The most expensive cat insurance claims

As a cat owner, there’s nothing like an unexpected vet bill to put pressure on those purse strings. We’d do anything for our pets, but with some unforeseen health issues running into the thousands of pounds, our finances can only stretch so far.

Understanding these conditions not only prepares you for potential emergencies but also highlights the importance of pet insurance to cover any sudden shocks.

With this in mind, here are the most expensive cat insurance claims recorded by Agria Pet Insurance, including details on what causes these conditions and how they’re typically treated.

Top 10 most expensive cat insurance claims*

1. Fracture of thoracic limb – humerus (site unspecified) - £5,632.24
2. Immune-mediated polyarthropathy - £5,577.00
3. Touch sensitivity (problem behaviour) - £5,148.66
4. Empyema (pyothorax) - £5,013.35
5. Pharyngeal cyst - £4,514.80
6. Middle ear polyp - £4,220.51
7. Skin neoplasm – £4,108.14
8. Fibrocartilaginous embolism (FCE) of the spinal cord - £3,970.17
9. Pyloric mass lesion - £3,945.14
10. Urinary bladder rupture - £3,904.13

*Based on all Agria Pet Insurance claims received between January and July 2026.

Here’s a look at each condition and its treatment in more detail.

1. Fracture of thoracic limb – humerus (site unspecified) – £5,632.24

The humerus is the long bone at the top of a cat’s front leg, between the shoulder and elbow. A fracture here is usually caused by a serious injury, such as a road accident or fall from height.

Treatment depends on where and how badly the bone has broken. Many humerus fractures require surgery to hold the bone in place using pins, plates or screws, although the right treatment will depend on the individual injury. Cats may also need X-rays or other scans, pain relief and several follow-up appointments. They’ll usually need to limit their movement while the bone heals. All of this can make treatment costly.

2. Immune-mediated polyarthropathy – £5,577.00

Immune-mediated polyarthropathy causes pain and inflammation in several joints. It happens when a cat’s immune system mistakenly attacks the tissues around its joints. Cats with the condition may appear stiff, limp on different legs, develop a high temperature or become less active than usual.

It’s an uncommon condition in cats, and getting a diagnosis may involve blood tests, X-rays and taking samples of fluid from the affected joints. Treatment usually includes medication to reduce the immune system’s response and ease inflammation. Some cats need treatment for several months, along with regular check-ups and blood tests.

3. Touch sensitivity (problem behaviour) – £5,148.66

Touch sensitivity means a cat reacts unusually strongly to being touched. They may flinch, become distressed, try to escape or behave aggressively when someone handles a particular area.

There can be several possible reasons for this behaviour, including pain, fear, stress or a previous negative experience. This means a vet will usually need to rule out medical problems before treating it as a behavioural issue. Tests, scans and referrals may be needed to identify the cause.

Treatment could then involve pain relief, changes around the home, medication or support from a qualified cat behaviourist. Complex cases can require ongoing care and several different forms of treatment.

4. Empyema (pyothorax) – £5,013.35

Pyothorax is a serious condition in which infected fluid or pus builds up in the space around a cat’s lungs. This makes it difficult for the lungs to expand properly and can leave the cat struggling to breathe. Other signs may include tiredness, a high temperature, loss of appetite and rapid breathing.

Cats with pyothorax need urgent veterinary treatment. A vet will usually drain the infected fluid from the chest and prescribe antibiotics. The cat may need to stay in hospital for several days for chest drainage, fluids, oxygen and close monitoring. In some cases, surgery may be needed. This intensive care helps explain why treatment can become so expensive.

5. Pharyngeal cyst – £4,514.80

A pharyngeal cyst is a fluid-filled swelling in or around the throat. Depending on its size and location, it may make it difficult for a cat to swallow or breathe. Signs can include coughing, gagging, noisy breathing, difficulty eating or a swelling around the neck.

