Dog Appetite Stimulants: 6 Vet Options and a Dose Chart

A dog who walks away from a full bowl is telling you something is wrong. Loss of appetite is a sign, not a diagnosis, so the first step is always finding out why. If an otherwise healthy adult dog has eaten little or nothing for more than a day or two, book a vet visit. Puppies, older dogs and dogs with an illness such as diabetes should be seen sooner.

Once the cause is being treated, your vet may add an appetite stimulant. Entyce (capromorelin) is FDA-approved to stimulate appetite in dogs. Mirtazapine and cyproheptadine are human medicines that vets use extra-label. Anti-nausea drugs, tempting food and acupuncture round out the six options below, with how each one works, what to watch for, and a sourced dosage chart with a weight calculator.

First, Find Out Why Your Dog Isn't Eating

The Merck Veterinary Manual calls anorexia (not eating) a common sign of many diseases (Merck). An appetite stimulant can get a dog eating again, but it does nothing about a swallowed sock, a rotten tooth or failing kidneys. That is why vets examine the dog first.

Common reasons a dog stops eating include (petMD):

• Stomach and gut problems: an upset stomach, inflammatory bowel disease, ulcers, constipation, or a blockage from something swallowed.
• Organ disease: kidney failure, liver disease, pancreatitis, or diabetes that has tipped into a crisis.
• Pain: dental disease, arthritis or an injury.
• Cancer.
• Medicines and toxins: some drugs reduce appetite as a side effect.
• Stress and change: a move, a new pet or baby, house guests, or cognitive decline in senior dogs.
• The food itself: spoiled food, a sudden diet change, or too many treats. If your dog skips meals but still takes treats, see why a dog won't eat his food but will eat treats.

When to call the vet (petMD):

• Book a visit: an adult dog that has refused food for more than 24-48 hours, or keeps losing interest in food over a couple of days.
• Call right away: a puppy that skips meals, or a dog with a known long-term illness such as diabetes that stops eating. These dogs can't go as long without food.
• Go now: not eating plus vomiting, diarrhea or lethargy; a tight or swollen belly, or yelping when the belly is touched. A dog that won't eat but drinks a lot of water may need emergency care too, so call your vet at the very least.

How Appetite Stimulants Work

They work in one of two ways:

1. Switch hunger back on. Entyce copies ghrelin, the "I'm hungry" hormone from the gut. Mirtazapine and cyproheptadine block certain serotonin and histamine receptors in the brain that help turn appetite down.
2. Remove what is stopping the dog from eating. A dog that feels sick won't eat, even if it never vomits. Anti-nausea drugs, pain relief and treating the underlying disease all work this way.

A quick word on "extra-label" (also called off-label). It means a drug is used in a way the FDA has not reviewed for that species or condition. It is legal and common in veterinary medicine, and it does not mean dangerous. It does mean your vet's directions, not the box, set the dose (VCA Animal Hospitals).

6 Appetite Stimulants for Dogs

1. Entyce (Capromorelin)

Entyce is a flavored liquid made by Elanco and FDA-approved for appetite stimulation in dogs. It is prescription only. Capromorelin binds to the ghrelin receptor in the brain's appetite center, so the dog feels hungry. It also raises growth hormone (Entyce label on DailyMed).

It acts fast. In healthy beagles, blood levels peaked within about an hour, and the drug has a short half-life of about 1.2 hours (label). The field study enrolled dogs from 4 months to 18 years old with all kinds of illnesses (arthritis, gut, dental, heart and kidney disease among them) that had eaten poorly for at least 2 days.

How long can a dog take it? The two main sources word this differently, so here they are side by side:

• Entyce label: "The effectiveness of ENTYCE has not been evaluated beyond 4 days of treatment in the clinical field study."
• Merck Veterinary Manual: its safety data are strong enough that capromorelin has "no treatment duration, age, or weight restrictions" (Merck).

So the study behind the approval lasted 4 days, and Merck sees no safety reason for a fixed limit. How long your dog stays on it is your vet's call.

Side effects in the label study (171 dogs on Entyce, 73 on a look-alike liquid without the drug, 4 days):

So most dogs tolerated it about as well as the placebo, with a little more drooling and thirst. For dogs that drool a lot on it, or won't take liquids, mirtazapine tablets may be an alternative (Clinician's Brief). If drooling seems excessive, see hypersalivation in dogs and tell your vet.

Your vet will be careful with Entyce if your dog has (label):

• Liver disease.
• Kidney disease.
• Heart disease or severe dehydration. Entyce can briefly lower heart rate and blood pressure, and some dogs have shown signs of a slow heart rate or low blood pressure after a dose.
• Diabetes. High blood sugar has been reported after dosing.
• Breeding, pregnancy or nursing. Safe use has not been evaluated.

The label also says to wash your hands after giving it and to keep the bottle where pets can't reach it. Entyce is made for dogs; the mirtazapine section below links our guide for cats.

