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  • Best Friend Family Vet
  • Doley Road,
  • Byford,
  • Western Australia,
  • Phone: (040) 735-2836

Megestrol Acetate

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medicationWhy has my veterinarian prescribed this medicine?

Megestrol acetate is a progestogen used to prevent and postpone oestrus (heat). In Australia it is recommended that non-breeding dogs and cats be desexed so the following sentence could be very confusing to pet owners, suggest deleting : It is important that your pet should have a normal oestrus every 18 to 24 months. It is often difficult to predict when your pet will come into oestrus (season) after megestrol acetate medication is stopped.

Megestrol acetate may also be used to treat hypersexuality in male dogs and behavioural problems. It has also been used to treat a variety of skin conditions.

How do I give this medication?

- Give this medicine to your pet as directed by your veterinarian. READ THE LABEL CAREFULLY.

- Try to give this medication at about the same time each day.

- DO NOT give your pet more medicine than directed and DO NOT give the drug more often than directed

- DO NOT stop giving this medication to your pet unless directed by your veterinarian.

-Try not to miss giving any doses.

What if I miss giving a dose?

Give the dose as soon as possible. If it is almost time for the next dose, skip the missed dose, and continue with the regular schedule. Do not give the pet two doses at once.

How do I store this medicine?

- Keep this medicine out of reach of children.

- Store this medicine in a cool, dry place at room temperature.

- Do not store this medicine in the bathroom, near the kitchen sink or in damp places. The medicine may break down if exposed to heat or moisture.

Potential side effects

- Tell your veterinarian if your pet is diabetic or if your male dog is intended for breeding.

- Potential side effects with megestrol acetate include mammary changes, uterine infection (pyometra), increased appetite, increased thirst, increased urination, personality changes (increased libido), and changes in hair colour. If these effects are seen, contact your veterinarian.

- Your pet may have abnormal oestrus cycles or come into season earlier than expected.

- Other side effects may occur. If the pet experiences anything unusual, contact your veterinarian.

Possible drug interactions

- Make sure to tell your veterinarian what other medication you are giving to your pet.

- Drugs may interact such that they can cause an increased or decreased effect or side effects. Although drug interactions may occur, it does not mean that there is necessarily a high risk of any of these occurring

- Contact your veterinarian if your pet experiences any unusual reactions when different medications are given together.

© Copyright 2025 LifeLearn Inc. Used and/or modified with permission under license. This content written by LifeLearn Animal Health (LifeLearn Inc.) is licensed to this practice for the personal use of our clients. Any copying, printing or further distribution is prohibited without the express written consent of LifeLearn. This content does not contain all available information for any referenced medications and has not been reviewed by the FDA Center for Veterinary Medicine, or Health Canada Veterinary Drugs Directorate. This content may help answer commonly asked questions, but is not a substitute for medical advice, or a proper consultation and/or clinical examination of your pet by a veterinarian. Please contact your veterinarian if you have any questions or concerns about your pet’s health. Created on Jul 31, 2015.