Trazodone for Dogs: Uses and Side Effects

A vet may prescribe trazodone for dogs who struggle with phobias, situational anxiety, or other behavioral issues. While trazodone may make these dogs less anxious, giving a new medication can be a bit anxiety-inducing for dog parents. To help you feel prepared, integrative veterinarian Dr. Julie Buzby explains the uses, dosage, side effects, and precautions for trazodone for dogs.

Phobias. Fireworks. Separation anxiety. Other anxiety-inducing situations. Sometimes when your dog is feeling nervous, help comes partially in the form of anti-anxiety medications like trazodone for dogs.

What is trazodone for dogs?

While trazodone is actually FDA approved as a human medication, veterinarians often prescribe trazodone off-label for dogs with anxiety disorders. In the past, you might have recognized trazodone by the brand names, Desyrel®, Oleptro®, and Trialodine®. However, these brand name products are now discontinued due to the availability of generic trazodone. 

Can you buy trazodone without a prescription?

Trazodone is a prescription medication, meaning you cannot buy it over the counter. Sometimes your veterinarian may send it home with your dog after an appointment or surgery. Other times, your vet may have you pick up the trazodone at a local human pharmacy since it is also a human drug.

What does trazodone do for dogs?

The anti-depressant and anti-anxiety drug trazodone is a serotonin antagonist reuptake inhibitor (SARI). In other words, trazodone blocks the receptor that is responsible for pulling circulating serotonin back into the nerve cells.

As a result of this blockade, the levels of “active” serotonin in the brain are higher. This translates to lower anxiety levels and a calmer dog because serotonin, the “happy hormone,” is a chemical messenger that works to stabilize mood. Interestingly, serotonin also has effects on sleep function, blood clotting, body temperature, and gastrointestinal health, but those aspects are less relevant here.

What is trazodone used for in dogs?

In veterinary medicine, dogs may take trazodone for any number of behavioral disorders. But the most common indications are anxiety and phobias. Unlike other anxiety medications that can take several weeks to make an obvious difference, trazodone works rapidly—often within one to two hours.

This makes it a great anti-anxiety medication for short-term use during stressful events. Plus, vets or veterinary behaviorists may find it helpful for situations where other therapies and medications have not been helpful.

Trazodone is commonly prescribed to help a dog with:

• Separation anxiety
• Noise phobia (e.g., storm noises, fireworks, construction, etc.)
• Veterinary visits, during a hospital stay, or before nail trims
• Travel (e.g. riding in cars or flying on airplanes)—anxiety can contribute to dog car sickness
• New situations (e.g., first time at doggy daycare or in boarding)
• New people or pets (when company comes over or you add a pet to the household)
• Generalized anxiety
• Keeping a dog calm after surgery or injury
• Sundowners in dogs (because some sundowning dogs become very anxious)
• Other behavioral concerns

What is the trazodone dosage for dogs?

When prescribing trazodone for those situations, the vet will base the dosage on your dog’s bodyweight. He or she may choose to calculate the dose on a mg/kg basis or consult a dosing chart. Since there is a wide effective dose range, it may take some trial and error to find the right trazodone dose for your dog.

Typically, the vet will start on the lower end of the dosage range, then gradually increase the amount based on your dog’s initial response. In other words, if there appears to be very little change in your pup’s anxiety, your dog’s doctor might tell you to increase the frequency or the amount of the trazodone.

How often can I give my dog trazodone?

Sometimes the vet will prescribe trazodone for use on an “as needed basis.” For example, your vet may tell you to give one dose of trazodone the night before a stressful event. And then he or she may have you give another dose about 90 minutes prior to the event.

If this strategy doesn’t work well, the vet may change the dose or timing the next time. Or he or she may suggest using a different medication like alprazolam or adding an additional medication like gabapentin.

Additionally, if your vet prescribed trazodone to help with your dog’s travel anxiety, he or she might ask you to give a “test dose” during the several days leading up to the trip. This allows you to figure out if your dog becomes adequately calm and see if he or she experiences any adverse effects. Then, based on the “trial run,” your vet can change the dose, directions, or medications as needed prior to the trip.

Using trazodone on a regular basis

In other situations, your vet may recommend giving trazodone two or three times a day on a regular basis. For example, this might be the case if the goal was using trazodone to facilitate post-surgical confinement in dogs or reduce generalized anxiety. Once again, it is beneficial if you give feedback on how your dog is doing at that dose of trazodone. That way your vet can change the dose if indicated.

Can a dog overdose on trazodone?

No matter whether your dog is taking trazodone occasionally or daily, it is important to follow the label instructions. Do not modify your dog’s trazodone dose on your own or share your prescription of trazodone with your dog. This is critical because while the dose range is large, it is possible for a dog to overdose on trazodone.

Signs of a trazodone overdose in dogs include:

• An unsteady gait (i.e. ataxia)
• Disorientation
• Urinary incontinence
• Seizures
• Tremors
• Changes in heart rate or blood pressure
• Depression

If you see these signs, contact your vet or bring your dog in for an emergency vet visit immediately.

