Statement of the Problem

A dog was evaluated because of high-pitched vocalizations described as screaming and crying noises when left alone in a crate during the owner's absence from the home.

Signalment

The patient was a 9-month-old 18-kg (39.6-lb) castrated male Siberian Husky.

History

The owner (an adult female) had adopted the dog from a breeder when it was approximately 3 months old. The owner and the dog first lived in a house with 2 other dogs. However, 3 weeks prior to the behavioral examination, they moved to a house without any other animals. The patient was described as making screaming and crying noises when it was left alone since the time of adoption. The dog had been kept in a crate when alone since adoption because it would chew and drag household objects if left uncrated. The dog slept in a crate in the owner's bedroom and would voluntarily go into a crate in the kitchen for naps; however, the dog made crying and screaming noises when left alone in the kitchen crate when the owner was away. The owner believed that the dog's behavior had become worse after moving to the new house. According to the owner, the dog followed her more than usual after she used a hair dryer in the morning. The owner believed the dog acted nervous when she was getting ready to leave the house. The patient started to make crying and screaming noises 1 to 2 minutes after it was locked in the crate in the morning. The owner recorded the dog's vocalizations while she was out of the house; the sounds continued for more than a few hours (at least until the recording stopped) under those conditions.

The owner had asked a dog trainer for help regarding the dog's behavior prior to the behavioral examination. The owner was told by the trainer to put the dog in a crate when she was at home, and to reward the dog for being quiet in the crate. The dog was quiet in the crate when the owner was visible. The owner was told not to let the dog out of the crate when it was vocalizing. She was also instructed to spray lemon water on the dog if it vocalized in the crate; because that technique didn't stop the dog from making screaming noises when the owner could not be seen by the dog, the trainer suggested that she should use a manually operated electric collar. Use of the electric collar worsened the dog's behavior and was discontinued. The owner jogged with the dog every morning because she thought that would tire the dog and it would sleep in the crate while she was away from the house.

The dog was evaluated by the referring veterinarian, and clomipramine hydrochloride^a (2.2 mg/kg [1.0 mg/lb], PO, q 24 h) was prescribed. The owner was also instructed to administer alprazolam (0.056 mg/kg [0.025 mg/lb], PO) and give the dog a toy when she left the house. The owner continued to record the dog's vocalizing behavior when she was not at home. The recordings indicated the dog was quiet for approximately 1 hour after the owner left the house; then it made crying noises for the duration of the recording. This behavior was detected while the dog was receiving the prescribed medications. The owner tried to take the dog with her when she left the house; she also took it to a daycare center for dogs. The dog made crying noises at the daycare center, but the behavior was considered better than when it was left alone in the house. The owner reported that the dog did not make these noises when it was left alone in a car.

Physical Examination Findings and Laboratory Results

The patient was evaluated by the referring veterinarian 6 days prior to the behavioral consultation. Results of physical examination, CBC, serum biochemical analyses, serum thyroid hormone testing, and urinalysis were unremarkable. These interpretations of the laboratory analyses were confirmed by a board-certified veterinary internal medicine specialist. Medical records of the referring veterinarian indicated the dog had been healthy since the time of adoption.

The patient did not seem to be anxious and did not whine, bark, or have destructive behavior during a 2-hour behavioral consultation. During the physical examination, the dog was cooperative and did not have signs of aggression attributable to anxiety.

Diagnosis

Differential diagnoses for the crying and screaming noises while the patient was in the crate included crate aversion, attention-seeking behavior, separation anxiety (with or without barrier frustration), and learned behavior that had started because of pain or physical abnormalities. A diagnosis of separation anxiety was made. Crate aversion and attention-seeking behavior were considered to be less likely causes for the behavior because the dog would go into the open crate and sleep when the owner was home. The dog had also been sleeping in a closed crate every night without behavior problems; therefore, a diagnosis of barrier frustration was also ruled out. The vocalizing was not considered attention-seeking behavior because the crying and screaming noises continued for more than a few hours when the owner was not home. The owner had not been releasing the dog from the crate when it vocalized, and reported that the dog had been quiet while confined in the crate when she was near. The dog's high-pitched vocalization behavior might have been learned and developed by association of pain or discomfort with crate confinement; however, this diagnosis was considered unlikely because the dog had no known history of illness or signs of pain when the behavior started.

The patient's behavior was attributed to separation anxiety because it was vocalizing only when confined to a crate alone at home. The owner described the dog's vocalizations as screaming or crying sounds, which differed from the typical barking or whining noises. Vocalization of dogs with high-pitched sounds is a sign of separation anxiety.^1,2 The dog seemed to respond to the owner's use of a hair dryer in the morning as a cue to her impending departure.

