Sudden Onset Blindness in Working Dogs

Tuesday, April 30, 2013

Hello again.

 I was thinking about a case I saw last year when a heading dog (border collie) was brought in to the clinic where I was working with a sudden onset blindness.The history was that the owner had been injecting his cattle for parasites with an ivomectin product. Apparently one cattle beast turned back in the race and got injected twice. The animal died soon after and in the usual practice  NZ farmer way they salvaged the meat from the carcass to feed the dogs.

Soon after the best dog appeared to lose its vison and so was brought into the vet clinic where it was treated for poisoning by giving fluids intravenously in an attempt to flush the ivomectin from the dogs body.

After two days there was no improvement until I decided to give 2 mls of Vitamin B complex into the drip bag. Withing a couple of hours the dog recovered its vision and was sent home with almost complete recovery of vision.

The important issues here were:

1. Is ivomectin toxic in the Border Collie breed or is it a genetic problem exacerbated by the toxin.

2. What is the normal levels of Vitamin B  in Border Collies.

3. If Ivomectin is toxic to dogs what is the status in humans and should we be concerned?

I don't know the answers to this but the implications are quite serious. Does any one have similar stories?