Dexamethasone for Cats

PetMD’s medications content was written and reviewed by veterinary professionals to answer your most common questions about how medications function, their side effects, and what species they are prescribed for. This content shouldn’t take the place of advice by your vet.

What Is Dexamethasone Used for in Cats?

Dexamethasone is a powerful anti-inflammatory prescribed to treat asthma, immune-mediated diseases (where the immune system is overactive and attacking its own tissues), severe allergic reactions, and deficiencies of natural body steroids (such as Addison's disease) in cats.

Dexamethasone can also be used in combination with other medications to treat certain types of cancer.

Dexamethasone is also commonly used as an injection in the hospital setting to aid in certain emergencies like an asthma attack, severe allergic reactions, certain dermatological (skin) conditions, and rarely, Addisonian crisis (underactive adrenal gland disease).

Dexamethasone may also be used as a part of testing to help diagnose Cushing’s syndrome, as well as other steroid hormone imbalances. 

The injectable version of dexamethasone is FDA-approved for use in cats, but tablets are currently only approved by the FDA for use in humans.

However, tablet versions of this medication are readily utilized in the veterinary field, and veterinarians can legally prescribe certain human drugs for use in animals in certain circumstances. This is called extra-label or off-label use because this use isn’t described on the drug label.

Compounded Dexamethasone for Cats

In certain circumstances, your veterinarian may recommend a compounded formulation of dexamethasone.

Compounded medications are prescribed if there’s a specific reason your pet’s health can’t be managed by an FDA-approved drug, such as if your pet has trouble taking pills in capsule form, the dosage strength is not commercially available, or the pet is allergic to an ingredient in the FDA-approved medication.

Compounded medications are not FDA-approved. They’re created by either a veterinarian or a licensed pharmacist on an individual basis to best suit a patient’s particular needs.

Your veterinarian will determine whether a compounded medication is right for your pet.

How Dexamethasone Works in Cats

Dexamethasone is a type of steroid medication called corticosteroids. It belongs to a subcategory of naturally occurring corticosteroids called glucocorticoids. Glucocorticoid medications have many functions depending on how they are administered.

Dexamethasone is considered a long-acting glucocorticoid and can have various effects on the body depending on the dose and treatment regimen:

• At lower doses, dexamethasone reduces inflammation and can replace normal body steroids.

• At higher doses, dexamethasone can suppress the immune system.

Your veterinarian will determine and prescribe the dose that is appropriate for your pet’s medical condition.

Dexamethasone Considerations in Cats

Because it can suppress the immune system and impact other bodily functions, dexamethasone is not used in cats with certain medical conditions such as viral infection, fungal infection, and other internal diseases.

Giving dexamethasone with certain medications can result in health risks to your pet, so it’s important to discuss your pet’s medications, including vitamins and supplements, and medical conditions with your veterinarian.

Dexamethasone for Cats Directions

Follow the directions on the drug label or as provided by your veterinarian. Check the label closely, as the recommended dosage may change over the course of treatment.

Your veterinarian may recommend giving dexamethasone with food, as this will lower the risk of digestive upset.

Treatment with dexamethasone for longer than one to two weeks can interfere with your pet’s body’s production of their own steroids. To account for this, veterinarians usually recommend that the dose or frequency be slowly decreased over time (tapered) until your pet is no longer on this medication. Make sure to follow all dosing tapering directions closely.

Do not stop the medication before completing the full course of treatment without first discussing it with your veterinarian. Abruptly stopping long-term treatment without tapering the dose can cause serious side effects.

Missed a Dose?

Speak with your veterinarian about what to do if you forget to give a dose of dexamethasone.

Generally, they may instruct you to give it when you remember, or, if it is almost time for your pet’s next dose, to skip the missed dose and resume your normal dosing schedule.

Do not give extra or double doses.

Possible Side Effects of Dexamethasone in Cats

Side effects from taking dexamethasone are highly dependent on what dose of medication your pet is receiving and how long they have been on the medication. 

The most common side effects in cats include:

• Increased appetite

• Increased thirst

• Increased urination (increased amount and/or frequency; may cause accidents inside the house)

• Vomiting/diarrhea

Additional side effects can be seen, especially when dexamethasone is given long-term or at higher doses. These additional side effects may include:

• Weight gain

• Thinning of the skin

• Poor haircoat or hair loss

• Muscle wasting (atrophy)

• Behavior changes (aggression, depression, lethargy) 

• Decreased energy level or weakness

• Bleeding into the digestive tract (may present as black and tar-like stools)

• Stomach or intestinal ulcers, or sores (may present as bright blood in vomit)

• Triggering or worsening of diabetes mellitus

• Pot-belly appearance (distended abdomen)

• Increased risk for infections 

If you believe your pet may be experiencing any side effects of dexamethasone, consult your veterinarian.

Abruptly stopping a steroid medication like dexamethasone can cause serious side effects, so contact your veterinarian before discontinuing dexamethasone. Your veterinarian can recommend a dose taper to reduce the likelihood of serious side effects.

Human Side Effects

Dexamethasone is also a prescription medication for humans, frequently with dosages different from those prescribed for your pet by a veterinarian.

Due to possible side effects, humans should never use medicine dispensed for their pets and pets should not be given any medicine dispensed for a human’s use.

If you accidentally ingest your pet’s medication, call your physician or the national Poison Control Center hotline at 800-222-1222.

Monitoring Your Pet

Your veterinarian is likely to recommend routine visits and testing while your pet is on this medication. Testing may vary depending on your pet’s individual needs, any other medications they may be on, and/or the issue that initially caused your pet to be placed on this medication.

When To Call Your Vet

Call your veterinarian if any of the following apply:

• Severe side effects are seen (see above)

• Your pet’s condition worsens or does not improve with treatment

• You see or suspect an overdose

• You have additional questions or concerns about the use of dexamethasone

Dexamethasone Overdose Concerns in Cats

Overdoses of steroids like dexamethasone can cause digestive upset and ulceration. Signs may include:

• Vomiting

• Diarrhea

• Decreased appetite

• Blood in the vomit

• Black, tar-like stools

If you suspect an overdose, immediately seek emergency veterinary care or contact an animal poison control center. Consultation fees often apply.

• Pet Poison Helpline 855-764-7661 

• ASPCA Animal Poison Control 888-426-4435 

How To Store Dexamethasone for Cats

• Always confirm storage requirements by reviewing the label.

• Dexamethasone should be stored at controlled temperatures of 68–77 degrees F (20–25 degrees C).

• Keep the container tightly closed to protect from moisture and light.

• Compounded medications should be stored according to the compounding pharmacy’s label.

• Keep out of reach of children and pets.