Corticosteroid use in pets: understanding gastric ulcers and how to monitor

Corticosteroids and the gut: what every veterinary student should know

If you’ve spent time with dogs, cats, or horses in a pharmacology class, you’ve likely heard how versatile corticosteroids are. They tame inflammation, calm immune responses, and can make a big difference in conditions from allergic skin disease to autoimmune problems. But there’s a catch: when these drugs are used for a long time, they carry a risk of side effects. One of the more important ones to recognize is gastric ulcers. Yes, those aching tums aren’t just a human problem—veterinary patients can be affected too.

The quick takeaway: gastric ulcers are a potential long-term side effect of corticosteroid use.

Why this matters in veterinary medicine

Corticosteroids act by dialing down multiple parts of the inflammatory cascade. That’s incredibly useful when a patient’s immune system is overreacting or when tissue damage is driven by inflammation. But “dialing down” isn’t without consequences. The stomach’s lining relies on a protective barrier of mucus, bicarbonate, blood flow, and prostaglandins to keep acids at bay. When corticosteroids are used chronically, that protective system can be weakened. The result can be erosion of the stomach lining, and in some cases, ulcers.

Here’s the thing: the risk isn’t just about a single drug or a single dose. It’s about duration, dose, and what other factors are at play. If a pet needs long-term corticosteroid therapy, you’ll want to stay vigilant about possible GI distress and think ahead about protective strategies.

How corticosteroids interact with the stomach, in plain terms

Let me explain the gut side of the story in a simple way. The stomach is a harsh environment. It’s constantly bathed in acid, and its lining depends on a good defense plan: mucus, bicarbonate, proper blood flow, and the ability to repair small injuries quickly. Corticosteroids suppress some of the protective signals the gut normally uses. They can reduce mucus production and diminish the stomach’s natural defenses. They may also affect blood flow to the gastric mucosa and slow down the repair of tiny injuries caused by acid. Put together, these changes tip the balance toward damage if the patient keeps a steady diet of steroids over weeks or months, especially when stomach lining defenses are already stressed by illness, stress, or other medications.

A note about combinations: the risk heightens when corticosteroids are used with NSAIDs (nonsteroidal anti-inflammatory drugs). Both can irritate the stomach, and together they can synergistically increase the chance of ulcers. In practice, veterinarians weigh the benefits of pain relief and anti-inflammatory effects against GI risk and often look for alternative pain-control strategies or gastroprotective steps if a combined approach is needed.

What long-term use looks like in a clinical setting

In many cases, corticosteroids are prescribed for weeks to months rather than just a few days. In chronic conditions—like dermatitis, autoimmune disorders, or certain gastrointestinal issues—the therapy may extend longer. With longer exposure, the cumulative effect on the stomach lining becomes more likely. That doesn’t mean you should abandon corticosteroids when they’re truly indicated; rather, it means you should plan for protection and monitoring from the start.

Monitoring is simple in concept but powerful in practice:

• Baseline assessment: before starting long-term therapy, document a pet’s GI history. Prior ulcers, chronic gastritis, or other GI diseases raise the risk.

• Watchful waiting: during treatment, look for signs of GI distress. Early detection makes a big difference.

• Tapering when possible: if the disease allows, lowering the dose gradually rather than stopping abruptly helps the body adapt and reduces the risk of rebound problems.

• Prophylaxis when indicated: in patients with higher risk, adding a protective strategy can prevent ulcers from forming.

Recognizing the signs: what to look for in patients

Catching trouble early matters. Here are some common signs that might suggest gastric trouble in veterinary patients:

• Vomiting that isn’t easily explained by diet or infection

• Poor appetite or weight loss

• Blood in vomit or stool (melena can indicate GI bleeding)

• Lethargy or abdominal discomfort

• Decreased energy, dehydration, or a reluctance to lie down comfortably

If you see any of these, especially in a dog or cat on long-term corticosteroids (or a dog on both steroids and NSAIDs), it’s time to flag it for a clinician and consider GI evaluation or protective measures.

Preventive strategies you’ll encounter in practice

The good news is that there are practical steps to reduce risk without sacrificing the benefits of corticosteroids. Here are some common strategies you’ll encounter in veterinary pharmacology notes and real-world practice:

• Use the lowest effective dose for the shortest duration. It’s a familiar refrain for a reason: it works.

