Foxglove (Digitalis) Poisoning in Dogs: Digoxin Toxicity
Published: 2026-08-15 · Updated: August 2026
Foxglove (Digitalis purpurea) is a beautiful but deadly flowering plant commonly found in cottage gardens and woodland areas. All parts of the plant — leaves, flowers, seeds, and stems — contain cardiac glycosides, primarily digitoxin and digoxin, which are the same compounds...
🚨 EXTREME EMERGENCY — Time-Sensitive
If your pet has ingested this substance, contact a veterinarian immediately. Do not wait for symptoms. Minutes matter.
| Scientific Name | Digitalis purpurea |
|---|---|
| Toxic Principles | Digitoxin, Digoxin (Cardiac Glycosides) |
| Danger Level | Extreme (Emergency) |
| Toxic Dose Limit | 0.3 g/kg |
| Target Organ | Heart (Cardiotoxicity) |
Foxglove (Digitalis purpurea) is a beautiful but deadly flowering plant commonly found in cottage gardens and woodland areas. All parts of the plant — leaves, flowers, seeds, and stems — contain cardiac glycosides, primarily digitoxin and digoxin, which are the same compounds used in human heart failure medications. In dogs, these compounds inhibit the sodium-potassium ATPase pump in cardiac muscle, causing a dangerous accumulation of intracellular calcium that leads to life-threatening arrhythmias. The toxic dose is extremely low: approximately 0.3 g/kg of body weight, meaning a single leaf can be fatal to a medium-sized dog. The dried leaves retain their toxicity, making dried plant material in gardens or flower arrangements equally dangerous.
Symptoms to Watch For
- Vomiting and diarrhea (often profuse, may contain blood)
- Severe drooling and hypersalivation
- Abdominal pain (whining, hunched posture)
- Slow or irregular heart rate (bradycardia, heart block)
- Weakness, collapse, and disorientation
- Dilated pupils and tremors
- Seizures and sudden death in severe cases
Timeline
Gastrointestinal symptoms appear within 30 minutes to 3 hours of ingestion. Cardiac effects develop within 2-6 hours. The toxins are rapidly absorbed and have a long half-life in dogs (approximately 23-38 hours for digitoxin). Without treatment, death from cardiac arrhythmia can occur within 12-24 hours. Even with treatment, cardiac monitoring is required for 48-72 hours due to the prolonged clearance time.
Treatment Guidance
Foxglove poisoning is a critical emergency. If ingestion was within 2 hours and the dog is asymptomatic, the veterinarian will induce vomiting and administer activated charcoal. Repeated doses of activated charcoal (every 4-6 hours) may be needed because digitoxin and digoxin undergo enterohepatic recirculation. Continuous ECG monitoring is essential. Anti-arrhythmic medications (lidocaine, atropine, phenytoin) are used to manage cardiac arrhythmias. Digoxin-specific Fab fragments (Digibind) — the definitive antidote — can be used in severe cases but are expensive and may not be available at all veterinary facilities. Electrolyte abnormalities (particularly potassium) must be carefully managed. The prognosis is guarded, with mortality rates of 20-30% even with aggressive treatment. Prevention is the best approach: avoid planting foxglove in yards accessible to dogs, and be aware that dried foxglove in flower arrangements remains toxic.
Symptom Timeline — What to Expect & When to Act
Time since ingestion is the most critical factor in toxicity outcomes. This is a general timeline — individual responses vary based on weight, breed, age, and pre-existing conditions.
| Time Since Ingestion | What's Happening | Symptoms | Your Action |
|---|---|---|---|
| First 30 Minutes | Toxin enters the stomach. Absorption begins. For most toxins, this is the golden window for intervention. | May be none visible yet. Mild drooling, lip-smacking, or restlessness possible. | Call vet or ASPCA Poison Control (888-426-4435) immediately. Do NOT wait for symptoms. |
| 30 Min – 2 Hours | Toxin enters the small intestine. Systemic absorption accelerates. For most toxins, clinical signs begin in this window. | Vomiting, diarrhea, lethargy, drooling, abdominal pain, restlessness or depression. | Transport to vet. Bring the substance packaging. Note the time and estimated amount consumed. |
| 2–6 Hours | Peak blood concentration for most toxins. Organ damage begins if the toxin targets liver or kidneys. GI symptoms intensify. | Persistent vomiting, bloody diarrhea, tremors, ataxia (wobbling), increased heart rate, fever or hypothermia. | If not already at vet: GO NOW. Do not wait for "one more hour." Organ damage may already be occurring. |
| 6–24 Hours | Toxin is either being metabolized and excreted, or organ damage is progressing. Recovery or deterioration becomes clear in this window. | Depends on the toxin: jaundice (liver), reduced urination (kidney), seizures, collapse, or gradual improvement. | If hospitalized: follow veterinary guidance. If recovering at home: monitor closely for 48 hours. Any regression = return to vet immediately. |
| 24+ Hours | Acute phase passing. Long-term organ function and recovery trajectory are being determined. Most pets that survive past 48 hours recover fully. | Residual GI upset, fatigue, increased thirst/urination possible as the body clears metabolites. | Follow-up vet visit. Blood work to check liver and kidney values. Bland diet for 3-5 days. Lots of water. |
This timeline is a general guide based on common toxin pharmacokinetics. Specific substances may have different absorption rates, peak times, and clinical courses. Always follow your veterinarian's specific advice for your pet's situation. This is not a substitute for professional veterinary care.
