Last week I was reminded of one the most common mistakes everyone makes, (Failure to read directions on the label.) A client called with a bull calf that had been eating and drinking normal, on grain and hay, and the calf had died within 3 hours after feeding it. He also noted that the calf was sold and to be delivered the next week. In doing a post-mortem examination and visiting with the owner, the cause of death was determined to be enterotoxaemia caused by Clostridium perfringins type B, C or D. Now most of you will not be able to pronounce that so, I like to put it in lay terms of GUT FORM BLACKLEG.
With a little more history about previous vaccination, the owner was vaccinating every 6 months. He was using a common over the counter blackleg vaccine. But, on the label it says that you must give 2 doses 2-4 weeks apart to confer immunity the first time in an animal’s life. With one dose of this vaccine you will only stimulate immunity to last about 45 to maybe 60 days. So, every 6 months we were getting immunity to 7-way blackleg for only about 45-60 days of those 180 days. This bull calf was due for a 6 month booster the coming weekend. This is an unfortunate lesson and a very costly lesson to learn. Please, either read the label and/or talk to your veterinarian for an explanation of those $20 terms used in the label. Some of us even have to use a magnifying glass or bifocals to read the fine print.
Another point with the weather we have had is to make sure this fall cutting of hay is cured out. Remember, with a lot of Johnson grass in the hay it needs to be totally cure and dry for Johnson grass to not be toxic to cattle or animals. This allows the prussic acid to leach out.
For more information, I suggest you call your county extension agent and/or have it tested. The main toxic Johnson grass will be the short and young tender grass that has shot up after the drought with the rain we have finally gotten. Again the toxic principle of Johnson grass is prussic acid which in reality is cyanide. It can kill your animals within 0.5-2 hours after eating a toxic dose. A little caution here, is worth quit a few live animals.
Dr. Tim E. O’Neill, DVM, owns Country Veterinary Service in Farmington, Ark.
