Anti-craving pills - DO NOT give them if you love your pet

For years, the Bulgarian pharmaceutical market has been selling hormonal veterinary-medical preparations in tablets designed for use with our pets - dogs and cats. The most common are ”Nonestron” and ”Nonovulin”, containing megestrol acetate. Since in recent years this medication has found wide use (and in our opinion it is also uncontrolled) by pet owners and due to the poor description of side effects in the leaflets attached to the products, we find it necessary to bring to the knowledge of people who love their four-legged friends the degree of risk involved in the use of Nonestron and Nonovulin.

Systemic use of megestrol acetate (this is the active substance of these medications) inevitably leads to one of the following side effects:

• Pyometra - chronic cystic - purulent inflammation of the uterus
• Endometritis – inflammation of the uterine lining
• Increased appetite - often not noticed by the owners
• Lethargy
• Transient hyperglycemia – increase in blood sugar values
• Diabetes
• Aspermatogenesis – stops the formation of spermatozoa
• Hyperplasia (growth) of the mammary glands - also in male animals
• Adenocarcinoma – malignant tumor of the mammary glands (also in male animals)
• Alopecia (hair loss), seborrhea and skin atrophy
• Adrenal gland dysfunction
• Changes in behavior

Contraindications for the use of the preparation are the following:

• Megestrol acetate is contraindicated in pregnant animals or in animals with uterine diseases, diabetes mellitus or tumors of the mammary glands.
• It is recommended not to use in dogs before the first estrous cycle (first heat) or in dogs with abnormal cycles.
• It should not be used for more than two consecutive treatments.

We are writing all this because the static effects of the active substance are extremely common - one or several of them appear in a high % of cases after its use. In the last two years, cases of chronic purulent inflammation of the uterus and tumors of the mammary glands have become more frequent in our country. in dogs and cats. The frequent cases of diabetes mellitus are also a cause for concern (for our clinic, they are 3 in the last 8 months). The treatment of diabetes mellitus after control of the acute stage can, as in humans, switch to life-long maintenance with insulin. Treatment of pyometra and mammary gland tumors is surgical and appears to be life-saving. In a conversation with the owners of sick animals, in about 90% of the cases we found that they had treated their pets with megestrol acetate at an earlier or later stage of their lives. Add to that the fact that megestrol acetate is not licensed for use in cats in the US. The uncontrolled supply of megestrol acetate (you can find it in almost any pet store or pet food store accompanied by the only instruction from the sellers - ”These are anti-stimulation pills”) and its low price make it widely used.

Bearing in mind the above, we believe that the manufacturers should state in the leaflet of the preparation ALL potential side effects and contraindications for its use. The manufacturer should know that good manufacturing practice includes informing the client about the possible side effects of the drug. This allows for easy detection of early signs of possible diseases caused by the hormonal preparation. We believe that you, the owners of pets, can judge the benefits and harms of the so-called ”anti-catastrophic pills” for yourself, and we, as veterinarians, advise you when you decide to use such a preparation to consult with us, at least until the manufacturer considers it necessary to familiarize you with all the actions of the medication.