Fine Needle Aspirate in cats

A fine needle aspirate (FNA) is a simple procedure that helps vets find out what’s inside a lump or swelling on your cat. It’s a safe and relatively inexpensive way to check lumps in cats of any age, size or breed. 

A fine needle aspirate doesn’t involve cutting into the skin. The procedure can often be carried out during a consultation, so your cat won’t even need to stay at the vet practice. Side-effects are uncommon and between 70 and 95% of FNA’s provide helpful answers. Vets use the results of a fine needle aspirate to work out the best treatment plan for your cat.

What it’s for

Fine needle aspirate in cats: what it’s for

It’s always worrying when you find a lump on your cat. Lots of swellings look the same. Most are harmless, but some are more serious. It’s impossible to be sure what a lump is just by looking at it. An FNA helps identify the type or cause of a swelling. And from there, decide on the best and safest course of treatment.

When will vets advise an FNA?

Vets may advise an FNA for lumps which are:

  • New
  • Growing quickly
  • Changing size, shape or colour
  • Becoming painful

Why do we want to know what a lump is?

  • Peace of mind: confirming whether a lump is innocent by finding out what cells are inside.
  • Deciding on treatment: using FNA results combined with physical examination for infections, abscesses, blood blisters.
  • Deciding on surgery: knowing what cells make up the lump helps us decide whether to remove it.
  • Diagnosing non-cancerous illnesses: liver disease, immune disorders and more.

How it’s done

Fine need aspirate in cats: how it’s carried out

FNA is simple, quick and relatively painless for your cat. It’s just like having an injection, but the vet takes a sample out instead of injecting medicine in! Most cats don’t need sedation, just the usual vet cuddles!

  • The vet inserts a fine, sterile needle into the lump and rotates it.
  • The needle collects a tiny sample of the lump (some cells, fluid, tissue etc) in the barrel
  • The vet pushes the needle contents out onto a microscope slide using a syringe full of air
  • The slide is put into special dyes to make cells visible under a microscope
  • A vet or pathologist examines the slide and identifies any cells present

The vet may examine the sample ‘in-house’ in their own laboratory. You’ll get results within a day or two.

Otherwise, the sample goes to a special laboratory for examination. In this case, results take 1-2 weeks, depending on the tests needed.


How to prepare your cat for an FNA

Little preparation is needed for an FNA. Often it is carried out during a consultation (so unplanned). Keeping them as still as possible, with lots of cuddles and a calm reassuring voice is all that’s needed.

Why your cat may need sedation for an FNA

Your cat may need sedation to make the test safer and/or more comfortable for them.

For example:

  • Relaxing your cat if they don’t like handling (especially not at the vet’s!)
  • Taking a sample from an awkward location or taking multiple samples.
  • Performing an FNA with ultrasound guidance. This allows a vet to carefully place the needle in the correct location to collect a sample from deep under the skin or inside the tummy.


Fine needle aspirate in cats: how much does it cost?

FNA is an inexpensive test. It’s quick and straightforward. There aren’t any surgery or hospital fees. Costs vary between practices but could be anywhere between £25 to £200 in practice, depending on:

  • Whether sedation is required.
  • How many lumps are sampled.
  • Location of the lumps.
  • Whether the sample is examined in-house or sent to a laboratory.
  • Where you live and the type of practice.
  • Whether or not laboratory fees are included.

Fees for examination of the sample (cytology) are usually in addition to FNA fees. But always check with your vet first.


Is a fine needle aspirate safe for my cat?

FNA is a very safe procedure. Risks or complications are rare but can include:

  • Bleeding from the sampling site.
  • Infection: the needle carries skin bacteria through the skin and into the swelling.
  • Allergic reaction: sampling lumps containing cells called ’mast cells’ may trigger an allergic response within 24-48 hours – swelling, redness and discomfort. If your vet suspects a mast cell tumour, they may give your cat an antihistamine injection before the FNA.

Call a vet if you notice any changes in the lump after an FNA


Recovery tips

Does my cat need special care after a fine needle aspirate?

FNA is a simple procedure, so we don’t need to worry too much about specific aftercare.

  • Keep the site clean and wipe away any bleeding or discharge.
  • Bathe gently with warm salt water if discharge is sticky or dried to the skin (1 teaspoon salt to one pint of warm water).
  • Discourage your cat from licking or scratching the site. Your vet may suggest a cone collar.

When to worry

When to worry after a fine needle aspirate in cats

Serious complications of FNA are extremely rare. When they happen it’s either due to infection or a severe allergic response called an anaphylactic reaction.

Anaphylactic reactions are life-threatening.

Find your nearest vet immediately if you think your cat is suffering an anaphylactic reaction:

  • Difficulty breathing and bluish gums.
  • Cold limbs, collapse.

Call a vet as soon as possible if your cat develops:

  • New redness, heat, and further swelling of the lump.
  • Pain or lethargy.
  • Reduced appetite, vomiting or diarrhoea.

Joii can help with:

  • Advice about lumps or bumps.
  • Monitoring swellings’
  • Treating some abscesses and infections
  • Managing allergies.
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