toxicology lecture 2 Flashcards
what are the 4 rodenticide toxicities
- warfarin
- bromethalin
- cholecalciferol (vitamine D3)
- zinc phosphide
what are anticoagulant rodenticides
- they are Vit K antagonists (our body can recycle and reuse Vitamin K)
- interferes with the production of vitamin K dependent clotting factors in the liver
what is the lag period of the coagulation system when vitamin K is depleted
3-5 days between exposure and appearance of clinical signs
how long does is take to see clinical signs if vitamin K is depleted
about 3 days, because then all the stored of vitamin K will have been consumed
what is the 1st generation of anticoagulant rodenticide toxicity
warfarin base
what is warfarin base
- warfarin, diphacinone, pidone
- short acting anticoagulant
- depress clotting factors for about 7 to 10 days
what is the 2nd generation of anticoagulant rodenticide toxicity
coumarin base
what is a coumarin base
bromadiolone, brodifacoum, super-warfarin - greater potency and accumulation effects in the liver
-depressed clotting factos for approx a month
what are the LD50 values for bromadiolone (super-warfarin)
rats 1.125 mg/kg b.w.
mice 1.75 mg/kg b.w.
rabbits 1 mg/kg/ b.w.
what are the LD50 values for warfarin
rats 3mg/kg
mice 437 mg/kg
rabbits 800 mg/kg
what are the clinic signs of anticoagulant rodenticide toxicity
3- 5 days post ingestion =
- intracavital bleeding (lungs and abd), melena, epistaxis etc.
- lethargy, excercise tolerance, inappetence, pallor, dyspnea
- sudden death - paricardium, cranium, thorax etc
- mild thrombocytopenia (secondary to blood loss, do not interfere with platelet production or function
* *check poo
what is the diagnosis of rodenticide toxicity
-prolongation of PT (prothrombin time) and greater than PTT (thromboplastin time) and development of CS
what is the treatment of rodenticide toxicity
antidote - vitamin K1
thoracocentesis
what is CNS rodenticide toxicity
bromethalin (fastra, tomcat)
decreases mitochronrial ATP production in brain and liver
in CNS rodenticide toxicity less than LD50 what are the paralytic signs and when do they start
1 -4 days
hind limb weakness, ataxia, tremors, loss of deep pain, decreased propriception
in CNS rodenticide toxicity more than LD50 what are the convulsant signs and when do they start
4 - 36 hrs
hyperthermia, seizures, hyperexcitability
what is calciferol rodenticide toxicity
cholecalciferol (vitamin D#)
- orhto-mouse-B-gone, quintox, rampage
- increase calcium absorption from food and bones -> soft tissues calcification, nephrosis, cardiac arrhythmia
- free calcium levels are high and lead to mieralization of blood vessels and tissues (organs) = system calcification
what are the clinical signs of calciferol rodenticide toxicity
12 - 36 hrs post ingestion
anorexia, vomiting, muscle weakness, PU/PD, arrhythmia, seizures, hypercalcemia
what treatment can be used for calciferol rodenticide toxicity
furosamide, prednisone, calcitonin (lowers the calcium level by excreting or slowing down)