Amoxicillin for Dogs Dosage Chart 🐾
Veterinary antibiotic use isn’t just a prescription pad and a pill bottle—it’s a high-stakes balancing act of dosage precision, safety vigilance, and public health accountability.
📌 Key Takeaways at a Glance
| ❓ Question | ✅ Quick Answer |
|---|---|
| What’s the safe dose? | 5 mg/lb, twice a day, adjusted by vet |
| Can I round doses? | Only under veterinary guidance |
| Is all vomiting a concern? | No—watch severity and timing |
| Can I reuse leftover amoxicillin? | Never, unless prescribed again |
| Can I cut or crush tablets? | Depends on formulation—ask your vet |
| Is Clavamox the same? | No—Clavamox includes clavulanic acid for resistant bacteria |
| Can I give it with food? | Yes, and it helps reduce nausea |
| What’s the overdose threshold? | Over 3–5x dose may trigger severe symptoms |
🧪 What If My Dog’s Weight Falls Between Chart Values?
Never guess or round blindly. Underdosing breeds resistance. Overdosing risks toxicity.
| 🐶 Weight (lbs) | 💊 Standard Dose (5 mg/lb) | 🧮 Rounded Strategy (Example Only) |
|---|---|---|
| 13 lbs | 65 mg | One-half of a 150 mg tablet (75 mg)* |
| 22 lbs | 110 mg | One 100 mg + one-fourth of 50 mg tab |
| 37 lbs | 185 mg | One 150 mg + one-third of 100 mg tab |
💡 Tip: Ask your vet to prescribe exact strengths to avoid splitting. If needed, liquid amoxicillin allows precision without the math.
🛑 Can I Use Leftover Antibiotics from a Previous Illness?
Absolutely not. Bacterial strains differ, and so does the severity and location of the infection.
| 🚫 Reason Not to Reuse | ❓ Explanation |
|---|---|
| Wrong infection target | Different bacteria, different antibiotic needs |
| Dosage mismatch | Each infection may need customized strength/duration |
| Storage degradation | Old meds = loss of potency or safety |
| Resistance risk | Incomplete or incorrect use breeds superbugs |
💡 Tip: Always return expired or unused meds to your vet clinic—never flush or trash them.
🤢 Is Mild Vomiting After Amoxicillin Normal?
Yes—sometimes. Especially if given on an empty stomach. But the pattern and intensity matter.
| 🧭 Symptom | 🟢 Benign | 🔴 Concerning |
|---|---|---|
| Nausea | One-time, after first dose | Persistent or worsening |
| Vomiting | Once, mild, right after dosing | Multiple episodes, unable to keep food down |
| Diarrhea | Soft stool once or twice | Bloody, mucousy, watery, frequent |
| Behavior | Slightly quiet | Lethargic, disoriented, shaking |
💡 Tip: Give doses with food unless directed otherwise. Add a small meal or treat to reduce GI upset.
🧾 What If My Dog Misses a Dose?
Timing matters more than panicking. You have a small window—but don’t double up.
| ⏰ Time Since Missed Dose | ✅ Action to Take |
|---|---|
| < 6 hours | Give it as soon as remembered |
| > 6 hours | Skip it; resume next dose on time |
| Repeated missed doses | Contact vet—may need restart or adjustment |
💡 Tip: Use a pill tracker app or tie dosing to meals or walks to stay consistent.
🧠 What’s the Difference Between Amoxicillin and Clavamox?
Clavamox = Amoxicillin + Clavulanic Acid, which defeats beta-lactamase-producing bacteria.
| 💊 Antibiotic | 🔍 Used For | 🛡️ Resistance Coverage |
|---|---|---|
| Amoxicillin | Basic infections, non-resistant strains | ❌ No beta-lactamase protection |
| Clavamox | Skin infections, dental abscesses, UTIs | ✅ Kills resistant Staph & more |
💡 Tip: Clavamox is often the go-to choice for skin or dental infections due to its broader power.
🚫 Can I Stop the Antibiotic Early If My Dog Feels Better?
