Hair Loss in Cats (Alopecia)

Hair loss (alopecia) can occur physiologically in cats due to the seasonal coat change or it can also be pathological. Parasites, hormonal disorders, or hereditary disorders of hair formation are just a few examples of causes of hair loss in cats:

How Does Hair Loss Occur in Cats?

Hair loss is not a disease in its own right, but a sign of a disease. For a better overview of possible causes, alopecia is therefore divided into real hair loss (due to non-itchy causes) and apparent hair loss (due to itching and scratching):

Non-itchy causes:

• Hormonal disorders: The formation of hair takes place in three different phases, which are controlled by various growth hormones. These are influenced, among other things, by the hormones of the adrenal glands or the thyroid gland, which is why diseases of these organs can lead to hair loss. In cats, the overactive thyroid gland (hyperthyroidism) is often observed as a cause of hair loss.
• Hereditary diseases that lead to functional or structural disorders of the hair roots (e.g. follicular dysplasia)
• Infections of the skin by bacteria (e.g. staphylococci or streptococci) as well as by fungi (e.g.
• Malassezia or dermatophytes).
• Tumorous events
• stress

Causes caused by itching:

• Ectoparasites such as fleas, ear mites, and hair follicle mites
• Allergic reactions (e.g. from pollen, house dust mites, or scented cat litter)
• Bacterial and fungal infections can also lead to hair loss in cats through itching

What other symptoms do you experience besides hair loss?

Cats can show hair loss all over or in specific areas of the body. Also, depending on the cause, the shape, the extent, the temporal occurrence (acute or chronic), and the symmetry vary. Affected cats often suffer from other symptoms, depending on the underlying disease:

• Itchy hair loss is usually caused by scratching and licking the affected areas of the skin.
• Hormonal disorders such as an overactive thyroid often lead to weight loss in cats despite increased food consumption. Gastrointestinal complaints or increased activity behavior are also frequently observed.
• Bacterial infections can be accompanied by purulent wound secretions and, if the course is severe, lead to life-threatening bacterial blood poisoning (sepsis). In the course of the event, the cats show a greatly reduced general condition and a high fever.

Which Diagnostic Measures are Possible?

Because of the many causes of hair loss in cats, it is advisable to seek advice from a veterinarian. Even during the owner survey (anamnesis), information about previous parasite prophylaxis or feeding and keeping methods can provide important information. Sudden changes in personality or the occurrence of other symptoms (e.g. diarrhea, vomiting, tiredness) are also asked about.

After the veterinarian has determined the current state of health as part of the general clinical examination, he can continue with a thorough inspection (inspection) of the affected skin areas. If, for example, a purulent secretion is visible on the skin, this can be a sign of bacterial skin inflammation (pyoderma). If the hair is only broken off, hair loss caused by itching is more closely suspected.

Unfortunately, the appearance does not always indicate the cause, which is why in some cases more time is required for a reliable diagnosis. The following diagnostic measures can help:

• A blood test can be used to find signs of inflammation, allergic reactions as well as parasite infestation, or diseases of various organs (e.g. the liver).
• A skin test (intradermal test) or an antibody test (in-vitro test) can also be carried out to clarify allergic reactions. Elimination diets also help diagnose feed allergies.
• Hormonal disorders can be detected using special hormone tests.
• A Trichogramma can be used to determine the hair cycle. For this purpose, individual hairs are viewed under a microscope and then examined for their characteristics.
• Surrounding skin layers can be examined for inflammatory cells, bacteria, and parasites with the help of a biopsy.

How is Hair Loss Treated?

In order to be able to eliminate hair loss in cats, targeted therapy of the cause is necessary:

• Bacterial infections usually heal over several days after regular wound cleaning. In some cases, more severe courses also require the administration of antibiotics in the form of ointments and/or tablets after the resistance test has been carried out.
• A parasite infestation can be treated with medication.
• Hair loss due to an allergy sometimes requires the administration of cortisone preparations. Eliminating the antigen from the cat’s environment also eases the symptom.
• Hormonal disorders can be treated with medication or surgery, depending on the cause. An overactive thyroid can be relieved with radioiodine therapy, for example.
• Tumorous diseases require radiation or chemotherapy, depending on the type of cell. Surgical interventions can also be curative.

What is the Prognosis?

Hair loss itself is not a major problem for most cats. However, serious illnesses can underlie the symptom. The prognosis is therefore strongly dependent on the cause and the therapy. However, if the underlying disease can be successfully combated, the hairless skin areas usually disappear quickly.

Can Cat Hair Loss be Prevented?

Some causes of hair loss in cats can be counteracted at an early stage. Special collars or spot-ons can be used as parasite prophylaxis, which uses pyrethroids to fight mites, fleas, and ticks. A balanced diet and good housing conditions also counteract underlying diseases.