Ovarian Cysts in Cats: Understanding a Hidden Hormonal Disorder

Ovarian cysts in cats are an uncommon but important reproductive condition that can lead to persistent hormonal changes, behavioural shifts and, in some cases, serious health complications. Because the signs are often mistaken for normal reproductive behaviour, the condition may go unrecognised for extended periods.

Understanding how ovarian cysts develop, how they affect the body and when to intervene is key to protecting your cat’s long-term health.

What Are Ovarian Cysts?

Ovarian cysts are fluid-filled or semi-solid structures that develop on or within the ovaries. The ovaries play a central role in hormone production, particularly oestrogen and progesterone, which regulate the reproductive cycle.

When cysts form, they can interfere with normal hormone regulation. Some cysts produce hormones themselves, leading to prolonged or abnormal reproductive behaviours.

In cats, ovarian cysts are most often associated with unspayed females and may be linked to irregular ovulation.

Types of Ovarian Cysts

Not all ovarian cysts behave in the same way. The two main types seen in cats are:

• Follicular cysts – develop when a follicle (which normally releases an egg) fails to ovulate and continues to grow
• Luteal cysts – form from structures that produce progesterone after ovulation

Follicular Cysts

These are the most common type and are often hormonally active. They may produce oestrogen, leading to prolonged or repeated signs of being “in heat”.

Luteal Cysts

These produce progesterone and can suppress normal reproductive cycling. They may be less obvious behaviourally but can still disrupt normal physiology.

Causes and Risk Factors

The exact cause of ovarian cysts in cats is not always clear, but several contributing factors are recognised.

Failure to Ovulate

Cats are induced ovulators, meaning ovulation typically occurs after mating. If ovulation does not occur, follicles may persist and develop into cysts.

Hormonal Imbalance

Disruptions in normal hormone signalling can prevent follicles from maturing or releasing eggs correctly.

Age

Ovarian cysts are more commonly seen in mature, unspayed female cats, although they can occur at any reproductive age.

Lack of Neutering

Spayed cats do not develop ovarian cysts, as the ovaries have been removed. This makes reproductive status one of the most significant risk factors.

Signs of Ovarian Cysts

The symptoms of ovarian cysts are often related to hormone production, particularly excess oestrogen.

Common signs include:

• Repeated or prolonged “heat” cycles
• Persistent vocalisation (calling)
• Increased affection or restlessness
• Rolling, lordosis (mating posture)
• Urine spraying or marking
• Attraction of male cats over extended periods

Unlike a normal heat cycle, which lasts several days, cats with ovarian cysts may appear to be in heat continuously or return to heat very quickly after a cycle ends.

In some cases, signs may be more subtle or absent, particularly with progesterone-producing cysts.

Complications of Ovarian Cysts

If left untreated, ovarian cysts can lead to secondary health issues.

Endometrial Changes

Prolonged exposure to hormones can cause changes in the uterus, increasing the risk of conditions such as:

• Cystic endometrial hyperplasia (CEH)
• Pyometra (uterine infection)

Pyometra is a life-threatening condition requiring urgent treatment.

Behavioural Stress

Constant hormonal stimulation can lead to chronic stress, restlessness and reduced quality of life.

Infertility

Ovarian cysts can disrupt normal ovulation, making successful breeding difficult or impossible.

Diagnosis

Diagnosing ovarian cysts can be challenging, as the ovaries are small and not easily examined without imaging.

A vet may recommend:

• Clinical history – noting prolonged or abnormal heat behaviour
• Physical examination
• Ultrasound imaging – the most reliable way to visualise ovarian cysts
• Hormone testing – assessing oestrogen or progesterone levels

In some cases, cysts are discovered incidentally during imaging or surgery.

Treatment Options

Treatment depends on the severity of symptoms, the cat’s reproductive status and whether breeding is intended.

Surgical Treatment (Spaying)

The most effective and definitive treatment is ovariohysterectomy (spaying).

This removes both the ovaries and uterus, eliminating:

• The cysts themselves
• The source of hormonal imbalance
• The risk of recurrence

Spaying also prevents serious complications such as pyometra.

Medical Management

In rare cases, hormonal treatments may be considered, particularly in breeding cats. However, these approaches are less predictable and may carry risks.

Because of this, surgery is generally preferred in most cases.

Prognosis

The prognosis for cats with ovarian cysts is excellent following surgical removal of the ovaries.

Behavioural signs typically resolve quickly once hormone levels stabilise. Cats often return to their normal temperament within days to weeks.

If complications such as pyometra are present, prognosis depends on how quickly treatment is initiated.

Prevention

The most reliable way to prevent ovarian cysts is early spaying.

Benefits of spaying include:

• Elimination of ovarian cyst risk
• Prevention of uterine disease
• Reduction in mammary tumour risk
• Elimination of heat-related behaviours

For cats not intended for breeding, spaying offers significant health and welfare advantages.

When to Seek Veterinary Advice

You should consult a vet if your cat:

• Appears to be in heat continuously
• Has very frequent or prolonged cycles
• Shows persistent vocalisation or behavioural changes
• Develops vaginal discharge
• Appears unwell or lethargic

Early investigation can prevent more serious complications.

Conclusion

Ovarian cysts in cats are a hormonally driven condition that can significantly affect behaviour and health. Because the signs often mimic normal reproductive activity, they are easy to overlook.

Persistent or unusual heat behaviours should never be ignored, particularly in unspayed cats. With appropriate diagnosis and treatment, most commonly spaying, the condition can be resolved effectively, restoring both physical health and behavioural balance.

As with many feline conditions, early intervention is key. Recognising subtle changes and seeking timely veterinary advice can prevent complications and ensure the best possible outcome for your cat.