Mirtazapine Use in Dogs As an Appetite Stimulant

Mirtazapine is used as an aperitif for dogs and cats that refuse to eat. It is also prescribed for long-term treatment of various patients suffering from nausea, vomiting and anorexia.

Your dog normally bounds to his food dish at dinner time, tail wagging, and ready to dig in. But when pets are suffering from serious diseases like liver failure or cancer, they may turn up their noses at even the most tempting treats. To ensure your dog gets good nutrition as she goes through treatment, your vet may prescribe an appetite stimulant to help revive interest in food.

Mirtazapine for dogs
Mirtazapine, whose brand name is Remeron, was developed as an antidepressant in humans. But in dogs and cats, it is often used to help persuade them to eat.

Mirtazapine stimulates neurotransmitters in the brain related to relaxation. At the same time, the drug acts on the nerve receptors of the stomach and intestine and provides anti-nausea relief. Taken together, these procedures provide an effective stimulus to the dog’s appetite.

Mirtazapine treats cases where dogs have bad appetite and nausea, and also includes gastrointestinal diseases, kidney and liver diseases. The drug is also used as a dog’s appetite stimulator for dogs treating cancer, especially those undergoing chemotherapy. Mirtazapine can also be used to treat behavioral problems, from separation anxiety to urination inside. Once the dog’s appetite returns, mirtazapine is stopped.

Mirtazapine administration
Mirtazapine is available in the form of tablets for dogs and cats. The transdermal gel absorbed by the skin of the ears is approved for cats only. Mirtazapine tablets are available in 7.5 mg, 15 mg, 30 mg, and 45 mg. The dose is determined by weight, and dogs usually take 3.75 to 30 milligrams a day.

One type of mirtazapine tablet dissolves in the mouth, but it may contain xylitol, which can be toxic to dogs. Also, when a dog has liver or kidney disease, its body may disinfect the drug more slowly, and the veterinarian may prescribe a 30 percent lower dose than is usually given to a dog of the same size.

Give your dog mirtazapine at about the same time every day. If you miss a dose, give it as soon as possible, but not if the next dose is about to end. It may take several weeks before the effect of mirtazapine begins fully.

Remeron side effects
The most common side effect of mirtazapine is drowsiness caused by its antihistamine properties. Another possible side effect is skin irritation and redness.

One of the less common side effects of Remeron, called Serotonin Syndrome, occurs if brain levels of Serotonin rise too high. Symptoms of this potentially serious syndrome include tremors, tremors, miosis, increased heart rate, increased body temperature, high blood pressure, and difficulty breathing. Some dogs will become hyperactive if they have Serotonin Syndrome. Cyproheptadine can be used as an antidote.

Mirtazapine can cause bone marrow abnormalities. While the drug can still be used as an aphrodisiac in dogs with leukemia, low platelets, or other blood disorders, it requires more vigilant monitoring. Care should also be taken when giving the drug to pregnant or lactating dogs. Talk to your veterinarian about any side effects that irritate or appear severe to your dog.

Drug interaction
Medications that inhibit Monoamine Oxidase-A (MAO-A inhibitors) interact with mirtazapine, which increases the risk of Serotonin Syndrome. While MAO-A inhibitors are rarely prescribed as a medicine for dogs, the active ingredient in some anti-scabies and scabies products contains amitraz, which is the MAO-A inhibitor. One example is the protective tick collar. Dip Metaban used to kill scabies mites also contains amitraz.

Serotonin syndrome is also a risk when taking mirtazapine with selective serotonin reuptake inhibitors (SSRIs), such as Prozac. Another drug interaction that increases the risk is opioid tramadol.