What is hyperkalemia?

Hyperkalemia means the potassium level in the blood is too high. It can affect heart rhythm and muscle function, with signs such as weakness, reduced appetite, or breathing changes. Blood tests and imaging may be needed to identify the cause, so ask your vet for an assessment.

What tests will the vet do to find the cause of hyperkalemia?

Common tests include a complete blood count (CBC), biochemistry and electrolyte testing, chest and abdominal X-rays, and ultrasound. Further imaging or specialist consultation may be recommended if needed. Your vet will decide the next steps based on the results.

How can I help my vet assess my pet's condition at home?

Record when signs started, food and water intake, toileting, and changes in activity. Use your phone to film abnormal breathing or episodes, then bring this information to the appointment to help your vet assess the situation quickly.

How often are blood tests needed during hyperkalemia treatment?

The follow-up schedule depends on the cause and response to treatment. Blood tests may be needed every few days to every few weeks to check treatment response and safety. Follow your vet's advice for rechecks and repeat blood testing.

How much do the tests and treatment usually cost?

Costs vary by clinic and region — ask your vet for an estimate before proceeding.

Disease Guide

Hyperkalemia in Dogs and Cats: Weakness, Diagnostic Imaging & Treatment Follow-Up [2025]

Hyperkalemia can cause abnormal heart rhythms, muscle weakness, and even cardiac arrest, making it an emergency. Common causes include urinary obstruction, kidney failure, and adrenal insufficiency. Urgent stabilisation of the heart rhythm is needed.

Take 1 minute to check the symptoms first

Last updated: 2026/01/05

Pethealthmap Editorial Team

Sources: AAHA, ACVIM, National Taiwan University Veterinary Hospital

When to See a Vet

Seek Emergency Care Immediately

•Persistently unresponsive or extremely lethargic and cannot be roused
•Gum color is noticeably pale or bluish-purple
•Sudden hind-limb weakness or collapse — unable to stand or walk on their own

Schedule a Vet Visit Soon (within 24–72 hours)

•Significantly reduced appetite lasting more than one day
•Noticeably low energy — lying down and reluctant to move
•Faster breathing or labored breathing while still conscious

01What symptoms suggest something is wrong?

In dogs and cats, hyperkalemia often appears as generalised weakness or reduced activity and may be accompanied by heart, lung, or abdominal signs.

A clear drop in activity, tiring easily, or lying down for long periods
Sudden severe collapse or reduced responsiveness
Localised or widespread pain when touched, with flinching, avoidance, or crying out
Ongoing abdominal discomfort, refusing food, or vomiting
Changes in heart rhythm or breathing, such as panting or rapid, shallow breathing

Seek emergency care immediately if you notice the following symptoms:

⚠️ Sudden weakness or paralysis of the hind limbs, or being completely unable to move
⚠️ Persistent collapse, inability to wake, or very poor responsiveness
⚠️ Abnormal gum colour, such as pale or bluish-purple gums

02How can you assess changes at home? Observation tips and when to seek emergency care

Keeping a clear record of changes at home helps your vet understand the timeline and possible causes more quickly.

Record changes in energy and activity each day, including the time and severity
Weigh your pet at the same time and track weight trends
Record daily food and water intake, including any periods of refusing food
Note the timing of urination and bowel movements, and any changes in stool or urine appearance
If episodes or unusual signs occur, record a video on your phone and note the time
If signs continue or worsen, arrange a veterinary consultation as soon as possible

03How will the vet diagnose it? Common tests

At the clinic, diagnosis usually starts with a physical examination, then combines imaging and blood tests to assess the cause and severity.

Physical examination

assessing the heart and lungs, gum colour, abdomen, and body surface

X-rays

checking the chest or abdomen for obvious disease changes or fluid build-up

Ultrasound

assessing heart function and the structure of abdominal organs

Computed tomography (CT)

used for more detailed assessment of organs or tumours

Blood tests

including a complete blood count (CBC) to assess red and white blood cell status

Biochemistry tests

checking key markers such as liver and kidney function and electrolytes

Choose a specialist clinic or hospital with blood testing and diagnostic imaging capability where possible

04How is it treated and managed after diagnosis? Medication, diet adjustments, and care

Treatment depends on the underlying cause and usually involves medication or supportive care, with regular checks to monitor response.

Follow the vet's diagnosis and plan for medication or supportive care, with scheduled rechecks
Have regular blood tests to monitor response and adjust the treatment plan when needed
Record medication responses and changes in vitality, and report anything unusual to your vet
Adjust the diet if needed and monitor weight and appetite changes
For complex cases or ongoing abnormalities, referral to a blood disease or cardiology specialist may be recommended

05What should you prepare before seeing the vet? Key information that helps identify the cause

List when the problem started, how signs have changed, and whether there has been any sudden worsening

Prepare records of food and water intake from at least the past 24 hours

Bring videos of toileting issues or episodes, noting the time and situation when they were filmed

Bring a list of current medications or supplements, including dose information

If you have previous test reports or images such as X-rays, ultrasound, or blood test results, bring them as well

Call ahead to book where possible, and mention whether blood tests or imaging may be needed

This content is for reference only and cannot replace a professional veterinary diagnosis. If your pet shows signs of illness, please seek veterinary care promptly.