The Dark Side of Short & Long-Term Steroid Use in Dogs

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Steroids are widely used in veterinary medicine for treating inflammatory and immune-mediated diseases. They’re most commonly prescribed for dermatological issues, allergies, ear infections, and arthritis. Steroids for dogs come in the form of tablets, injections, topical creams, or a combination of the three. Prednisone, prednisolone, and dexamethasone are the most popular choices. Ideally, steroids would reduce inflammation and help with the harsh symptoms of the underlying disease — and this is where it gets complicated.

Steroids don’t treat the condition but only attempt to manage the symptoms on the surface. The side effects of corticosteroid treatment are often worse than the original symptoms, including wounds that don’t heal, skin infections, diabetes, and many others. This article explores a realistic picture of short & long-term steroid use in dogs, sharing the dark side of its side effects that too many dog owners aren’t warned about. 

Steroids Work by Immunosuppression 

The “modus operandi” of steroids is immunosuppression — they suppress the response of the immune system, which is why the symptoms “disappear” on the surface. The symptoms are masked and suppressed, not actually resolved! 

The hypothalamic-pituitary-adrenal axis (HPA axis) is a crucial part of this process because it regulates the body’s stress response. It produces natural steroid hormones, such as cortisol. Synthetic corticosteroids suppress the functioning of the HPA axis, compromising the body’s immune response, endocrine function, mood regulation, metabolism, and more. Research continuously confirms that steroids negatively affect all of the body’s large systems, including the neurological, cardiovascular, digestive, and urinary systems. Studies have shown that the HPA axis suppression can persist from 4-12 weeks (even if only topical treatments are used) or 6-12 months after the steroid treatment has been stopped! 

This method of functioning is the reason why steroids have so many dangerous side effects that impact the whole body, all while the underlying disease causing your dog’s original symptoms remains unaddressed. 

Short-Term & Long-Term Side Effects of Corticosteroids

When speaking about side effects, veterinarians differentiate short-time steroid use from long-term use. For steroids, long-term use is considered anything over two weeks! A common argument in the steroid conversation is that side effects depend on the dose and length of treatment, implying that lower doses and shorter treatments don’t have as many side effects. Except research shows otherwise.

A study looking at 148 steroid side effect cases in dogs showed that 65% of them happened before the two-week mark, with almost 17% of cases discontinuing treatment as a result! Another smaller study, looking at 31 dogs, found that 90% of them experienced side effects in the first two weeks and 74% already by day five. This tells us that side effects are the norm, not the exception, even in short-term corticosteroid use. The same study also showed that doses of prednisone and prednisolone lower than the recommended anti-inflammatory range resulted in just the same side effects — all dogs on lower doses showed side effects by day five. 

Most of us would not automatically consider two weeks as long-term, and yet this timeframe is clearly more than enough for steroids to show their dark side. The most common short-term side effects of corticosteroids are polydipsia (increased thirst), polyuria (excessive urination), and polyphagia (increased appetite). Dogs experience insatiable thirst and hunger due to the dysregulated cortisol levels as a direct result of HPA suppression. Other frequently recorded side effects are vomiting, diarrhea, shaking, lethargy, panting, and sudden behavioral changes. 

As weeks pass, these side effects can grow into long-term conditions, such as diabetes, Cushing’s syndrome, urinary tract infections, skin infections, poor wound healing, loss of muscle, kidney disease, liver disease, and more. Let’s take a closer look at some of the most concerning ones. 

Skin Infections — Worse Than Original Symptoms

Dermatological conditions are the most common reason for steroid prescriptions in veterinary medicine. A UK study found dermatitis (skin inflammation) and otitis (ear inflammation) representing over 70% of all steroid prescriptions. Another study reported that 20% of all dermatological cases resulted in corticosteroid therapy. 

It’s hard to watch your dog struggling with allergies, so it’s understandable that dog owners want to give their pets quick relief from the itching, even before the underlying cause can be found and addressed. But what happens when steroids cause skin problems that are worse than the original symptoms? 