• Consider alternate-day dosing when appropriate, or tapering schedules that minimize exposure without compromising disease control.

• Protect the stomach with gastroprotectants when risk is higher. Sucralfate can help coat and shield the mucosa; proton pump inhibitors like omeprazole reduce acid production; H2 blockers (famotidine, ranitidine) can also be useful. In some cases, misoprostol (a prostaglandin analog) is used for mucosal protection, though it has its own set of side effects to monitor.

• Schedule regular follow-ups to monitor for GI signs and, if needed, adjust therapy. A proactive approach often pays off in better outcomes and fewer complications.

• Review concurrent medications. If a patient needs NSAIDs for pain along with steroids, discuss protective measures and GI monitoring with the clinician.

Bringing it home with real-world nuance

Think of corticosteroids like a skilled handyman: they’re excellent at fixing a problem fast, but they can wear down the workspace if used too long without rest or protection. In veterinary practice, that means you lean on steroids when they’re truly needed, but you don’t let a good tool turn into a source of trouble.

That said, you’ll encounter plenty of cases where the benefits outweigh the risks. For example, an allergic dog with severe dermatitis may respond dramatically to steroids, enabling a better quality of life while a longer-term plan gets sorted. The key is transparency with clients about potential GI side effects, early symptom monitoring, and a plan to reduce exposure when the disease allows.

A quick sample scenario to illustrate the point

Imagine a middle-aged Labrador with chronic inflammatory skin disease. The veterinarian prescribes a moderate course of prednisone, with a clear plan to taper as the skin inflammation improves. The owner is given simple signs to watch for—vomiting, appetite changes, dark stools—and a schedule for recheck. The clinician also suggests a light gastroprotectant regimen during the dose period and cautions about NSAID use for any concurrent pain. If signs appear, adjustments are made before the problem escalates. It’s not about scaring pet owners; it’s about arming them with what to watch for and keeping the gut safe while the skin heals.

Common questions that come up in practice—and their answers

• Do all animals on steroids get ulcers? Not everyone, but the risk rises with duration, dose, age, existing GI disease, and concurrent NSAID use. The goal is to minimize risk with careful planning.

• Can we prevent ulcers entirely? No single magic bullet, but a combination of lowest effective dose, protective meds when indicated, and regular monitoring dramatically lowers risk.

• Are there signs I should tell clients to report right away? Yes—vomiting that won’t stop, black or bloody stools, severe abdominal pain, or a sudden decline in appetite or energy warrant prompt veterinary assessment.

Key takeaways that stick with you

• Gastric ulcers are a recognized long-term risk of corticosteroid therapy in animals.

• The mechanism involves reduced protective factors in the gastric lining and potential changes in mucosal defense, especially when steroids are paired with NSAIDs.

• Preventive care—dose optimization, tapering, GI protection, and vigilant monitoring—makes a real difference.

• Early detection of GI signs can prevent serious complications and keep pets comfortable and healthy.

If you’re studying veterinary pharmacology, this topic isn’t just about memorizing a correct answer. It’s about understanding the balance between therapeutic benefit and safety. Corticosteroids remain a cornerstone in many treatment plans, but their use requires thoughtful planning, a watchful eye, and a clear line of communication with clients. When you combine pharmacology knowledge with practical watching-and-adjusting, you’ll be well-equipped to protect animals from avoidable harm while delivering the care they need.

Bonus practical note for students and future veterinarians

As you review drug classes, try to connect the pharmacology to the patient’s real-world experience. Picture a dog’s daily routine—eating, playing, and resting—and think about how a medication might alter that rhythm over weeks or months. That human element—how it feels to be on a treatment, how side effects show up in everyday life—often makes the science click more clearly. And in the end, that clarity translates into better outcomes for the animals you’ll treat.

If you’re digging into corticosteroids and their GI implications, you’re not alone. It’s a topic that comes up again and again, because prevention and early intervention matter. Keep the signs in mind, keep the plan practical, and you’ll be ready to guide patients—and their people—toward safer, more comfortable lives.