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| | ==Treatment== | | ==Treatment== |
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| − | The treatment of anticoagulant rodenticide poisoning aims to correct the hypovolaemia and coagulopathy. A whole blood or plasma tranfusion provides immediate access to vitamin K dependent clotting factors and helps to restore blood volume<sup>1-9</sup>. This may need to be followed with larger volumes of crystalloids to compensate for large volumes of fluid loss. The specific treatment of anticoagulant rodenticide toxicosis is administration of vitamin K<sub>1</sub>. This is given as a subcutaneous loading dose at 5mg/kg, and is followed by oral or subcutaneous administration at 1.25-2.5mg/kg once daily, for 1-6 weeks. If given ''per os'', giving a small amount of fat such as canned dog food aids absorption<sup>7</sup>. Intravenous administration of vitamin K<sub>1</sub> is contraindicated as anaphylactic reactions may occur. Treatment with vitamin K<sub>3</sub> is also contraindicated as it is not efficatious in the face of anticoagulant rodenticide toxicity. | + | If ingestion of rodenticide occured in the past three hours, vomiting should be induced in an attempt to reduce absorption. If animals fail to vomit, stomach lavage may be indicated. |
| − | Vitamin K1 (5 mg/kg) should be given as a loading dose
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| − | subcutaneously at multiple sites, followed by subcutaneous
| + | The treatment of anticoagulant rodenticide poisoning aims to correct the hypovolaemia and coagulopathy. A whole blood or plasma tranfusion provides immediate access to vitamin K dependent clotting factors, helps to restore blood volume and, in the case of whole blood, supplements red blood cells and platelets<sup>1-9</sup>. This may need to be followed with larger volumes of crystalloids to compensate for large volumes of fluid loss. The specific treatment of anticoagulant rodenticide toxicosis is administration of vitamin K<sub>1</sub>. This is given as a subcutaneous loading dose at 5mg/kg, and is followed by oral or subcutaneous administration at 2.5-5mg/kg once daily, for 1-6 weeks. If given ''per os'', giving a small amount of fat such as canned dog food aids absorption<sup>7, 8</sup>. Intravenous administration of vitamin K<sub>1</sub> is contraindicated as anaphylactic reactions may occur. Treatment with the less expensive vitamin K<sub>3</sub> is also contraindicated as it is not efficacious in the face of anticoagulant rodenticide toxicity. The duration of treatment depends on the anticoagulant as well as patient factors, and coagulation parameters should be monitored to detmine the progress being made. |
| − | or oral doses (1.25 to 2.5 mg/kg) at eight to 12
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| − | hour intervals for as long as necessary (until the toxin is
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| − | metabolised or excreted). The duration of treatment will
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| − | depend on the anticoagulant involved. A one-week treatment
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| − | may be undertaken initially. The PT and PTT must
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| − | be checked 48 to 72 hours after cessation of vitamin K1 | |
| − | therapy. With the more persistent anticoagulants, these
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| − | clotting tests may become prolonged again, indicating a
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| − | residual toxic effect and the need for continued vitamin
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| − | K1 therapy. In some patients, treatment for a month or
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| − | more may be required.
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| − | Although less expensive, vitamin K3 is relatively
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| − | ineffective and is not recommended as a treatment for
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| − | anticoagulant rodenticide toxicity.
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| | Hypocoagulable patients are at great risk of internal | | Hypocoagulable patients are at great risk of internal |
| | haemorrhage. Physical activity must therefore be | | haemorrhage. Physical activity must therefore be |
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| | contraindicated, as is the administration of agents by | | contraindicated, as is the administration of agents by |
| | intramuscular injection. | | intramuscular injection. |
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| − | If ingestion was recent (in past three hours) induce vomiting. Stomach lavage may also be indicated if dogs fail
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| − | to vomit. Coumarin rodenticide preparations are often in the form of blue or green granules.
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| − | *Give the specific antidote - vitamin K. Phytomenadione, a vitamin K1 analogue available as tablets or injection
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| − | (Konakion; Roche), is the drug of choice and reverses low prothrombin levels in 30 minutes. Menadiol (Synkavit; Roche)
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| − | is a synthetic K3 and is not as effective.
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| − | Dose. 2 - 5 to 10 mg three times daily orally for five days because most coumarins are metabolised and excreted slowly
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| − | over two to four days, and longer in some instances.
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| − | If clinical signs are severe can give 5 mg intravenously over six to eight hours. However, as anaphalactic reactions
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| − | to intravenous administration have been reported in the dog intramuscular route is preferable.
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| − | *Give a whole blood transfusion - this replaces the clotting factors as well as replacing blood loss through haemorrhage.
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| − | Vitamin K1 is antidotal. Recommended dosages vary from 0.25-2.5 mg/kg in warfarin (coumarin) exposure, to 2.5-5 mg/kg in the case of long-acting rodenticide intoxication (diphacinone, brodifacoum, bromadiolone). Vitamin K1 is administered SC (with the smallest possible needle to minimize hemorrhage) in several locations to speed absorption. IV administration of vitamin K1 is contraindicated, as anaphylaxis may occasionally result. The oral form of K1 may be used daily after the first day, commonly at the same level as the loading dose (divided bid). Fresh or frozen plasma (9 mL/kg) or whole blood (20 mL/kg) IV is required to replace needed clotting factors and RBC if bleeding is severe. One week of vitamin K1 treatment is usually sufficient for first-generation anticoagulants. For intermediate and second-generation anticoagulants or if anticoagulant type is unknown, treatment should continue for 2-4 wk to control longterm effects. Administration of oral vitamin K1 with a fat-containing ration, such as canned dog food, increases its bioavailability 4-5 times as compared with vitamin K1 given PO alone.
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| − | Coagulation should be monitored weekly until values remain normal for 5-6 days after cessation of therapy. Vitamin K3 given as a feed supplement is ineffective in the treatment of anticoagulant rodenticide toxicosis. Additional supportive therapy may be indicated, including thoracocentesis (to relieve dyspnea due to hemothorax) and supplemental oxygen if needed.
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| | ==Prognosis== | | ==Prognosis== |