'Occasional' coughing is probably due to dust/allergy and nothing to be concerned about, however, if your goat has been 'dry' coughing 'a lot', the coughing is becoming more frequent, if he/she coughs particularly after exertion (running or playing hard), and has no nasal discharge or fever, you might suspect lung worm.
Lung worm can do some serious damage to the lung tissue. If lung worm is present for a long time, it will do irreversible damage to the lungs and your goat may begin to have bouts of pneumonia due to the irritation. Eventually the lungs will become so badly damaged the goat could die.
Even if it's been wormed with other wormers (Ivomec/Ivomec 'Plus'/Panacuar/Safeguard, these are not very effective against lung worm. These wormers are VERY effective for parasites found in the gut, but do not work as effectively in the respiratory system where you find lung worm.
A wormer that works very well for the eradication of lung worm is levamisole. (brand names are Levasol, Tramisol) It is OTC, you may find it at feed stores or a Tractor Supply, but you can order it online also.
http://www.pbsanimalhealth.com/cgi-l...fe4+1131908159
Dose is 2cc per 100 lbs, Injected SQ...three seperate times...spaced 10 days apart to kill all eggs/larvae as they hatch and before they reach adulthood and begin to lay more eggs.
There is also a powdered Levasole Sheep Drench. The goat dose would be 1 1/2 times the sheep dose.
http://www.wormer.com/sheep-goat-wormer.htm
Since the lungworm eggs are partially embryonated as they pass out through the bowel of the host, they are heavier than other species of worm eggs, thus they sink to the bottom of the slide, below the normal field of visibility, and may not be detected during fecal flotation tests, so it is a good idea to treat for lungworm if you have a goat with an unexplained persistant cough.
Levamisole is quite safe to use during pregnancy and while nursing babies as well. And BTW, there is NO withdrawal time for human consumption of milk from a doe that's been treated with Levamisole! Levamisole has been 'reported' to cause abortions... But this is
ONLY when used at
3X or higher recommended dosage