CASEOUS LYMPHADENITIS (CL) AND THE TEXAS VET LAB VACCINE FOR GOATS
Caseous Lymphadenitis (CL) is a contagious bacterial infection affecting goats and sheep. The organism, corynebacterium pseudotuberculosis, infects the animal through wounds caused by head butting, punctures, and shearing, as well as by oral ingestion of the exudate (pus) from a ruptured abscess.
The lymph system filters the bacteria from the goat's body and puts it into a thick-walled encapsulated abscess attached to the inside of the skin so that it can't harm the goat. Visible abscesses usually don't appear for months after infection. CL abscesses are seldom seen in a young goat because its immune system isn't fully functional until the animal approaches one year of age. Therefore, blood testing for CL can be inaccurate in goats under about 8 to 10 months of age. The disease is not painful to the goat but is a management nuisance to goat raisers. Although considered incurable, CL is easily managed. You don't have to get rid of the goat.
Goats with Caprine Arthritic Encephalitis (CAE) should be culled and sent to slaughter. Goats with Johnes Disease must be culled and sent to slaughter. This is not true of goats with Caseous Lymphadenitis (CL), unless the animal is heavily abscessed all over its body, making management difficult. The presence of external abscesses does not necessarily mean that internal abscesses exist. Internal abscesses are far more common in sheep.
CL is not the disease equivalent of CAE or Johnes. Since May 2012, goat raisers have had an excellent vaccine made by Texas Vet Lab that prevents and controls CL abscesses and reduces the frequency and severity of recurrence.
CL is much more likely to be spread among goats that are kept in close quarters and in over-crowded conditions. All breeds of goats can develop CL. Vectors for spreading the bacteria include insects, birds, wild animals, domestic pets, needles, ear taggers, scissors, feed troughs (especially wood troughs), clippers, shoes, and clothing. It is wise to use a disinfecting mat saturated with disinfecting solution to step in when you or visitors go into and out of your pens and pastures. Jeffers carries this product #WEBAPDA. No one knows how long pus from ruptured CL abscesses can survive in hay, soil, and equipment, but we do know that hot and dry weather conditions kill the bacteria faster than wet and cold.
When a CL abscess is mature and ready to be lanced, it is attached to the underside of the hide and can be pulled away from the body by putting your fingers around it. I no longer recommend injecting 10% Formalin into a ripe (soft) abscess because people don't follow the directions and inject too much, causing discomfort for the goat. Lancing the abscess, removing the pus, flushing with iodine, having the pus tested by Bob Glass at Pan American Vet Lab in Texas (512 964 3927 or bglass@pavlab.com), and vaccinating with the Texas Vet Lab vaccine for CL in goats is the best protocol.
A "positive" blood test means that the goat possesses antibodies to the disease. It does not mean that the goat is a carrier or shedder of the bacteria or is infected with the CL organism. A positive titer means that the goat's immune system has encountered that organism before, either naturally or by vaccination, and its immune system has either mounted a response against it or it has received passive antibodies from its mother. A "CL positive" goat may never display clinical signs of CL (abscesses) nor does it have to be contagious to other goats. EXPOSED DOES NOT MEAN INFECTED. Vaccinate and stop worrying.
In May 2012, Texas Vet Lab Inc. of San Angelo, Texas, received approval from the USDA of its new vaccine to protect against CL in goats. Under the supervision of my vet, Dr. Mark Swening, Coleman Vet Clinic, Coleman, Texas, two hundred fifty two (252) of my goats participated in the field trials of the vaccine in summer 2011. I have first-hand experience with this vaccine.
TVL sent this license to state veterinary officials in all 50 states to obtain instructions under which it could be sold in each state. Each state has set its requirements. The TVL website, www.texasvetlab.com, has a chart indicating state approvals and requirements that are regularly updated under the link "Corynebacterium Pseudotuberculosis Bacterin Information." You can also call Jeffers 1-800-533-3377 and find out your state's requirements.
