10 Most Reported Galliprant Side Effects in Dogs
📋 Key Takeaways at a Glance
| 🔑 Question | 💬 Quick Answer |
|---|---|
| Most common side effect? | Vomiting—occurred in 17% of dogs in clinical trials |
| Does Galliprant damage liver/kidneys? | According to one study, Galliprant does not cause injury to the liver, kidneys, or stomach, even at high doses |
| Who should avoid Galliprant? | Dogs under 8 lbs, under 9 months old, pregnant/nursing, or with heart disease |
| MDR1 gene concern? | Dogs with this gene mutation have a harder time breaking down certain types of medications including Galliprant |
| Can you give with food? | Yes, but absorption decreases significantly—bioavailability drops from 89% to 33% |
| Serious side effects? | Neurologic: ataxia, seizures—rare but reported post-approval |
| Long-term safety? | In one study, dogs were given 25 times the recommended dose for nine months to assess safety. All the dogs remained healthy |
| Recovery from side effects? | The vast majority of patients with drug related adverse reactions have recovered when the signs are recognized, the drug is withdrawn |
#1: Vomiting Affected 17% of Dogs in Clinical Trials—More Than Placebo Groups
In the field study, vomiting occurred in 24 dogs receiving Galliprant compared to only 9 dogs in the vehicle control group (N=141 vs N=144).
That’s nearly three times the vomiting rate in treated dogs versus placebo. While the European regulatory data confirms vomiting was observed very commonly in clinical studies, what most owners don’t realize is that the timing matters enormously.
📊 Vomiting Patterns and Management
| ⏰ When It Occurs | 📋 What It Means | 🎯 Action |
|---|---|---|
| Within hours of first dose | Initial GI irritation; adjustment period | Try giving with small amount of food |
| First 1-3 days | Common; usually self-limiting | Monitor; contact vet if persistent |
| After weeks of use | Less expected; may indicate intolerance | Discontinue and consult vet immediately |
| With blood present | Vomiting (with or without blood) reported post-approval | Emergency—stop medication, seek care |
💡 Critical Insight: You will need to immediately discontinue the Galliprant as vomiting is a common side effect. Unlike mild nausea that passes, persistent vomiting warrants stopping the medication—not pushing through.
#2: Diarrhea and Soft Stool—The Second Most Frequent Complaint
Diarrhea and soft stool occurred in 17 Galliprant-treated dogs versus 13 in the control group.
While the difference seems modest, in a field study conducted in 366 client-owned dogs, the most common adverse reactions related to treatment were diarrhea, vomiting and inappetence.
📊 Stool Changes Spectrum
| 🔬 Type | 📋 Description | ⚠️ Concern Level |
|---|---|---|
| Soft-formed stool | Slightly looser than normal | Low—often resolves |
| Mucoid stool | Mucus coating visible | Moderate—monitor closely |
| Watery diarrhea | Liquid consistency | Moderate to high—dehydration risk |
| Bloody stool | Blood visible or dark/tarry | 🚨 High—GI bleeding possible |
| Melena | Dark, tarry stool (digested blood) | 🚨 Emergency—upper GI bleeding |
In very rare cases, haematemesis or haemorrhagic diarrhoea was reported following clinical use.
💡 Critical Insight: The majority of cases of anorexia, inappetence, diarrhea, soft stool and vomiting resolved after a few days. Most GI disturbances are transient—but bloody stool is never “wait and see.”
#3: Decreased Appetite Signals More Than Just Finickiness
Anorexia and inappetence affected 9 Galliprant-treated dogs compared to 7 in placebo.
This side effect deserves more attention than it typically receives. While slight appetite reduction might seem minor, in an arthritic dog already struggling, reduced food intake can cascade into muscle wasting, weakness, and poor pain tolerance.
📊 Appetite Changes Assessment
| 🍽️ Change | ⏰ Duration | 🎯 Action |
|---|---|---|
| Eating slower than usual | 1-2 days | Normal adjustment; observe |
| Leaving 25-50% of food | 2-3 days | Try giving medication with food |
| Refusing meals entirely | 24+ hours | Contact veterinarian |
| Weight loss visible | Any duration | Discontinue; reassess treatment |
General adverse events include: anorexia, lethargy, weight loss, panting, hyperactivity.
💡 Critical Insight: A dog in chronic pain who stops eating on pain medication isn’t being picky—they may be telling you the medication is causing more distress than the condition it’s treating.
#4: Lethargy That’s Different From Normal “Slowing Down”
Lethargy occurred in 6 Galliprant-treated dogs versus only 2 in the placebo group—triple the rate.
