My 14.6 lb puppy somehow got hold of a 2.5 mg warfarin

Warfarin can cause some serious issues. The best course is to seek emergency treatment. Monitor for signs of bleeding, bruising, etc. Allow me a moment to see if I have some reference materials for you.

Warfarin

(war-far-in)

Coumadin®

Anticoagulant (Systemic Drug)

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Dosages

Dosage Forms

Drug Interactions

Adverse Effects

Veterinary Medication Guide

Prescriber Highlights

Coumarin derivative anticoagulant used primarily for long-term thromboprophylaxis, primarily in dogs. Requires careful monitoring & dosage adjustment.

Full anticoagulant effect requires several days to be achieved; may need additional anticoagulant during this time.

Recommend not using in cats; current evidence suggests a lack of efficacy & an intolerable rate of adverse events.

Contraindications: Preexistent hemorrhage, pregnancy, those undergoing or contemplating eye or CNS surgery, major regional lumbar block anesthesia, surgery of large, open surfaces, active bleeding from the GI, respiratory, or GU tract; aneurysm, acute nephritis, cerebrovascular hemorrhage, blood dyscrasias, uncontrolled or malignant hypertension, hepatic insufficiency, pericardial effusion, & visceral carcinomas.

Adverse effects: Dose-related hemorrhage; death is possible.

Teratogenic; contraindicated in pregnancy.

Many potentially significant drug interactions.

Frequency and expense of monitoring are limiting factors.

Uses / Indications

In veterinary medicine, warfarin has been used primarily for the oral, long-term treatment (or prevention of recurrence) of thrombotic conditions, primarily in dogs. Use of warfarin in veterinary species is somewhat controversial, especially in cats, due to unproven benefit in reducing mortality, increased expense associated with monitoring, and potential for serious effects (bleeding), many do not recommend its use.

Pharmacology / Actions

Warfarin inhibits vitamin K epoxide reductase (VKORC1), which interferes with the action of vitamin K1 in the synthesis of the coagulation factors II, VII, IX, and X, as well as the anticoagulant proteins C and S. Warfarin acts indirectly as an anticoagulant (it has no direct anticoagulant effect) to prevent the extension of an existing thrombus, and reduce formation of new clots. Sufficient amounts of vitamin K1 can override this effect. Depletion of existing clotting factors occurs gradually over the first several days of treatment, and additional anticoagulant therapy (eg, heparin) may be required. Warfarin is administered as a racemic mixture of S(+) and R(-) warfarin. The S(+) enantiomer is a significantly more potent vitamin K antagonist than the R(-) enantiomer in species studied.

Pharmacokinetics

Warfarin is rapidly and completely absorbed in humans after oral administration. In cats, warfarin is also rapidly absorbed after oral administration.

After absorption, warfarin is approximately 99% bound to plasma proteins in humans. Only free (unbound) warfarin is active. It is reported that there are wide species variations with regard to protein binding; in cats, more than 96% of the drug is protein bound. and horses have a higher free (unbound) fraction of the drug than do rats, sheep or swine. While other coumarin and indanedione anticoagulants are distributed in human milk, warfarin does not enter milk.

Warfarin is principally metabolized in the liver to inactive metabolites that are excreted in urine and bile (and then reabsorbed and excreted in the urine). The plasma half-life of warfarin may be several hours to several days depending on the patient (and possibly species). In cats, the terminal half-life of the S enantiomer is approximately 23 to 28 hours and the Renantiomer approximately 11 to 18 hours.

Contraindications / Precautions / Warnings

Warfarin is contraindicated in patients with preexistent hemorrhagic tendencies or diseases, those undergoing or contemplating eye or CNS surgery, major regional lumbar block anesthesia, or surgery of large, open surfaces. It should not be used in patients with active bleeding from the GI, respiratory, or GU tract. Other contraindications include: aneurysm, acute nephritis, cerebrovascular hemorrhage, blood dyscrasias, uncontrolled or malignant hypertension, hepatic insufficiency, pericardial effusion, pregnancy, and visceral carcinomas. Warfarin should not be used in patients with heparin-induced thrombocytopenia until platelet counts have stabilized. Anticoagulated patients have experienced hematomas after spinal or epidural anesthesia. Clients must be willing to comply with the frequency and expense of routine monitoring.

