Cat Scratching and Itching – Causes of Scratching and Itching in Cats

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(Last Updated On: November 12, 2018)

 

At a glance

Itching and scratching are one of the most common symptoms a cat can display and have a range of causes. Prolonged scratching can cause self trauma, and lead to skin infections.

Causes:

  • Fleas
  • Allergies
  • Ear mites
  • Ringworm
  • Ear mites
  • Notoedric mange (feline scabies)
  • Cheyletiellosis (walking dandruff)
  • Feline miliary dermatitis
  • Insect bite or sting
  • Seborrhea
  • Folliculitis
  • Malassazea
  • Skin infection
  • Adverse reaction to a topical flea product

Treatment:

The goal of treatment is to find and treat the underlying cause.

 

why is my cat scratching?

Cat fleas

The most common cause of itching in cats is due to fleas. They are most abundant in the summer months, although in tropical areas may be found all year around.Cats become infested when they come into contact with fleas in the environment, another animal or even when humans bring fleas inside. Fleas not only cause discomfort but can also transmit diseases, parasites and cause anemia.

Symptoms:

  • Fleas in the coat, they can be hard to see on dark coloured cats
  • Salt and pepper debris where the cat sleeps, which is flea eggs and feces
  • Excessive scratching

Treatment:

There are a number of products available to kill fleas on the cat. These include spot-on products which are applied to the skin on the back of the cat’s neck, shampoos, tablets and flea collars. Speak to your veterinarian or vet nurse who will be able to recommend the best product.

The environment will either need to be treated with a flea bomb or a pest controller, along with some thorough washing and vacuuming. For further information on cat fleas read here.

Flea allergy dermatitis

As the name suggests, it is caused by an allergic reaction to a flea bite. There are 15 known allergens in flea saliva, each one is capable of causing an allergic reaction in the cat. Just one bite from a flea is enough to trigger an allergic reaction in your cat.  FAD is one of the major causes of miliary dermatitis in cats.

Symptoms:

  • Frequent scratching and biting of the fur, especially on the back and the base of their tail.
  • Raised bumps (papules) or scabs on the skin and thinning fur in the affected area.

Your veterinarian will be able to diagnose flea allergy dermatitis. Signs of fleas on your cat are a good indicator. However, extremely sensitive cats will have few if any fleas on them. This is due to excessive self-grooming.   In such cases, to get a definite diagnosis that your cat is, in fact, allergic to flea bites and not something else then an intradermal skin testing is required.

Treatment:

  • Eliminating fleas from your cat and environment, and preventing re-infestation of fleas.
  • Treating secondary skin infections caused by excessive biting and scratching of the skin. This may involve a course of antibiotics, medicated shampoo and or a topical medication.
  • Antihistamines or steroids to control inflammation and reduce itching.
  • Hyposensitisation (desensitisation). This involves injecting minute amounts of flea antigen into the cat in the hope that it will re-programme the immune system so it’s not hypersensitive to flea antigen.

Allergies

Allergies are a common cause of skin disease in cats. The purpose of the immune system is to keep infectious microorganisms, such as certain bacteria, viruses, and fungi, out of the body, and to destroy any infectious microorganisms that do invade the body. Allergies are caused by an inappropriate response to a substance which is harmless. In an allergic animal, the immune system overreacts and mounts an immune response against it. Four types of allergy exist in cats:

  • Contact – Anything that comes into contact with your cat’s fur and skin, which may include shampoos or creams, plants, wool, detergents.
  • Food – Caused by an allergic reaction to one or more ingredients in the cat’s food with the most common causes of food allergies including are fish, beef, eggs, and wheat.
  • Inhalant – Pollen, cigarette smoke, dust mites, moulds.
  • Insect – Fleas are the most common cause of insect allergy, but other insects such as mosquitos can also cause an allergic reaction.

