Tuesday, November 18, 2008

Mary, Button, and vaccines


Mary and Button were both bred in early July.

In September we vaccinated the ewes for Campylobacter fetus. C. fetus is a bacteria the lives in the gallbladder and intestines of ewes. When the ewe gets pregnant, the bacteria goes into her uterus, into the placenta, and then kills the fetus. 90% of ewes who have this problem will abort their fetus, but, it is like chicken pox in that they will be immune from this after they have had it once. They can be carriers and infect other ewes, though. This shot protects them from aborting. It is given at the beginning of breeding as well for new ewes and then just an annual booster. The vaccine is also to protect against late-term abortions caused by Chlamydia psittaci. Once there is an outbreak of C. psittaci the vaccine will not cure it. It comes from infected fetal membranes, a dead fetus, and uterine discharges. If the flock becomes infected; abortion rates can get as high as 60%.

We also vaccinated them with CD&T. The T stands for tetanus. "Enterotoxemia type C, also called hemorrhagic enteritis or "bloody scours," mostly affects lambs during their first few weeks of life, causing a bloody infection in the small intestine. It is often related to indigestion and is predisposed by a change in feed, such as beginning creep feeding or a sudden increase in milk supply, perhaps caused by the loss of a littermate. Enterotoxemia type D, also called overeating disease or "pulpy kidney disease," usually affects lambs over one month of age, usually the largest, fastest growing lamb(s) in the flock. It is precipitated by a sudden change in feed that causes the bacteria, already present in the lamb's gut, to proliferate, resulting in a toxic reaction. Type D is most commonly observed in lambs that are consuming high concentrate diets, but can also occur in lambs nursing heavy milking dams." To protect the lambs, we vaccinate the ewes late in their pregnancy (yesterday for Mary and Button). The vaccine will be in the ewe's milk and protect the lambs for about 10 weeks. We will vaccinate the lambs in January again.
We also wormed Mary and Button yesterday. We did that because pregnancy and nursing is very stressful on ewes and if they are sick with a bunch of worms they will not get the nutrients they need. We will probably move them into a new enlosure in the barn in a few days after the worm eggs pass so they are on clean straw with their lambs.
The whole worm issue is not a fun one for me. I do not like giving the sheep too many pharmaceuticals. So, I purchased artemesia seeds (wormwood) to plant in the pasture. Sheep do not like wormwood and will probably avoid it even though it does a decent job in reducing worms in their intestnes. So, if they do not eat it, I will dry it and add it to their hay. If they refuse that, I will powder it and add it to their water. We will still need to use wormers, but if we use natural defenses and rotational grazing we should not need to do it as often.

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