Vets may use scans or a small camera to look inside the throat and work out exactly where the cyst is. The fluid can sometimes be drained, but if the cyst fills up again surgery may be needed to remove it. The delicate location of the cyst and the need to protect the cat’s airway can make investigation and treatment more complex.

6. Middle ear polyp – £4,220.51

Middle ear polyps are non-cancerous growths that can develop within a cat’s middle ear. They’re more often seen in younger cats and may cause repeated ear infections, head shaking, balance problems or a head tilt. Some cats may also scratch at the affected ear or develop discharge.

Treatment usually involves removing the polyp under a general anaesthetic. In some cases, the vet can gently pull the growth out. However, polyps can return if tissue is left behind. A more involved operation, known as a ventral bulla osteotomy, may be recommended to access and clear the middle ear more thoroughly. Scans, specialist surgery and follow-up care can all add to the cost.

You can read more about ear problems in cats in our guide.

7. Skin neoplasm – £4,108.14

A skin neoplasm is an abnormal growth or tumour on or beneath the skin. Some of these growths are harmless, while others are cancerous and may spread or damage nearby tissue. It isn’t always possible to tell what a lump is simply by looking at it.

A vet may take a small sample of cells or remove part of the lump for laboratory testing. Further tests or scans might be needed if cancer is suspected. Treatment often involves surgery to remove the growth and an area of surrounding tissue. Depending on the type of tumour, a cat may also need specialist care, further surgery, chemotherapy or radiotherapy.

It’s always worth asking your vet to check any new lump, particularly if it grows, changes shape, bleeds or seems to bother your cat.

8. Fibrocartilaginous embolism (FCE) of the spinal cord – £3,970.17

A fibrocartilaginous embolism, or FCE, happens when material believed to come from one of the cushions between the bones of the spine blocks a blood vessel supplying the spinal cord. This interrupts the blood supply and can cause sudden weakness or loss of movement. It’s sometimes described as a spinal stroke.

FCE is considered rare in cats. The signs usually appear suddenly and may affect one or more legs. Diagnosis can involve neurological tests and an MRI scan to rule out other spinal problems.

There’s no medicine or operation that can remove the blockage. Treatment instead focuses on nursing care, physiotherapy and helping the cat regain as much movement as possible. Recovery varies depending on how badly the spinal cord has been affected.

9. Pyloric mass lesion – £3,945.14

The pylorus is the opening that allows food to leave the stomach and enter the small intestine. A mass in this area can partly or completely block that opening, making it difficult for food to pass through normally.

Affected cats may vomit, lose weight, eat less or become dehydrated. A pyloric mass can have several possible causes, including inflammation or a tumour. Tests such as blood work, ultrasound scans, X-rays or an examination using a small camera may be needed to find the cause.

Treatment depends on what the mass is and whether it can be removed. Some cats require specialist surgery, followed by laboratory testing of the tissue. They may also need fluids, medication, nutritional support and hospital care.

10. Urinary bladder rupture – £3,904.13

A bladder rupture is a tear in the bladder that allows urine to leak into the abdomen. It can happen after a serious injury, such as being hit by a car. It may also develop if the flow of urine becomes blocked and pressure builds inside the bladder.

This is an emergency that can quickly make a cat seriously unwell. Signs may include difficulty passing urine, abdominal pain, vomiting, tiredness or collapse.

A vet may use blood tests, urine tests and scans to diagnose the rupture and check its effects on the body. Treatment usually involves stabilising the cat with fluids and other emergency care before surgically repairing the bladder. The cat may then need a hospital stay, pain relief and close monitoring as they recover.

Why cat insurance is essential

These claims show just how suddenly a cat can need expensive veterinary care. And follow-up appointments, medication, rehabilitation and further tests can all increase the overall bill.

Having the right cat insurance in place means you can focus on helping your cat recover. As long as you renew your policy, lifetime cat insurance can help cover eligible conditions year after year, up to your annual vet fee limit. This can be particularly important if your cat develops a condition that needs ongoing treatment.

What’s more, all Agria policies come with 24/7 access to vet video calls through the Agria app.