In all my 32 years as a veterinarian, I don’t recall ever seeing any
kind of animal with a goiter. Then I received a phone call from a Boer
goat raiser named Joel. He had just started kidding, and several of his
first kids were born dead with odd lumps in their throats. Photographs
he sent showed the classic bilaterally symmetrical swellings in the
location of the thyroid gland. They could have been textbook photos of
From the tone of his voice, I could tell Joel was quite
concerned. If he’s not the most conscientious goat breeder I know, he is
at least in the top two. His herd management has always been top-notch.
So why was he having this problem? And why now?
think of anything he was doing that was different. He was feeding the
same grain mixture and minerals he had used for the last few years.
Furthermore, the moms that were producing the kids with goiters were his
older does who never had any issues like this before.
A goiter is
an enlargement of the thyroid gland. Typically in goats, it occurs as
the result of an iodine deficiency. The thyroid gland utilizes iodine in
the production of thyroxine, or thyroid hormone. If iodine levels are
low, thyroxine cannot be produced, thus causing the “master gland of the
body”- the pituitary, to produce thyroid stimulating hormone, which is
sent to the thyroid gland. This prompts the thyroid gland to work extra
hard to try to produce it’s hormone, and almost like a muscle lifting
weights, it will enlarge.
In addition to low levels of iodine in
the diet as a cause of goiters, there are certain plants which are
termed “goitrogenic.” These plants interfere with the uptake of iodine
in the thyroid gland, and include cabbage, broccoli, kale, cauliflower,
Brussels sprouts, soybeans, and turnips. I discussed these plants with
Joel, but it was kind of a moot point. His goats ate none of those
I heard from Joel again about three weeks later on a
Friday afternoon. His report was not good. Twenty-one kids had been born
dead with goiters, including a set of twins that morning. He inquired
about having them necropsied, the animal version of an autopsy.
are not the best day of the week for collecting tissue samples, because
they have to sit over the weekend before being shipped off on Monday. I
asked Joel if he would be willing to drive the kids down to the Ohio
Department of Agriculture Lab in Reynoldsburg that afternoon. He had no
problem with that. Like I wrote before, he is conscientious.
spoke to the pathologist who worked on Joel’s kids, he confirmed the
goiter diagnosis. He also told me this: “Boer goats are more susceptible
to goiters than any other breed.” I didn’t know that, and I see a lot
of Boer goats. The pathologist then told me that goiter development
usually occurs between the first and second month of a goat’s five month
When I relayed this information to Joel, he had a
revelation for me. He found out the clover hay he had purchased, which
he fed for the first couple of months of his does’ pregnancies, was
harvested from a field that had a cover crop of turnips on it the winter
Cover crops are becoming more popular in this area for a
variety of soil improvement reasons. Turnips, by virtue of their large
bulbs and deep root systems, help to decrease soil compaction and open
the soil for worms and nutrient penetration. However, as they decompose,
apparently some of those goitrogenic properties can be taken up by
growing clover plants.
In Joel’s herd, it was only the older does
who had the affected kids. Even though they were fed the same clover
hay, his younger does were supplemented with a grain ration that did
contain some iodine. It wasn’t a large amount, but evidently it was
So goat breeders, before the next kidding season arrives,
make sure there is adequate iodine levels in your feed and mineral
mixes, or supplement the herd with iodized salt. Then, hopefully, the
only lump in the throat you have to deal with is the one in your own.
The source, of course, coming from the pride you feel when you see your
beautiful new kids.