2. Mirtazapine

Mirtazapine is a human antidepressant (brand name Remeron). Merck explains that it works by blocking alpha-2 and certain serotonin receptors, not by the reuptake route most antidepressants use. It boosts appetite and also settles nausea and vomiting (Merck). Its use in dogs is extra-label.

For years the dog evidence was mostly anecdotal (Clinician's Brief). A 2025 study added real numbers. In hospital records of 107 dogs with poor appetite, 68.6% of dogs given mirtazapine ate better, compared with 37.5% of dogs that did not get it. In a small placebo-controlled trial, all 14 dogs ate on their first day on mirtazapine, versus 7 of 11 on placebo, though the difference faded by day 2. No side effects were seen (Theodoro et al., 2025). Encouraging, but small and short.

Possible side effects (VCA): sleepiness, restlessness or agitation, vocalizing, vomiting, wobbliness, muscle tremors and drooling. VCA says it usually takes effect within 1-2 days.

Who needs extra care: dogs with liver, kidney or heart disease, diabetes or glaucoma, and pregnant or nursing dogs. Mirtazapine must not be given within 14 days of an MAOI drug such as selegiline or amitraz (an ingredient in some tick collars and dips). Combined with SSRIs, tricyclic antidepressants or tramadol, it can in theory contribute to serotonin syndrome (Merck, Clinician's Brief). Tell your vet about every medicine, flea and tick product, and supplement.

Mirtazapine is used even more in cats, including an ointment made for cats that goes on the ear. That story is in our post on mirtazapine for cats.

3. Anti-Nausea Medicines

These are not appetite stimulants in the strict sense, but a dog that feels queasy will turn down food, and often that dog never actually vomits. Treat the nausea and many dogs start eating (petMD).

• Maropitant (Cerenia): FDA-approved for dogs to prevent and treat acute vomiting and to prevent vomiting from motion sickness (Cerenia tablets label). Its label doses and cautions are in our Cerenia for dogs guide.
• Ondansetron: a human anti-nausea drug vets also use. See ondansetron for dogs.
• Meclizine: an antihistamine that calms motion sickness and the dizziness of vestibular (balance) disease, which can put a dog off food. See meclizine for dogs.

Your vet picks the drug and dose based on what is causing the nausea.

4. Cyproheptadine

Cyproheptadine is an older antihistamine that also blocks serotonin. Merck describes it as used in cats as an appetite stimulant; in dogs it is extra-label, and VCA lists it mainly for itchy skin and allergies (Merck, VCA). It can lower the seizure threshold, so it is a poor fit for dogs with epilepsy. Other side effects include sleepiness, dry mouth, vomiting and diarrhea. It should not be combined with mirtazapine without your vet's say-so.

5. Food Your Dog Can't Resist

Merck's own approach starts here: drugs are considered when a sick animal won't take small amounts of very tasty food (Merck). With your vet's OK for your dog's condition (some diseases need a prescription diet), these can help:

• Warm wet food slightly so it smells stronger. Stir well and test it, because microwaves leave hot spots (petMD).
• Offer something tempting on top, such as plain, boneless, skinless cooked chicken, or switch from kibble to canned food.
• Hand-feed a few bites and sit with your dog.
• Feed in a quiet spot, away from noise and other pets (Clinician's Brief).
• Don't put out several new foods at once. Offering lots of different foods can teach a sick dog to dislike them.

Never force food into a sick dog's mouth. It can make the dog dislike food even more, and food can go down the wrong way into the lungs (Clinician's Brief). Ask your vet before adding herbs, supplements or "appetite booster" products.

6. Acupuncture

Some vets are trained in acupuncture and use it alongside standard treatment. Its best evidence in dogs and cats is for pain, and the WSAVA pain guidelines include it as a non-drug option (Vet Sci review, 2022). For a dog that isn't eating because it hurts, easing the pain may help. We found little research on acupuncture for appetite itself, so treat it as an add-on, never a replacement for finding the cause.

What About CBD?

The FDA has not approved cannabis for any use in animals and says it cannot ensure these products are safe or effective (FDA). Merck adds that evidence for cannabinoids as appetite stimulants is limited, and studies of CBD and food intake have been inconclusive (Merck). Talk to your vet before giving any CBD or hemp product, and never give your dog cannabis products made for people.

Other drugs that raise appetite. Steroids such as prednisone and the hormone drug megestrol acetate make dogs hungry as a side effect. Vets use them only in specific situations: Merck warns that long-term steroid use breaks down muscle, and megestrol is not used in pregnant dogs or dogs with diabetes, uterine disease or mammary tumors (Merck). Never give a leftover steroid to spark appetite.

Dog Appetite Stimulant Dosage Chart

Only give what your vet prescribed, at the dose they set. The Entyce numbers come from its FDA-approved label. The mirtazapine numbers are published extra-label doses, and our two sources disagree on how often to give it, so both are shown. For every other drug in the chart, your vet sets the dose.