Never. The infection may not be fully cleared—and resistant bacteria will multiply.
| 🚨 Danger of Stopping Early | 💣 Consequence |
|---|---|
| Infection relapse | Can return stronger |
| Resistance formation | Bacteria survive, adapt |
| False sense of recovery | Inflammation may decrease, but bacteria still thrive |
💡 Tip: Continue at least 48 hours past symptom resolution unless your vet instructs otherwise.
📊 Dog Amoxicillin Dosage Chart (🧠 5 mg/lb Standard Dose, Twice Daily)
| 🐶 Weight | 💊 Dose per Administration | 📦 Tablet Combination Suggestion |
|---|---|---|
| 5 lbs | 25 mg | ½ of 50 mg tab |
| 10 lbs | 50 mg | 1 x 50 mg |
| 20 lbs | 100 mg | 1 x 100 mg |
| 30 lbs | 150 mg | 1 x 150 mg |
| 50 lbs | 250 mg | 1 x 150 mg + 1 x 100 mg |
| 70 lbs | 350 mg | 1 x 200 mg + 1 x 150 mg |
| 100 lbs | 500 mg | 1 x 400 mg + 1 x 100 mg |
📝 Note: Always match the exact strength to the prescribed dose. Splitting tablets should only be done when approved by a vet. Oral liquid suspensions offer easier dosing for small dogs or picky eaters.
🚨 What Are Signs of Overdose in Dogs?
Even “safe” drugs have a limit. Overdosing may trigger neurological signs in rare cases.
| ⚠️ Symptom | 🚑 Urgency Level |
|---|---|
| Vomiting/Diarrhea | Moderate—call your vet |
| Muscle twitching | High—urgent care needed |
| Seizures | Emergency—rush to clinic |
| Collapse | Emergency—call ER vet |
💡 Tip: If accidental overdose occurs, call Pet Poison Helpline (855-764-7661) or your emergency vet immediately.
🧊 Storage Cheat Sheet: Keep It Safe and Potent
| 💊 Form | 🧴 Storage Rules | ⏳ Shelf Life |
|---|---|---|
| Tablets | Room temp, dark, dry | Until expiry date |
| Oral Liquid | Refrigerate once mixed | Discard after 14 days |
FAQs 🐶📋
💬 “Can I give amoxicillin meant for humans to my dog if I calculate the dose correctly?”
Absolutely not without veterinary guidance. While the active ingredient may be identical, human-formulated amoxicillin often includes additives, flavorings, or excipients (like xylitol or certain dyes) that are toxic to dogs. Moreover, pharmaceutical quality control differs between human and veterinary batches.
| ⚖️ Risk Factor | 🚫 Why It’s Dangerous |
|---|---|
| Inactive Ingredients | May include toxic flavorings (e.g., grape, xylitol) |
| Dosing Precision | Human capsules aren’t scored or adjustable |
| Shelf Stability | Storage conditions may have degraded potency |
| Legal Concerns | Off-label use without a prescription is illegal |
💡 Tip: Only use veterinary-specific medications prescribed for your dog, even if you “know the math.” Safety depends on more than just milligrams.
💬 “Why does my dog get diarrhea every time she takes amoxicillin?”
Antibiotics alter the gut’s microbial ecosystem. Amoxicillin doesn’t discriminate between harmful bacteria and beneficial gut flora, and this disruption often leads to soft stools or diarrhea. Some dogs are more sensitive due to breed-specific GI sensitivity, previous GI disease, or concurrent diet.
| 🧬 Possible Contributors | 📉 Effect on Gut |
|---|---|
| Kills beneficial bacteria | Disrupts digestion and nutrient absorption |
| Alters pH balance | Increases gut motility |
| Triggers mild inflammation | Promotes water loss in stool |
| Interacts with food | Certain diets worsen effects |
💡 Tip: Ask your vet about adding a canine-specific probiotic like FortiFlora during treatment. Administer probiotics separately from the antibiotic (at least 2 hours apart) to ensure colonization.
💬 “Can I just give half a pill if my dog is between weights?”
