Dog - Megestrol Acetate

Why has my veterinary surgeon prescribed this medicine?

Megestrol acetate is used to prevent and postpone oestrus (heat). 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 does this medicine work?

Megestrol acetate is a progestogen (type of hormone). Progestogens exert a negative feedback on the hypothalamic-pituitary axis in the brain thereby suppressing the secretion of gonadotrophins and cyclical ovarian activity, which normally results in oestrus and ovulation.

How do I give this medication?

• Give this medicine to your pet as directed by your veterinary surgeon. 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 veterinary surgeon.
• Try not to miss giving any doses.
• Wash your hands after handling the medication.
• In case of accidental ingestion, seek medical advice immediately and show the package leaflet or label to the physician.

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 your 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 veterinary surgeon 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 veterinary surgeon.
• Your pet may have abnormal oestrus cycles or come into season earlier than expected.
• Other side effects may occur. If your pet experiences anything unusual, contact your veterinary surgeon.

Possible drug interactions

• Make sure to tell your veterinary surgeon 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 veterinary surgeon if your pet experiences any unusual reactions when different medications are given together.