I'm going to third the vote on checking/treating for parasites.. My guess would be coccidia, but this time of year is also reallyreally bad for barberpole worms, which are voracious bloodsuckers.
If you aren't able to have a fecal egg count done anywhere*, and if they've not been wormed or treated at all for coccidiosis....I'd probably just go on and do it.
The coccidia med that's generally accepted as the best way to go is called sulfadimethoxine -- DiMethox. You can get either a 12.5% drinking water solution or a 40% injectable, but both are given ORALLy, right out of the bottle.. The dosage on the 12.5% is 1ml/5lbs on day one, then 1ml/10lbs no days 2-5 or 7. The 40% is 3x as strong, so it's 1ml/15lbs followed by 1ml/30lbs..
I generally do about 1ml/15lbs of the 40% everyday for 5 days as a preventative...and I probably overdose, even on that schedule, as I'm more or less guestimating weights and I usually round up.
As for deworming...it's as much an art as a science, and there are many -- MANY -- different schools of thought on the subject. One thing everyone pretty much agrees on, though, is that worms are a huge problem for goats on pasture in most of the US..
Depending on how you see things, there are either 3, 4, or 5 different classes of dewormers on the market right now..
1) Benzamidazoles...safe guard, valbazen, etc.. They're the "white" dewormers. Benzamidazole-resistant barberpole worms are widespread at this point. They will kill some of them (how many or few depends on YOUR worms), so some folks -- myself included -- consider them to be a "mild" dewormer. I keep Safe-Guard on hand for three reasons...one, because it lends itself to being used to lessen a worm burden without killing them all at once and causing a badly infested goat to bleed out...two, because benzamidazoles happen to kill tapeworms where other dewormers won't....and three, because -- for whatever reason -- it seems to be helpful for seemingly light parasite burdens that seem to occur outside of the regular "barberpole season."
2) Macrocyclic lactones, aka Macrolides...ivermectin, doramectin, eprinomectin, and possibly moxidectin -- though some folks consider moxidectin to be another class.. I don't agree with that, but some do. Macrolides (you might hear them called "clear" dewormers) are generally considered to be more "stronger" than the white dewormers. Ivermectin -- and therefore
macrolide -- resistant barberpoles are also widespread, but it seems like you can get a better % of kill against a population of macrolide-resistant barberpoles than you get by using benzamidazoles against benzamidazole-resistant barberpoles, if that makes sense.. Lots of times, the suggestion is to go white -> clear (safe guard -> ivomec, for instance), so that you get that 1-2 punch..
3) Imidazothiaoles/Tetrahydropyrimidines...levamisole, and morantel/pyrantel. Personally, I think levamisole should be a different class than morantel/pyrantel, simply because it's generally accepted that levamisole is WAY STRONG, whereas morantel/pyrantel are fairly mild. They apparently all kill worms in the same manner, though, and if a barberpole gains resistance to one, it will apparently be resistant to all. I read once that tetrahydropyrimidines (morantel/pyrantel) are the most infrequently used dewormers in the southeast US, which may be a good thing...the more a dewormer is used, the more poorly it works. Personally, I have no experience using morantel/pyrantel in goats.
Ok, so there are the three that are generally accepted by the experts.. Now...
4) Moxidectin...either Cydectin, or Quest gel for horses. As I mentioned earlier, it's a macrolide. However, it's generally considered to be 'stronger' than ivermectin/doramectin/eprinomectin, and I've read studies which indicate that it can kill up to 50% of ivermectin-resistant worms...but even ivermectin will kill a certain percentage of an ivermectin-resistant population. Still, it does work better.. If a goat is really, really bad off, the suggestion may be Safe Guard->Ivermectin->Cydectin or Levasole.. Unfortunately, though, moxidectin-resistant barberpoles are becoming alarmingly common...I personally know two people who have lost the use of moxidectin on their farms.
5) Levamisole...Levasole, Tramisole, or Prohibit. It's an old dewormer that was used in cattle and sheep for years and years, then largely abandoned when Ivermectin came out. Seems that folks mostly forgot about levasole until sheep/goat people stopped having luck with macrolides and benzamidazoles, so the old became new again -- even to the worms. Given that most populations of barberpole worms had never seen levamisole (or, perhaps, hadn't seen it in a long enough time that they reverted to susceptibility), it works.....until you use it a few times. Like moxidectin, I personally know of at least one person who has lost the use of levasole on their farm..
Sooo...there's a primer on dewormers.. Now, when to use them?
If you can run fecals, go for it.. If not, learn how to check the mucous membranes of their lower eyelids against a FAMACHA chart and go from there.. Do expect to see worm burdens increase in late spring and get really bad in mid/late summer through the first frost, though, as that's basically "barberpole season" in small ruminants.. That's when you want to be checking weekly, at least..
Personally, if I see a bit of paleness coming on and it seems a little early yet, I might only use a benzamidazole to try and knock the burden back a bit. If we're getting into full swing and I see some paleness -- but nothing that looks to serious -- I might drench with ivermectin. If someone comes up really pale all of a sudden and I'm not comfortable hitting them with anything very strong, I might use a benzamidazole for several days, followed by a ivermectin, and possibly followed by cydectin if necessary.
If we're in absolute full swing of barberpole season and someone looks not great, but I think I can hit it pretty hard without hurting them...I might go straight for cydectin.
Like I said, it's an art and a science. You gotta know what worms your likely fighting, what each dewormer does, how strong or mild it is, etc...and after that it's just a judgement call.
Whew... I'm tired now.
*My vets just check for the presence of eggs, and they SUCK at telling one egg from another, therefore a "fecal" from my vet is basically of zero diagnostic value in goats. Reason being, pretty much any goat on pasture will have some worm eggs and some coccidia oocysts in their feces.. It's perfectly normal, and the sheer presence of eggs doesn't necessarily mean the animal is unhealthy. For instance, a goat on pasture can have literally HUNDREDS of barberpole eggs per
gram of feces and still be perfectly fine.
) This monster doesn't know guns exist, so he's not expecting to be shot at...which means you could possibly shoot and kill the monster.. 
