Sertraline (Zoloft®) for Dogs

Updated Feb. 2, 2024
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PetMD’s medications content was written and reviewed by veterinary professionals to answer your most common questions about how medications function, their side effects, and what species they are prescribed for. This content shouldn’t take the place of advice by your vet.

What Is Sertraline for Dogs?

Sertraline is a prescription antidepressant human medication sometimes used in veterinary medicine to help modify certain behaviors associated with fear, anxiety, stress, obsessive-compulsive disorders, and aggression in dogs and cats, as well as house-soiling (inappropriate elimination) in cats.

Sertraline is FDA-approved for human use under the brand name Zoloft® and as generic sertraline. Sertraline is currently not FDA-approved as a veterinary medication. However, it is readily utilized in the veterinary field, and veterinarians can legally prescribe certain human drugs in animals in certain circumstances. This is called extra-label or off-label use because this use isn’t described on the drug label.

In certain circumstances, your vet may recommend a compounded formulation of sertraline. Compounded medications are prescribed if there’s a specific reason your pet’s health can’t be managed by an FDA-approved drug, such as if your pet has trouble taking pills in capsule form, the dosage strength is not commercially available, or the pet is allergic to an ingredient in the FDA-approved medication.

Compounded medications are not FDA-approved. They are created by either a veterinarian or a licensed pharmacist on an individual basis to best suit a patient’s particular needs. You can learn more about compounded medications here.

Sertraline Considerations for Dogs

Sertraline should be used with caution in pets with certain medical conditions, such as diabetes and liver disease, in older pets, and in pets who are hypersensitive to it or to similar medications.

Giving sertraline with certain medications can result in health risks to your pet. If your pet is taking more than one type of medication that also increases serotonin levels in the body, a serious condition known as serotonin syndrome can occur. It is important to discuss your pet’s medications, including vitamins and supplements, and medical conditions with your veterinarian.

Studies have not been performed to evaluate the safety of sertraline in breeding, pregnant, and nursing animals.

Specific monitoring or routine testing while your pet is on this medication may be recommended by your veterinarian depending on your pet's individual needs, other medications they may be on, and/or the issue that initially caused your pet to be placed on this medication.

The Association of Racing Commissioners International (ARCI) has designated sertraline as a Class II substance. Use of sertraline may not be allowed in certain animal competitions. Please check the competition’s rules and regulations before entering your animal while they are taking this medication.

How Sertraline Works in Dogs

Sertraline is classified as an SSRI (selective serotonin reuptake inhibitor). Sertraline works by blocking serotonin, a chemical messenger responsible for affecting mood and behavior, from being absorbed back into the nervous system. This helps to increase the levels of serotonin, thereby decreasing stress and anxiety.

Sertraline Directions for Dogs

Follow the directions on the drug label or as provided by your veterinarian.

It can take several weeks for the full effect of sertraline to be seen.

If your pet has liver disease, your veterinarian may recommend that you give them a lower dosage and administer it less frequently.

If your veterinarian decides to take your pet off this medication, they may recommend that the dose or frequency be slowly decreased over time (tapered) until your pet is no longer on this medication. Make sure to follow all tapering directions closely.

Missed a Dose?

Speak with your veterinarian about what to do if you forget to give a dose of sertraline. Generally, they may instruct you to give it when you remember, or if it is almost time for your pet’s next dose, to skip the missed dose and resume your normal dosing schedule. Do not give extra or double doses.

Sertraline Possible Side Effects in Dogs

  • Decreased appetite (anorexia)

  • Gastrointestinal upset (vomiting, diarrhea)

  • Behavior changes (anxiety, irritability, difficulty sleeping, hyperactivity)

  • Panting (dogs)

Since sertraline can stay active in the body for several days, some side effects may persist even after you have stopped administering the medication to your pet. Side effects may also last for a longer time in animals with liver or kidney disease.

Human Side Effects

Sertraline is also a prescription medication for humans, frequently with dosages different from those prescribed for your pet by a veterinarian. Due to possible side effects, humans should never use medicine dispensed for their pets and pets should not be given any medicine dispensed for a human’s use.

If you accidentally ingest this medication, immediately call your physician or the national Poison Control Center hotline at 800-222-1222.

Call Your Vet If:

  • Severe side effects are seen (see above)

  • Your pet’s condition worsens or does not improve with treatment

  • You see or suspect an overdose

You have additional questions or concerns about the use of sertraline

Sertraline Overdose Information in Dogs

An overdose of sertraline can cause lethargy, sedation, loss of balance, hyperactivity, changes in heart rate and blood pressure, vomiting, diarrhea, loss of appetite, tremors, and increased body temperature.

If you suspect an overdose, immediately contact your veterinarian, seek emergency veterinary care, or call an animal poison control center. Consultation fees often apply.

Pet Poison Helpline (855) 764-7661

ASPCA Animal Poison Control (888) 426-4435

Sertraline Storage for Dogs

Always confirm storage requirements by reading the prescription label. Compounded medications should be stored according to the compounding pharmacy’s label.

Sertraline should be stored at controlled room temperature from 68 to 77 F. Brief excursions from 59 to 86 F are permitted.

Keep the container tightly closed in order to protect the medicine from moisture and light.

Keep out of reach of children and pets.

Sertraline for Dogs FAQs

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

Studies have not been performed to evaluate drug absorption of sertraline in dogs, but it is thought that sertraline takes a few weeks to take full effect. You may notice gradual improvements in your dog’s behavior within several days.

Is dog Zoloft® the same as human Zoloft®?

Yes. Zoloft® (active ingredient sertraline) is FDA-approved for human use and may be prescribed for extra-label or off-label use by veterinarians for animals in certain circumstances. Never give your dog or cat medication intended for human use.

No vet writer or qualified reviewer has received any compensation from the manufacturer of the medication as part of creating this article. All content contained in this article is sourced from public sources or the manufacturer.

Featured Image: shironosov/iStock via Getty Images Plus


Fitzgerald K, Bronstein AC. Selective serotonin reuptake inhibitor exposureTopics in Companion Animal Medicine. 2013;28(1):13-17.

Thomas DE, Lee JA, Hovda LR. Retrospective evaluation of toxicosis from selective serotonin reuptake inhibitor antidepressants: 313 dogs (2005–2010). Journal of Veterinary Emergency and Critical Care. 2012;22:674-681.


Molly Price, DVM


Molly Price, DVM


Dr. Molly Price has practiced small animal medicine for over 20 years and is a graduate of Texas A&M College of Veterinary Medicine. She...

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