Why is my cat scratching so much?

Why is my cat scratching so much?
February 26, 2018 kernow

Itching is fairly common in cats… However, we don’t always recognise it! In addition, there are a very wide range of possible causes, all of which may need to be investigated. So for more information about scratching cats, read on!

Do you know whether your cat is itchy?

Well it’s pretty obvious if they’re constantly scraping themselves and digging with their claws! However, not every cat is as blatant as that (of course – they’re very subtle and often shy creatures). One of the most common signs of an itchy cat is a bald cat. Now, while baldness in dogs (and humans for that matter) is commonly due to hormone disorders or imbalances (for example, Cushing’s Disease, Hypothyroidism, or testosterone toxicity), in cats these are incredibly rare. Nine times out of ten, a cat who is balding is losing their hair because they’re scratching it out when no-one’s looking…

So, what’s causing it?

If they’re itchy, there’s a HUGE range of possibilities. However, there’s one that’s head and shoulders above all the others…


Yes, these little critters are responsible for the vast majority of itchy cats. The adults suck blood, which causes an itch and a scratch, a lick and a groom, as the cat tries to catch the bloodsucker. However, while a flea bite is itchy, it’s not normally enough for a cat to rub themselves raw, unless there are a lot of them (which there can be – we occasionally see poor moggies whose coat is actually crawling there are so many of the beasties living in it).

However, more commonly in cats that are owned and loved the problem is flea allergy dermatitis. This occurs when the cat becomes allergic to the saliva that the fleas dribble into the skin as they feed, and it can drive a cat utterly wild after even a single bite. The problem, of course, is that while ten thousand fleas are rather easy to spot, ten or even just one can be really hard to find. Our vets and nurses have a clever trick to detect them though – it’s called the Wet Paper Test. It works because flea droppings are basically dried blood – but they just look like black dust. If you get them wet, on a sheet of white paper though, hey presto! They turn to red, proving the presence of a flea.

Flea control can be complex, because it’s so important to deal with all the babies (hiding in your carpets and soft furnishings!). However, there are a wide range of prescription-strength medications now available that are very effective in killing the bugs.

However, it does occasionally happen that we search and search and never find a flea. If so, we’ll usually treat against fleas anyway (just in case!), but we also have to look for other causes. These can include…


Cats can be bitten by a range of mites, including:

  • The Harvest Mite (Trombicula autumnalis) which is, unsurprisingly, most common in the autumn. The nymphs climb onto the cat’s skin and bite them, causing itching.
  • The Mange Mites cause really, really serious itchiness and hair loss. There are two species: Sarcoptes, which causes scabies in humans and mange in dogs and cats; and Notoedres, which lives almost exclusively on cats but is very rare now in the UK.
  • The Ear Mite (Otodectes cyanotis) which normally lives in the ears, but occasionally wanders out and causes itching on the head and neck, too.

To diagnose mites, our vets normally have to do skin scrapes to find them; however, most mites in cats are relatively easy to kill with modern medicines.

Food allergies

Occasionally, an animal’s immune system decides that a harmless piece of chicken, or beef, or whatever, is a dangerous enemy and attacks it. In humans, this often causes gut symptoms, but in cats, skin itching is the more common response. Unfortunately, this can be very hard to diagnose, but an exclusion diet (feeding the cat ONLY from a special hydrolysed diet that the immune system cannot respond to) is the best and most reliable way. Once we know what the cat is responding to, then you just have to avoid feeding that substance – although it’s usually easier to stay on the hydrolysed diet, or move to a hypoallergenic food.

Atopic dermatitis

This is poorly understood in cats, but is a condition where the cat’s immune system goes haywire and starts attacking harmless substances like dust or pollen – but instead of just one allergic condition, the cat often develops many different allergies simultaneously. It’s hard to diagnose, and treatment is expensive, relying on suppressing the abnormally active immune system. However, the medication is quite effective for most cats, who can go on to live a normal life in most respects.

Skin infections

Yes, cats can get skin infections too! Either on their own, or as a complication of any of the other diseases. These may be bacterial infections, yeast infections, or fungal infections e.g. Ringworm. The trick is for our vets to take swabs and smears and tape strips, and see what’s growing on the poor cat’s skin. Then they can prescribe the right meds to kill it – as creams, or tablets, or shampoos, or sometimes injections. It just depends what they find!

Itching is a nasty and uncomfortable state for a cat to be in – don’t leave them to suffer, make an appointment so we can get to the bottom of it and have them back to normal!