Statement of the Problem
A dog was evaluated because of snapping at the owners’ 1-year-old child, barking and growling at unfamiliar people, and hiding during thunderstorms.
Signalment
The patient was a healthy 9-year-old 31-kg (68-lb) spayed female mixed-breed dog (Boxer mix).
History
The dog was adopted by the clients from a pet store when it was 12 weeks old. The owners did not use any training programs to expose the dog to specific stimuli during the socialization period. When the dog was a puppy, it ran up to unfamiliar adults with its tail wagging and had neutral body postures. However, when toddlers tried to feed the dog treats, it backed away and would not eat the treats.
The owners’ only child was born 1 year before behavioral evaluation of the dog. The patient often lay nearby as the owners rocked their daughter to sleep. When the owners first brought their daughter home, the dog's ears perked up at the sound of her crying, but within 3 weeks, the dog's body postures were relaxed during such times. When the child started crawling, the patient followed her. However, when the child started walking and approached the dog, the dog ran away from her with its ears back and tail tucked. During the month before the behavioral evaluation, the child approached the dog and grabbed its neck on 2 occasions: once when the dog was lying in its bed and once when the dog was lying in a corner of a room. The dog responded by leaning away and snapping with its ears back. The father quickly moved his daughter away, and the dog relaxed.
Starting when the dog was 4 years old, it had pulled away from unfamiliar people during walks and growled with its ears back if they approached, but looked back and sniffed the air after they passed. The dog barked and growled at unfamiliar people passing the house with its tail up and a forward body posture. If such people entered the house (particularly men), it would bark and growl, raise its hackles, hold its tail between the hind limbs, and hold its ears back before running away. The owners responded by confining the dog to a separate room when unfamiliar people visited the house.
The dog had been exposed to 12 thunderstorms during its life; from an early age, it responded by shaking and hiding under furniture with its ears back. Within 10 minutes after a storm ended, the dog would come out from under the furniture and lie down with a relaxed body posture. The dog was calm, had neutral body postures, and did not hide when other loud noises, such as fireworks and gunshots, were heard.
Physical Examination Findings and Laboratory Results
In the examination room during the behavioral evaluation, the child repeatedly approached the dog. The dog did not growl or snap at the child, but backed away with its ears back until the owner moved the child away. The dog approached the child with neutral body postures when the child had food. The dog's ears perked up when the child fed it. Once, the child laid her head on the dog's hips; the dog's body postures remained relaxed, but the owners were instructed to move their daughter away immediately, which they did. When handled by the clinician for a physical examination, the dog averted its gaze and panted with its ears back and tail down and refused treats. Results of physical examination, including orthopedic and neurologic examinations, were unremarkable. Signs of pain were not detected during palpation of the dog's neck or any other part of its body. Results of a CBC and serum biochemical analyses were unremarkable.
Diagnosis
Differential diagnoses for snapping at the child included fear-related aggression, predatory aggression, possessive aggression, dominance-related aggression, redirected aggression, play aggression, pain-elicited aggression, irritable aggression, and cognitive dysfunction.1,2 The dog had fearful body postures (eg, leaning away with its ears back) when it snapped at the child; this behavior supported a diagnosis of fear-related aggression.1,2 A fear-related aggressive response typically occurs when a dog is unable to avoid the inciting stimulus.1,2 Inadequate socialization likely contributed to development of this behavior.1 The dog did not chase, but ran away from the child, and the dog's aggression was inhibited; this ruled out predatory aggression.1 Possessive aggression was a possible diagnosis because the dog snapped at the child when she approached the dog in proximity to a possession (the dog bed); however, this was ruled out because the dog snapped at the child another time when no known possessions of the dog were present.1 Although the dog snapped at the child when the child approached and handled the dog on its bed, dominance-related aggression was ruled out because the dog lacked an assertive temperament and had fearful body postures.1 The child was the original target for aggressive arousal, which ruled out redirected aggression.1 Play aggression typically occurs in young dogs with playful, not fearful, body postures; therefore, that diagnosis was ruled out.1
