Are you wondering how contraception works in cats? We have already explained how sex works with cats. If you don’t want any kitten, contraception is important. Here you can find out how sensible it is and what methods are available.
Pregnancy and birth are physically and psychologically stressful and sometimes dangerous. Simply mating two animals without genetic background knowledge, knowledge about breeding and behaviour, the necessary space and financial possibilities is definitely not recommended. Therefore, you should think carefully about whether kittens are really desired.
What is the purpose of contraception in cats?
In principle, it is clearly about not having any unwanted offspring. In this case, the desire/not desire for kittens does not lie with your pet, but with you. Therefore, you are also responsible for the offspring of your pet.

What methods are there now?
There are several methods of contraception, which will now be discussed in more detail.
Surgical procedures
Castration is a safe option for birth control, as pregnancy is eliminated after a properly performed procedure. However, sterilisation is less advisable for cats as they continue to go through the cycle, become perpetually randy and are therefore subject to a high level of stress. This issue can also be important for male cats that show excessive sexual behaviour. If your cat has outdoor access, this type of intervention must be done to prevent unwanted offspring. Discuss with your vet which procedure would be best for your cat.
Hormonal contraception for cats
- Hormone injection: This is injected every 3-5 months, depending on the preparation. After discontinuing the injections, the cat can become pregnant again.
- Hormone chip: In the so-called “chemical castration”, a GnRH implant is injected under the skin of the animal, which releases hormones. The active ingredient here is deslorelin. For the next 6-12 months (in male cats even up to 24 months) the sperm and testosterone production is significantly reduced. The effect and side effects are the same as with castration, except that after the hormone chip has expired, everything is more or less as it was. Therefore, the method is more useful for testing and is only a permanent solution in exceptional cases.
- Melatonin chip: This is placed between two heat cycles and suppresses the next heat cycle for 3-4 months. After that it can be repeated.
The administration of hormones has an influence on the entire organism and can promote certain diseases. Hormonal contraceptive methods are mainly used when, for example, a breeding cat is taking a “break” but is expected to give birth to puppies again later. Especially preparations containing progestogen are often associated with severe side effects on the uterus and uterine region. It is advisable to consult your veterinarian.
Caution: With some preparations, the animals are still capable of procreation for up to two months.
What to do when it happens?
The “morning-after pill” is also available for our cats in the form of so-called anti-hormones. Never separate the cats during sexual intercourse, this can cause nasty injuries. If fertilisation has occurred, antiprogesterone is injected so that the egg does not implant in the uterus. This is given in the first 10 days after mating, but you should decide to have it as soon as possible for ethical reasons. It works relatively reliably, but there is a residual risk that individual foetuses survive, sometimes with severe impairments. Therefore, it should only be used in an emergency.
What is the legal situation?
In most federal states, neutering is compulsory for outdoor cats! This makes perfect sense, because they reproduce quickly and two cats can become 80 million cats in the course of 10 years of uncontrolled mating. Many of the animals are sick, there are inbreeding problems in some places and the vegetation often suffers from the many offspring (hunting birds, mice, etc.).

Summary
There are many options for contraception in cats, but not all of them are risk-free. Which method is most suitable for your pet depends on many factors and must be decided individually.