Treatment

Treatment considerations included reduction of the dog's anxiety with medication, identification of the amount of time the owner had to conduct behavior modification exercises, teaching the dog to be independent by means of obedience training (including crate training), and exercises to desensitize and countercondition the dog to the owner's departure from the house. The referring veterinarian had started treating the dog with clomipramine hydrochloride,^a an FDA-approved medication for treatment of separation anxiety in dogs.^3,4 Clomipramine hydrochloride is a tricyclic antidepressant (one of a class of drugs also known as serotonin reuptake inhibitors). Among evaluated tricyclic antidepressants, clomipramine hydrochloride has the strongest serotonin uptake inhibiting effect⁵; therefore, this drug is expected to be the most effective tricyclic antidepressant for the treatment of anxiety disorders in dogs. After the behavioral consultation, the dosage of clomipramine was increased to 2.2 mg/kg, PO, every 12 hours because the typical starting dosage for treatment of anxiety in dogs is 2 to 4 mg/kg (0.9 to 1.8 mg/lb) every 12 hours.^1,5

Alprazolam had also been prescribed prior to behavioral consultation. However, the owner was not satisfied with effects of the drug because the dog was quiet for only 1 hour after administration. Therefore, a benzodiazepine with a long duration of action (clorazepate dipotassium; 0.83 mg/kg [0.38 mg/lb]; recommended dose range, 0.5 to 2.0 mg/kg [0.23 to 0.91 mg/lb], PO)⁶ was prescribed for treatment of anxiety; the drug was to be administered 30 to 60 minutes prior to the owner's departure from the house. This drug was added to the treatments because the effects of the increased dosage of clomipramine might not have been detected for several weeks.^6,7

The owner was instructed to put the dog in the crate in the kitchen with interactive treat-filled chew toys 15 to 20 minutes prior to her departure. She was also instructed to ignore the dog before she left for work and when she first returned home. The patient reportedly had nervous behaviors when the owner used a hair dryer; therefore, she was asked to vary her morning routine and dry her hair at randomly selected times. Dogs can remember routines and sequences of a person's behavior, and anxiety may increase if the animal recognizes signs that the owner will depart soon. Also, the owner was instructed to turn on the hair dryer or carry it in the house during evenings so that its use would not be associated with her departure.

The owner was advised to purchase a larger crate and place it in the basement, where renovations were planned to accommodate the dog. A larger crate was recommended because dogs with separation anxiety typically prefer to be in large space when they are alone rather than being confined in a small crate.⁸ The owner was advised to use the new crate during desensitization and counterconditioning exercises in the basement as follows. Crate training was to be conducted with treats, praise, and toys to encourage the dog to associate the crate with rewards and relaxation. The dog was to be confined in the crate with treats when the owner was near and when the owner was in the house but out of sight for short periods. A specific bell was to be rung as a departure cue. While the dog was confined in the crate, the owner was to ring the bell and move out of the dog's sight for a few seconds. Gradually, the owner was to increase the amount of time away from the dog after ringing the bell. The owner was told not to put the dog in the new crate in the basement until it was able to stay in the crate for a few hours without any vocalization when she was out of sight. Ringing of a specific bell as a safe departure cue is a technique used to teach a dog to relax and wait after the cue; the method teaches a dog that the owner will return after the cue.

The owner was also instructed to practice obedience training (including treats as a reward) with the dog daily. Sit-stay and down-stay exercises were recommended. These exercises were intended to help teach the dog to relax while the owner was out of sight. The owner was asked to continue jogging with the dog because aerobic exercise might reduce overall anxiety.⁹

Follow-up

Two weeks after the behavioral consultation, the owner reported that the patient had started to have destructive behaviors when left alone in the car and was still making screaming noises (determined from an audio recording) for 4 hours after she left the house. The patient was receiving clorazepate dipotassium at a dose of 0.83 mg/kg as prescribed. The recommended clorazepate dipotassium dose is 0.5 to 2.0 mg/kg⁶; the owner was instructed to increase the dose to improve the patient's relaxation (maximum dose, 1.6 mg/kg [0.73 mg/lb] with a maximum frequency of q 2 h).⁶ At this time, the owner had started crate training of the dog with the new crate located in the basement of the home.

One month after the behavioral consultation, the owner reported that the dog's behavior had improved substantially. No screaming noises were heard for at least 3 hours after the owner's departure, and it had good behavior for 10 to 15 minutes while in the new crate when the owner was home but out of sight. At this time, clorazepate treatment was discontinued.

Five months after the first behavioral consultation, the dog was brought by the owner for a recheck behavioral examination. At this time, the patient was 14 months old, but its body weight was similar to the weight determined during the first behavioral examination (19 kg [42 lb]). The owner reported that the dog's appetite had been poor since the start of clomipramine administration. Serotonin reuptake inhibitors such as clomipramine can affect appetite because of effects on serotonin in the gastrointestinal tract.⁵ Results of physical examination were unremarkable; therefore, administration of clomipramine was continued at the same dosage. Blood sample analyses were not performed but further examination by the referring veterinarian was recommended if the dog's appetite decreased. The owner reported that the dog was able to stay alone in the new crate for more than 5 hours with good behavior.

Six months after the first behavioral consultation, the dog had good behavior (without making screaming noises) in the crate for the duration of the owner's absence from the home. Therefore, the dose of clomipramine was decreased to 1.05 mg/kg (0.48 mg/lb) for 2 weeks, then was decreased to 0.53 mg/kg (0.24 mg/lb) for 2 weeks, and finally discontinued.

Nine months after the first behavioral consultation, the dog had not received medication for 2 months and had not had high-pitched vocalization in the crate while the owner was at work during that interval. Because the dog seemed to enjoy visiting the daycare facility, the owner continued to take it there twice each week. The owner was satisfied with the substantial improvement in the dog's behavior.