Psychopharmaceutical Options for Canine Thunderstorm Phobia and General Anxiety
When thunderstorm phobia and/or general anxiety are highly vexing, highly problematic, or particularly severe, a CPT behavior modification program may become further potentiated when implemented in conjunction with an appropriately selected psychopharmaceutical medication. In many cases, a properly designed and diligently implemented behavior modification program may result in a successful goal outcome without the inclusion of medication. However, circumstances occur where the client pets progress plateaus far short of goal level, the pet continues destroying property, the pet injures himself/herself, or the pet suffers deleterious physiological effects as a direct result of either general anxiety or anxiety related to a specific stimulus, such as thunderstorms, separation, or a new pet. In such cases, psychopharmaceutical strategies for resolving canine general anxiety, thunderstorm phobia, and other stimulus specific anxieties and/or phobias work synergistically with a CPT behavior modification program.
The information garnered below was collected from academic research, academic publications, and medical drug encyclopedias. Our research found that no single psychopharmaceutical strategy is universally preferred. Nevertheless, certain protocols are more frequently preferred based either on conclusions from veterinary research studies, generally accepted applications in human medicine, or historically accepted applications in veterinary medicine.
Psychopharmaceutical inclusion in veterinary medicine is a fairly recent phenomenon. Moreover, research studies usually have small sample bases or are anecdotally generated. Thus, both the academic community and the practicing veterinary community have not reached a consensus regarding prescribed methodologies.
Furthermore, since canine neurochemistry closely resembles human neurochemistry and humans may vary greatly from individual to individual in how they metabolize specific medications, one may expect that trial and error is required to match the proper chemical and dosage with the needs of each individual animal. Consequently, we will list the most frequently recommended medications first, but also list less common alternatives.
Most Widely Recommended:
For thunderstorm phobia, the most widely accepted protocol is prescribing a combination of amitriptyline (elavil) on a daily maintenance basis in combination with either diazepam (valium) or alprazolam (xanax) prn on the day a thunderstorm is forecasted. Amitriptyline is a tricyclic antidepressant. Tricyclic antidepressants are used to counter depression, anxiety, sleep disorders, chronic pain, and enuresis (urinary incontinence). Amitriptyline potentiates the neurotransmitters serotonin and norepinephrine and inhibits the neurotransmitter acetylcholine. Contraindications include lethargy, sedation, blurred vision, dry eyes, dry mouth, hypotension, constipation, and arrhythmias. The recommended dosage for canines is 1 -2 mg/kg of body weight every 12 hours. 1 kilogram equals 2.2046 pounds. 1 pound equals .454 kilograms. Thus, a 60-pound dog weighs approximately 27 kg and would receive 27 54 mg of elavil twice per day. Since tablets come in 10 mg, 25 mg, and 50 mg varieties, the vet would probably prescribe 25 mg twice per day when beginning therapy. Onset is 2 3 weeks.
Valium and xanax are both from a class of drugs called benzodiazepines. Benzodiazepines are used as anxiolytics, sedatives, hypnotics (sleep aids), anticonvulsants, and muscle relaxants. Valium potentiates the inhibitory neurotransmitter gamma-aminobutyric acid (GABA) and produces skeletal muscle relaxation by inhibiting spinal polysynaptic afferent pathways. The recommended dosage for canines is .5 2 mg/kg of body weight as needed. Onset is 30 60 minutes. Contraindications include dizziness, drowsiness, lethargy, physical dependence, and tolerance. Xanax reduces anxiety through several undetermined effects in the central nervous system. The recommended dosage is .03 - .1 mg/kg of body weight as needed with a maximum of 4 mg per application. Onset is 1 2 hours. Contraindications include dizziness, drowsiness, lethargy, and physical dependence. Valium is an older drug than xanax and has been used longer in veterinary medicine. Therefore, many vets will recommend valium due to a lack of familiarity with xanax. However, researchers have found that xanax sedates less than valium, while equivalently or more effectively reducing anxiety. In addition, xanax lasts longer. In studies determining the effects of both drugs on dogs suffering from thunderstorm phobia, valium lasted between 2 -4 hours, whereas xanax lasted up to 10 hours. Consequently, since one cannot accurately predict the exact onset or duration of a thunderstorm while away from home for long periods of time, xanax provides superior results. Moreover, some articles recommended xanax as a stand-alone solution for both thunderstorm phobia and general anxiety.