Only if the tablet is scored and your vet explicitly approves. Tablets are scored for a reason—they ensure even distribution of the active ingredient. Breaking an unscored tablet risks under- or overdosing.
| 💊 Tablet Type | ✅ Split? | ⚠️ Why or Why Not |
|---|---|---|
| Scored tablet | Yes, if vet approves | Dose is evenly divided |
| Unscored tablet | No | Uneven active compound |
| Coated or ER tabs | Never | Splitting ruins release profile |
💡 Tip: If tablet splitting is necessary, invest in a pill cutter for accuracy. Avoid splitting by hand, which often causes crumbling or uneven halves.
💬 “How soon should I see improvement after starting amoxicillin?”
Visible improvement usually starts within 48 to 72 hours, depending on the infection type, the dog’s immune status, and bacterial load. However, absence of immediate change doesn’t mean failure—deep tissue infections or urinary tract conditions may take longer to show resolution.
| ⏱️ Infection Type | ⌛ Typical Response Time |
|---|---|
| Urinary Tract Infection | 24–48 hours |
| Skin Infection (mild) | 2–4 days |
| Respiratory Infection | 2–3 days |
| Dental Abscess | 3–5 days (with pain meds) |
💡 Tip: If no change occurs by day 4 or your dog worsens at any point, contact your vet immediately. They may run a culture and sensitivity test to adjust treatment.
💬 “My dog’s symptoms returned right after finishing the antibiotics. What went wrong?”
The infection likely wasn’t fully eradicated, or the causative bacteria developed resistance. Incomplete clearance can result from shortened courses, incorrect dosing, or deep-seated infections that required longer treatment durations.
| 🔄 Possible Cause | 🧪 Veterinary Action Needed |
|---|---|
| Bacterial resistance | Culture and sensitivity test |
| Incomplete therapy | Repeat course or alternative antibiotic |
| Wrong antibiotic | Switch to broader-spectrum or potentiated drug |
| Misdiagnosis | Rule out fungal, viral, or inflammatory cause |
💡 Tip: Don’t restart leftovers. Let your vet reassess—repeating a failed treatment without diagnostics risks creating a chronic, resistant infection.
💬 “Is it okay to use amoxicillin preventively after a cut or wound?”
No. Prophylactic antibiotics are used sparingly and selectively in veterinary medicine. Most minor cuts do not require antibiotics unless signs of infection (redness, pus, swelling) develop. Overusing antibiotics “just in case” is a major driver of antimicrobial resistance.
| 🩹 Wound Type | 💊 Antibiotics Needed? |
|---|---|
| Minor scrape | No, clean with saline only |
| Puncture wound | Maybe, especially if deep or near joints |
| Surgical incision | Sometimes, as prescribed by vet |
| Bite wound | Usually, due to high bacterial load |
💡 Tip: For minor skin wounds, your vet may recommend topical antimicrobials like silver sulfadiazine instead. Always clean with chlorhexidine or saline first.
💬 “What’s the real danger of stopping antibiotics early if my dog looks better?”
Bacteria don’t die at the same rate. Clinical symptoms (like reduced coughing or appetite return) often improve before the most resistant bacteria are eliminated. By stopping treatment prematurely, you’re allowing the hardiest survivors—often the ones that evolve resistance—to flourish and repopulate.
| 🧬 Stage | 🦠 What’s Happening | ⚠️ If You Stop Early |
|---|---|---|
| Day 1–2 | Weak bacteria die first | Dog improves—deceptively |
| Day 3–4 | Moderate strains decline | Still contagious internally |
| Day 5–7 | Stubborn strains targeted | Early stop = mutation risk |
| After meds | Full recovery achieved | Relapse, stronger infection |
💡 Tip: Always administer every dose, even if your dog seems “completely fine.” Antibiotics are not symptom suppressors—they’re microscopic assassins with a mission.
💬 “My dog has kidney disease—should amoxicillin still be used?”