Use with extreme caution in cats. Most no longer recommend use in cats due to an increased mortality rate and a high rate of significant adverse events, including fatal hemorrhage.1

Excessive anticoagulation can be managed by withholding one to several doses, with or without administration of vitamin K and/or blood products, with a subsequent dose reduction. Presurgical management may require withholding warfarin for up to several days prior to surgery and use of alternative anticoagulants (eg, heparin), although warfarin may continue uninterrupted if the surgical bleeding risk is low.

Adverse Effects

The principal adverse effect of warfarin use is dose-related hemorrhage, which may manifest with clinical signs of anemia, thrombocytopenia, weakness, hematomas and ecchymoses, epistaxis, hematemesis, hematuria, melena, hematochezia, hemathrosis, hemothorax, intracranial and/or pericardial hemorrhage, and death. In humans, skin necrosis, calciphylaxis, and cholesterol microemboli have been reported.

Reproductive / Nursing Safety

Warfarin is embryotoxic, can cause congenital malformations, and is considered contraindicated during pregnancy. If anticoagulant therapy is required during pregnancy, most clinicians recommend using low-dose heparin. In humans, the FDA categorizes this drug as category X for use during pregnancy (Studies in animals or humans demonstrate fetal abnormalities or adverse reactions; reports indicate evidence of fetal risk. The risk of use in pregnant women clearly outweighs any possible benefit). In a separate system evaluating the safety of drugs in canine and feline pregnancy,2 this drug is categorized as class D (Contraindicated. These drugs have been shown to cause congenital malformations or embryotoxicity).

Based on limited published data, warfarin has not been detected in the breast milk of humans treated, and is generally considered safe to use in nursing patients but the nursing infant should be monitored for bruising or bleeding.

Overdose / Acute Toxicity

Acute overdoses of warfarin may result in life-threatening hemorrhage. In dogs and cats, single doses of 5 – 50 mg/kg have been associated with toxicity. It must be remembered that a lag time of 2 to 5 days may occur before signs of toxicity occur, and animals must be monitored and treated accordingly.

Cumulative toxic doses of warfarin have been reported as 1 – 5 mg/kg for 5 to 15 days in dogs and 1 mg/kg for 7 days in cats. There were 204 single agent exposures to warfarin reported to the ASPCA Animal Poison Control Center (APCC) between 2009 and 2013. Of the 193 dogs, 20 were symptomatic with lethargy (50%) being the most common clinical sign. Of the 9 cats, 4 were symptomatic with 50% having anorexia, hematuria, lethargy, and vomiting.

If overdose is detected early, prevent absorption from the gut using standard protocols. If clinical signs are noted, they should be treated with blood products and vitamin K1 (phytonadione). Refer to the phytonadione monograph for more information.

Drug Interactions

Drug interactions with warfarin are perhaps the most important in human medicine. Warfarin is metabolized principally by CYP2C9, but also by many other CYP enzymes. The following drug interactions have either been reported or are theoretical in humans or animals receiving warfarin and may be of significance in veterinary patients. Unless otherwise noted, use together is not necessarily contraindicated, but weigh the potential risks and perform additional monitoring when appropriate.

A multitude of drugs have been documented or theorized to interact with warfarin. The following drugs or drug classes may increase the anticoagulant response of warfarin (not necessarily a complete list):

ACETAMINOPHEN

ALLOPURINOL

AMIODARONE

ANABOLIC STEROIDS

AZOLE ANTIFUNGALS (eg, fluconazole, itraconazole, voriconazole)

CEPHALOSPORINS (eg, cefazolin, cefpodoxime, cephalexin)

CHLORAMPHENICOL

CISAPRIDE

CLOPIDOGREL

DANAZOL

FISH OIL

FLUOROQUINOLONES

GLUCOSAMINE

HEPARINS (unfractionated and low molecular weight heparins)

LACTULOSE

MACROLIDE ANTIBIOTICS (eg,azithromycin, clarithromycin, erythromycin)

METRONIDAZOLE

MIRTAZAPINE

NEOMYCIN

NSAIDs

PENICILLINS (eg, penicillin G, amoxicillin, dicloxacillin, piperacillin)

PENTOXIFYLLINE

PHENYLBUTAZONE

PPIs (eg, omeprazole, pantoprazole)

QUINIDINE

SALICYLATES

SSRIS (eg, fluoxetine, sertraline)

SULFONAMIDES, including combinations with ormetoprim and trimethoprim

THYROID MEDICATIONS

TRAMADOL

VITAMIN E

The following drugs or drug classes may decrease the anticoagulant response of warfarin (not necessarily a complete list):

BARBITURATES (eg, phenobarbital)

CORTICOSTEROIDS

CYCLOSPORINE: Additionally, warfarin may reduce cyclosporine efficacy.

