Dog Behaviour Science Lesson 4 Pharmacology

Transcription

1 Dog Behaviour Science Lesson 4 Pharmacology

2 Introduction This lesson will take an in depth look at the role the pharmacology plays in behaviour modification. This I an advanced topic that should only be handled in depth by a veterinary profession, and a behaviourist should also be involved, so it would be a case that you would currently refer on. However, the use of pharmacology, and its impact on behaviour, is often misunderstood. The goal of this lesson is to introduce you to different medications, and supplementary treatments, so that you have a better understanding of the potential treatments available to domestic dogs. Goals of This Module By the completion of this module you will have gained a superior understanding in how medication works, the different types of behavioural medication commonly used, which medication vets and clients should be avoiding, and the general terminology involved in behavioural medicine.

3 The use of behavioural medication is about creating an effective, scientifically based, multi-focal, integrated and humane treatment program that respects everyone s needs. Dr. Karen Overall world leading canine expert Psycho-pharmaceutical Intervention Therapy It is often said that there are no bad dogs, just bad owners, and commonly we are told that all behaviour problems are due to the way the animal was brought up. While nurture usually is responsible for common behaviour problems, nature cannot be underestimated, and many dogs have been born predisposed to serval behaviour challenges. Dog behaviour issues can often appear very similar to human psychological disorders, and in truth it is likely that they are very similar though in the past many dogs with serious psychological disorders have been euthanized resulting in lower frequencies of psychological disorders seen in dogs, but they do exist. The use of behaviour pharmacology can help these dogs live today by helping their bodies return to near homeostasis. Many think that the use of medication to treat behaviour is wrong, a cop out, sedates dogs, has too many side effects and so on. The industry often looks at the use of medication to treat behaviour as unethical and unnecessary. In many many cases all of the above can be correct. However, once you understand how medication works, how to choose the right treatment and which cases are appropriate then we can see how unethical it can be to NOT treat he animal with mediation. Often training and behaviour modification is tried first, then drugs are a fall back choice. This can often be the case when the client is apprehensive about using medication. However, in many cases, and from experience, you can often regret not

4 using medication earlier to maximise the effectiveness of the training and behaviour problem. The objective of using medication is to manipulate the neural and endocrine activity artificially to mimic natural activity to help an animal return to homeostasis. Whether that is to increase neural activity, create new synapses and connections, increase number of receptors, increase neurochemicals being released, increase hormone molecules available, increasing the frequency of neurochemical release, increasing the duration of availability, and so on to stimulate the cells to function normally.

5 Misconceptions Medication causes sedation. Behaviour pharmacology has been designed not to sedate, which is what helps it stand apart. Drugs are dangerous. When looked after responsibly, and the client is compliant, then the drugs stored safely pose no danger. Medication can alter the dog s personality. Often the behaviour problem is altering the dog s personality. Mediation can help relieve the anxiety / fear / obsession etc. to allow that dogs personality to shine through again. The dog must be on the medication for life. Sometimes true, more often not. This is case by case and often if the dog needs to stay on the medication for life it is because the dog already has an abnormality that the medication is resolving, or the dog s quality of life is substantially decreased if not on medication. Medication is addictive. Some drugs can have addictive tendencies though the dog is always weaned off medication slowly, and the clients vet will discuss this with them, so quality of life should not suffer. Drugs are just a new phase. Once you understand how drugs work you will understand that this is not the case.

6 Why Use Medication Animals neurochemistry wrong. Should the animal have excessively high or low neurochemicals medication can be essential in helping the dog to function normally. The dog s quality of life is not good. If a human was suffering with depression we would recommend counselling with medication, but we often overlook the suffering that animals go through when experiencing behaviour problems such as fear or anxiety. If the animal is suffering the humane option is to find them relief from the suffering in every way possible. If the client is unable to change the behaviour through behaviour modification and management alone we need to be able to help them. When NOT to Use Medication If the client will not be able to responsibly administer, store, and keep track of mediation it can become a risk. If there is a member of the household who has, had, or may potentially abuse medication then many dog behaviour medications cannot be stored safely in this home. If the animals condition does not need it. If the client is not able to afford the medication it may be unethical to recommend medication. Who Can Recommend Medication ONLY a registered veterinary professional can prescribe medication. A certified behaviour consultant may make suggestions to the client, and it is recommended that such recommendations are put in writing for that clients veterinary professional. Often the vet and the behaviourist will liaise and explore options. Veterinary behaviourists are limited in Ireland, so often the dogs vet may have limited knowledge of behavioural medicine, which is where you, or the behaviourist can point them toward literature which backs up recommendations.