With careful monitoring and dose adjustment, yes. Amoxicillin is eliminated almost entirely by the kidneys. In dogs with compromised renal function, standard dosing can accumulate the drug, increasing the risk of toxicity—even at normal doses.
| 🩺 Kidney Status | 💊 Amoxicillin Strategy |
|---|---|
| Normal kidneys | Standard dosing (5 mg/lb BID) |
| Mild dysfunction | Adjusted dose or extended interval |
| Moderate-severe CKD | Lowered dose, monitor bloodwork |
| On dialysis | Case-by-case, use with caution |
💡 Tip: Ask your vet to perform a pre-treatment creatinine/BUN test. Dogs with elevated values often require a 25–50% dosage reduction.
💬 “Can amoxicillin affect my dog’s behavior?”
Yes—indirectly. While not a psychotropic drug, amoxicillin can cause gut-brain axis disturbances through GI inflammation or microbiome disruption. Dogs may exhibit lethargy, clinginess, restlessness, or irritability, especially if they feel nauseated or bloated.
| 🧠 Behavioral Change | 💡 Possible Cause |
|---|---|
| Pacing or restlessness | GI discomfort, mild nausea |
| Depression or withdrawal | Gut disruption, systemic fatigue |
| Attention-seeking | Stress response to feeling unwell |
| Agitation or growling | Rare—but could signal allergic discomfort |
💡 Tip: Don’t dismiss “mood changes” as bad behavior. Behavior is one of the earliest clinical signs dogs show when something internal isn’t right.
💬 “What’s the shelf life of liquid amoxicillin after mixing, and why so short?”
Just 14 days when refrigerated. Once water is added to the dry powder, the solution becomes chemically unstable—losing potency over time and potentially harboring bacterial contamination if not stored correctly.
| 🧴 Form | ❄️ Storage | ⏳ Shelf Life |
|---|---|---|
| Dry powder (unmixed) | Room temp | Check expiration label |
| Reconstituted liquid | Refrigerated (2–8°C) | 14 days max |
| Left unrefrigerated | Unsafe | Discard immediately |
💡 Tip: Use a permanent marker to label the “Mix Date” and “Discard By” date directly on the bottle for clarity.
💬 “What if my dog has multiple conditions—how do we avoid drug interactions?”
This is where veterinary pharmacology shines. Amoxicillin can safely be given with most NSAIDs, antihistamines, and heart meds, but can interact negatively with drugs like methotrexate, allopurinol, or certain diuretics. Drug synergy and timing are everything.
| ⚖️ Medication Category | 🤝 Amoxicillin Compatibility |
|---|---|
| NSAIDs (e.g., carprofen) | ✅ Yes, but monitor GI health |
| Antihistamines | ✅ Yes, no known interaction |
| Methotrexate | ⚠️ Risk of toxicity—avoid |
| Probiotics | ✅ Yes, just time doses 2 hrs apart |
| Furosemide (Lasix) | ⚠️ May increase kidney strain |
💡 Tip: Always provide a full med + supplement list to your vet—including topicals and treats like CBD oil or vitamins.
💬 “Why does my dog salivate heavily right after taking the antibiotic?”
It’s likely a taste aversion. Amoxicillin has a bitter, metallic taste, especially in crushed or uncoated tablets. Some dogs exhibit excessive salivation, head shaking, or lip smacking after dosing. This is not usually allergic, but behavioral.
| 👅 Symptom | 🧪 Probable Cause | 💡 Solution |
|---|---|---|
| Drooling | Bitter aftertaste | Hide in stronger-smelling food (peanut butter) |
| Pawing at mouth | Lingering flavor | Follow with treat or water |
| Refuses next dose | Negative association | Use pill pockets or flavored suspensions |
💡 Tip: Don’t crush the pill unless advised. Many tablets are coated for a reason—to mask flavor or aid absorption.
💬 “Is it true that giving amoxicillin without food causes nausea in dogs?”
