Corticosteroids

Corticosteroids are synthetic hormones that mimic the body’s own messenger substances of the adrenal cortex. In veterinary medicine, they belong to the most prescribed active ingredients at all – and for good reason: no other medication works so quickly and reliably against inflammation, allergies and autoimmune diseases in dogs.

What are corticosteroids?

Basically, corticosteroids are synthetic copies of those hormones that the adrenal cortex itself produces. Two main groups are distinguished:

Glucocorticoids – such as prednisone or dexamethasone – are the representatives used far more frequently in small animal practice. They dampen inflammatory reactions and regulate the immune system, but also intervene deeply in carbohydrate, fat and protein metabolism.

Mineralocorticoids such as fludrocortisone play a significantly smaller role in veterinary medicine. Their main task: keeping electrolyte balance and blood pressure in equilibrium.

Indications

The range of applications is broad – sometimes surprisingly broad.

Allergies and skin diseases: In flea allergy dermatitis, environmental allergies (atopy) or food allergies, corticosteroids noticeably relieve itching, swelling and redness, often within a few hours.

Autoimmune diseases: Diseases such as autoimmune haemolytic anaemia or lupus require targeted braking of the overactive immune system – exactly what corticosteroids do here.

Inflammatory joint diseases: In arthritis, especially in acute flare-ups, they can quickly push back joint inflammation and thus significantly improve the dog’s quality of life.

Asthma and respiratory diseases: Chronic bronchitis or asthma involve permanently inflamed airways. Corticosteroids counteract this inflammation and make breathing easier.

Eye and ear inflammation: When applied locally – as eye drops or ear drops – they can be used for uveitis or severe ear infections without burdening the entire organism.

Inflammatory bowel diseases: In IBD (inflammatory bowel disease), they help to calm inflammation in the digestive tract and reduce symptoms such as diarrhoea and vomiting.

Shock and emergencies: In life-threatening situations – anaphylactic shock, severe trauma – corticosteroids can be used short-term to stabilise circulation.

Forms of Administration

Depending on the condition and urgency, there are various ways to administer the active ingredient.

Oral (tablets or capsules): The most common form for long-term treatment. Prednisone is the best-known example here – practical to handle and easy to dose.

Injections: Act faster and are preferred in acute situations, such as severe arthritis, asthma attacks or strong allergic flare-ups.

Topical application (ointments, creams, eye drops): Skin conditions, ear infections or eye inflammation can often be treated locally – with fewer systemic side effects than oral administration.

Inhalation: For chronic respiratory diseases, the active ingredient can be delivered directly into the airways via an inhaler – a method that is increasingly being used in small animal medicine.

Side Effects

Corticosteroids are effective. But they come at a price – especially with longer-term use.

Increased thirst and frequent urination: Polydipsia and polyuria are among the most common accompanying symptoms. Many dog owners notice this first: the bowl is suddenly constantly empty, walks become more frequent.

Weight gain: Appetite increases noticeably, which can quickly lead to weight gain. The amount of food should therefore be monitored.

Weakening of the immune system: The dampened immune system makes the dog more susceptible to infections – an aspect that vets always take into account when weighing up options.

Muscle weakness and muscle wasting: With prolonged use, muscle weakness can occur because corticosteroids promote protein breakdown in muscle tissue.

Thinning of the skin: Long-term therapy can make the skin thinner and more prone to injury – sometimes visible as slightly tearing or poorly healing areas.

Gastric ulcers and gastrointestinal problems: The gastric mucosa is sensitive to corticosteroids; the risk of gastric ulcers increases, especially when non-steroidal anti-rheumatics are given simultaneously.

Diabetes: Long-term use can promote insulin-resistant diabetes, as these substances raise blood sugar levels.

Behavioural changes: Restlessness, nervousness or a certain irritability are possible – not in every dog, but often enough that owners report it.

Cushing’s syndrome (iatrogenic hyperadrenocorticism): With long-term or high-dose administration, a drug-induced Cushing’s syndrome can develop. Typical signs are weight gain, thin skin, hair loss and muscle breakdown – symptoms that often develop gradually and are easily overlooked.

Long-term Use and Monitoring

Anyone treating their dog with corticosteroids on an ongoing basis cannot avoid regular check-ups. The aim is always to keep the dose as low as possible while still keeping the condition under control.

Important: The dosage must not be stopped abruptly. The vet usually prescribes a tapering schedule so that the adrenal glands do not simply stop their own cortisol production – stopping on your own initiative can have serious consequences.

The dose is reduced step by step until the lowest effective amount is reached. Regular blood tests and checks of organ function are not bureaucratic effort, but simply necessary – they show early whether the body tolerates the therapy well or whether complications are developing.