7 How drugs work The parts of the brain that we discuss are not independent organs or sections that can be seen visually, but instead they are different cell types that can be identified with staining. The caudate nucleus of the brain, located just above the hippocampus, is a part of the brain where a lot of serotonin connections can be observed. In humans (and assumedly dogs) those with obsessive behaviours have less cells in the caudate nucleus than those without obsessive behaviours, indicating that these individuals are experiencing less serotonin exposure than non-obsessive counterparts. It has been observed in twins where one displays OCD behaviours and the other does not. Different channels of the brain can be observed when looking at different neurochemicals. The role of behavioural medication is to alter the action potentials of chemical pathways which will then alter the motivation for performing behaviours. Put very simply, different medications will generally either Increase or decrease the production of a neurochemical in the pre-synaptic neuron Increase or decrease the duration of time that the neurochemical is available in the synaptic cleft for, which will alter the strength of the connection Alter the receptors on the post synaptic neuron affecting the likelihood of the action potential continuing Drugs do this often in targeted ways, targeting specific proteins to allow them to transport neurochemicals, affecting specific receptors only, affecting neurochemical pumps which recycle drugs and so on. Once you have a generalised understanding of the function of the drug, and the affect that neurochemical has on behaviour, you will be able to picture the impact that the drug may have. Remember, any abnormalities in the dog may affect the function of the drug. For example, if the dog is not producing enough serotonin, adding a drug that increases the post synaptic receptors function may not help massively if there is not enough serotonin available initially.

8 Which Classes of Drugs are used in Veterinary Behavioural Medicine? Benzodiazepines Tricyclic Anti-Depressants (TCA s) Selective Serotonin Re-Uptake Inhibitors (SSRI s) Newer Antipsychotic Agents Noradrenergic / NE reuptake inhibitors (NRI s) Duel Serotonin agonist with serotonin reuptake inhibitors (SARIs) Noradrenergic / NE and specific serotonergic anti-depressants (NaSSAs) Drugs No Longer Recommended Acepromazine (ACP) This is a phenathizine derivative tranquillizer that works via dis associative effects. You can still perceive the stimulus but cannot cognitively put it together. The animal is aware of what is happening but cannot process it correctly, in most cases making it more fearful of future exposures. As it is licenced for use in dogs and cats results in it being the drug of chose for many vets as many can be wary of using off-licence drugs. Dogs on ACP will become extra noise sensitive. Chlorpromazine is almost identical to ACP and should not be used behaviourally (is used to sedate dog s pre-surgery). Phenobarbatol This is a sedative drug that effects the amount of time that channels are open. This drug is also toxic to the liver. Progestins Often used in the past to alter the sexual behaviours of male dogs, but no longer recommended due to side effects.

9 Benzodiazepines Diazepam (Valium) Clorazepate Chlordiazepoxide Alprazolam (Xanax) Oxazepam When choosing which BZ to use for different behaviour issues it very much depends on the dog and often you will trial different medications over several months before the right match is found. As a generalisation, for storms or noises that you know to expect (fireworks, storms etc.) alprazolam or diazepam would be the drug of choice. For situations that trigger panic or extreme distress alprazolam can be best as it can have memory wiping affects. Fear of car rides or visits to the vets or groomers, alprazolam first, then diazepam. If using alprazolam, it should be given 1 hour before event, and it will last for about 6 hours in the dog. Generalised anxiety choose alprazolam and loperamide. Remember, drugs that can have memory loss effects are of course not suitable when the dog is undergoing training. If using SSRI which takes a few weeks to build up, for example in phobias, alprazolam while the SSRI is building up. Can both be continued if necessary.