Yes, it often does. While amoxicillin can technically be given on an empty stomach, many dogs experience gastrointestinal upset—including nausea, vomiting, or excessive drooling—when it’s administered without food. This is especially true for higher doses or long-term regimens.
| 🍽️ Feeding Status | 🤢 GI Tolerance | 💊 Absorption Effect |
|---|---|---|
| With a full meal | ✅ Better tolerated | Slightly slower, still effective |
| Light snack | ⚠️ Moderate relief | Still acceptable |
| Empty stomach | ❌ Nausea likely | Faster absorption, but risky |
💡 Tip: Pair the antibiotic with high-value protein (like boiled chicken or a pill-hiding treat). It doesn’t reduce efficacy but significantly enhances comfort.
💬 “What’s the difference between Amoxicillin and Clavamox?”
Clavamox is amoxicillin fortified with clavulanic acid—a beta-lactamase inhibitor. This added compound neutralizes bacterial enzymes that would otherwise destroy the amoxicillin molecule, making it far more effective against resistant pathogens, especially in skin or dental infections.
| 💊 Formulation | 🔬 Coverage Strength | 🦠 Target Infections |
|---|---|---|
| Amoxicillin alone | Standard spectrum | UTI, basic respiratory or skin infections |
| Clavamox (amoxicillin + clavulanate) | Broad-spectrum + beta-lactamase resistant | Chronic wounds, dental abscesses, complex pyodermas |
💡 Tip: If your vet switches to Clavamox mid-treatment, it’s likely due to emerging resistance—not failure of your dog’s immune system.
💬 “My dog is on a raw diet. Will that interfere with amoxicillin?”
Not directly, but it does change the gut microbiome. Dogs on raw diets often host different bacterial populations than kibble-fed dogs, including higher levels of environmental microbes (both beneficial and pathogenic). This may amplify GI side effects or cause unique interactions.
| 🍗 Feeding Type | 🔬 Microbiome Effect | 💥 Antibiotic Impact |
|---|---|---|
| Commercial kibble | Stable, regulated flora | Predictable response |
| Raw/home-prepped | More variable flora | May lead to harder-to-predict GI reactions |
| Freeze-dried/raw hybrid | Intermediate impact | Often well-tolerated with meds |
💡 Tip: During antibiotic therapy, consider pausing fermented ingredients or raw bones, and introduce a dog-safe probiotic to maintain balance.
💬 “Can I reuse leftover amoxicillin from last year if it wasn’t expired?”
No—and here’s why: Even if the expiration date hasn’t passed, the stability and sterility of the drug can degrade once the packaging is opened, especially in warm, humid environments. More importantly, you don’t know if the leftover dose is appropriate for your dog’s current condition.
| 🗓️ Time Since Opened | ⚠️ Viability Risk | 🚫 Why Not Reuse |
|---|---|---|
| Under 2 weeks (suspension) | Likely inactive | Liquid loses potency |
| Over 6 months (tablets) | Storage-degraded | Could be subtherapeutic |
| Unknown duration | Unsafe | No assurance of full effect or safety |
💡 Tip: Self-prescribing leftovers often leads to under-dosing or misapplication, both of which fuel antibiotic resistance and delay healing.
💬 “Does amoxicillin cause yeast infections in dogs like it can in humans?”
Yes, it can—especially in predisposed breeds. By wiping out commensal bacteria, amoxicillin may unintentionally give Malassezia (yeast) room to overgrow, particularly in ears, paws, and skin folds of dogs prone to moisture retention.
| 🐶 Breed Risk Level | 🧴 Common Yeast Hotspots | 🚨 Signs of Overgrowth |
|---|---|---|
| High (e.g., Bulldogs, Cocker Spaniels) | Ears, interdigital spaces, anal folds | Itchiness, greasy coat, odor |
| Medium (Labs, Shepherds) | Ears, groin | Mild redness, scratching |
| Low (Short-hair breeds) | Rare unless allergic | Usually no issue |
💡 Tip: If your dog’s scratching increases after antibiotics, talk to your vet about adding an antifungal shampoo or ear cleanser as a preventative step.
💬 “My dog’s breath smells weird since starting amoxicillin. Is that normal?”