Here’s where distinguishing drug effects from disease progression becomes challenging. Is your arthritic senior dog tired because of the medication, or because arthritis naturally causes fatigue?
📊 Lethargy Assessment Guide
| 😴 Type | 📋 Characteristics | 🔬 Likely Cause |
|---|---|---|
| Mild drowsiness | Resting more but responsive; eating normally | May be medication effect |
| Activity reduction | Less interested in walks but still engaged | Could be both drug and disease |
| Profound lethargy | Difficult to rouse; refusing food/water | 🚨 Stop medication; see vet |
| New-onset lethargy | Started clearly after beginning Galliprant | Drug-related until proven otherwise |
Galliprant does not typically make dogs sleepy, but they may experience more tiredness and seem less energetic than usual.
💡 Critical Insight: If you notice your pet sleeping a lot more while taking this medication, please let your veterinarian know right away.
#5: Decreased Blood Protein Levels—The Hidden Laboratory Finding
Adverse reactions in dogs receiving Galliprant may include decreases in serum albumin and total protein.
This side effect rarely produces visible symptoms but appears consistently in clinical trial data. Decreases in serum albumin and total protein were seen with increasing doses of grapiprant.
📊 Blood Protein Changes
| 🔬 Finding | 📊 Clinical Trial Data | ⚠️ Significance |
|---|---|---|
| Hypoalbuminemia | Hypoalbuminemia and hypoproteinemia were reversible when treatment was discontinued | Usually mild; dose-dependent |
| Hypoproteinemia | Seen more at higher doses | Monitor with bloodwork |
| Clinical impact | There was no clinical impact related to these clinical pathology changes | Typically not symptomatic |
💡 Critical Insight: Blood proteins are essential for transporting materials, and their decrease is not significant unless the dog already has a condition affecting their levels. Dogs with liver disease, kidney disease, or protein-losing conditions should be monitored more closely.
#6: Elevated Liver Enzymes—What the Post-Approval Data Reveals
Hepatic: elevated liver enzymes appears in the FDA’s post-approval adverse event reporting.
This is where Galliprant’s reputation as “gentler on organs” meets real-world complexity. The EMA states, regarding documents submitted for Galliprant’s European licensure in 2017, “Furthermore, no treatment-related effects were found on liver or kidney function, or gross or histopathological findings of the liver, kidney, or stomach.”
Yet post-approval experience tells a nuanced story:
📊 Liver Safety Profile
| 🔬 Evidence Source | 📋 Finding |
|---|---|
| Pre-approval safety studies | No liver toxicity even at 25x recommended dose |
| Long-term study (9 months, 25x dose) | All dogs completed the study in a clinically normal fashion, with no evidence of GI ulceration, and no kidney or liver problems |
| Post-marketing (Canada) | Elevated liver enzymes including elevated ALT reported very rarely (less than 1 dog in 10,000) |
| Real-world owner reports | Some dogs show individual sensitivity |
💡 Critical Insight: Regular monitoring of liver and kidney values through blood tests is recommended during long-term use to catch any early signs of damage.
#7: Kidney Effects—Rarer Than Traditional NSAIDs But Not Zero
Renal/Urinary adverse events include: increased BUN or creatinine, polydipsia, urinary incontinence/inappropriate urination, polyuria, renal failure.
Galliprant’s selective mechanism was specifically designed to spare kidney-protective prostaglandins. When used in doses 15x larger than the recommended, Galliprant does not cause kidney or liver toxicity.
However, elevated BUN and elevated creatinine appear in post-marketing surveillance—albeit very rarely.
📊 Kidney-Related Symptoms to Monitor
| 👀 Sign | 📋 What It Indicates | ⚠️ Action |
|---|---|---|
| Polydipsia (increased thirst) | May indicate kidney stress | Track water intake; report to vet |
| Polyuria (increased urination) | Kidneys not concentrating urine | Monitor frequency; note volume |
| Urinary incontinence | Can be drug effect or coincidental | Discuss with vet; may be unrelated |
| Decreased appetite + lethargy + increased drinking | Classic signs of kidney issues | Seek immediate veterinary evaluation |
💡 Critical Insight: Dogs with kidney disease or liver disease should not take Galliprant.
#8: GI Ulceration and Bleeding—Rare But Serious
Gastrointestinal adverse events reported post-approval include: gastrointestinal ulcer, elevated pancreatic enzymes/pancreatitis.
While Galliprant’s non-COX mechanism theoretically spares GI-protective prostaglandins, in very rare cases, haematemesis or haemorrhagic diarrhoea was reported following clinical use.