The second most widely recommended drug for thunderstorm phobia, buspirone (buspar), is also widely recommended for general anxiety. Buspirone is classified as an anti-anxiety agent. Buspar reduces anxiety by binding to serotonin and dopamine receptors in the brain and increasing norepinephrine metabolism. The recommended veterinary dosage for canines is 1 mg/kg of body weight one time per day. Onset is 7 10 days. Contraindications include dizziness, drowsiness, fatigue, headache, insomnia, nervousness, blurred vision, nasal congestion, sore throat, tinnitus, tachycardia, nausea, rashes, myalgia, and incoordination. Despite the longer list of contraindications, buspar has been successfully used for many years in veterinary medicine when treating cats for litter box issues arising from stress or anxiety. Several veterinary researchers prefer buspar to benzodiazepines or a tricyclic-benzodiazepine combination therapy. Buspar is more mildly sedating and less physically addictive than valium or xanax.
Other Medications (by category and medication, not by popularity):
Hydroxyzine pamoate (vistaril) is used as an anxiolytic, preoperative sedative, antiemetic, and antipruritic. Vistaril depresses production of acetylcholine and histamines at the subcortical CNS level. Contraindications include drowsiness and dry mouth. Hydroxyzine is not a popular choice as it heavily sedates the animal. Onset is 15 30 minutes. I do not have veterinary dosages.
Clorazepate (tranxene) is used in human medicine to treat anxiety, manage alcohol withdrawal, and manage seizures. Tranxene is occasionally used in veterinary medicine to manage anxiety. Tranxene stimulates GABA receptors, inhibits spinal polysynaptic afferent pathways, and enhances presynaptic inhibition. Contraindications include dizziness, drowsiness, lethargy, and physical dependence. Onset is from 1 2 hours. Veterinary dosages range from .5 2 mg/kg of body weight as needed. Tranxene is sometimes used prn in lieu of valium or xanax in combination with amitriptyline. It tends to last longer than valium, but dissipates faster than xanax.
Beta-adrenergic Blocking Agent:
Atenolol (tenormin) is used in human medicine to manage hypertension and angina pectoris and prevent myocardial infarction. In veterinary medicine, tenormin is used for cardiac management and rarely to reduce anxiety. Tenormin blocks stimulation of beta1 myocardial adrenergic receptors, which in turn decreases blood pressure and heart rate. Unlike inderal, tenormin does not usually affect beta2 receptor sites. Contraindications include fatigue, weakness, bradycardia, congestive heart failure, and pulmonary edema. Onset is from 0 60 minutes, depending on whether administration is intravenous or oral. I do not have veterinary dosages.
Propranolol (inderal) is often used in human medicine to manage hypertension, angina pectoris, and arrhythmias. Off-label uses include managing alcohol withdrawal, aggressive behavior, situational anxiety, and antipsychotic-associated akathisia. In veterinary medicine, inderal is used to manage hypertension and arrhythmias and occasionally to reduce situational anxiety. Inderal blocks stimulation of beta1 myocardial and beta2 (pulmonary, vascular, and uterine) adrenergic (epinephrine) receptor sites, which in turn decreases heart rate and blood pressure. Contraindications include fatigue, weakness, bradycardia, and pulmonary edema. Onset is from 0 30 minutes, depending on whether administration is intravenous or oral. I do not have veterinary dosages.
Comfort Zone is a trade name for a product that emits the primary pheromone secreted by a lactating female dog. The product is available either as a spray or wall plug-in. In theory and in research provided by the manufacturer, the pheromone unconsciously relaxes anxious puppies and dogs without physical contraindications or sedation. The manufacturer recommends Comfort Zone in resolving general anxiety, thunderstorm phobia, separation anxiety, marking, chewing, barking, and obsessive-compulsive disorders.
