Cat Pregnancy: What to Expect

Cat pregnancy encompasses a relatively short duration of time, but a lot can happen during those 63 days of gestation. The process of a female cat or “queen” giving birth is called queening. 

Most pregnant cats instinctively know what to do in order to manage pregnancy and delivery. You’ll likely notice changes in your cat’s behavior and appearance as she progresses. As a pet parent, it’s important to know what’s coming so you can monitor her at each stage.

Did you know kittens as young as 4 months old can become pregnant? And queens can continuously go into heat every two to three weeks during their mating season? Unless you plan to responsibly breed your cat, veterinarians typically advise getting her spayed at 4 to 6 months of age to prevent any complicated or unwanted pregnancies.

Cat Puberty and Pregnancy Basics

A cat reaches sexual maturity between 4 and 6 months old, signaled by her first heat, or estrus cycle. Your cat won’t bleed while she’s in heat, but her behavior will change. She may suddenly become more affectionate, demanding, and vocal. She may also present her backside when you stroke her. 

When Can She Get Pregnant?

Female cats are seasonally polyestrous, which means they can go into estrus multiple times in one breeding season. Her estrus cycle will last from three to 20 days and then, if she is not bred, her estrus cycle will end. Ten to 40 days later, however, she will again enter estrus. This repeated cycling in and out of estrus will continue until she becomes pregnant or until her breeding season ends. 

The length of a cat’s breeding season depends on environmental factors. Queens typically begin their estrus cycle when the days get longer (at least 12 hours of sunlight). However, if you live in a climate that remains warm year-round, or your cat lives solely indoors, her breeding period could be year-round. 

How Do Cats Become Pregnant? 

Cats are induced ovulators. When a female cat in estrus mates with a tomcat, a reflex triggers the release of Luteinizing Hormone (LH) from a gland within the brain. The release of this hormone triggers ovulation. The efficiency of this system maximizes the chances that a cat will become pregnant if bred.

Ovulation occurs in 50 percent of queens after one copulation, and approaches 100 percent after four copulations in a 24-hour period. One mating session may only take 1 to 2 minutes, so it is possible for a female to mate multiple times with multiple partners in a short window of time. Therefore, it’s possible for a litter of kittens to have multiple toms as fathers. 

How Long are Cats Pregnant? 

Cat pregnancies typically last for 60 to 65 days, or roughly nine weeks.

How to Tell Your Cat is Pregnant

Physical changes: You will notice your cat’s belly growing, beginning approximately 30 days after mating. It’s both a wide and deep distention of her abdomen. You may also notice her nipples are enlarged and redder than usual—but only if you know to look for it. In rare cases, cats may experience a brief period nausea and decreased appetite in early pregnancy, similar to “morning sickness” in humans. It’s important to note, however, that many people do not recognize any signs of pregnancy in their cat until very late in pregnancy. Visible signs are often subtle. 

Behavior changes: Some cats become more affectionate when they’re pregnant, while others become more aggressive. Your cat may also appear more tired than usual. You will likely notice her hiding away as she begins her queening process. This is similar to the nesting instinct in other species. 

Early Stages of Cat Pregnancy 

The feline gestation period lasts 63 days, or just over two months. In most cases, you will not realize your cat is pregnant until she starts showing signs after 30 days. But here’s a look at what’s been going on during those first few weeks. 

• 4-5 days post-copulation: Each embryo from a successful ovulation enters the uterus.
• 6-8 days post-copulation: These embryos spread out to find their own space in the uterus. 
• 12-13 days post-copulation: The embryos implant. The more ovulations, the less likely these embryos are to implant. For example, five embryos each have a 90 percent chance of implanting, whereas nine to 11 ovulations become overcrowded and only have a 53 percent chance of implanting. This leads to an average litter size of four kittens.

Later Stages of Cat Pregnancy and Diagnosing 

If you suspect your cat is pregnant, you should make an appointment with your veterinarian to properly diagnose her. There are a number of diagnostic tests available, each of which can detect pregnancy at a different time in gestation. 