📊 GI Bleeding Warning Signs
| 🚨 Sign | 📋 Description | 🎯 Urgency |
|---|---|---|
| Dark/tarry stool | Digested blood from upper GI | Emergency |
| Fresh blood in stool | Lower GI or severe upper GI bleeding | Emergency |
| Hematemesis | Vomiting blood | Emergency |
| Coffee-ground vomit | Partially digested blood | Emergency |
| Abdominal pain | Hunched posture, reluctance to move | Urgent evaluation |
💡 Critical Insight: It is important to stop the medication and contact your veterinarian immediately if you think your dog may have a medical problem or side effect while on Galliprant.
#9: Neurological Effects—Seizures and Ataxia in Post-Approval Reports
Neurologic adverse events reported post-approval include: ataxia, seizures.
This is perhaps the most alarming category—and the least expected given Galliprant’s mechanism. Neurological side effects of Galliprant are relatively rare, affecting less than 1% of dogs taking the medication.
📊 Neurological Side Effect Breakdown
| 🧠 Effect | 📋 Description | 📊 Frequency |
|---|---|---|
| Ataxia | Loss of coordination, stumbling | Rare |
| Seizures | Convulsions, loss of consciousness | Very rare |
| Disorientation | Acting confused, walking in circles, staring into space | Very rare |
| Tremors | Shaking or trembling | Very rare |
In rare cases, Galliprant has been linked to seizure activity, especially in dogs that may already have a predisposition to neurological conditions.
💡 Critical Insight for MDR1 Dogs: Galliprant should be used with caution in dogs with the MDR1 gene mutation (common in Collies, Shelties, and Australian Shepherds). Dogs with this gene mutation have a harder time breaking down certain types of medications including Galliprant.
A study specifically on MDR1 collies found the Cmax and AUC were approximately fourfold and sixfold greater, respectively, than those reported in normal Beagles. Higher drug exposure means higher side effect risk.
#10: Hematologic Changes—Anemia and Thrombocytopenia
Hematologic adverse events include: anemia, thrombocytopenia.
In the original field study, one case of immune mediated hemolytic anemia occurred in a Galliprant-treated dog versus zero in placebo.
📊 Blood Cell Warning Signs
| 🩸 Condition | 👀 Visible Signs | 🎯 Action |
|---|---|---|
| Anemia | Pale gums due to anemia | Check gum color; urgent vet visit |
| Thrombocytopenia | Unusual bruising, petechiae (small red dots) | Immediate veterinary care |
| Weakness | Collapse, exercise intolerance | Emergency evaluation |
💡 Critical Insight: Regular blood tests are essential to monitor your dog’s liver and kidney health while on Galliprant, especially if it’s being used for long-term treatment.
🚨 The Critical MDR1 Gene Warning Most Owners Miss
Dogs prone to having two copies of the MDR1 gene mutation (homozygous) like collies may be at an increased risk of side effects.
This isn’t a minor footnote—it’s a fundamental pharmacogenetic concern.
📊 Breeds with MDR1 Mutation Risk
| 🐕 High Risk Breeds | 🐕 Moderate Risk Breeds |
|---|---|
| Rough Collie | Australian Shepherd |
| Smooth Collie | Shetland Sheepdog |
| Border Collie | Old English Sheepdog |
| Longhaired Whippet | Silken Windhound |
A short note reported the pharmacokinetics of grapiprant in Mdr1-deficient collies. Eight adult collie dogs homozygous for the Mdr1 mutation were treated with approximately 2 mg/kg grapiprant orally once daily for 28 days. The Cmax and AUC were approximately fourfold and sixfold greater, respectively, than those reported in normal Beagles.
Cerenia, ondansetron, and Galliprant should be avoided in anesthetic protocols for MDR1-affected dogs, according to veterinary anesthesia specialists.
💡 Critical Insight: If your dog has this gene mutation, your vet may decrease your dog’s dosage accordingly. Testing before starting Galliprant is wise for at-risk breeds.
⚠️ Contraindications and Drug Interactions: What NEVER to Combine
Galliprant should not be given with aspirin, other non-steroidal anti-inflammatory drugs (such as carprofen or meloxicam) or corticosteroids (such as prednisone).
📊 Dangerous Combinations
| ❌ Do Not Combine With | 📋 Reason | ⏰ Washout Period |
|---|---|---|
| Carprofen (Rimadyl) | Additive GI and kidney risk | 5-7 days before switching |
| Meloxicam (Metacam) | Same drug class risks | 5-7 days before switching |
| Firocoxib (Previcox) | Compounded NSAID toxicity | 5-7 days before switching |
| Prednisone/Corticosteroids | The combination can be toxic to dogs | Variable; consult vet |
| Aspirin | GI bleeding risk | 5-7 days minimum |
If additional pain medication is needed after a daily dose of Galliprant, a non-NSAID/non-corticosteroid class of analgesic may be necessary.
