Q  I just had an 8-week-old buck die of enterotoxemia. He was vaccinated with CD/T at 4 weeks of age. How did this happen? I had been gone for the weekend and left the goats in the care of a neighbor. I returned on Sunday and it appeared that they had not received their afternon feeding, as the water buckets were empty. They all seemed fine. I fed them morning and afternoon on Monday (no ill animals) and when I went to feed on Tuesday morning he was dead.

A Enterotoxemia is caused by Clostridium perfringens Type C & D, normal bacterial inhabitants of the ruminant digestive system. Two types of vaccinations are available - an antitoxin and a toxoid. Antitoxin can be difficult to obtain and should only be used on the recommendation of your veterinarian as a treatment when a goat is suspected of having enterotoxemia. Toxoid is given to spur the immune system to make antibodies to protect the goat from getting the disease.

No vaccine is 100% effective. CD/T is probably 80% effective. Vaccinations like CD/T require a booster 14-30 days after the initial dose - no sooner than 14 days. The first dose only boosts immunity minimally, whereas the second dose of vaccine boosts it seven-fold. A third dose at the same booster interval of 14-30 days boosts the immunity as high as it can go.
 

 
It is probable that your feeding schedule or feeding amounts was altered by your neighbors. Any dietary change can cause the bacteria (Clostridium perfringens), which are always present to some degree, to die. When they die, they produce toxins. The amount of toxins produced by a small population of dying bacteria are tolerable, because they move rather rapidly through the alimentary tract. With a short life span of about eight minutes, the organism can quickly reproduce to become a very large population, and when they die in great numbers there the amount of toxins they generate poisons the goat from within.

I suggest starting the vaccination program even before kids are born. By vaccinating the dam at four months gestation, you ensure, as much as humanly possible, that the kids will be protected by passive immunity for up to 8 weeks of age if they receive adequate colostrum. However, if a doe is not vaccinated you can begin the vaccination program as early as 4 weeks, but only as a precautionary measure. Don't expect to gain much from immunity from vaccinating this early. Eight weeks of age is a more realistic time to start the program. A booster vaccination should be administered at least two weeks later and a third given around six months of age. A follow-up booster should be given at one year and every year after that.

It is possible that the goat itself did not respond to the original vaccination. You can have a successful vaccination program for years and then something like this will occur.

It would not hurt to use a new bottle of vaccine to revaccinate those animals you vaccinated the same time as the buck kid in case there was a problems with the vaccine itself. Giving a second CD/T booster will not hurt the animals but, as you have discovered, not giving the shot may.