Cognitive dysfunction was not a likely cause for the dog's aggression toward the child and unfamiliar people because of the lack of other clinical signs.3,4 Although any medical problem can cause irritability leading to aggression,1 pain-elicited aggression (eg, aggression attributable to osteoarthritis pain), irritable aggression, and other differential diagnoses attributable to medical problems (including metabolic, endocrine, neurologic, dermatologic, ophthalmologic, infectious, and systemic diseases) were also considered unlikely causes for these signs on the basis of unremarkable laboratory results and physical examination findings. Performance of other diagnostic procedures, such as MRI, would have helped to detect underlying intracranial diseases, had such procedures been indicated.5
Regarding the patient's behavior toward unfamiliar people, diagnoses of fear-related aggression (determined on the basis of the dog's body postures [eg, tail tucked and ears back] and retreat from unfamiliar people while barking and growling) and territorial aggression (because the dog barked and growled at unfamiliar people passing and approaching the house with confident body postures) were determined.1,2,6 Social animals are typically territorial.6 Play aggression was ruled out because such aggression typically occurs in young dogs with play-soliciting behavior.1 Because of the types of triggers identified for the dog's behavior, possessive aggression and redirected aggression were ruled out.1
A diagnosis of thunderstorm phobia7 was also determined for the patient on the basis of the history of shaking and hiding during storms. The dog was calm in the presence of other noises, which ruled out other noise phobias.7 Once, the owners returned home and found the dog hiding during a storm, indicating the behavior persisted in their absence. In addition, the owners had always ignored the dog during storms, which ruled out attention-seeking behavior.8 Cognitive dysfunction was ruled out because of a lack of other clinical signs and the fact that the behavior started when the dog was young.3,4 Other medical and neurologic causes of this behavior were considered unlikely on the basis of the unremarkable laboratory and physical examination results.
Treatment
The most important concern was that the dog might bite a person, especially the child. Results of a recent study9 indicate that dog bites of children that occur indoors are most often inflicted by a family pet that the child knows well, with a parent present, during an interaction, by dogs that are lying still, and to children under 7 years old; all those factors were applicable for the dog of the present report. Positive prognostic indicators for this patient were that the dog's aggression toward the child had only 1 trigger, which was predictable and consistent, and the dog only snapped when cornered, indicating bite inhibition and a high threshold for aggression. However, the large size of the dog and the difficulty in preventing the child from approaching the dog were concerns.1,10–12 Euthanasia and relocating the dog to a home without children were discussed as the most acceptable options if the owners could not maintain a safe environment. Treatment was implemented because the owners agreed to prevent their daughter from approaching the dog and they understood that the dog's aggression could not be cured (because it is a normal part of the behavior of dogs).2,13 This decision was to be reassessed 1 month after the start of treatment.
Avoidance of the dog's triggers for aggression would improve safety for people near the dog and prevent reinforcement of the behavior.1,12,13 Direct adult supervision when the child and dog were together7 and preventing the child from approaching the dog were considered essential. To eliminate the dog's exposure to unfamiliar people, the owners were instructed to avoid people during walks, cover the windows in the house, and confine the dog to a separate room when visitors were in the house.13 If the dog was aggressive, the owners were instructed to immediately remove it from the situation.2 A command-response-reward program would provide consistent interactions for the dog and help it to rely on the owners for guidance during difficult situations.13,14 The dog was taught an eye contact command to help it focus on the owners during systematic desensitization and counterconditioning. A head collara was used to improve the owners’ ability to control the dog, and a basket muzzle was used for safety during desensitization and counterconditioning. The owners were advised to attach a long dragline to the dog's head collar when it was loose, with supervision, in the house but to ensure that the line did not snag on furniture and that the child did not pick it up.13 Desensitization and counterconditioning of the patient to the child and unfamiliar people would help to replace the unwanted behavior with a positive emotional response. Undesirable behavior would be modified by use of classical and operant conditioning.15,16
During desensitization and counterconditioning, one owner would engage the child in a quiet activity; at the same time, the other owner would work with the dog in an area away from the child, giving it commands and rewarding appropriate responses with palatable treats. The owners were shown how to closely monitor the dog's body postures. During successive sessions, the distance between the dog and child was to be reduced, as long as the dog was calm. If the dog had any undesirable behavior, its distance to the child was to be increased so that the patient could be rewarded for relaxed behavior. During repeat desensitization and counterconditioning sessions, the child was to be gradually engaged in increasingly exuberant activities.
