Certain areas of Australia are more prone to iodine deficiency than others e.g. Tasmania, the tablelands of New South Wales and the Granite Belt of Queensland. Certain pastures are also known to be goitrogenic (goitre causing). Some clovers, kale, canola, cabbage and turnips are known to cause goitre. Leucaena, a tropical fodder shrub, has also caused goitre in calves.
Kids born to does that are deficient in iodine have swelling of the thyroid glands located either side of the windpipe (trachea), near the Adam’s apple (larynx). There are also have very thin hair coats and are very susceptible to cold. The case shown above is an extreme case. Sometimes the swellings are very small. Kids can appear relatively normal but die of cold stress in the first night after birth.
Diagnosis can be done by dissecting out and weighing the thyroid gland of dead kids. A normal kid’s thyroid weighs about 2 grams. The weight of the thyroid glands and the kid’s weigh should be determined and then a ratio calculated. If this ratio is more than 0.8 grams per kg then iodine deficiency is highly probable.
Treatment should be given to the remaining pregnant does by drenching with potassium iodide plus having a salt lick containing iodine. Seaweed meal can be used as an alternate supplement. Selenium deficiency can predispose towards goitre so the selenium levels may need to be investigated as well.
Goat Note- Iodine and the Thyroid Gland - http://www.acga.org.au/goatnotes/C004.php
Author: Dr Sandra Baxendell, PSM, BVSc (Hons), PhD MANZCVS, GCertAppSC(RurExt), GCertPSectMgt, PGDAppSc, MRurSysMan
Director, Goat Veterinary Consultancies –goatvetoz www.goatvetoz.com.au