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Frequently Asked Emergency Questions
My pet just ate this — what should I do right now?
Call a veterinarian or the ASPCA Animal Poison Control Center at (888) 426-4435 immediately. Do not wait for symptoms. Do not induce vomiting unless a vet instructs you to — some substances cause more damage coming back up. Have ready: what your pet ate, how much, how long ago, and your pet's weight.
How much is toxic — will a small amount hurt my pet?
The toxic dose depends on your pet's weight and the specific substance. Even small amounts can be dangerous for small pets or with highly toxic substances. There is no universally safe amount. Always call a vet to assess based on your pet's weight and estimated consumption.
How long until symptoms appear?
Some toxins show effects within 30 minutes to 6 hours. Others take 24-72 hours. Waiting to see if symptoms develop is dangerous — by the time you see signs, organ damage may already be underway. The best intervention window is immediately after ingestion.
Can my pet survive if treated quickly?
With a danger level of Extreme (Emergency), early veterinary intervention dramatically improves outcomes. Pets treated within hours of ingestion have the best prognosis. Never assume your pet will be fine — always err on the side of caution.
Can I induce vomiting at home with hydrogen peroxide?
Do NOT induce vomiting unless a veterinarian specifically instructs you to. Some toxins cause MORE harm when vomited. Hydrogen peroxide can irritate the esophagus. Call a vet or poison control first — they will tell you whether home treatment is safe.
Dog behavior researcher with 10 years of experience working with rescue dogs and studying canine communication. I've volunteered at shelters across three states, rehabbed dozens of anxious and reactive dogs, and helped hundreds of owners understand what their dogs are really saying. My writing combines hands-on training experience with current behavioral science — because good dog ownership starts with understanding how dogs see the world.
From the Author — Marcus Chen
I've worked with dogs in shelters and rescue settings for over a decade, and the single most important thing I've learned is that most 'problem behaviors' are communication. The dog who chews your shoes isn't being spiteful — he's anxious, under-stimulated, or teething. The dog who growls at visitors isn't aggressive — she's scared and asking for space. I've seen hundreds of dogs labeled 'difficult' transform into calm, confident companions once their owners learned to read their signals. Every article I write comes from this perspective: your dog is always telling you something. The question is whether you're listening.
Real Case — From Marcus Chen's Experience
At the shelter where I volunteered, we had a 2-year-old pit bull mix named Daisy who'd been returned twice for 'aggression.' The first session with her showed me the problem immediately: she was terrified of men wearing hats. Someone had clearly traumatized her. We set up a desensitization program — volunteers wearing hats at a distance, gradually decreasing the distance over weeks, paired with high-value treats. Four months later, Daisy was adopted by a family with a father who wore a baseball cap every day. She's been with them for three years now. That case taught me that almost all 'aggression' in dogs is fear, and fear responds to patience, not punishment.
References & Further Reading
- ASPCA Animal Poison Control Center. Animal Poison Control FAQ. aspca.org/pet-care/animal-poison-control
- U.S. Food & Drug Administration, Center for Veterinary Medicine. Animal Health & Safety. fda.gov/animal-veterinary
- National Institutes of Health, PubMed. Veterinary Toxicology Research Database. pubmed.ncbi.nlm.nih.gov
- Pet Poison Helpline. 24/7 Animal Poison Control Emergency Service. petpoisonhelpline.com
Citations are provided for educational reference. Content is reviewed periodically but does not replace professional veterinary advice. If your pet shows signs of illness, contact a licensed veterinarian immediately.