ESTROGENS

GRISEOFULVIN

MERCAPTOPURINE

RIFAMPIN

PHENOBARBITAL

SPIRONOLACTONE

SUCRALFATE

VITAMIN K

Should concurrent use of any of the above drugs with warfarin be necessary, enhanced monitoring is required. Refer to other references on drug interactions for more specific information.

Laboratory Considerations

Warfarin may cause falsely decreased theophylline values if using the Schack and Waxler ultraviolet method of assay.

Dosages

DOGS:

Thromboprophylaxis (extra-label): No studies have prospectively evaluated the effectiveness of any warfarin regimen in animals. Initial doses of 0.22 mg/kg have been suggested, but a retrospective study described an initial dose of 0.05 – 0.2 mg/kg PO every 24 hours, with dosage adjusted (see Monitoring) to achieve an International Normalized Ratio (INR) of 2-3. The two most important principles in adjusting warfarin were to keep the dose adjustments small and to make adjustments to the total weekly dose rather than the total daily dose.1,3,4

CATS:

No longer recommended.

HORSES: (NOTE: ARCI UCGFS CLASS 5 DRUG)

Anticoagulant (extra-label): Rarely recommended today. An anecdotal dose for adjunctive treatment of laminitis has been noted: 0.0198 mg/kg PO every 24 hours; monitor OSPT (one-step prothrombin time) until prolonged 2-4 seconds beyond baseline.5

Monitoring

Note: The frequency of monitoring is controversial, and dependent on several factors including dose, patient’s condition, and concomitant problems. See Dosage section above for more information.

While prothrombin times (PT) or INR (not validated for veterinary patients1) are most commonly used to monitor warfarin, PIVKA (proteins induced by vitamin K antagonists) has been suggested as being more sensitive. PTs are usually recommended to be 1.5 to 2 times normal and INRs to be between 2 and 3.1,4,6 A retrospective study in dogs used INR to adjust dosage. In that study, some dogs required weekly or biweekly dose adjustments based on the calculated INR value for the first 2 to4 weeks. Based on concurrent disease processes or concomitant drug therapy, it is recommended that dogs (sensitive to diet changes or concomitant medications) have an INR value checked at least every 3 months.3

Platelet counts and hematocrit (PCV) should be done periodically.

Occult blood in stool and urine; other observations for bleeding.

Clinical efficacy.

Client Information

Many drugs and foods can interact with warfarin and can either increase the risk for bleeding or reduce warfarin’s anticoagulant effects. Before starting a new drug, including OTC (over the counter; without a prescription) drugs, or stopping drugs that your animal is currently taking, talk with your veterinarian or pharmacist.

Do not allow your animal to be in situations where it might be injured or cut as serious bleeding could occur. If abnormal bleeding is seen, contact your veterinarian immediately.

To assure the dose is correct, routine blood tests will be needed.

If a dose is missed, it should be taken as soon as possible on the same day. Do not double up doses the next day.

Download Veterinary Medication Guide (Requires Internet Connection)

Chemistry / Synonyms

A coumarin derivative, warfarin sodium occurs as a slightly bitter tasting, odorless, white, amorphous or crystalline powder that discolors in light. It is very soluble in water and freely soluble in alcohol. The commercially available products contain a racemic mixture of the two optical isomers.

Warfarin Sodium may also be known as sodium warfarin, warfarinum natricum, Coumadin®, Jantoven®, or Panwarfin®; there are many other trade names internationally.

Storage / Stability

Warfarin sodium tablets should be stored in tight, light-resistant containers at temperatures less than 40°C, preferably at room temperature.

Compatibility / Compounding Considerations

A method of suspending warfarin tablets in an oral suspension has been described.7 To make 30 mL of a 0.25 mg/mL suspension: Crush three 2.5 mg tablets with a mortar and pestle. Add 10 mL glycerin to form a paste; then add 10 mL of water; add sufficient amount of dark corn syrup (Karo®) to obtain a final volume of 30 mL. Warm gently; shake well and use within 30 days.