• Ultrasound: Starting as early as 15 days, pregnancy can be detected on ultrasound. At approximately 20 days, heartbeats are visible in the fetus. An ultrasound typically costs $250-$500, but not all veterinary clinics have ultrasound equipment available. 
• Palpation: As early as day 16, your veterinarian may be able to feel uterine changes within the abdomen. This is a relatively subjective test and is not always reliable. Your veterinarian may have trouble performing a thorough palpation if your cat resists restraint or is overweight. Even in well-behaved, slender cats, the ability to palpate a pregnancy may be limited by the cat’s conformation. This test is typically included as a part of your veterinarian’s physical exam.  
• Testing hormone levels: Around day 25 to 30, the hormone relaxin (which is released in pregnant cats) is detectable. This test is not commonly used, but may be available in some practices. Costs for this test may vary depending on the laboratory used by your veterinary clinic. 
• X-Rays: After day 45, the skeletons in the kittens are calcified and can typically be detected by radiography. X-rays are often used as both a means of diagnosing pregnancy and a method to estimate litter size. This is the most commonly-used test for pregnancy diagnosis in cats. Cost ranges from $150-$250 in most practices. 

At approximately 63 days, your cat will be ready for the queening process. You may notice her visiting the litter box more often, anxiously nesting, or following you around. (More on this to come.)

How to Manage Cat Pregnancy 

The best thing you can do for your pregnant cat is to provide adequate nutrition and exercise, as well as keeping her safe from outside dangers and disease. 

Medications: There are certain vaccines that should be avoided in pregnant queens, most notably the Modified Live Virus form of the Feline Panleukopenia virus vaccine. This particular vaccine can have harmful effects on the kittens’ brain development. Other vaccines are typically evaluated on a case-by-case basis. There may be risks associated with vaccinating a pregnant cat, but there also may be benefits (especially if your cat has not had prior vaccines). Talk to your veterinarian to determine which vaccines and medications are safe for your cat to receive during pregnancy.

Diet and Nutrition: During pregnancy, you should feed your cat a high-quality kitten food. Kitten food has additional calories and nutrients, ensuring that all of your cat’s nutritional needs are met during pregnancy. This diet should be continued until the kittens have finished nursing. At that time, you can transition your cat back to her regular cat food. 

Any time you change your cat’s diet, it’s important to do so gradually, over a period of one week. This will minimize the chances of your cat developing diarrhea or other gastrointestinal issues with a sudden food transition. 

Signs of Trouble: During pregnancy, monitor your cat carefully for any signs of illness or problems with the pregnancy. If you have concerns, take your cat to the veterinarian as soon as possible. Signs of trouble may include, but are not limited to:

• Vaginal bleeding
• Dramatic weight loss
• Anorexia (refusal to eat) or vomiting
• Weakness or significant lethargy

Helping Your Cat Prepare for Queening

In the final two weeks of pregnancy, you can help your cat prepare for queening. If she’s an indoor/outdoor cat, she should be confined to indoor spaces in the final week of her pregnancy so you can keep a close eye on her changing condition. 

Find a private and quiet area in your home to create a queening area, with soft bedding (old or washable blankets). Whether through an electric blanket, hot water bottles, or heat lamp, the temperature in the queening area should be maintained at 85 to 90 degrees Fahrenheit once the kittens are born. 

Knowing the number of kittens ahead of time will help you monitor her progress during the queening process. Once labor begins, one kitten will typically arrive every 30 to 60 minutes. If your cat has been having contractions for 60 minutes without producing a kitten, there may be a problem. Contact your veterinarian, or the nearest emergency clinic, immediately. Cats may have trouble in delivery and some cats may require a C-section. 

How to Prevent Pregnancy in Cats

Whether you have a new kitten or a cat who has already queened a litter, it’s important to know your options. 

Because cats can become fertile at such a young age, most veterinarians recommend spaying your cat at 4 to 6 months old to prevent unwanted pregnancies. Until she is spayed, your cat should remain indoors and not be allowed access to any unneutered males. 

In addition to preventing pregnancy, spaying your cat offers significant medical benefits. An intact female cat is seven times more likely to develop mammary cancer than a cat that is spayed prior to 6 months of age (1). Spaying your cat at 4 to 6 months of age is also less stressful than spaying her as an adult, with shorter anesthetic times and a more rapid recovery (2). Finally, the behavior of a cat in heat can be frustrating for many owners; spaying your cat will prevent this behavior.  

However, if you’re a pet parent planning on breeding your cat, it is important to be mindful of the risks. Breeding cats is a task that should not be taken lightly. First, you should check the laws on breeding and selling cats in your country, and understand the complexity of breeding responsibly. Reputable breeders spend decades studying the history of breeds and proper methodologies. 

Related Conditions 

• Mastitis
• Eclampsia
• Dystocia
• Pyometra
• Pseudopregnancy