Additionally, if you accidentally give your dog more trazodone than what is recommended on the prescription label, it is best to seek veterinary advice. To get help, you can call your regular veterinarian, your local emergency vet, or an animal poison control center like the Pet Poison Helpline or the ASPCA Animal Poison Control Center. (A fee may apply when calling an animal poison control center.)

How do you administer trazodone?

When you get ready to give the trazodone to your dog, you will notice that it typically comes in 50 mg, 100 mg, 150 mg, or 300 mg tablets for oral use. However, if your dog won’t take pills, your vet can contact a compounding pharmacy about making trazodone into a liquid or chewable tablet.

To help increase its absorbability, it is best to give your dog the trazodone with food or a small treat. Trazodone can still work on an empty stomach. But giving it with food can increase its bioavailability (i.e. amount of drug that enters circulation) by 20 percent. 

How long does it take for trazodone to work in dogs?

For the average dog who needs short-term relief of anxiety, it takes about one to two hours for trazodone to kick in. And when used daily as a long-term anxiety management strategy, trazodone takes about two to three weeks to reach maximal efficacy. This is relatively quick compared to other anti-anxiety medications like fluoxetine, which can take four to six weeks to achieve the full effect.

How long does trazodone last in dogs?

Generally, the effects of trazodone will last several hours. And a single dose should wear off completely within 24 hours from the time of administration. However, if your dog has been taking trazodone more frequently, it can take longer for the effects to wear off.

Also, trazodone is one of many medications that relies on the liver and kidneys for clearance from the body. This means that the effects of trazodone can last longer than normal if your dog has liver disease in dogs or kidney failure in dogs.

What are the side effects of trazodone in dogs?

While preparing to give your dog trazodone, you may also want to be aware of any potential side effects. Thankfully, studies indicate that about 80 percent of dogs taking trazodone will experience no side effects. Also, since it is a short-acting medication, any unexpected side effects will likely wear off after several hours.

Trazodone side effects in dogs can include any of the following:

Vomiting

Trazodone can upset a dog’s stomach and cause vomiting, especially when given on an empty stomach. Typically, giving the trazodone with food is an easy solution for this problem.

Diarrhea

Since trazodone may cause colitis (i.e. inflammation of the colon), you might notice your dog is having diarrhea but acting fine.

Gagging

Your dog may make a gagging or retching sound. It may or may not be accompanied by vomiting.

Agitation or increased anxiety

Occasionally trazodone has the opposite effect than intended and actually makes the dog more anxious or agitated.

Aggression

It is important to use caution when giving trazodone to dogs with aggressive tendencies because it could potentially contribute to behavioral disinhibition (i.e. dog doesn’t stop him or herself from doing an undesirable behavior like biting). This is a risk with many behavior-modifying or anti-anxiety drugs, not just trazodone.

Increased appetite

Your dog may seem hungry all the time, start counter surfing, or raid the trash.

Sedation or lethargy

Some sedation is common with certain dosages of trazodone, and that isn’t necessarily a bad thing if the dog is recovering from surgery or facing a stressful event. However, if you don’t know that your dog might be acting a bit sleepy or spacy or being a lethargic dog, it can throw you off.

Hypersalivation

Your dog might be drooling more, or you may notice your dog keeps licking his or her lips.

Increased panting

Even when it is not warm out or your dog hasn’t recently exercised, he or she may still be panting. Sometimes he or she might also be panting and pacing.

Ataxia

Dogs who received a higher dose of trazodone IV did show some ataxia (i.e. wobbly gait), in a small study, but dogs receiving the same amount by mouth did not become ataxic. (The same was true with arrythmias—they were present in dogs who got the dose IV but not by mouth).

Urine retention, urinary accidents, or increased urge to urinate

At this time, the verdict is out on whether changes in urination are truly a side effect of trazodone in dogs. In humans, trazodone can cause urine retention or an increased urge to urinate. However, it isn’t known if the same is true for dogs, or if the urinary changes some dog parents may report are unrelated to trazodone.

An additional explanation is that if the dog is more sedate due to the trazodone, it is possible that he or she may awake from a deep sleep, suddenly realize he or she desperately need to urinate, and not be able to make it outside in time. The end result could be a urinary accident or leaking urine.

Withdrawal side effects

Also, if your dog has taken trazodone regularly for many weeks or months, and you suddenly stop giving it to him or her, there may be an increased risk of anxiety, agitation, and trouble falling asleep. Therefore, it is important to slowly wean dogs off of trazodone to prevent these withdrawal side effects.

Serotonin syndrome in dogs

All of the common side effects we discussed up to this point are fairly mild and should not be life-threatening. However, when trazodone is combined with other anxiety medications like fluoxetine, sertraline, or selegiline for dogs, there is an increased risk of developing a disorder called serotonin syndrome. This dangerous disorder occurs when there are excessive amounts of circulating serotonin.

