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Feline acne is a common multifactoral skin disorder characterised by the presence of blackheads on the cat's chin and lips. It can affect cats of any age, sex or breed. There may be a slight predilection in neutered male cats.
Sebaceous glands secrete oils (known as sebum) which lubricate the skin, preventing dryness and irritation. The sebaceous glands are mostly found in dorsal, eyelids, chin, the surface of the base of the tail, lips, scrotum, and prepuce. They are connected to the hair follicles. These glands also play a role in territorial marking and any observant cat owner will have seen their cat rubbing his face and chin along objects. Over time this rubbing will leave greasy patches.
The exact cause of feline acne isn't known. There are several possible causes however including:
- Stress - Stress triggers the release of various hormones which lead to the sebaceous glands producing more sebum.
- Plastic food bowls - This type of food bowl discouraged, particularly in cats with feline acne. These types of bowls porous and over time can develop lots of scratches both of which trap bacteria when the cat eats, the bacteria is then transferred to the cat's chin which can cause swelling, inflammation and infection. It has also been suggested that an allergic reaction to the plastic food bowl may be a cause.
- Poor grooming, the chin is a rather difficult area on cats to clean.
- Overactive sebaceous glands or abnormal sebum production.
- Hormonal imbalances.
- Atopic and food allergies.
- Immunosuppression may predispose cats to feline acne, these include feline leukemia virus and feline immunodeficiency virus infections.
- Upper respiratory viral infections from feline calicivirus may be responsible for feline acne where entire multi-cat households are affected.
- Excessive chin rubbing may be a causative factor, particularly in multi-cat households. Cats have scent glands around their lips and chin, this is your cat's way of marking his territory (in a nicer way than spraying).
Note the small blackheads around the cat's lip
Cats with feline acne develop follicles which become blocked with a black sebaceous material, which over time oxidise resulting in characteristic blackheads. Hair follicles may become irritated, swollen and infected, leading to the development of pustules. Keratanisation (hardening of the skin) and hyperplasia (enlargement) of the sebaceous glands may occur over time. Acne may be mild, moderate or severe.
Symptoms may be sporadic, coming and going or persistent.
- Mild to moderate feline acne is characterised by blackheads (comedones) and possibly reddened skin under the chin and occasionally extending to the lower lips. Comedones are often mistaken for dirt or food residue. A small amount of hair loss may also occur in the affected area. Some cats may remain at this stage.
- If the condition progresses, redness, papules, pustules, swelling and pruritis (itching) may develop.
- Severe cases may develop with painful firm nodules and draining lesions. Over time, scarring and thickening of the skin can develop.
- Secondary infection can develop, with the most common microorganisms including gram-positive Streptococcus spp, Staphylococcus spp, Pasteurella bacteria and Malassezia yeast.
- Local lymph nodes may be swollen.
- Anorexia may develop in severe cases due to pain.
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Your veterinarian will perform a physical examination of your cat and tentative diagnosis is usually made based on the appearance of comedones on the chin.
There are a number of conditions with similar symptoms which your veterinarian will need to rule out. These include eosinophilic granuloma complex, demodicosis (mites), Malassezia (fungi), neoplasia and ringworm.
Skin scrapings to look for demodicosis (mites).
Fungal culture if ringworm or malassazia is suspected.
Bacterial culture may be performed if bacteria are present, this will allow your veterinarian to determine the most effective antibiotic for treatment.
Skin cytology involves taking a sample from the affected area with sticky tape, directly applying a glass slide, or a mild skin scraping, applying a dye and examining the sample under a microscope to look for high numbers of malassazia yeast.
Biopsy and histopathology (microscopic examination of the biopsy sample) may be required in severe cases or to help your veterinarian rule out other conditions, evaluate for neoplasia.
Food elimination trial, flea elimination trial or skin allergy testing may be recommended if your veterinarian suspects an allergy is a causative factor.
Anesthesia is usually required for skin scrapings and biopsy due to the amount of pain experienced in cats with severe acne.
Treatment of feline acne depends on the severity of the condition. Products to inhibit the formation of blackheads, remove excess sebum and flush the hair follicles as well as treating secondary infections and eliminating the underlying cause if found.
- Severe cases may necessitate clipping of the area by your veterinarian prior to treatment.
- Topical antiseborrheic medications: Cleaning the skin with an ointment or gel containing benzoyl peroxide 2.5 to 5% (such as OxyDex) which is a broad-spectrum, antibacterial product which also has anti-pruritic (itching) properties. Some cats may experience irritation with this product. Salicylic acid is another topical medication which can be used topically, brands include Stri-dex and Clearasil.
- Topical antibiotic ointment such as 2% mupirocin, clindamycin or tetracycline containing products will be administered when furuncles (boils) and draining tracts are present on the chin.
- Topical antifungals will be necessary if the acne is complicated with Malassezia. These may include miconazole, chlorhexidine or ketoconazole.
- Topical glucocorticoids to reduce inflammation or oral glucocorticoids such as prednisone for severe inflammation and swelling.
- Oral antibiotics will be required to treat secondary bacterial infections, these will be administered for several weeks.
- Oral antifungals such as itraconazole or fluconazole may be prescribed for severe Malassezia.
- Oral synthetic retinoids may be necessary for cats who are unable to tolerate topical treatment or whose acne isn't responding to the above treatments. These demonstrate anti-keratinisation and anti-inflammatory properties.
- Omega fatty acids may be recommended as these are known to reduce inflammation.
- Feliway may be used to help cats suspected of excessive chin rubbing. This is a synthetic pheromone which mimics your cat's own feel-good pheromones.
It helps if you apply a warm, damp cloth to the chin for 30 seconds prior to applying treatments, this allows the medications to penetrate the skin more thoroughly.
Look out for signs of redness or inflammation when treating your cat with topical products. Consult your veterinarian if your cat does show signs of irritation, he will be able to recommend a more suitable product, or a varied skin treatment schedule. As the condition improves, your veterinarian will recommend you taper treatment.
Treatment may be lifelong. Always consult your veterinarian if you suspect feline acne and never treat your cat at home with an anti-acne treatment designed for humans.
Switch from plastic to glass, ceramic or metal food bowls as plastic can exasperate acne. Wash food and water bowls in hot soapy water daily. Rinse well and dry thoroughly.
If your cat is prone to acne, gently wash his chin after eating with warm water.
Administer medications as prescribed by your veterinarian. Always finish the entire course of oral antibiotics, even if symptoms have resolved.
Watch for signs of reaction to topical products.
Ongoing maintenance cleansing programmes may be recommended by your veterinarian. If the acne resolves, routinely monitor for relapse.
What is the prognosis for cats with acne?
The prognosis is good, however, pet owners must be aware that lifelong symptomatic treatment may be necessary.