Yes, and here’s why—it’s usually metabolic, not dental. Amoxicillin can affect the oral and gut microbiota, leading to sulfuric or sour-smelling breath, especially when the GI tract is mildly inflamed. It’s also possible the infection being treated (especially a dental abscess) is releasing necrotic odor as it resolves.
| 🐶 Breath Type | 🔍 Potential Cause | 🔧 Suggested Action |
|---|---|---|
| Metallic or bitter | Drug aftertaste | Offer water or bland treat post-dose |
| Sulfuric or eggy | Gut flora imbalance | Add vet-approved probiotic |
| Rotten/fishy | Infection drainage | Monitor—likely self-resolving |
| Chemical-like | Unusual, vet should evaluate | Possible metabolic side effect |
💡 Tip: Use stainless steel bowls during antibiotic use—they reduce bacterial film buildup and odor transfer better than plastic.
💬 “Is there a difference between giving the full dose once per day versus splitting it in half?”
Yes—timing matters for amoxicillin’s efficacy. This drug has a short half-life (roughly 1–1.5 hours in dogs), meaning blood levels drop significantly within hours of dosing. Giving the full daily dose all at once can lead to subtherapeutic gaps, allowing bacteria to rebound.
| ⏰ Dosing Frequency | 💊 Effectiveness | ⚠️ Risk |
|---|---|---|
| Once daily | Less effective | Bacteria may adapt |
| Every 12 hours (BID) | Optimal | Maintains steady plasma levels |
| Every 8 hours (TID) | Used in some severe cases | Requires strict schedule |
💡 Tip: Set reminders (phone, calendar, smart speaker) to ensure 12-hour dosing is consistent. Irregular timing lowers success rate dramatically in some infections.
💬 “Why do some dogs vomit within 10 minutes of taking the medication?”
That’s a direct gastric response to irritation. Amoxicillin in tablet form can activate acid production in the stomach, and in sensitive dogs, this triggers immediate emesis. It’s not an allergy—just an intolerance to oral dosing on a sensitive gut lining.
| 🤮 Vomiting Pattern | 📍 Mechanism | 🛠️ Remedy |
|---|---|---|
| < 15 minutes post-dose | Local gastric irritation | Give with food, not on empty stomach |
| Delayed (30–60 min) | Nausea from systemic absorption | Ask vet about switching to suspension |
| Vomits tablet whole | Physical gag reflex or texture aversion | Hide in soft pill pocket or cheese |
💡 Tip: If vomiting persists after every dose despite food, ask your vet about compounded forms—like chewables or flavored liquids designed for sensitive GI tracts.
💬 “Does amoxicillin affect dogs differently depending on their age?”
Yes—pharmacokinetics change with age. Puppies metabolize drugs faster due to higher hepatic blood flow, while seniors may clear amoxicillin more slowly due to reduced kidney function or circulation. This affects dose strength, frequency, and monitoring.
| 🐾 Life Stage | ⚙️ Metabolic Rate | 💊 Dose Consideration |
|---|---|---|
| Puppy (under 6 mo) | Rapid clearance | May require closer timing or higher mg/kg |
| Adult | Standard metabolism | Normal protocol (5 mg/lb BID) |
| Senior (8+ yrs) | Slower renal excretion | Monitor kidney function; may need adjusted dose |
💡 Tip: For elderly dogs, always request pre-treatment lab work (BUN, creatinine, urinalysis) to confirm renal safety before beginning antibiotics.
💬 “My dog became constipated on antibiotics. Isn’t diarrhea the usual side effect?”
Surprisingly, yes—constipation can also occur. While most expect loose stools, amoxicillin may reduce normal peristalsis in some dogs or cause them to eat less, resulting in slower transit and harder stools. It may also disrupt hydration if paired with vomiting.
| 🚽 Symptom | 🔬 Root Cause | 🧃 Solution |
|---|---|---|
| Straining, dry stool | Dehydration or decreased gut motion | Add water to meals, pumpkin puree |
| Fewer bowel movements | Lower food intake | Small, frequent meals |
| Withholding defecation | Stress from meds or vet visit | Extra walks, exercise for stimulation |
💡 Tip: A teaspoon of plain canned pumpkin (not pie filling) adds moisture and fiber. Do not add mineral oil or human laxatives without vet approval.
