. There is a tendency to start isolating the dog in areas where "accidents" will not harm the rug; however, the coincidental social isolation is usually a serious problem. Changes in the dog's elimination routines occur in later years. In part, the noc-
650
KATHERINE
A.
HOUPT AND BONNIE BEAVER
turnal patterns reflect biologic needs, but for others it provides an opportunity to get human social contact and thus involves a learned component. Two of the side effects of chronic renal disease and some forms of cardiovascular disease are polydipsia and polyuria. It is not surprising that these signs may lead to urination in the house. In most cases, the urination is involuntary because of the fullness of the bladder. In these cases, the owner must simply take the dog outside more often or provide papers for the dog that is paper-trained. So many dogs are now left for nine or more hours a day while owners work that leaving papers in one spot so that the dog can urinate or defecate with impunity would seem a humane thing to do. This should be advised especially in the cast~ of the old dog in congestive heart failure. A dog that has been accustomed to going outdoors for a decade may also require paper-training. There are other cases in which there seem to be both pathologic and behavioral causes for urination in the house. A Dachshund with chronic renal disease began to urinate in the house. There was a definite pattern to its urination, however, in that it always took place in one part of the house. In addition, the dog, a male, did not squat, but rather lifted its limb and scent-marked vertical objects such as table legs. The predisposing cause appeared to be the granddaughter of the owners. The child, a toddler, had recently moved into the grandparents' home. She was given the job of feeding the dog, a job that had previously been performed by the grandmother. The dog urinated only in the section of the house where the child slept. In this case the owners did not wish to attempt treatment and the dog was euthanatized. Defecation in the house may also be a problem. This is particularly true of breeds predisposed to psychogenic diarrhea. German Shepherd Dogs appear to be a predisposed breed. A young widow purchased a German Shepherd for protection and companionship for herself and her young children shortly after her husband died. The dog was very successful in its role and became very sensitive to the woman's feelings. It would vocalize in response to her as some dogs vocalize to one another. Eventually, however, the woman remarried and moved to
BEHAVIORAL PROBLEMS OF GERIATRIC
DoGS AND CATS
651
several days they moved the game farther and farther into the house. This was successful in encouraging the dog to enter the new house. Diabetes Obesity predisposes dogs to diabetes, 1 although the exact causal relationship is unknown. Once diabetes is diagnosed, weight reduction is usually advised. Management of a diabetic dog is difficult at best, and a behavioral problem often complicates the medical one. Diabetic dogs are usually ravenous unless exogenous insulin completely compensates for the lack of endogenous insulin. The dog is ravenous because its brain is deprived of glucose. This is true despite the high plasma glucose levels of the diabetic dog because insulin is necessary for glucose to enter those parts of the brain that are involved in the control of ingestive behavior. Although the rest of the brain is relatively independent of insulin this is not the case for the hypothalamic areas believed to integrate signals from the periphery to regulate body weight. The diabetic dog acts as if it were starved because, in fact, its cells are starved for glucose. It is difficult to resist feeding a diabetic dog that cries and begs so urgently for food. The owners should be made aware of the physiologic cause of this paradoxical hunger so that they can understand it and be able to limit the dog's food intake as necessary. Resistance to Change Probably the most noticeable change exhibited by the geriatric pet is its resistance to changes in routine. As already described, new ventures can be met with aggression. However, a number of other pets react to the changes with increased social demands, changes in eating or eliminating patterns, or self-induced isolation. Cats are particularly prone to demonstrate these changes when their environment is altered. Visiting grandchildren, newly introduced cats, or family moves can be particularly upsetting. By providing a dark, quiet hiding place such as an isolated room or even a box in an outof-the-way corner, the owner can do much to ease the cat' s tension. When new cats are to be introduced, it is best to isolate the new individual in a separate room for a week or so to allow the resident to become accustomed to the odors. Gradual introduction is generally much more successful, although a number of resident cats will never accept new introductions. Dogs are also susceptible to changes in routine especially if they decrease the normal amount of human contact. In any situation, owners must be particularly careful to maintain interactions with the dog on as much of a schedule as possible. Hospitalization of any geriatric patient can be particularly difficult for the animal, and serious attempts should be made to provide the closed-in security desired by the cat and the human reassurance needed by the dog. Other geriatric animals are faced with moves by their owners and the establishment of new routines and territories. With a few
652
K>..THERINE
A.
HOUPT AND BONNIE BEAVER
days of quiet, most cats will adjust without many problems. Dogs that are faced with different surfaces to eliminate on may try not to urinate or defecate as they normally would. If used to a backyard and then confined to an apartment, the dog may have difficulty changing to walks on a leash, to concrete, or to asphalt. It may take a gradual change with a generous amount of owner praise to accomplish the transition. Summary Dogs and cats that have been perfectly acceptable pets for many years may develop behavioral problems with old age. Most often these problems develop in animals that have never been very well behaved but have been tolerated by the owners until the problem has somehow exacerbated secondary to some other geriatric problem. The behavioral problems of old dogs most likely to be encountered by the practitioner are those of deaf dogs, dogs that house-soil because of renal, cardiovascular or gastrointestinal problems, and dogs that are aggressive because of a change in the number of animals or humans in the household or that are aggressive secondary to a chronic painful condition such as arthritis. Common feline problems may concern changes in the eat's environment. The treatment of behavioral problems of old animals is similar to the treatment of the problems of young animals, except that the physical limitations and disabilities of the old, usually ill, animal must be considered. Owners should be advised of the behavioral problems that may occur secondary to degenerative diseases and also be persuaded to keep social and environmental changes to a minimum in an old animal's life. REFERENCES l. Andersen, G. L., and Lewis, L. D.: Obesity. In Kirk, R. W. (ed.): Current Veterinary Therapy VII. Philadelphia, W. B. Saunders Co., 1980. 2. de Lahunta, A.: Veterinary Neuroanatomy and Clinical Neurology. Philadelphia, W. B. Saunders Co., 1977. 3. Fox, M. W., and Bekoff, M.: The behaviour of dogs. In Hafez, E. S. E. (ed.): The Behaviour of Domestic Animals, Edition 3. Baltimore, Williams and Wilkins Co., 1975. 4. Innes, J. R. M., and Saunders, L. Z.: Comparative Neuropathology. New York, Academic Press, 1962, pages 316-317. 5. Scott, J. P., and Fuller, J. L.: Dog Behavior: The Genetic Basis. Chicago, The University of Chicago Press, 1965.
Department of Physiology New York State College of Veterinary Medicine Cornell University Ithaca, New York 14853