Most behavioral conditions in small animals arise from stress and anxiety. These include aggression, inappropriate urination, lick granuloma, separation anxiety, and storm and other phobias. Herbal medicines provide a number of interesting alternatives to conventional veterinary mood-modifying drugs. The approach depends upon the nature of the behavioral disturbance and the severity and duration of the condition. Other perpetuating factors and health issues such as pain or endocrine disturbances, which can contribute to aggression and anxiety, must be considered.
Nervines are the traditional class of herbs employed for emotional conditions in humans, and they have applications in veterinary medicine, too. Nervines can be further classified. Nervine relaxants have anxiolytic, sedating, or hypnotic activity. They include herbs such as Valerian, Hops, Lavender, Lemon balm, and Passion flower, and may be prescribed for anxiety, hyperactivity, restlessness, and irritability. Nervine stimulants are perhaps the least used group in veterinary medicine, but they may be beneficial for a depressed or hypoactive nervous system. They may be used extensively by veterinary staff in the form of tea and coffee. Others, such as Kola nut and Guarana, can induce anxiety and tension. Perhaps the most useful one in practice is St. John’s wort (Hypericum performatum), which can be helpful in mild depression. Adaptogens should also be considered for animals where stress is a cause or outcome of the condition.
What is most surprising about herbal medicine is the fact that herbs have actives that just happen to bind to and interact with neurotransmitter receptors in animals (and humans). For example, American ginseng extracts may regulate GABA-ergic neurotransmission. Withania extract contains a constituent with GABA-mimetic activity. Chamomile oil also affects GABA-ergic activity. In Chinese medicine, Dan Shen is used to “Nourish the Heart and Calm the Spirit” and has been shown to bind to the same sites as benzodiazepines on the γ-aminobutyric acid (GABA) receptor complex. Baicalin and Baicalein in Baical skullcap (Scutellaria baicalensis) and Skullcap (Scutellaria lateriflora) are also known to bind to the benzodiazepine site of GABA-A.
The lignan hydroxypinoresinol, a constituent of Valerian, binds benzodiazepine receptors and Valerenic acid inhibits the breakdown of GABA. Aqueous extracts of valerian root contain significant amounts of GABA, though oral bioavaibility of this neurotransmitter is unknown. St. John’s wort has a number of constituents thought to be active neurochemicals. Hypericum extract is theorized to indirectly activate sigma receptors. Hyperforin leads to non-selective inhibition of uptake of many neurotransmitters, as well as interaction with dopamine and opioid receptors.
In addition to appropriate behavioral modification, the following herbs can help address behavioral conditions in veterinary practice.
- 1 Ashwaganda (Withania somnifera)
- 2 Bacopa (Bacopa monniera)
- 3 Skullcap (Scutellaria lateriflora) and Baical skullcap (Scutellaria baicalensis)
- 4 Chamomile (Matricaria recutita)
- 5 Lemon balm (Melissa offtcinalis)
- 6 Passion flower (Passiflora incarnata)
- 7 Kava kava (Piper methysticum)
- 8 St. John’s wort (Hypericum perforatum)
- 9 Valerian (Valeriana offtcinalis)
- 10 California poppy (Eschscholzia californica)
Ashwaganda (Withania somnifera)
Withania is a very useful adaptogen for animals suffering from stress of any kind. The species name somnifera refers to the Latin word for sleep; it is a relaxing nervine. Several studies support the use of Withania in nervous exhaustion due to stress and in cachexia to increased body weight. The use of withania as a mood stabilizer in clinical conditions of anxiety and depression has been supported by studies. Withania alkaloids have exhibited a taming effect and a mild depressant (tranquilizer) effect on the central nervous system in cats, dogs, monkeys, rats, and mice.
Bacopa (Bacopa monniera)
Bacopa reduces anxiety, pain, and depression in laboratory animals. In rats, a standardized extract of bacopa (5, 10, and 20 mg / kg) was found to be comparable to the anxiolytic activity of lorazepam at 0.5 mg / kg IP. It was also comparable to the anti-depressant activity of imipramine in a rat model of depression using a standardized methanolic extract of bacopa (bacoside A) at 20 and 40 mg / kg PO once daily for 5 days. Significant improvements in visual information processing, learning rate, anxiety, and memory consolidation were found following bacopa administration in a double-blind, placebo-controlled clinical trial of people. They were tested after 5 and 12 weeks of administration of 300 mg of bacopa or placebo daily.
Traditionally, Skullcap has been used to treat epilepsy and nervousness. Both species of Skullcap have the constituents baicalin and baicalein. S. lateriflora demonstrated anxiolytic effects in rats in an observation study in which they spent more time in the center of an “open-field arena” in a maze test, indicating reduced anxiety. A double-blind, placebo-controlled study of healthy human subjects showed that the effect of Skullcap on anxiety was pronounced, and results were superior to the placebo. The flavonoids Baicalein, Baicalin, and Wogonin (in Baical skullcap) have anxiolytic effects similar to diazepam but without the typical adverse effects (sedative and myorelaxant) of benzodiazepines.