Dosage Forms / Regulatory Status

VETERINARY-LABELED PRODUCTS: None.

The ARCI (Racing Commissioners International) has designated this drug as a class 5 substance. See Appendix for more information.

HUMAN-LABELED PRODUCTS:

Warfarin Sodium Oral Tablets (scored): 1 mg, 2 mg, 2.5 mg, 3 mg, 4 mg, 5 mg, 6 mg, 7.5 mg, & 10 mg; Coumadin®, Jantoven®, generic; (Rx).

References / Revisions

Reviewed and updated by James A. Budde, PharmD, FSVHP, DICVP. Last update September 2017.

Smith SA. Antithrombotic Therapy. Topics in Companion Animal Medicine. 2012;27(2):88-94.

Papich M. Effects of drugs on pregnancy. In: Kirk R, ed. Current Veterinary Therapy X: Small Animal Practice. Philadelphia: Saunders; 1989:1291-1299.

Winter RL, et al. Aortic thrombosis in dogs: presentation, therapy, and outcome in 26 cases. Journal of veterinary cardiology : the official journal of the European Society of Veterinary Cardiology. 2012;14(2).

Arai S, Callan MB. Warfarin therapy in a dog with acute arterial thrombosis and pyometra. Canadian Veterinary Journal-Revue Veterinaire Canadienne. 2014;55(11):1066-1068.

Brumbaugh G, et al. The pharmacologic basis for the treatment of laminitis. The Veterinary Clinics of North America: Equine Practice. 1999;15:2(August).

Lake-Bakaar GA, et al. Aortic thrombosis in dogs: 31 cases (2000-2010). J Am Vet Med Assoc. 2012;241(7):910-915.

Enos LR. Personal Communication.

I am not a bot.

This may be up to a 0.4mg/kg dose.

WARFARIN

Used as anticoagulation therapy for deep vein thrombosis and thrombophlebitis, also used as a prophylaxis treatment to prevent
Treatment is aimed at prevent extension of the thrombosis, embolisation and to prevent reoccurrence
The effects of warfarin are not instant so often combined initially with other medications and then continued as a long term control, recently warfarin has been replaced with other medications, deemed safer

WARFARIN
Warfarin absorption is steady and complete
Around 90% of the ingested dose is absorbed
Peak serum from a single dose, 3 hours post ingestion
S-warfarin mainly metabolised by P450 CYP2C9 to produce inactive hydroxylated metabolites
R-warfarin metabolised by CYP1A1, CYP1A2 and CYP3A4 pathways to produce inactive hydroxylated metabolites
The hydroxylated metabolites may then be conjugated prior to excretion in urine or bile
A very small amount of warfarin is excreted as the parent drug, excretion is in the inactive metabolite form, mainly in urine and to a lesser amount in faeces
Elimination half life R-warfarin 37-89 hours in humans, S-warfarin 21-43 hours
The average half life in dogs is shorter at 14.5 hours
Canine therapeutic vet dose 0.1-0.2mg/kg Oral Q24
Feline therapeutic vet dose 0.1-0.2mg/kg Oral Q24
AVAILABLE FORMULAS
1mg (pink), 2mg (lavender), 2.5mg (green), 3mg (tan), 4mg (blue), 5mg (peach), 6mg (teal), 7.5mg (yellow), 10mg (white)

MEDIUM DANGER RISK

EFFECTS OF WARFARIN
Warfarin inhibits the synthesis of clotting factors II, VII, IX and X
This is done by competitively inhibiting vitamin K dependent gamma carboxylation of the precursor proteins
The speed of the depletion of the clotting factors will depend on their half lives
Clotting factor VII is depleted first, half life 4-6 hours
Clotting factor IX second, half life 20-24 hours
Clotting factor X third, half life 48-72 hours
Clotting factor II fourth, half life over 60 hours

ONE OFF INGESTIONS OF WARFARIN
As the average elimination half life of warfarin is 14.5 hours, this may only deplete factors VII and partially IX, peak effect of warfarin is only reached when all four factors are depleted, poisoning in the form of a 'one off' ingestion have moderate risk of haemorrhaging

SEVERAL DAYS OF WARFARIN
Ingestion over 5 days -120 hours
This will see depletion of all factors and a much higher risk of haemorrhaging

DOSE DEPENDENT EFFECTS
As the inhibition is competitive, this means the higher the dose, the worse the effect and also indicates vitamin K can be a form of treatment to out compete the warfarin

