TO, you made me do some digging..... and found out some interesting stuff!
This was taken from a toxicology web site.
http://pmep.cce.cornell.edu/profiles/extoxnet/pyrethrins-ziram/warfarin-ext.html
"Warfarin:
ECOLOGICAL EFFECTS
Effects on Birds
The acute avian toxicity of warfarin indicates that it is practically non-toxic to game birds. In subacute studies, warfarin ranged from moderately toxic to practically non-toxic to upland game birds and waterfowl (13). Another source indicated that an acute oral mallard duck study was performed with a 10% formulation of warfarin. This formulation of warfarin was considered moderately toxic to mallard ducks (LC50 greater than 120 mg/kg) when administered as a single dose. However, when exposed to 60 mg/kg for a period of 14 days, 4 out of 5 ducks died (12).
Chickens are relatively resistant to warfarin (4).
Effects on Aquatic Organisms
The toxicity of warfarin to aquatic organisms is felt to be of low potential due to the fact that warfarin is insoluble in water. A long field experience shows no potential hazards to aquatic organisms (13).
A 96-hour rainbow trout study was performed using a 0.54% formulation of warfarin sodium salt. With a 96-hour LC50 of greater than 10,000 ppm, this formulation is considered non-toxic to rainbow trout (12).
Effects on Other Animals (Nontarget species)
Warfarin used as a prepared bait (0.13%) is considered non-toxic to bees when used as prescribed (1, 3).
The use of warfarin as a hand-placed bait limits the potential for any secondary exposure of nontarget animals. However, because of its high degree of mammalian toxicity and its use patterns, warfarin could adversely affect endangered or threatened species (13). One study exists on a 50/50 percent formulation of warfarin-sulfaquinoxaline technical. The warfarin- sulfaquinoxaline caused secondary poisoning in mammalian carnivores such as mink and dogs when ingesting prey killed after they were provided with treated bait (carrots containing 0.025% by weight of the test material). The first death occurred after 8 days of continuous exposure to treated nutria (12). "
So I would conclude that BOTH Jim and the Vet are right to a degree. It just depends on how much of the animal is eaten and for how long.
TO, ask your vet if giving your dog heartworm preventative during the winter makes any sense; and if they say yes you should, then why would you need to have your dog tested for heartworm every year even though you have been continuously giving the heartguard????
The students at UW-GB did a study on the life cycle of the heartworm; and found that the parasite is only active when temps are above 50*...... I think that counts out a few months.
Ok back to work!
This was taken from a toxicology web site.
http://pmep.cce.cornell.edu/profiles/extoxnet/pyrethrins-ziram/warfarin-ext.html
"Warfarin:
ECOLOGICAL EFFECTS
Effects on Birds
The acute avian toxicity of warfarin indicates that it is practically non-toxic to game birds. In subacute studies, warfarin ranged from moderately toxic to practically non-toxic to upland game birds and waterfowl (13). Another source indicated that an acute oral mallard duck study was performed with a 10% formulation of warfarin. This formulation of warfarin was considered moderately toxic to mallard ducks (LC50 greater than 120 mg/kg) when administered as a single dose. However, when exposed to 60 mg/kg for a period of 14 days, 4 out of 5 ducks died (12).
Chickens are relatively resistant to warfarin (4).
Effects on Aquatic Organisms
The toxicity of warfarin to aquatic organisms is felt to be of low potential due to the fact that warfarin is insoluble in water. A long field experience shows no potential hazards to aquatic organisms (13).
A 96-hour rainbow trout study was performed using a 0.54% formulation of warfarin sodium salt. With a 96-hour LC50 of greater than 10,000 ppm, this formulation is considered non-toxic to rainbow trout (12).
Effects on Other Animals (Nontarget species)
Warfarin used as a prepared bait (0.13%) is considered non-toxic to bees when used as prescribed (1, 3).
The use of warfarin as a hand-placed bait limits the potential for any secondary exposure of nontarget animals. However, because of its high degree of mammalian toxicity and its use patterns, warfarin could adversely affect endangered or threatened species (13). One study exists on a 50/50 percent formulation of warfarin-sulfaquinoxaline technical. The warfarin- sulfaquinoxaline caused secondary poisoning in mammalian carnivores such as mink and dogs when ingesting prey killed after they were provided with treated bait (carrots containing 0.025% by weight of the test material). The first death occurred after 8 days of continuous exposure to treated nutria (12). "
So I would conclude that BOTH Jim and the Vet are right to a degree. It just depends on how much of the animal is eaten and for how long.
TO, ask your vet if giving your dog heartworm preventative during the winter makes any sense; and if they say yes you should, then why would you need to have your dog tested for heartworm every year even though you have been continuously giving the heartguard????
The students at UW-GB did a study on the life cycle of the heartworm; and found that the parasite is only active when temps are above 50*...... I think that counts out a few months.
Ok back to work!