The CL vaccine for goats should not be used on pregnant or lactating does or on kids under three months of age, nor should it be used on sheep. It must be kept refrigerated but not allowed to freeze or get hot. Shake before each use, but if the ingredients separate in the bottom of the bottle and the liquid at its base is brown, the vaccine has been compromised and must be thrown away. Normal liquid separation takes place at the top of the bottle. Based upon my personal experience with this vaccine, I don't follow the dosage interval instructions on the bottle. Instead, I give the 1 cc doses FOUR weeks apart. This protocol reduces injection site reactions and other side effects. I am not a vet. This is what I have learned works for my herd.
When administering the Texas Vet Lab vaccine to protect against Caseous Lymphadenitis, use an 18 gauge needle and give the vaccine SQ (under the skin) at the neck because the neck is where the largest number of lymph glands exist and this bacteria usually enters the body via the mouth. Give the first injection on one side of the neck and the follow-up booster injection on "naive" (never-before-vaccinated goats) on the other side of the neck. Taking the chill off the vaccine by removing the bottle from the refrigerator and putting it in a climate-controlled environment for a short time increases its flow through the syringe and is more comfortable for the goat. Vaccinate all non-pregnant and non-lactating goats and yearlings, including those testing positive for CL and all goats with visible abscesses.
With the CL vaccine for goats from Texas Vet Lab, some swelling at the injection site can be expected. If it occurs, an injection-site reaction "knot" should be firm (not soft). If it is soft, it could be caused by bacteria on the needle or on the surface of the skin and may need to be drained. Do not inject Formalin into these knots. These knots are vaccine granulomas and are a result of the goat's immune response to the vaccine. The adjuvant (vaccine's carrier) and the antigen (active ingredient) are recognized as foreign bodies by the goat's immune system and an inflammatory response occurs at the injection site. They usually resolve themselves over time and that timeframe is dependent upon the size of the granuloma. If the goat is going to slaughter, the granuloma will come off with the hide. If the goat is breeding stock or a show animal and you want the granuloma gone, lance and drain and flush with iodine. It is likely a sterile abscess, staph, or arcanobacterium pyogenes. It is not CL.
Some vaccines are being used "curatively" as well as preventatively; this is one of those vaccines. However, USDA labeling does not permit the claim that the vaccine prevents the disease. No vaccine of any kind prevents disease in 100% of the population to which it is targeted. Wording like "aids in the reduction of," "aids in the control of," "aids in the reduction of severity," or "aids in the reduction of infection or shedding" are label requirements. This label wording should not deter you from using the only CL vaccine approved for goats.
I would much rather own goats that test positive because they have been vaccinated to prevent CL than susceptible-to-disease goats that test negative. Remember, a negative test means "negative" at a single point in time, i.e. when the blood was drawn for the test. Like an inspection on a house you are buying, there is no guarantee that the equipment will be in the same condition beyond that single moment in time when the inspection was done. Vaccination provides some promise of continuing protection against disease. Since no vaccine of any kind is ever 100%, the efficiency of the goat's immune system has much to do with how it processes the benefits that the vaccine provides. A vaccinated goat is much less likely to develop CL than an unvaccinated goat. There is no such thing as a "disease free" herd.
Some goat raisers oppose vaccination because testing for CL does not distinguish between a goat that has been vaccinated with the CL vaccine and one that is infected with the organism. This position doesn't hold up under analysis. Vaccines are made from the substance being vaccinated against and they work by tricking the goat's immune system into mounting a response to a modified (usually "killed") version of that bacteria. A "modified" or "killed" bacteria cannot infect the goat.
Of course the goat is going to test "positive" for CL once it has been vaccinated. A good immune system will mount a vigorous attack against the killed organism and produce antibodies. This is how a vaccine works.
Responsible producers should want to eradicate a disease via vaccination rather than raising a herd of naive (never vaccinated) goats that might contract the disease if they are exposed. Smallpox and polio were eradicated in the USA through widespread vaccination of the population. That was a good thing. Using this vaccine to prevent/control CL is a good thing.
Blood tests for CL are not 100% accurate; false positives and false negatives are a possibility. Testing the pus is the only way to be 100% sure what the organism is. Are you as a producer willing to risk the possibility of false positive, false negative, or "borderline" test results so you can have goats that test "negative" for CL at a single point in time? This is not a responsible way to raise goats. Diligent use of the vaccine by all goat raisers can eradicate this disease from the goat industry.
Suzanne W. Gasparotto, Onion Creek Ranch, Briggs, Texas 6.1.20