Symptoms: 

  • Non-seasonal itching
  • Crusting along the cat’s back, close to the base of the tail, and around the head and neck
  • Hair loss
  • Raw and inflamed skin, especially on the inside of the hind legs
  • Vomiting or diarrhea

Diagnosis: 

A thorough physical examination and medical history including onset of symptoms, any products or chemicals which may have come into contact with the cat (deliberate or unintentional). If the veterinarian suspects allergies it will be necessary to undergo tests which may include:

  • Skin prick testing: An area of skin is shaved and a number of common allergens are introduced to the skin to see if a reaction occurs to one or more.
  • Food elimination trials: The cat is put on a novel protein such as duck or kangaroo, during this time, no other food or treats can be given to the cat. If symptoms clear up, the cat is challenged by being re-introduced to the normal diet to see if symptoms return.

Treatment:

  • Avoidance of the allergen where possible.
  • Diligent flea control on both the cat and inside the home.
  • Change to a hypoallergenic diet for cats with food allergies. If storage mites are the cause, switching to a canned or raw diet will resolve the allergy.
  • Antihistamines or corticosteroids can be prescribed to relieve symptoms of itching.

Ear mites (Otodectes cyanosis)

Ear mites are a common spider-like external parasite which causes significant discomfort to the cat. Although the name would suggest otherwise, ear mites can live on any part of the body although they generally live in the ear canal of cats. They are the most common cause of otitis externa (inflammation of the outer ear canal) in cats.

Symptoms:

  • Not all cats will display symptoms of ear mites but often they will scratch at their ears and or shake their heads.
  • Reddish/brown discharge in the ear,  bleeding from the ear
  • Coffee-grounds like appearance in the ear
  • Scratch marks and trauma
  • Odour

Treatment:

  • Removal of the exudates from the ear by instilling a few drops of mineral oil and gently massaging the base of the ear. This will loosen the exudate, which will make it easy to remove.
  • Your veterinarian will be able to prescribe a commercial insecticide to kill the mites. Products vary from country to country, but below is a list of popular products which may be prescribed. These treatments must be carried out over several weeks, it is not possible to kill the eggs or pupae. The aim of treatment is to kill adults as they reach maturity and break the life cycle of the mite.
  • Treat all household cats and dogs at the same time.

Notoedric Mange (feline scabies)

This highly contagious, intensely itchy skin disease, caused by the mite Notoedres cati. These mites are closely related to the Sarcoptic mange, which causes mange in dogs.The first sign of notoedric mange is usually intense pruritus (itching) along with hair loss and a thick/crusty and scabby appearance to the skin, especially on the tip of the ears. It then progresses to the face and neck, and if untreated can progress to other parts of the body.

Symptoms:

  • Scratching the affected areas causes the skin to become raw, red and inflamed, which can cause potentially dangerous secondary bacterial infections

Diagnosis:

  • Scraping of the cat’s crusty skin examine it under a microscope for the presence of mites or mite eggs

Treatment: 

  • Your veterinarian may clip semi and longhaired cats before treatment. Cleansing of the area to soften thick crusts, followed by a weekly lime sulfur dip.
  • Amitraz is another effective dip, this product hasn’t been approved for use on cats though
  • Ivermectin, administered via injection. It hasn’t been approved for use in cats, although reports are that it is safe.
  • Revolution: This product is typically a flea and worm product but has shown to be effective on notoedric mange.

Cheyletiellosis

Also known as walking dandruff, cheyletiellosis  is a highly contagious skin disease caused by the Cheyletiellosis mite. Cats are most commonly infected with Cheyletiella blakei. Young cats are more often infected although cats of any age can have these mites.The mites live out their entire life cycle (approximately 30 days) on the cat, living on the skin surface keratin. They occasionally burrow their head pincers (known as chelicerae) into the skin and feed on tissue fluids.

Symptoms:

Often the mites can be seen moving around, hence the name walking dandruff.

Diagnosis:

Cheyletiellosis is diagnosed by flea combings, skin scrapings, fecal flotation or acetate tape preparations.

Treatment:

There are several ways to tackle cheyletiellosis, your veterinarian will recommend the best treatment.

  • Weekly dipping with either lime sulfur or pyrethrin for 6 – 8 weeks. Long-haired cats may need to be clipped.
  • Ivermectin has not been approved for use in cats but is commonly prescribed extra-label to treat Cheyletiellosis.
  • The environment will also need to be treated with a suitable insecticide

Feline miliary dermatitis

Miliary dermatitis (miliary eczema, papula crusting dermatitis or scabby cat disease) isn’t a specific disease but a disease complex. It is characterized by a red and crusty rash around the head, neck, and back, often with intense itching.There are several causes of miliary dermatitis including flea bite hypersensitivity, Allergies; food intolerance, inhalant allergy, food allergy, bacterial infections, mites, mange, ringworm, yeast infections, immune-mediated diseases, drug hypersensitivity, poor diet and hormonal/endocrine disorder.