Because of their immunosuppressive action, corticosteroids negatively impact the skin in several ways. They cause:

• Delayed wound healing → the proper mechanisms for healing are suppressed, which is especially dangerous for dogs who have had surgery or are otherwise more prone to injury. 
• Thinning of the skin → steroids break down collagen, the crucial protein for skin structure. 
• Skin infections → increased chances of bacterial and fungal infections due to lowered immune function. 
• Calcinosis cutis → gray or white, itchy, bumpy skin lesions, mostly on the legs, the back, and the groin area. If they get infected, swelling and discharge can appear. This condition is caused by imbalanced levels of calcium in the blood (triggered by steroids), leading excess crystals to build up in the skin. 

Iatrogenic Cushing’s Syndrome 

It’s not a coincidence that the most common side effects of corticosteroids are also the symptoms of Cushing’s disease in dogs — excessive drinking and urination, increased appetite, irritability, panting, and even skin infections. Cushing’s syndrome (hyperadrenocorticism) is caused by too much cortisol, the “stress hormone” regulated by the HPA axis. As steroids suppress the functioning of this axis, the natural production of cortisol is weakened. Steroids then mimic the effects of high cortisol in the body, which quickly leads to chronic overexposure because of long-term use. This causes iatrogenic Cushing’s disease, meaning the disease was caused by medical treatment. 

Dogs with Cushing’s syndrome are more prone to urinary tract infections, another overlap with long-term steroid use. 30% of dogs treated with steroids develop UTIs! These infections sometimes go unnoticed because steroids mask their symptoms and hide the infection, so the only way to detect them is through regular urine testing. Yet another overlap is muscle weakness and atrophy (deterioration). Cortisol regulates how the body uses up energy sources (protein and fat for dogs) — when there’s too much cortisol present, or the body’s natural cortisol production is disrupted by synthetic steroids, the dog’s body begins to break down its own muscles and fat for energy, leading to visible muscle deterioration. 

If your dog develops iatrogenic Cushing’s disease because of corticosteroid treatment, your natural first instinct would be to take them off steroids as soon as possible. That’s where steroids pose yet another complication and danger. Steroids need to be tapered slowly! Abrupt discontinuation can cause symptoms of Addison’s disease (hypoadrenocorticism) — the opposite of Cushing’s, meaning there’s too little cortisol in the system. The symptoms are weakness, lethargy, loss of appetite, vomiting, and diarrhea. 

In the best-case scenario, steroid-induced Cushing’s syndrome can be reversed … but it’s not a guarantee. After experiencing prolonged synthetic suppression, the adrenal glands can struggle to function properly in the future. 

Steroid-Induced Diabetes 

Diabetes is another endocrine disorder that can develop as a consequence of long-term steroid use. Diabetes occurs when the body is unable to produce (or successfully use) enough insulin, the hormone that regulates blood sugar. Steroid-induced diabetes happens when synthetic corticosteroids increase the body’s blood sugar levels by interfering with insulin and causing insulin resistance — the body no longer responds to existing insulin, so too much glucose remains in the blood. 

One study showed that dogs diagnosed with diabetes were four times more likely to have been exposed to steroids in the span of six weeks before their diagnosis! Steroid-induced diabetes can develop in dogs with a history of diabetes (making their condition worse), pre-diabetic dogs, or completely healthy dogs with no previous history of diabetes. Dogs over the age of seven are known to be at a higher risk. 

Many symptoms of diabetes are similar to Cushing’s syndrome, as corticosteroids cause metabolic side effects in both conditions — increased thirst & hunger, excessive urination, weight changes, urinary tract infections, skin infections, etc. The difference is that in Cushing’s syndrome, corticosteroids cause elevated cortisol levels, and in diabetes, they cause elevated blood sugar levels. The overlapping clinical signs can initially complicate getting the right diagnosis. At a minimum, blood and urine testing is required. It’s also possible for dogs on steroids to develop both diseases simultaneously, further complicating the treatment and positive health outcomes! 

Behavioral Changes — Aggression, Barking, Fearfulness

Dogs can experience behavioral changes, too, in addition to all the physical side effects of corticosteroids. Because natural steroid hormones regulate the stress response, synthetic corticosteroids dysregulate this response and make dogs much more sensitive to their environment. They decrease natural stress tolerance and increase emotional distress and reactivity. In other words, prednisone and other steroids intensify negative emotional states in dogs, and so cause problematic behavioral responses. 