Besides the symptoms mentioned above, other signs of serotonin syndrome in dogs can include:

• Difficulty breathing (i.e. a dog who is breathing fast)
• Dilated pupils or blindness
• Excessive salivation
• Hypotension (i.e. low blood pressure)
• Elevated heart rate or abnormal heart rhythm—which is why knowing how to check your dog’s vital signs is important
• Hyperthermia (i.e. higher body temperature)
• Disorientation and abnormal gait (i.e. ataxia or a dog who is wobbly and off balance)
• Seizures in dogs
• Coma and/or death

If any of these more serious side effects occur, you should contact your veterinarian immediately. Typically, he or she will instruct you to take your dog to the clinic or an emergency veterinary hospital.

Can trazodone be administered with other medications?

This risk of serotonin syndrome emphasizes the importance of informing your vet about any medications or supplements that your dog may be taking. While there are plenty of situations where it may be safe to give trazodone at the same time as another medication or supplement, there are other times when it can be quite dangerous.

Trazodone and gabapentin for dogs

Trazodone can safely be prescribed with gabapentin for dogs, and this is a fairly common combination for some situations. To understand why they play well together, it is helpful to know that veterinarians use gabapentin in dogs to relieve pain (especially nerve pain), control seizures, and reduce anxiety.

So sometimes there may be a situation where a dog is already taking gabapentin for pain and the vet will want to add on trazodone for situational anxiety. Or there may be cases where your vet asks you to give gabapentin and trazodone simultaneously prior to a veterinary appointment if your dog is fearful and aggressive.

Since both these drugs can cause sedation, please keep in mind that using trazodone plus gabapentin may cause your dog to be even more sedate than giving either drug on its own. This isn’t necessarily a bad thing, just something to be aware of.

Does trazodone help with pain in dogs?

Trazodone has one main sphere of action—controlling anxiety and promoting calmness. Unlike gabapentin, trazodone does not help with the physical sensation of pain in dogs in a significant way. However, since there is also a psychological aspect of pain, trazodone can help painful dogs be less anxious from the pain.

Remember though, if you are seeing signs your dog is in pain, please reach out to your vet for advice rather than reaching for the trazodone. There are more effective options for pain control in dogs than trazodone on its own.

Trazodone and other drugs: unsafe combinations

As we just mentioned, combining trazodone with some anxiety and anti-depressant medications can be dangerous due to the risk of serotonin syndrome. This is particularly the case for medications like selective serotonin reuptake inhibitors (SSRIs) and monoamine oxidase inhibitors (MAOIs) because they also increase serotonin levels. Therefore, dogs who are on other anxiety medications should not take trazodone unless directed by a veterinarian or a board-certified veterinary behaviorist.

Also, since trazodone can have a mild sedative effect, be careful when using it with other calming medications and supplements. This combination can lead to excess sedation or central nervous system depression.

Studies also suggest that giving trazodone with non-steroidal anti-inflammatory drugs (NSAIDs) or anticoagulant medications may increase the risk of gastrointestinal ulcers and bleeding. Additionally, you need to be cautious giving trazodone to a dog who is taking any of the following prescriptions:

• Antibiotics (especially fluoroquinolones and macrolides)
• Antifungal medications (e.g., ketoconazole)
• Blood pressure medications (e.g., digoxin)
• Diuretics (e.g., furosemide)
• Prokinetic drugs (e.g., metoclopramide, cisapride)
• Tranquilizers (e.g., acepromazine)

Which dogs should not take trazodone?

In addition to being cautious when prescribing trazodone for use with certain medications, there are also a few situations in which trazodone is contraindicated.

If your furry friend has had problems taking trazodone in the past, it is best to avoid using it. Instead, ask your vet for other recommendations regarding your dog’s anxiety. This may involve trying other medications, calming supplements, or environmental modifications.

Since trazodone can lower blood pressure, it should be avoided in cases of heart disease in dogs. Also, trazodone may worsen glaucoma in dogs, a condition where the pressure inside of the eyes is higher than normal. Finally, if the liver or kidneys are impaired, it may be more difficult for trazodone to be metabolized by the body, thus causing lingering effects.

In reproductive studies for animals, very high doses of trazodone negatively affected fetal development. And there currently isn’t any information available that describes the safe use of lower-dose trazodone in pregnant or lactating dogs. Therefore, it may be best to avoid trazodone in these cases unless your vet determines the benefits outweigh the risks.

Talk to your vet about trazodone for dogs

If a long car trip, going for a vet visit, or having company over is stressing out your dog, why not talk to your vet about trazodone? It is generally safe for dogs, works quickly, and is well-suited for situational anxiety. Hopefully, with a bit of trazodone your dog can start feeling more relaxed in those situations. And you can feel better knowing that your dog isn’t so anxious anymore.

How has trazodone helped your dog’s anxiety?

Please comment below.