Melatonin is a homeopathic remedy used to relieve anxiety and insomnia. Anecdotal research demonstrates that melatonin may have beneficial effects in relieving canine anxiety. The recommended dosage is one 3 mg tablet three times per day.
Selective Serotonin Reuptake Inhibitors (SSRIs)
Fluoxetine (Prozac) has repeatedly tested successfully in canines for improving dominance issues, aggression, anxiety, and reactivity. Prozac is the researchers drug of choice when observing reactive behavior, especially dominance aggression or fear aggression. In human medicine, prozac is used to treat depression, obsessive-compulsive disorders, anxiety, bulimia, anorexia, fibromyalgia, obesity, and premenstrual syndrome. Fluoxetine selectively inhibits the reuptake of serotonin in the central nervous system. Veterinary dosages range from .5 1 mg/kg of body weight every 24 hours. Onset is from 1 4 weeks. Contraindications include anxiety, drowsiness, headache, insomnia, diarrhea, itching, tremors, and seizures.
Paroxetine (paxil) has not been researched in canines as extensively as its related drug, prozac. In human medicine, paxil is used to treat depression, panic disorders, and obsessive-compulsive disorders. Paxil inhibits neuronal reuptake of serotonin in the CNS, which potentiates serotonin activity. Unlike tricyclic antidepressants, there is little or no effect on norepinephrine or dopamine. Onset is from 1 4 weeks. Contraindications include anxiety, dizziness, drowsiness, headache, insomnia, weakness, constipation, diarrhea, dry mouth, nausea, and tremors. I do not have veterinary dosages.
Sertraline (zoloft) is chemically similar to both prozac and paxil. However, veterinary behavioral researchers have not studied the effects of zoloft as extensively as they have prozac. In human medicine, zoloft is used to manage depression, panic disorders, and obsessive-compulsive disorders. Zoloft inhibits neuronal reuptake of serotonin in the CNS, which potentiates serotonin activity. Unlike tricyclic antidepressants, there is little or no effect on norepinephrine or dopamine. Onset is from 2 4 weeks. Contraindications include dizziness, drowsiness, fatigue, headache, insomnia, diarrhea, dry mouth, nausea, and tremors. I do not have veterinary dosages.
Clomipramine (Clomicalm) is the only psychopharmaceutical to receive FDA approval for reducing separation anxiety in canines. Off-label veterinary use has included applications for depression, general anxiety, and other behavioral disorders. Clomipramine has been used in human medicine to alleviate obsessive-compulsive disorders and reduce depression. Clomicalm potentiates the effects of serotonin and norepinephrine. The recommended veterinary dosage is 1 3 mg/kg of body weight every 12 hours. Onset is 1 6 weeks. Contraindications include lethargy, sedation, weakness, blurred vision, dry eyes, dry mouth, constipation, nausea, vomiting, seizures, and arrhythmias.
Doxepin (sinequan) is used orally in human medicine to manage depression and anxiety and topically to relieve pruritus (itching) stemming from eczema and other forms of dermatitis. In veterinary medicine, researchers have found doxepin beneficial in managing both general anxiety and thunderstorm phobia. Doxepin prevents the reuptake of serotonin and norepinephrine by presynaptic neurons and reduces the effects of acetylcholine and histamines. Onset occurs in 2 3 weeks. Contraindications include fatigue, sedation, blurred vision, hypotension, constipation, and dry mouth. I do not have veterinary dosages.
Imipramine is used in human medicine to treat depression, juvenile incontinence, adult incontinence, vascular headaches, cluster headaches, and chronic pain. In canine medicine, imipramine is occasionally used to alleviate anxiety. Imipramine potentiates the effects of serotonin and norepinephrine while reducing the effects of acetylcholine. Onset occurs in several hours. Contraindications include drowsiness, fatigue, blurred vision, dry eyes, hypotension, constipation, dry mouth, and arrhythmias. I do not have veterinary dosages.
© Copyright Mark Spivak and Comprehensive Pet Therapy, Inc., February 2007, All rights reserved.