Melatonin (Melatonex®) for Dogs and Cats

Melatonin (Melatonex®) for Dogs and Cats

melatonin for dogs and catsmelatonin for dogs and cats
melatonin for dogs and catsmelatonin for dogs and cats

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Overview of Melatonin for Dogs and Cats

  • Melatonin, also known by the names of Melatonex®, Dermatonin® and Regulin®, is used to help manage separation anxiety and other fearful conditions, such as noise phobias in dogs and cats, suppress heat cycles in cats, help with hair loss disorders in dogs, as well as other uses.
  • Behavioral disorders in dogs and cats are a common reason for veterinary visits. Unacceptable or dangerous animal behavior problems are also a common reason why owners elect to have their pets euthanized.
  • Recently, veterinarians have placed greater emphasis on training and behavior, and specialists working in the field of animal behavior have increasingly adopted drugs used in human behavior for animal use. Melatonin is one of those drugs.
  • Melatonin is a neurohormone and is also an antioxidant that combats “free radicals.” Free radicals have been attributed to brain deterioration.
  • Melatonin is best known for its ability to regulate body rhythms and reproductive cycles, but it also appears to have uses as a sedative and anti-convulsant.
  • Melatonin is available over the counter but should not be administered unless under the supervision and guidance of a veterinarian.
  • This drug has not been specifically approved for use in animals by the Food and Drug Administration (FDA), but may be prescribed legally by a veterinarian as an extra-label drug.

Brand Names and Other Names of Melatonin

  • This drug is registered for use in humans only.
  • Human formulations: Melatonex® (SunSource) and various other generics
  • Veterinary formulations: Rerretonin® (marketed for ferrets), Dermatonin®, PrimeX® marketed for use in mink, Regulin®

Uses of Melatonin for Dogs and Cats

  • There are many uses of melatonin, some with more scientific proof than others.
  • Melatonin is used to help manage separation anxiety in dogs and cats as well as sleep cycle disorders and cognitive dysfunction in older pets.
  • Melatonin is used in mink to accelerate their fur growth.
  • Melatonin can be used to suppress estrus (heat cycles) in cats.
  • It is also used to treat other fearful conditions, such as noise phobias.
  • Melatonin is used in dogs to treat some causes of alopecia (hair loss) such as Alopecia X, canine pattern baldness and canine flank alopecia.
  • Melatonin has also been used in dogs with platelet disorders such as idiopathic thrombocytopenia (ITP).
  • Melatonin has been used to help induce sleep in pets that are hyperactive at night and to treat elderly pets suffering from an impairment in their biological clock (resulting in so-called “sundowner syndrome.”)

Precautions and Side Effects

  • While generally safe and effective when prescribed by a veterinarian, melatonin can may side effects in some animals.
  • Melatonin should not be used in animals with known hypersensitivity or allergy to the drug.
  • Melatonin has very few side effects and is very safe. However, it may disrupt desirable hormonal influences in bitches.
  • Melatonin may interact with other medications. Consult your veterinarian to determine if other drugs your pet is receiving could interact with melatonin. Such drugs include sedatives and tranquilizer, monoamine oxidase inhibitors and corticosteroids.

How Melatonin is Supplied

  • Melatonin is available as a 300 mcg, 1mg and 3 mg tablets.
  • Melatonin is also in implants in sizes 2.7 mg, 5.4 mg, 8 mg, 12 mg and 18 mg.

Dosing Information of Melatonin for Dogs and Cats

  • Medication should never be administered without first consulting your veterinarian.
  • For small dogs, melatonin is dosed at 0.5 to 1 mg per dog orally whenever necessary up to every 8 hours. For medium-sized dogs, melatonin is dosed at 1 to 3 mg per dog up to 8 hours. In large dogs, melatonin is dosed at 3 to 9 mg dog orally up to three times a day.
  • Melatonin Implants can be injected subcutaneously (under the skin) in dogs. The following sizes have been used:  Dogs less than 20 pounds receive the 8 mg implant, dogs 21 pounds to 36 pounds the 12 mg implant and dogs over 37 pounds receive the 18 mg implant. Effects of Melatonin implants can range from 6 to 12 months in dogs. 
  • In cats, melatonin is dosed at 1.5 to 6 mg per cat orally whenever necessary up to every 12 hours. The 18 mg implant has been used to suppress estrus in cats for 2 to 4 months. 
  • The duration of administration depends on the condition being treated, response to medication and the development of any adverse effects. Be certain to complete the prescription unless specifically directed otherwise by your veterinarian.


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