Behavioral side effects in dogs receiving steroid therapy are well documented in multiple studies. Dogs treated with corticosteroids show a decrease in behaviors associated with positive emotional states (such as play & exploration) and an increase in behaviors that display negative emotional states (barking, aggression, resource guarding, restlessness, agitation, reactivity, hypervigilance, avoidance, and fearfulness). While these behaviors can appear in dogs with no previous history of behavioral issues, dogs with a known history of fearfulness & aggression are more prone to these changes, making their existing issues even worse.

Dog owners reported their dogs experiencing heightened anxiety, especially around food — as steroids increase their hunger, dogs can begin to display signs of food guarding. They’re more likely to growl, snap, and bite their owners because their brains perceive the situation as more threatening than it actually is. Some dogs show signs of avoidance when on steroids, shying away from people and from physical touch (including from their owners), becoming more fearful of their environment. If avoidance cues are missed or ignored, those dogs can turn aggressive in response too.

This category of side effects has huge implications for the whole family the dog is living with, especially if there are small children and other pets in the home! Veterinarians should inquire about the dog’s behavioral history before prescribing steroids and warn the owners of the possible behavioral changes that could compromise their safety!

So … Are Steroids for Dogs Worth It? 

The use of steroids in veterinary medicine is concerning, considering the rate at which corticosteroids are being prescribed — a study looking at 455,557 dogs in veterinary care showed that 6.2% of them received some form of steroid treatment within one year, which is a very sizable percentage! A treatment this common should not have so many serious side effects that impact the dog’s most vital systems and compromise their functioning. In light of all the adverse effects, steroids are still only a temporary relief from the original symptoms.

We have to ask ourselves whether the symptoms we’re trying to mediate are actually worse than the potential development of Cushing’s syndrome, diabetes, skin infections, UTIs, aggression, etc.? And if we do choose the route of steroids, are we prepared for the constant monitoring of urine and blood to make sure other diseases aren’t developing as a result of the treatment? 

Before you ever consider steroids, there are so many natural options you should try FIRST! We have written about several of them, so you can start right here: 

• Natural remedies for arthritis 
• Quercetin for allergies
• CHIRP superfood topper for allergies, with hundreds of positive reviews!
• 5 Apoquel alternatives for allergies
• Home remedies for ear infections
• CBD for Cushing’s disease 

Sources

Weir, Malcolm. Hunter, Tammy. Ward, Ernest. “Steroid Treatment – Effects in Dogs.” VCA Animal Hospitals. 

Edwards, H.  Scott. “Corticosteroids in Animals.” 11/2022, MSD Manual. 

Younes, K. Areej. Younes, K. Noor. “Recovery of steroid-induced adrenal insufficiency.” 10/2017, PubMed. 

Notari, Lorella. Kirton, Roxane. Mills, S. Daniel. “Psycho-Behavioural Changes in Dogs Treated with Corticosteroids: A Clinical Behaviour Perspective.” 03/2022, PubMed.

Elkholly, A. Doaa.  Brodbelt, C. Dave. Church, B. David. et al. “Side Effects to Systemic Glucocorticoid Therapy in Dogs Under Primary Veterinary Care in the UK.” 14/08/2020, PubMed. 

Sauvé, Frédéric. “Use of topical glucocorticoids in veterinary dermatology.” 07/2019, PubMed. 

Gober, Margaret. Hillier, Andrew. “Perception and usage of short-term prednisone and prednisolone in dogs.” 24/07/2023, PubMed. 

Heeley, M. Angela. Brodbelt, C. Dave. O’Neill, G. Dan. Church, B. David. Davison, J. Lucy. “Assessment of glucocorticoid and antibiotic exposure as risk factors for diabetes mellitus in selected dog breeds attending UK primary-care clinics.” 22/02/2023, BVA Journals. “Calcinosis Cutis.” Dermvet Olympia.

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Luna’s passion for learning about canine psychology and behavior began when she adopted a severely reactive puppy from a local shelter. She is now a big advocate for positive reinforcement and compassionate training. As a writer, she strives to spotlight the topics that fly under the radar and be the voice for all who cannot speak for themselves.