10 Tricyclic Anti-Depressants (TCA s) Clomipramine is the only TCA licenced for use on animals. Often used for OCD and separation anxiety. TCAs cause a short term increase in serotonin and norepinephrine. It inhibits the reuptake and breakdown of the chemicals. The longer availability of the chemical actually decreases the production of the neurochemical as the neurons can sense the availability of it, but it does continue to stimulate the receptors on the post synaptic neuron which increases its functionality and efficiency. Selective Serotonin Re-Uptake Inhibitors (SSRI s) Fluoxetine is Prozac, and most common SSRI used. Also available for use are sertraline, parozetine, and fluvoxamine. SSRI s cause a short term increase in serotonin. Newer Antipsychotic Agents Beta Blockers These will reduce sympathetic nervous system activity, by slowing down epinephrine. It is used to treat acute anxiety behaviourally (though vets are more familiar with using it for cardiac complications). They also reduce muscle tension, relaxing the muscles while reducing anxiety. Can be administered as needed or all the time. Very minimal side effects. It will also increase serotonin. Beta blockers are used to treat stage fright in humans. Melatonin You may remember melatonin from our endocrine lesson. It is the hormone that triggers sleep and as a medication has some anti-anxiety potential. It is very safe and available over the counter. Clonidine This is initially used to treat blood pressure, but prevents the release of norepinephrine from the pre-synaptic neuron, and is very safe. It is used in storm anxiety, separation anxiety and fear aggression. Great for a noisy brain! There are very minimal side effects.

11 The dosage is dependent on the vet, but maximum would be 0.5mg per kg weight of dog, either as needed or up to twice daily. Start low and administer 90min before anxiety event then gradually inch up. Buspirone Buspirone is a new, smart drug. It will attach to the serotonin receptors on the postsynaptic neuron, and has a targeted impact, so it will do maximum specific work with minimal side effects. It will also increase dopamine and norepinephrine activity. It has been recommended for generalised anxiety. It can be taken for immediate effects in high dosage (e.g. for car rides). For general anxiety it is taken in slow dosages and built up in the system over 2 weeks to allow for constant impact.

12 Guidelines If ineffective, try at least three! When a vet works with a client with behaviour problems, it is usual to try the most likely medication first, but to be prepared, and know when, to move on and try another, as each dog is an individual and there is no one size fits all Full Veterinary Assessment Prior It is unacceptable to treat a dog with behaviour problems medically (or behaviourally) without first having a thorough medical check-up. The vet is looking for any sources of pain, or evidence of endocrine disorders / disease / infection or abnormalities. Teach People to Take Pulse It is recommended that the vet teach the client to take a dog s pulse, so that they can monitor the animal as the medication kicks in. Any increase or decrease in pulse can then be reported to the vet though in reality side effects are very minimal when correct dosage administered. Client MUST Be Organised The client must realise how important drug timing, commitment, and dedication is, especially during the changeover between drugs. They must also be aware of side effects so they can watch out for them and report back to the vet.

13 Ongoing Monitoring This is essential, and should be holistic. The client, the behaviourist and the vet should be in constant communication. Ongoing bloodwork is often necessary to monitor effect of the drug, and behaviour changes should be logged and reported. The client should be encouraged to keep a check sheet, when and how much medication administered, behaviours observed, environmental changes and so on so that the true impact of the medication can be recorded. Behaviour Modification Essential Medication can help to speed up learning, new neural connections, and recovery in the animal. Using medication without behaviour modification is foolish, minimises success, and can be unethical.

14 Rough Guideline *Remember, every dog is an individual Mild anxiety Mild anxiety but dog becomes sedate on above drug Social phobia Panic / Generalised anxiety Outburst aggression and anxieties Ritualistic behaviours with anxiety Amitriptyline nortriptyline paroxetine Sertraline Fluoxetine clomipramine Further recommendations as per Karen Overall Treating various forms of Anxiety PUFAs daily Gabapentin daily Alprazolam daily SARI s daily SSRI daily Zylkene Harmonaese Anxitane Affect GABA receptors Affects glutamate transporters Treating fear PUFAs daily Gabapentin daily Alprazolam situationally Trazodone daily TCA/SSRIs daily Zylkene Anxitane Harmonaese Anxitane Affect GABA receptors Affects glutamate transporters Treating Panic PUFAs daily Gabapentin daily Alprazolam situationally or daily if preventative Clonidine TCA/SSRIs daily Affect GABA receptors