Dexamethasone for Dogs: Uses and Side Effects

Written and verified by the biologist Cesar Paul Gonzalez Gonzalez

Last update: 22 December, 2022

Dexamethasone is a drug used to fight inflammation, and so it’s a common treatment for various types of ailments. In dogs, several diseases can be treated by administering dexamethasone, so it’s a great ally for canine health. Of course, it should only be taken with a prescription and the advice of a qualified veterinarian.

Despite being a very useful drug, it also has some side effects. For this reason, you should never self-medicate your pet, as it could be counterproductive.

Remember that the information provided in this article is for informational purposes only; in case of any questions or emergencies, go to an animal health professional. Read on to learn more about dexamethasone.

What is dexamethasone for dogs?

Dexamethasone is a corticosteroid that closely resembles the hormone cortisol. Because of this, the drug is able to get into the cells of the body, allowing it to control inflammation in certain areas. However, this mechanism of action also has an immunosuppressive effect and causes a reduction in the efficiency of the dog’s immune system.

These effects are what make it difficult to prescribe a treatment with dexamethasone, because although it can be beneficial, it leaves the body susceptible to other types of threats. Therefore, only a veterinarian can recommend the use of this drug, as it must evaluate the situation of each patient. Even so, it isn’t all bad, news, because, in many situations, dogs treated with this drug will improve quite a lot.

Dexamethasone isn’t a drug that can only be used in dogs;  it’s also used in humans and other animals. However, the dosage and presentation change in each species, so it isn’t recommended to use the human drug in dogs and vice versa. If in doubt, consult your trusted veterinarian.

Uses of the drug

The main effect of dexamethasone is immunosuppression, as the immune system is the cause of several medical conditions in dogs. Because of this, there’s a wide variety of diseases in which it can be useful. The following are some of the uses of this drug in dogs:

• Inflammation: This reaction of the body is caused by the immune system, because when the body experiences any type of damage, the affected region begins to expand the blood vessels, which allows the body’s protective cells to arrive and begin to repair the injury. This is what causes inflammation, so reducing the activity of the immune system also reduces this problem.
• Allergies: An allergy could be taken as a sudden overreaction of the immune system, which causes several problems such as inflammation, tearing, and skin irritation. For this reason, when the activity of the immune system is reduced, the allergy is also controlled.
• Musculoskeletal problems: Such as osteoarthritis, myositis, and arthritis. All of these cases cause inflammation in different areas of the body, and so anti-inflammatory drugs are very helpful in dealing with severe symptoms.
• Diagnosis of endocrinopathies: This refers to diseases caused by poor regulation of hormones. In dogs, the most common is Cushing’s syndrome, for which dexamethasone is used as part of a diagnostic test.

Most of the uses that this drug has are palliative in nature. This means that it’s only limited to reducing or controlling the symptoms, but not eradicating the problem. Also, the side effects can also be risky, so only a professional should prescribe and monitor the use of this drug.

Dosage of dexamethasone for dogs

The dose of dexamethasone for dogs varies in each case, because in emergencies vets may recommend a higher amount of the drug. Even so, the general rule is to administer between 0.1 and 2 milligrams per kilogram of weight of the animal. The normal presentation of this drug is in injectable solution, but there are also tablets that can be administered orally.

In addition to the above, a veterinarian needs to prescribe the corresponding dose, as there are certain restrictions for long-term use. It must be administered and withdrawn gradually because otherwise it could cause side effects in the dog (such as Cushing’s syndrome).

Contraindications of the drug

The use of dexamethasone is contraindicated in cases of fungal infections, viruses or bacteria, since its immunosuppressive effect could aggravate the situation. This drug has several effects on the dog’s body, and there are several scenarios in which it shouldn’t be administered. Some of its contraindications are as follows:

• Diabetes: Dexamethasone causes an increase in blood sugar levels, so dogs with diabetes may have problems with their disease. Also, this drug reduces the effect of diabetes medications.
• Kidney failure: The drug is usually eliminated through the kidneys, so it can be more demanding and aggravate the kidney problem. Very low doses of the drug are recommended in some cases, but only under veterinary diagnosis and monitoring.
• Heart failure: In the long term, dexamethasone causes sodium retention, which leads to an increase in blood pressure. In dogs with heart failure, the heart often can’t withstand these changes in pressure.
• Hyperadrenocorticism (Cushing’s syndrome): This syndrome refers to an excess of cortisol in the blood, which causes different symptoms in the dog. The use of dexamethasone can cause this problem, as it affects the natural regulation of cortisol.
• Osteoporosis: Osteoporosis is a chronic degenerative disease that weakens bones. Corticosteroids can also have this effect over the long term, so using them while you have this disease increases the rate at which you lose bone mass.
• Gastrointestinal ulcers. Heartburn is mediated by prostaglandins, which are inhibited by the use of dexamethasone. In the long term, this could lead to the complication of canine ulcers.
• Hypersensitivity (allergy). This refers to an excessive immune response to dexamethasone, which may result in anaphylactic shock.
• Pregnancy: Corticosteroids induce labor in animals and malformations in fetuses, so their use isn’t recommended in pregnant females.

In addition, dexamethasone can have interactions with other medications, so it’s necessary for a veterinarian to evaluate the conditions in each case. Make sure you tell the specialist about the drugs and vaccines that the dog has recently taken. In this way, they can prescribe the appropriate treatment without any major complications.

Side effects

Short-term doses of this drug don’t usually cause any problems. However, when the treatment is long term there may be certain side effects that should be taken into account. The most common side effects include the following:

• Fluid retention.
• Adrenal insufficiency: Corticosteroids are a synthetic form of the hormone cortisol produced by the body, so when used for a prolonged period of time they can cause an incapacity in the glands responsible for producing it naturally (adrenal glands). This is what leads to Cushing’s syndrome.
• Glycemia: increased glucose in the blood.
• Polyuria: increased urine production.
• Polydipsia: increased fluid intake.
• Polyphagia: increased food intake.
• Delayed healing: the immunosuppressive effect prevents rapid healing.
• Ulcers: inhibition of prostaglandins causes ulcers to appear or worsen.
• Secondary infections: the immune system is restricted, so the dog is susceptible to infection by other bacteria, fungi, or viruses.
• Reduced milk production.

Usually, these side effects go away after dexamethasone treatment ends. However, in the case of adrenal insufficiency, the drug is usually withdrawn gradually in order for the body to adapt to the natural production of the hormone.

The importance of going to the vet

As you can see, the use of dexamethasone must be prescribed and monitored by the veterinarian, as it could cause problems for your pet. Don’t self-medicate your dog, as the consequences could be fatal; your dog’s health isn’t a game.