To eliminate the territorial component of behavior, desensitization and counterconditioning to unfamiliar people would begin during walks away from the house. The owners would use commands for the dog and reward it for responding at a site distant from unfamiliar people. As long as the dog remained calm, it would gradually be moved closer to unfamiliar people who would toss treats to it at a distance of 5 to 8 feet. Then, such people would give commands to the dog and toss treats to it when it responded.
Because the dog's aggression was primarily attributable to fear and anxiety, and such factors are associated with central serotonergic dysfunction,17 an antianxiety medication that increases serotonin concentrations, such as a selective serotonin reuptake inhibitor18 or a tricyclic antidepressant,19 could have helped decrease the dog's fear and anxiety and aided behavior modification2,16; however, such drugs are not approved for the treatment of aggression. Because of the risk of an increase in the dog's aggression,18 medication was not prescribed at that time as a first treatment; instead, safety measures were implemented first, and the dog's response to treatment was assessed.2,13 Use of a pheromone-releasing collarb was suggested to help decrease anxiety in the patient.13 Desensitization and counterconditioning combined with administration of a tricyclic antidepressant and a benzodiazepine can decrease or eliminate storm phobia in a dog.20 Such treatment would have been used for the dog of the present report if thunderstorms had occurred regularly where the owners lived.
Follow-up
At the time of a recheck evaluation 1 month after the initial behavioral evaluation, the triggers for the dog's aggression had been avoided. The child followed the dog when a 10-foot dragline was attached to the head collar, but not when a 4-foot dragline was used. The pheromone-releasing collar did not seem to have an effect on the patient's behavior. At this time, the dog no longer ran away from and had not acted aggressively toward the child. During desensitization and counterconditioning when the child was in the bathtub, the dog wore the head collar and basket muzzle while calmly following commands 5 feet away from the child. The child was too young to actively participate, but when she was older, during desensitization and counterconditioning she would be allowed to give the dog commands and toss it treats when it responded. The dog looked at the owners when unfamiliar people passed during walks. The dog obeyed commands from and ate treats tossed by unfamiliar people. At that time, the owners were to repeat the desensitization and counterconditioning exercises when unfamiliar people passed by or entered the house. Because of the dog's excellent progress with behavior modification methods, antianxiety medications were not administered to treat aggression. However, alprazolam (0.064 to 0.097 mg/kg [0.029 to 0.044 mg/lb], PO, as needed 1 hour before a storm) was prescribed for use during storms (which rarely occurred) because that drug has a rapid onset of short-term anxiolytic effects.20,21 Results of serum biochemical analyses performed at that time indicated values of hepatic and renal variables were unremarkable. Extralabel use and potential adverse effects of alprazolam, including aggression, were discussed with the owners.21 The anxiety relief provided by benzodiazepines can result in disinhibition leading to aggression, so alprazolam was to be administered when the dog was separated from the child and unfamiliar people.21
At the time of follow-up telephone calls to the owners 3 and 6 months after the initial behavioral evaluation, the dog had no signs of aggression toward the child. The dog was calm when the child moved around it. Desensitization and counterconditioning to the child and unfamiliar people were continued. The dog needed to be supervised in the yard because it barked at the neighbors 3 or 4 times when it was unsupervised. The dog responded to commands of household guests and was rewarded with treats, after which the patient lay down and relaxed. There had not been any thunderstorms during that time, but the male owner had given the dog a test dose21 of alprazolam (0.064 mg/kg, PO) when he was home alone with the dog, and no adverse effects were noticed.
Gentle Leader head collar, Premier Pet Products LLC, Midlothian, Va.
Dog Appeasing Pheromone collar, Ceva Animal Health Inc, Lenexa, Kan.
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