Reported lethal doses have a large variance as they are dependant on the length of exposure and the warfarin salt, there are many references to lethal doses without specifying the salt

REPORTED LETHAL DOSES OF WARFARIN

SpeciesCat Dog Rabbit

Warfarin
Warfarin Sodium
Warfarin Potassium
6mg/kg
5-30mg/kg
-
3mg/kg
20-50mg/kg
200 mg/kg
-
-
800mg/kg

SpeciesPigChickenMouse

Warfarin
Warfarin Sodium
Warfarin Potassium
1mg/kg
-
-
-
-
942mg/kg
60mg/kg
374mg/kg
760mg/kg

SpeciesHumanGuinea PigRat

Warfarin
Warfarin Sodium
Warfarin Potassium

6.7mg/kg
-
-

-
180 mg/kg
-
1.6mg/kg
9.7mg/kg
58mg/kg
The main concerns with warfarin ingestions are haemorrhaging and secondary effects from this, gastrointestinal upsets will probably be seen and occasionally signs of liver toxicity
Warfarin can cross the placenta, resulting in foetal bleeding

CLINICAL SIGNS

GASTROINTESTINAL
Inappetence, vomiting, diarrhoea, pancreatitis, oesophageal ulceration
CARDIOVASCULAR
Persistent haemorrhaging can occur at any site
Anaemia and secondary signs of hypovolaemic shock, tachycardia, hypotension, pale mucous membranes, petechial or ecchymotic haemorrhages of the sclera, or mucous membranes
Pulmonary haemorrhages may result in dyspnoea and coughing
NEUROMUSCULAR
Neurological signs may be from intracranial bleeding, or secondary to hypovolaemia, paresis, ataxia and seizures are possible
HEPATORENAL
Raised hepatic figures and/or secondary renal failure is possible in severe cases

TREATMENT

GASTRIC DECONTAMINATION
If recent large ingestion, perform emesis if within 2 hours
Otherwise consider lavage, window of benefit up to 3 hours
Activated charcoal is believed to be of benefit, as are repeat doses
EMESIS
Apomorphine 0,02-0.04mg/kg SC - Naloxone 0.04mg/kg to reverse IV SQ IM
or
3% Hydrogen peroxide 1-3ml/Kg, can repeat after 5-10 minutes if no vomiting
GASTRIC LAVAGE
Sedate, place cuffed ET tube and lavage with stomach tube
ACTIVATED CHARCOAL
Activated charcoal by mouth or stomach tube
1-3gm/kg in 50-100ml of water
1 heaped teaspoon in 40ml of water /2.5kg
Repeat in 4 hours at half dose, unless aspiration risks outweigh
CATHARTIC
Administer With First Activated Charcoal
Cathartic if no diarrhoea or dehydration to eliminate charcoal bound toxin from the body
Saccharide cathartic sorbitol 70% solution 1-3ml/kg ORAL
ANTIEMETICS
Maropitant 1mg/kg SC Q24
or
Metoclopramide 0.2-0.5 mg/kg IV IM SC Q 8-12 or 1-2 mg/kg IV Q24 as CRI
NEUROMUSCULAR
Anticonvulsants
Diazepam 0.25-0.5mg/kg IV (1st choice)
Repeat after 10 minutes if needed, up to 3 times
If Not Effective
Phenobarbital 1-4mg/kg slow IV to effect, care with sedative effect, can take 20 minutes for full effect
If Still Not Effective
Propofol 1-4mg/kg slow IV to effect, intubate and ventilate
SUPPORTIVE IV FLUIDS
Crystalloid fluids and electrolyte therapy
Rate based on clinical signs of hypotension, hydration, shock and oliguria
Maintenance rate taken as 50-80 ml/kg/day
Consider rates of up to 4-6ml/kg/hour as needed
CARDIOVASCULAR SHOCK AND HAEMORRHAGE
HYPOTENSION
For hypotension start fluid rates at 4-6ml/kg/hour and if severe consider giving 20-30ml/kg IV over 20-30 minutes in aliquots, while blood pressure is monitored
COLLOID IF NO ACCESS TO BLOOD PRODUCTS
Only consider if no access to blood products, as can exacerbate coagulopathy problems
Gelatine (Oxypolygelatine) 20ml/kg maximum in 24 hour period
WHOLE BLOOD TRANSFUSION
Maximum possible transfusion rate is 20ml/kg/hour
Maximum daily amount 20ml/kg
2ml of blood transfused/kg should raise PCV by 1%