Chamomile (Matricaria recutita)
In mice, the constituent Apigenin showed anxiolytic activity without sedation, muscle relaxant effects, or anticonvulsant action. A mild sedative effect was gained with a 10-fold increase in dosage. The oil had significant sedative effects in mice, and inhaling Chamomile oil vapor decreased stress-induced increases in the plasma adrenocorticotropic hormone (ACTH) level in rats.
Lemon balm (Melissa offtcinalis)
A randomized, placebo-controlled, double-blind, balanced crossover study in healthy, young human subjects using a high dose (1,600 mg) suggests that Lemon balm can improve cognitive performance and mood; the most notable effects were improved memory and increased calmness. 42 patients with mild to moderate Alzheimer’s disease in a 4-month, parallel-group, placebo-controlled trial were given 60 drops daily (equivalent to 1,500 mg per mL) of an extract in 45% alcohol. Compared to the placebo, the Lemon balm extract produced a significantly better outcome in terms of cognitive function, and agitation was more common in the placebo group. The essential oil of Lemon balm was investigated for agitation in people with severe dementia in a placebo-controlled trial. Seventy-two people with clinically significant agitation with severe dementia were randomly assigned to aromatherapy with Melissa essential oil or placebo (sunflower oil). Sixty percent of the active treatment group and 14% of the placebo-treated group experienced a 30% reduction in agitation, and quality of life indices were significantly greater in the treatment group.
Passion flower (Passiflora incarnata)
Passion flower is a traditional herb used to treat patients with nervous disorders. The methanol leaf extract of P. incarnata exhibited significant sedative, anticonvulsant, and CNS-depressant activities at 200 mg / kg, as well as analgesic and anti-inflammatory activities in mice. Anxiolytic effects were demonstrated with methanol extracts of leaves, stems, flowers, and whole plants at 100, 125, 200, and 300 mg / kg, respectively. Roots were practically devoid of anxiolytic effects. Passion flower (45 drops per day) had comparable anxiolytic effects to oxazepam (30 mg / day) in a double-blind, randomized trial of 36 humans with generalized anxiety disorder. Oxazepam provided a more rapid onset of action but a significantly greater number of adverse effects related to impaired job performance. This study suggests that Passion flower is an effective treatment for the management of generalized anxiety disorder.
In the Pacific Islands there is a long tradition of Kava consumption for its mind-altering effects. A meta-analysis reviewing the effectiveness and safety of Kava extract for treating anxiety suggested a significant reduction in anxiety in patients receiving Kava extract compared with placebo. Adverse events were mild, transient, and infrequent. It was concluded that Kava extract is an effective symptomatic treatment option for anxiety and is relatively safe for short-term treatment (Pittler 2003). In 50 patients with nonpsychotic anxiety, a placebo-controlled double-blind outpatient trial showed Kava at 50 mg 3 times daily was a safe and effective treatment and was well tolerated. A randomized, reference-controlled, double-blind, multicenter clinical trial concluded that Kava kava is as effective as buspirone and opipramol in the acute treatment of generalized anxiety disorder and is well tolerated. In mice, Kava extract demonstrated anxiolytic-like activity and a reduced locomotor activity.
St. John’s wort (Hypericum perforatum)
St. John’s wort was found to produce significant positive responses for mild to moderate depression in a meta-analysis that reviewed 37 randomized, double-blind, controlled trials. St. John’s wort was more effective than a placebo but not for severe depression. However, it was as effective as conventional antidepressants for mild to moderate depression. In another review of 38 trials, representing 34,804 patients, adverse events were mild and transient in almost all cases. In a study of 12 people with obsessive compulsive disorder, treatment with 450 mg of 0.3% hypericin twice daily for 12 weeks, 5 of 12 patients were much or very much improved, 6 were minimally improved, and 1 exhibited no change. Significant change was noted at 1 week and continued to increase in the responsive patients.
Valerian (Valeriana offtcinalis)
Valerian has traditionally been used for insomnia, anxiety, maniacal and aggressive behavior, and seizures. A constituent of Valerian binds the 5-hydroxy tryptamine receptor area of the brain implicated in the sleep-wake cycle. A review of Valerian for insomnia concluded that studies were inconsistent and that Valerian needs further study. One trial showed equal efficacy for Valerian (600 mg / day) when compared to oxazepam for the treatment of insomnia. When Valerian is used for insomnia, it does not work immediately. The onset of action is generally 2 to 3 weeks after beginning supplementation. In a double-blind trial, adults who were given Valerian in laboratory social stress tests reported reduced symptoms of anxiety. In another randomized, double-blind study, 270 mg daily of a standardized Valerian extract was as effective and well tolerated as clobazapam in people with various anxiety syndromes. Cats administered Valerian extract (10 mg / kg) by gastric lavage showed significant decreases in restless, fearful, and aggressive behaviors.