Vet said in the past, the oral vaccines caused too many problems and caused some dogs to become sick for months. Since there hadn’t been lepto in so long, he quit giving it. Now days, the injection version doesn’t have the same reaction but to still be on the lookout for a couple of days after the shot.
He doesn’t know why it’s back. Texas is always hot and dry in the summer but it has rained a bit more this year. With daily 100 degree temps, it’s hard to imagine any standing water but who knows.
My vet said that all it takes is for an infected rabbit, deer, etc. to pee on wet grass or in a small puddle and another animal to come into contact with it. Extremely cold climates don’t have it because it doesn’t normally survive extreme cold dry conditions. From what I read about it, if an infected animal urinates on the ground and it rains it can survive in minimally wet conditions. Even if we go two weeks without rain, the grass near the ground is always wet when the grass is high due to our extremely high humidity. Tennessee gets a lot of rain so infected ground water washes into ponds. It’s very easy to spread. It’s kind of like mosquitoes. They can breed and mature in a thimble. :-) It doesn’t survive in fast flowing water but will in standing water.