CALCULATION FOR WHOLE BLOOD TRANSFUSION

Volume Of Donor Blood To Be Transfused
=
Patient Weight✖️85✖️Patient Desired PCV
➖
Current PCV➗PCV Of Donor Blood

PACKED RED BLOOD CELLS
2ml of packed blood cells/kg should raise PCV by 2%
PLATELET INFUSION
1 unit of platelet rich plasma or concentrate/10kg
OXYHAEMOGLOBIN
If Transfusion Not Possible
Haemoglobin based oxygen solution
Oxyglobin 10-30ml/kg over 4-8 hours
TEMPERATURE CONTROL
Hyperthermia could signify bleeding into cavities, cool with cold water towels and fans
RESPIRATORY ASSISTANCE
Provide oxygen as supportive treatment for respiratory distress, be ready to intubate and ventilate if needed
GASTROINTESTINAL
H2 Antagonists
Famotidine 0.5-1mg/kg IV IM SQ Oral Q12-24
or Ranitidine 1-2 mg/kg IV SQ Oral Q8-12
or Cimetidine 5-10mk/kg IV IM Oral Q6-8
Slow IV over 30 minutes if hypotension or arrhythmias
Proton Pump Inhibitor
Omeprazole 0.5-1.5mg/kg oral Q24
Prevent Oesophageal/Gastric/Duodenal Ulceration
Sucralfate 0.25-2g Oral Q8
Could effect bioavailability of H2 antagonists so give 2 hour gap

VITAMIN K1 ANTIDOTE
Avoid IV route as risks outweigh any possible benefit
Oral route is believed more rapid than subcutaneous injections, rapid absorption and quick distribution to the target organ (liver)
Vitamin K1 1-5mg/kg Q24 Oral
or
Vitamin K1 2.5mg/kg multiple sites
Followed By
Vitamin K1 oral 1-2.5mg/kg either Q24 for 1 week

OSPT BLOOD CHECKS
Ideally check One Stage Prothrombin Time 48-72 hours after last vitamin K1 and then if normal, repeat again in 48-72 hours
Any prolonged result repeat course and then check again, continue until both tests are normal

LAST RESORT VASOPRESSORS
Only use if cardiac arrest imminent from cardiovascular hypovolaemic shock
Dopamine 2-10 mcg(micro)/kg/min IV as a CRI
or
Epinephrine 0.05-0.4 mcg(micro)/kg/min IV as a CRI
or
Norepinephrine 0.1-1.0 mcg(micro)/kg/min IV as a CRI

ANALGESIA
Avoid NSAID As Likely Gastrointestinal Damage
Care with sedative effect
Buprenorphine 0.02 mg/kg IV IM Q6 hours if needed
or
Pethidine 2-10 mg/kg IM SC Q2 hours if needed
OLIGURIA / ANURIA
Place urinary catheter and measure urine production
Oliguria (0.5ml urine/kg/hour)
Anuria (less than 0.5ml/kg/hr)
Increase fluid rate to 2-3 times maintenance
Monitor hydration and respiratory rate
HEPATIC SUPPORT
If hepatic figures raised significantly
SAM's OR SILYBIN
S-Adenosylmethionine 20mg/kg Oral Q24
or
Silymarin (milk thistle) 50-250 mg/kg/day oral
HYPOKALAEMIA
Rate of potassium must not exceed 0.5 mmol/kg/h

POTASSIUM DEFICITAMOUNT TO ADD TO 250ML 0.9% NaCl

Under 2 mmol/l20 mmol

2 - 2.5 mmol/l15 mmol

2.5 - 3 mmol/l10 mmol

3 - 3.5 mmol/l7 mmol

3.5 - 5.5 mmol/l5 mmol

PROGNOSIS

A single large ingestion would have a lesser impact on clotting factors, only really effecting factor VII, however if high enough dose, toxic effects on clotting can be seen
Chronic ingestions of high doses will inhibit all four factors, so a much lower dose can result in a lethal poisoning

That’s much lower than the published toxic dose. I would have an ER hospital sought out just in case and monitor closely for about a week. You might seek veterinary care during regular hours tomorrow for vitamin k therapy.