For information only. These are typical published dose ranges, not a prescription and not medically verified for your pet. Your veterinarian sets the dose after examining your pet. Never start, stop or change a medicine without their OK.

A few things the chart doesn't show:

• Entyce comes with its own syringe. The label dose works out to 0.1 mL of liquid per kg of body weight. Use only the syringe in the box and the volume your vet wrote on the label.
• The label's field study ran 4 days, while Merck sets no duration limit for Entyce (both are quoted in the Entyce section above). Your vet decides how long.
• Merck gives mirtazapine as a set amount per dog by weight band, not an exact per-kg figure. Your vet matches it to the tablets available.
• More is not better. In Clinician's Brief, higher Entyce doses did not increase the effect.

If your dog got into the bottle or the tablets, or you gave the wrong dose, call your vet straight away. If they are closed, call the ASPCA Animal Poison Control Center at (888) 426-4435 or the Pet Poison Helpline at (855) 764-7661.

Side Effects and When to Call the Vet

Mention it at your next check: a little drooling or extra thirst after Entyce, or sleepiness on mirtazapine.

Call your vet soon: vomiting or diarrhea that continues, restlessness or crying out, wobbly walking, or a dog that still isn't eating after a day or two on the medicine.

Call now or go to an emergency clinic: collapse, fainting or extreme weakness, trouble breathing, a seizure, or severe agitation and muscle tremors on mirtazapine, which VCA notes can be signs of serotonin syndrome. Slow heart rate, low blood pressure and loss of consciousness are among the reactions reported after Entyce (Entyce label).

How to Give Medicine to a Dog That Won't Eat

Hiding a pill in food doesn't work when the dog won't touch food. A few options:

• Liquids by syringe. Entyce is made for this: the label says to draw up the dose with the syringe in the box, give it into the dog's mouth, then rinse the syringe and wash your hands.
• Ask about other forms. A compounding pharmacy can sometimes make a medicine into a flavored liquid or chew, or a gel that is rubbed on the inner ear flap. Merck warns that absorption through the skin can be inadequate or variable, which makes results unpredictable (Merck), so let your vet decide.
• Injections. For a dog that is actively vomiting, the Cerenia label recommends starting with the injection so the dose stays down (Cerenia injection label).

If a dog still can't or won't eat enough, vets may place a feeding tube through the nose, the neck or into the stomach. That sounds drastic, but it lets the dog get nutrition and medicine without stress at the bowl while the illness is treated. Merck lists tube feeding as the next step when drugs fail, and nutrition specialists consider nutritional support once a pet has gone more than 3 days without eating (Merck, Clinician's Brief).

Do Appetite Stimulants for Dogs Work?

For many dogs, yes, at least in the short term. In Entyce's field study of 177 dogs, owners reported a better appetite after about 3 days in 68.6% of dogs on Entyce, compared with 44.6% on a placebo liquid (Entyce label). Treated dogs also gained a little weight (1.8% of body weight in 4 days, versus 0.1% on placebo, per Clinician's Brief). The mirtazapine figures are similar but come from smaller studies.

Two honest limits. Nearly half the dogs on placebo also ate better, so a stimulant adds to treating the cause rather than replacing it. And a stimulant alone rarely gets a sick animal eating all the calories it needs (Clinician's Brief). Stimulants work best as a bridge: they buy time while the illness behind the empty bowl gets treated.

So if your dog has gone quiet at mealtimes, start with the vet visit. Find the cause, treat it, and let your vet decide whether Entyce, mirtazapine or an anti-nausea drug should help bridge the gap.

Originally written by Alianna Munakata. Updated by the I Love Veterinary editorial team.

Sources

• DailyMed (Elanco): Entyce (capromorelin oral solution), FDA-approved label, NADA 141-457
• Merck Veterinary Manual: Drugs That Affect Appetite in Monogastric Animals
• DailyMed (Zoetis): Cerenia (maropitant citrate) Tablets, FDA-approved label
• DailyMed (Zoetis): Cerenia (maropitant citrate) Injectable Solution, FDA-approved label
• Merck Veterinary Manual: Drugs Used to Stimulate Appetite (table)
• Clinician's Brief: Drugs Used for Appetite Stimulation in Dogs & Cats
• Clinician's Brief: Nutritional Support for Critically Ill Dogs & Cats
• Theodoro et al. (2025): Evaluation of the Short-Term Effects of Mirtazapine on Appetite Stimulants in Dogs, Animals (Basel)
• VCA Animal Hospitals: Mirtazapine
• VCA Animal Hospitals: Cyproheptadine
• FDA: Regulation of Cannabis and Cannabis-Derived Products, Including CBD
• Veterinary Sciences (2022): Evidence-Based Application of Acupuncture for Pain Management in Companion Animal Medicine
• petMD: Dog Not Eating? Causes and When To Call Your Vet
• petMD: Appetite Stimulants for Dogs
• ASPCA: Animal Poison Control Center
• Pet Poison Helpline

This article is for general information and is not a substitute for advice from your veterinarian.