📊 Side Effect Frequency Summary: FDA Field Study Data
Based on the controlled field study with 285 dogs:
| 📊 Side Effect | 💊 Galliprant (N=141) | 💊 Placebo (N=144) | ⬆️ Increased Risk |
|---|---|---|---|
| Vomiting | 24 dogs (17%) | 9 dogs (6.3%) | ~2.7x higher |
| Diarrhea/soft stool | 17 dogs (12%) | 13 dogs (9%) | ~1.3x higher |
| Anorexia/inappetence | 9 dogs (6.4%) | 7 dogs (4.9%) | ~1.3x higher |
| Lethargy | 6 dogs (4.3%) | 2 dogs (1.4%) | ~3x higher |
| Buccal ulcer | 1 dog | 0 dogs | — |
| Immune-mediated hemolytic anemia | 1 dog | 0 dogs | — |
🛡️ How to Minimize Side Effect Risk
📊 Risk Reduction Strategies
| 🎯 Strategy | 📋 How It Helps |
|---|---|
| Use the lowest effective dose for the shortest duration | Minimizes drug exposure and cumulative risk |
| Baseline bloodwork before starting | Establishes kidney/liver function baseline |
| Follow-up testing every 3-6 months | Catches early organ changes |
| Before starting your dog on grapiprant, your veterinarian will do a full workup | Identifies contraindications |
| MDR1 testing for at-risk breeds | Determines if dose adjustment needed |
| Give with small amount of food if GI upset occurs | Reduces stomach irritation |
🏥 When to Stop Galliprant Immediately
Owners should be advised to discontinue Galliprant therapy and contact their veterinarian immediately if signs of intolerance are observed.
📊 Stop Immediately If You See:
| 🚨 Sign | 📋 What It May Indicate |
|---|---|
| Black, tarry, or bloody stool | GI bleeding |
| Vomiting blood or “coffee grounds” | Upper GI hemorrhage |
| Yellowing of gums, skin, or whites of the eyes | Liver damage (jaundice) |
| Pale gums | Anemia |
| Incoordination or seizures | Neurological toxicity |
| Collapse or extreme weakness | Multiple possible causes—all serious |
💡 The Good News: The vast majority of patients with drug related adverse reactions have recovered when the signs are recognized, the drug is withdrawn, and veterinary care, if appropriate, is initiated.
📋 Final Comparison: Galliprant vs. Traditional NSAIDs Safety
📊 Safety Profile Comparison
| 🔬 Factor | 💊 Galliprant | 💊 Traditional NSAIDs (Carprofen, Meloxicam) |
|---|---|---|
| GI ulceration risk | No evidence of GI ulceration even at high doses | Well-documented risk |
| Kidney damage | Does not cause injury to the kidneys even at high doses | Known nephrotoxicity risk |
| Liver damage | Does not cause injury to the liver even at high doses | COX-inhibiting NSAIDs can cause liver injury |
| Platelet function | Spares COX-1 involved in clotting | May impair platelet function |
| Long-term safety | Can be used safely for a long time | Requires careful long-term monitoring |
| MDR1 sensitivity | Higher exposure in MDR1-deficient dogs | Variable by drug |
💡 The Bottom Line
Galliprant represents a genuine advancement in osteoarthritis pain management for dogs—its selective EP4 receptor blockade delivers anti-inflammatory and analgesic effects while preserving protective prostaglandins that traditional NSAIDs destroy.
But “safer” doesn’t mean “without risk.”
In clinical studies, the following mild and generally transient adverse reactions have been observed: vomiting, soft-formed faeces, diarrhoea and inappetence. These are common enough that every owner should expect the possibility—especially during the first week.
More serious effects—GI bleeding, neurological signs, hematologic changes—remain rare but real. Not all adverse events are reported to FDA/CVM. It is not always possible to reliably estimate the adverse event frequency or establish a causal relationship to product exposure using these data.
Your responsibilities as an owner:
- Know the warning signs
- Report changes immediately
- Commit to recommended monitoring bloodwork
- Test for MDR1 mutation if you own an at-risk breed
- Never combine with other NSAIDs or corticosteroids
Carefully consider the potential benefits and risks of Galliprant and other treatment options before deciding to use Galliprant.
For most dogs with osteoarthritis, those benefits—improved mobility, reduced pain, better quality of life—substantially outweigh the risks. But informed consent requires knowing both sides of the equation.
