Abscess, boil, goiter, .... whatever you call it, most shepherds and veterinarians will immediately panic
and assume that it is the dreaded and very infectious Caseous Lymphadenitis or CL. But this page is not about CL, it is
about another cause of abscesses in sheep - one that is not infectious, but does need to be treated - CRUELS - which
is found in Dr. David Henderson's "The Veterinarian Book for Sheep Farmers." Cruels is caused by Actinobacillus
lignieresii, a normal flora found on sheep. It can become a problem when a sheep is poked in the skin, usually the
tender skin of the mouth or face, and enters the bloodstream and infects the lymp system. Once it enters the lymph
system, it can cause abscesses or boils that are quite disturbing to look at, and almost always misdiagnosed as CL.
Following is an article about cruels that was written by the late Stefania Sveinbjarnardottir Dignum and is important
information for breeders of sheep, in particular Icelandic sheep, as it seems that this breed is more prone to the
problem. In fact, in Iceland, the word "kylapest" literally meaning "boil pest" identifies this as something fairly
common to the breed.
by Stefania Sveinbjarnardottir Dignum
"More often than I care to remember, I have gotten calls from frantic breeders that either think themselves, or have
been told by their vets, that the sheep have CL, only to be reassured by me, rightly, that it is cruels."
That concern is very understandable since this is a rather unpleasant condition and many believe that this is Caseous
Lymphadenitis or CL. Fortunately these abscesses usually are not CL, but what is called "Cruels"by Dr. David
Henderson's book. The causative agent is a bacterium called Actinobacillus lignieresii which is an organism that lives
on the skin and in the gut of a normally healthy animal. The abscesses are usually round, the size varying from a
marble size up to a golf ball. Sometimes two or more are located very close, almost in a cluster. They are usually
located on the head, the lower jaw and lips, occasionally on the neck close to the head. The puss is greenish and
thick, but not like in CL where the puss is like a cream cheese and whitish in color.
The bacterium lives on usually healthy animals, but can gain access to the tissue through cuts or wounds. I find
this most common when thistles are plentiful in pastures. I have also read that cruels is very common in cactus
Fortunately this is a condition that can be treated. Treatment consists of draining the abscess when ripe. The sign
of ripeness is when a bald spot forms on top of the "ball." After draining, the hollow can be cleaned out with
hydrogen peroxide and a shot of long acting penicillin should be given. I have had good results in curing cruels.
Cruels can occur several times in the same animal as no immunity is built up.
Chances are that you will find cruels in your sheep sooner or later. Don't panic, but don't ignore it. You might
want your vet to make a sample of the puss to make sure that it is not CL. Many vets are unfamiliar with cruels in
sheep and automatically assume this is to be CL. Mine did. It was not until after I had read about "boil pest" (kylapest
in Icelandic) and creuls, and finding that both were caused by the same bacterium (i.e. it is the same disease) and we
had taken THREE samples of puss to try to culture CL, that we realized what this was.
After talking with other shepherds, I would like to share some more information about cruels here.
1) Sheep are more susceptible to getting cruels when the hay they are eating is "pokey" - i.e. stemmy or the type of
hay that has sharp seed heads in it. The lips and mouths and snouts of sheep are extremely tender and the skin is
easily pierced. Since the bacterium lives on their skin, it gains entrance thru these pokes (or cuts) and enters the
bloodstream of the sheep. It attacks the lymph system, and quite often the abscesses or boils will appear in places,
especially at the jaw/neck line, that mimic where CL is found. This is why most veterinarians immediately assume
the problem is CL and don't look further. The problem with this assumption is that if CL is misdiagnosed, sheep are
usually put down for no reason; cruels can be cured quite easily.
2) The site of entrance is often the lip area, and if you notice a sheep with a swollen lip, looking like it got "punched"
you can suspect a case of Cruels waiting to happen. Get in the habit of watching your sheep chewing; if their mouth
or lips are swollen or they look "funny," hold the animal and run your finger on the inside of the lip to see if there are
any small abscesses or sores there. Sometimes thorns, and hay can get caught in this area and you should use your
finger to clean it out if you see a swollen lip. Flush the area with iodine or hydrogen peroxide. Preventative
measures include making sure your sheep have good quality hay that is not full of sharp seed heads or stemmy;
Cheat grass is a common culprit in causing this problem. Also, be sure that there is not rough cut lumber around
your sheep which can cause slivers.
3) The abscess needs to be drained and flushed out. One can use iodine or hydrogen peroxide.
4) The animal must receive a course of long lasting antibiotics (like LA200)
5) One flockmaster said that it was only after getting the selenium intake of their flock under control, that they were
able to eliminate almost all cases of cruels. The recommendation was that if you find a sheep with cruels, to also
give them a Bo-SE shot and extra Vitamin E to prevent reoccurence. Be sure that your sheep are getting enough
selenium in their mineral mix and hopefully you will never see an abscess on your sheep.
6) Many times cruels are not observed if the sheep is in full fleece. Oftentimes the abscess or boil is not discovered
until the day of shearing. If you discover a boil or abscess at shearing, separate the animal and treat it. But do use
latex gloves and be sure to dispose of the puss so that it does not spread on surrounding surfaces or other animals.
If your flock has never had CL and you've not seen abscesses before, and if you have not brought new animals onto
your farm, chances are very good that it is cruels and not CL, so do not panic. If the animal is new to your farm, it
is a good idea to have the drainage cultured for CL just to be safe. During this waiting time, keep the animal isolated
from other sheep just to be safe until cruels is confirmed.
7) The main thing to remember is DO NOT PANIC if you see an abscess - especially if you raise Icelandic sheep -
cruels seems to be quite common with this breed and it is important not to be too rash in decision making, no matter
what the veterinarian says, until you know for sure.
Thank you for Susan Mongold for this information relayed through a phone conversation.