Clonidine for Dogs

A vet may prescribe clonidine for dogs battling general anxiety and fear-based behaviors, such as leash-reactivity, fear-based aggression, and even separation anxiety. Here’s what you need to know about clonidine for dogs.


Clonidine is a medication worth trying to treat your dog’s anxiety, especially if none of the more popular medicines (such as fluoxetine, trazodone, or clomipramine) prescribed by your veterinarian have worked so far. It’s not one of the first-line medications typically reached for by practitioners, but it just might be the ticket.

Anxiety in dogs manifests in many different ways, some of which can be dangerous to you, other people and even your dog. Anxious, fearful dogs sometimes lash out with aggressive behavior in an effort to create more space for themselves. Others become destructive, potentially injuring themselves. Clonidine can help dogs with severe anxiety and is an ideal adjunct to gentle behavior modification techniques. Clonidine dosages depend upon the dog’s weight and may be adjusted to find the ideal level for an individual dog.

While there are several medications commonly used in veterinary medicine for anxiety, not every drug will work for every dog. Occasionally a medication may have a paradoxical effect in a dog and cause increased agitation. Sometimes the side effect of a medication makes it unpleasant for you or your dog. Often, a combination of medications is necessary, along with behavior modification. The process may require a fair amount of tweaking in the beginning, trying different medications and dosages in order to achieve the desired effect with minimal side effects.

How does clonidine work?

Clonidine is categorized as an alpha-2 agonist. This class of drugs inhibits the release of adrenaline (norepinephrine) in the central nervous system. It is best used as an add-on medication, as opposed to stand-alone help for anxiety.

Adrenaline is the hormone released by the adrenal glands in response to fear, stress, and anxiety. It’s the one responsible for the “fight or flight” response. When something threatens or scares you, what happens? You get an adrenaline rush. Your heart rate increases, your blood pressure increases, your muscles tense up, you feel upset, ramped up, and tense.

The same thing happens in your anxious dog. But by inhibiting the release of adrenaline with clonidine before the dog gets upset we can decrease his arousal and overreaction to triggers. It’s imperative for this medication to be given before the stressful or fear-invoking event. Clonidine inhibits the release of adrenaline, but if your dog is already bathing in the stuff, it’s too late. So be sure to give it 90 minutes before the event. It’s short-acting, wearing off after four to six hours; it can be repeated after six hours if necessary.

When used as part of a long-term behavior management plan for anxiety, clonidine is typically given twice daily, along with a longer-acting anxiolytic (anti-anxiety) medication like fluoxetine or clomipramine. One of the benefits of clonidine is that, as an alpha 2 agonist, it’s in a completely different class of drugs than the other anti-anxiety meds commonly used, so you can conceivably add benefit to your medication protocol without doubling up on side effects specific to each class of drug.

Dosage of clonidine for dogs

Most veterinarians start their canine patients on the lowest effective dose and incrementally increase the dosage as needed. The starting recommended dose is 0.01 milligram (mg) of clonidine per kilogram (kg) of the dog’s body weight, and the maximum is 0.05 mg/kg.

Ideal uses for clonidine in dogs

Clonidine works best for treatment of fear-based behaviors. Examples of these would include separation anxiety, leash reactivity, fear-based aggression, noise phobias (thunderstorms, fireworks), and fear associated with veterinary or grooming visits. For these cases, clonidine can be used “as needed” before the inciting situation. You might give a dose to your dog who suffers from separation anxiety about 90 minutes before you leave. If you walk your leash-reactive dog twice a day, you can pre-medicate him for his walks. Thunderstorms may be difficult to predict in advance, but the Fourth of July is a no-brainer. If your dog struggles during veterinary visits in spite of trazodone and gabapentin, a popular combination prescribed by veterinarians for vet-visit anxiety, ask if adding clonidine is an option.

Dogs with daily stressors that can’t be avoided (for example, if you live by an airport or train tracks and the sounds make your dog anxious) may benefit greatly from adding clonidine twice a day on a regular basis.

Clonidine side effects

The side effects caused by clonidine are not too bad. The biggest one is sedation. Because of this, your veterinarian will start with a lower dose, to see how your dog reacts to it. If sedation is not an issue and the unwanted behavior persists, the dose will be increased. Dry mouth is a known side effect of alpha 2 agonists in humans. Some owners observe side effects of increased water consumption and lip smacking, which may be a consequence of dry mouth in your dog. Alpha 2 agonists lower blood pressure and heart rate. Because clonidine is mild, this is rarely an issue, although caution is advised when used in dogs with cardiovascular disease.

When is clonidine contraindicated?

To avoid compounding effects on blood pressure and heart rate, it is best not to combine clonidine with other alpha 2 agonists, like Sileo (oral dexmeditomidine), a sedative that is sometimes dispensed for use at home, or to be given before vet visits. Clonidine should not be used with monoamine oxidase inhibitors like Anipryl (selegiline), a medication used for treating canine cognitive dysfunction. Make sure your veterinarian knows about all medications that you give your dog.

Clonidine is not a federally controlled substance in the United States. There are no currently approved veterinary products that contain clonidine, which means its use is considered extra-label. This is not unusual for behavior-modifying medications in veterinary medicine. Your veterinarian will discuss the risks and benefits of using this medication off-label, allowing you to give informed consent. Rest assured, clonidine has been used extensively in veterinary medicine and is recommended by veterinary behavior specialists on a regular basis.

A relaxed, calm dog is a happy dog and a wonderful companion. If your dog suffers from fear-based anxiety and the medications that have been prescribed for him are not getting the results you want, ask your veterinarian about adding clonidine to your dog’s medication regimen. It has great potential for promoting calm, which helps your dog handle his stressful challenges.