Symptoms:

  • Red, crusty bumps, especially around the head, neck, and back
  • Intense itching
  • Hair loss

Treatment:

  • Fleas: Removal of the fleas from the cat and environment should cure the problem. Strict flea control are necessary to control fleas.
  • Mites, mange, fungal or yeast infections: Treat the cause and miliary dermatitis should go away.
  • Intestinal parasites: Anti-worming medication.
  • Food allergy: A hypoallergenic diet may be tried if parasites, yeast infections, fungal infections etc., are ruled out.

In addition to the above treatments, supportive care to manage symptoms are necessary.

  • Antibiotics for secondary skin infections, if required.
  • Shampoos to relieve itching and inflammation.
  • Other possible treatment options include fatty acids, antihistamines, and corticosteroids.

Ringworm

Also known as dermatophytosis (pronounced der-mato-ptosis), ringworm a common fungal infection which affects the skin, fur, and nails of cats. It is caused by a microscopic group of parasitic fungal organisms known as dermatophytes, meaning “plants that live on the skin“.Ringworm invades the dead, outer layers of the skin, claws, and hair. The name ringworm comes from the ring like, circular lesions which develop on the cat’s skin. The fungus is more common in areas of high humidity and temperatures.

Symptoms:

  • Circular patches of hair loss, especially around the head and limbs
  • Grey, patchy areas of baldness, with or without redness and itching
  • Seborrhea sicca (a type of dandruff)
  • Dry/flaky skin, onychomycosis (infection of the claw and claw bed)

Diagnosis:

It may be possible to diagnose ringworm based on presenting symptoms, however the veterinarian may decide to confirm diagnosis with a Wood’s Lamp, which will causethe infected hair shafts will glow a fluorescent green when exposed. Other diagnostics include microscopic examination of the hair shaft and a fungal culture.

Treatment:

Once a diagnosis has been made, it will be necessary to treat both your cat and the home. If you live in a multiple cat household, all cats in your home will need to be treated. It is easier if you can keep all cats confined to just one room while treatment is underway to avoid spreading spores around the home.

There are a number of treatment options which include oral medications, medicated dips and lime sulfur dips.

Insect bite or sting

Ants, mosquitoes, bees, wasps and many other insects all have the potential to bite your cat which can cause an allergic reaction. This is usually self-limiting unless your cat develops an allergy.

Treatment:

Ice compress to relieve itching. Your veterinarian may also recommend an antihistamine.

Malassezia

This yeast lives on the skin of cats and ear canal of cats in low numbers and usually causes no problems. However, in some cats, the yeast begins to grow to the point where it causes disease. This is usually the result of immunosuppression (such as a cat with feline immunodeficiency virus or feline leukemia virus), long-term antibiotic use, allergies which damage the skin, endocrine disorders and certain tumours.

Symptoms:

Itching, hair loss, greasy lesions, unpleasant odour, swelling of the affected area, and waxy build-up of the ears

Treatment:

Addressing the underlying cause, anti-fungal sprays or shampoos, and medications such as Itraconazole for severe cases.

Seborrhea

Seborrhea is a skin disorder caused by an overproduction of sebum, an oily substance produced by the sebaceous glands which lubricate and protects the skin. It is reasonably common in the dog, but not the cat. It is characterised by the accumulation of oil and debris on the skin which leads to scaling, flaky skin.There are two forms of seborrhea, seborrhea sicca, which is a dry, scaly form or seborrhea oleosa, a moist oily form. It can be primary or secondary. Primary seborrhea is an inherited condition, seen most often in Persian cats, secondary seborrhea is associated with a number of underlying diseases or conditions such as parasites,  Cushing’s syndrome, diabetes, hyperthyroidism, poor diet, food or inhalant allergy. The most common type of seborrhea in cats is secondary.

