Iris and Flopsy, the two goats who were sick, are much better now. I think the terrible diarrhea was caused by the Ivermectin - a wormer - that I gave them. They had both had moderate diarrhea for a week or so, and when I brought fecals in to the vet, they showed a "moderate" load of stomach worms. I asked if I should just wait until they had kidded, but the vet suggested I go ahead and worm them. I wormed the whole herd. My guess is that the medication caused the expulsion of everything in them along with the worms. I'm glad, of course, that it seems to have resolved, but I have a number of questions to answer if I want to be a better goat husbandry-man (goat husbander? not, surely, goat husband?).
Friday, May 8, 2009
Iris and Flopsy are distinct from the rest of the herd in two ways: They are pregnant; and they are the only Nubians. Pregnancy is known to cause a lowered immune response, and that may very well be the reason that they were troubled by worms when no-one else was. Then again, Nubians have the reputation of being rather delicate compared to other breeds. They are an African breed, adapted to a much drier and warmer climate than exists here in western Washington. I guess the only way to distinguish between these two factors is to wait until they aren't pregnant anymore and see if they are still particularly susceptible to parasites. If so, I may switch to another breed, even though I adore the Nubians. Hardiness matters more to me that adorability. Plus, I like LaMancha milk more than I like Nubian milk.
Questions about individual goats aside, worms are going to be an ongoing problem. They are in almost every goat herd in this area. I was lucky; I started out with clean land that had never been used by ruminants before. And I started out with healthy goats. But apparently, no goat is ever completely worm free. A year and a half later, I have enough worms that they will continue to be a problem unless I adopt some very stringent management techniques.
You can't simply nuke the worms with medication. You'll kill your goats before you kill all the worms. The idea is to have supremely healthy animals, animals who can tolerate a small number of parasites without becoming symptomatic. And, of course, to avoid a "parasite-crisis" in which the worm-load becomes high enough to sicken even your healthiest goats. That means:
1) rotational grazing. This is probably the most important component. The life cycle of the most common and problematic worms is 3 weeks. Therefore, when you worm the goats, switch pastures about 48 hours later. They will expel all the worms on the first pasture, and then go graze on a clean pasture. As long as you keep them off the wormy pasture for more than 3 weeks, the worms will die before they can be ingested again. Also, be mindful of the "parasite zone." According to my reading, larvae can climb up a grass stem to a height of approximately 4 inches. When the grass has been cropped to below four inches, it's time to rotate pastures. Of course, goats prefer browse to grass anyway, and if you have woody browse and bushes and blackberries and such for them to eat, they will largely ignore the grass. Most books say you need a minimum of three pastures to rotate through, and four is better. I have three.
2) a sensible worming program that avoids - as much as possible - resistance. In some areas, worms have already become very resistant to most wormers. That's not the case where I am, thankfully. I have three classes of wormers to choose from, and so far I have used only one of them. If I use it according to my vet's guidelines, I hope it will remain effective for many years. If not, well, there's always the other two classes.
3) Good husbandry (there it is again) that promotes and maintains your animal's health. That means good barn hygiene (replacing soiled bedding promptly, feeding from mangers off the ground, adequate ventilation, etc), adequate nutrition year round, vigilant hoof care to avoid foot rot, and prompt attention to any health issues that crop up. Also, no stressing the animals through overcrowding or overbreeding.
Sheesh. And that's just off the top of my head.