Symptoms:

  • Itching may or may not be present depending on the underlying cause
  • Seborrhea sicca may present as patches of dull, dry, dandruff-like flakes in the coat
  • Seborrhea oleosa presents as patches of greasy/oily scales or crusts with a pungent odour
  • Secondary bacterial or fungal infection occur quite often

Treatment:

Finding and treating the underlying cause is necessary. This may include:

  • Antibiotics for bacterial infection.
  • Anti-fungals for fungal infection.
  • Medicated antiseborrheic shampoos applied every three days until the condition is under control. There are different types of shampoo depending on which form of seborrhea your cat has.
  • Fatty acid supplements may be of some use for treating this condition in cats.

Folliculitis

Folliculitis is an inflammation or infection of the hair follicles that is characterised by the presence of red bumps on your cat’s skin. The condition occurs when bacteria, which normally reside on the skin invade the hair follicle, usually due to damage caused by itching, scratching or inflammation. Feline acne, allergic dermatitis, mites, metabolic disorders, flea bite allergy and stud tail can both lead to folliculitis in the cat.

Symptoms:

  • Red or pus-filled papules on around one or more hair follicles
  • Small fissures (splits or cracks) or ulcers may occur in more severe cases
  • Thinning or bald patches may occur in the affected area
  • If feline acne is present, the follicles may contain blackheads, with surrounding skin red and inflamed
  • Itchiness. Your cat may frequently scratch and rub the affected area
  • Localised lymph node swelling
  • Pain

Treatment:

The goal of treatment is to find and address the underlying cause, which may include:

  • Switch from plastic to glass or ceramic food bowls and wash daily.  Clean the skin with iodine (diluted to the colour of weak tea), Epsom salts or witch hazel.
  • If an allergy is a cause, removing the allergen if possible. Common allergens include plants, food, chemicals, soaps, and detergents.
  • Medicated shampoos or topical preparations to help dry up the pustules and relieve itching.
  • Antibiotic therapy for 2-4 weeks.
  • Topical glucocorticoids to reduce inflammation and itchiness.

Adverse reaction to flea products

Topical flea products (known as spot on) have made treating fleas (and worms) so much easier. They come in liquid form,  and are applied to the skin on your cat’s neck (between the shoulder blades)  once a month.The most common topical flea products used on cats include Frontline, Revolution, Program and Advantage. While these are all safe to use when instructions are carefully followed (and I use them on my own cats), in rare cases, cats can have a reaction.

Symptoms:

Can range from mild itching to severe chemical burns which may include redness, hair loss, bleeding and ulceration.

Treatment:

  • If your cat suffers a chemical burn to a flea product, rinse the area with lukewarm water for 20 minutes.
  • If he has licked some of the product off, rinse his mouth in with water.
  • Get him to a veterinarian. Bring along the packaging so your veterinarian knows the active ingredient.

Skin infection

Anything that affects the integrity of the skin has the potential to lead to a skin infection. Most often this is caused by trauma (such as a bite or scratch), self-mutilation (over grooming but more often than not, damage due to biting or scratching itchy skin due to an allergic reaction, hypersensitivity, parasites), endocrine disorders and poor immunity.

Causes: 

  • Parasites
  • Allergies
  • Ringworm
  • Seborrhea
  • Hypothyroidism (underactive thyroid gland)
  • Cushing’s disease
  • Diabetes

Symptoms: 

  • Crusting and scaling, often with short hairs which can easily be pulled out
  • Papules or pustules on the skin
  • Alopecia (baldness)
  • Ulcerations or erosions which may ooze
  • Unpleasant odour
  • Pruritis may or may not be present, this can depend on the underlying cause

Treatment: 

  • Oral antibiotics for 3-4 weeks.
  • Topical antibiotics or antibiotic shampoos may also be necessary to help soften the crusts and treat the infection.
  • Address the underlying cause.

Home care

Anthistamines and/or corticosteroids may be prescribed to relieve symptoms of itching. Always administer as prescribed.

Use a reliable flea control programme and remember to treat the home as well as cat.

Speak to your veterinarian about using a fish oil supplement which is applied to food once a day. This can help to reduce inflammation associated with itching.

If you notice any discharge or unpleasant odours to the skin, speak to the veterinarian as self trauma and secondary skin infections can occur if the cat is scratching due to constant itching.

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