Dustin Oedekoven, DVM
State Veterinarian
e-mail Dr. Oedekoven

411 South Fort Street
Pierre, South Dakota 57501
Phone: 605-773-3321
Fax: 605-773-5459

Current Issues  |  News  |  Forms  |  Pamphlets  |  Positions Available  |  Links  |  Contact Us  |  Home

Disease Control

Meat Inspection

Livestock Auctions

Certification Programs

State Import Requirements

Animal Disease Traceability

Certification Programs

• Johne's

• PRRS

• CWD

• SD BQA/CMP Site

NATIONAL PARATUBERCULOSIS CERTIFICATION PROGRAM (JOHNE'S)

FAQs

What is Johne’s Disease?

• Pronounced "Yonees"

• Also called Paratuberculosis

• A chronic (months to years) infection causing intermittent to continuous diarrhea and wasting

• In cattle usually over two years of age

• Also disease of sheep, goats and other ruminant animals

What causes Johne’s Disease?

• "Mycobacteria paratuberculosis" - a bacteria closely related to the organism responsible for TB (tuberculosis).

• This is a very slow growing bacterial organism requiring three to four months to grow even under ideal laboratory conditions.

• Dr. Heinrich Albert Johne discovered this organism in 1895.

What are the signs of Johne’s Disease in cattle?

• Cattle are usually two years old and older when signs of the disease occur (even though infection usually occurs as a calf less than 6 months of age or even prior to birth).

• Diarrhea, weight loss, normal appetite, normal appearance otherwise.

• As disease progresses over several weeks to months, severe diarrhea, wasting away of flesh, literally "starved appearance".

Where does Johne’s come from?

• M. paratuberculosis is a very "tough" bacteria capable of surviving weeks to months in soil or manure under the right conditions.

• Infection of the fetus in the uterus of an infected cow may occur in as many as 25% of cases.

• Newborn calves - Milk (even colostrum) may contain the organism: Calves nursing infected dams and contamination of udders and environment with manure are the major sources of infection. The organism can be shed profusely in the manure of infected cattle.

• Fecal contamination of water and feed from shedding animals is a source of the bacteria and thus spread to other adult animals cannot be ignored.

How does Johne’s Disease develop?

• After ingestion of the bacteria the organism grows slowly in the wall of the intestine. Thickening and inflammation of the intestine occurs. This causes failure to absorb nutrients, hyperactivity of intestine, and loss of nutrients (and from leaking of proteins) and electrolytes from the body into the diarrhea fluid.

How long is the incubation period for Johne’s Disease?

• Several months to several years

• Calves (especially newborn) and younger cattle are most susceptible to infection

• Johne’s is usually not recognized in an animal until two years of age or older

• Factors affecting the length of the incubation period include:

  • extent of exposure due to degree of contamination of environment by animals shedding disease

  • nutrient status of animals

  • general quality of husbandry in the herd

  • stresses of production and handling, i.e. breeding, milking, crowding, shipping, weather, other disease, etc.

What breeds or types of animals does Johne’s effect?

• All ruminant animals seem to be susceptible.

• Dairy cattle seem to be affected more than beef (probably due to husbandry).

• Beef cattle are also affected - in fact some surveys show more beef cattle infected than dairy cattle.

Is Johne’s a new disease?

• No - it has been recognized for many years.

• Johne’s Disease does seem to be increasing both in number of herds affected and also in number of cattle affected within herds.

How do I know if I have Johne’s in my herd?

• Cows or bulls showing signs of chronic diarrhea, continuing to eat, slowly wasting away. (clinical diagnosis)

• Confirm the disease by consulting your veterinarian and taking appropriate samples for laboratory diagnosis.

Is there a good vaccine for Johne’s?

• No

How do I get a diagnosis?

• Clinical signs of diarrhea and wasting in one or more adult animals.

• Laboratory diagnosis

What are the laboratory tests?

• Due to the nature of the disease, i.e. a slow growing bacteria, extremely long incubation period, intermittent shedding of the organism, inconsistent immune response of affected animal, there is no one good test to confirm the disease. All available tests have relatively poor sensitivity but good specificity. The table below lists various tests used:

TESTS FOR JOHNE’S DISEASE
 

What are the costs of Johne’s Disease in my herd?

• loss of animals due to death or early culling

• decreased milk production by affected cows

• decreased slaughter weight on salvageable animals

• loss of valuable animals for show, sale, breeding

• veterinary costs for diagnosis and treatment

Are there Laws regulating Johne’s Disease?

• No - not other than as with any other disease - affected animals are not eligible to be sold other than for slaughter.

• Reportable Disease – all positive test results are reportable to the Animal Industry Board.

How do I control or eliminate Johne’s Disease?

• With your veterinarian

  • evaluate the extent of infection (it is estimated that for every animal showing signs there may be 15 to 25 more infected in a given herd)

  • set up plan to identify infected animals

  • determine best program for your herd

  • monitor progress of efforts (record keeping)

For Commercial Beef Herds:

• Recognize Johne’s Disease

  • If you never observe a cow or bull with the signs of Johne’s you may not have it in your herd and then prevention is all that you may want to pursue.

• Prevent introduction of Johne’s

  • Be aware of the disease and purchase animals from sellers who are aware of the disease and are attempting to control or eliminate Johne’s.

  • Consider testing any replacements over 20 months of age.

• Test your herd or a percentage

  • Consult your veterinarian to see which test would be best suited to your herd based on incidence, time frame, cost effectiveness, etc.

• Cull positive animals in a timely manner

  • Do not let animals obviously infected become shedders to contaminate the environment.

  • Especially be aware of any potentially affected animals prior to and during the calving season where newborn calves which are most susceptible could get infected.

• Cull any offspring of affected animals

  • There is high probability that these offspring have become infected either during gestation or at nursing. These offspring could become silent carriers and break with Johne’s Disease after they mature.

Pure Bred and Dairy Herds:

• Value of animals along with production costs in purebred and dairy herds makes Johne’s a more significant problem in these herds.

• Subclinical Johnes decreases milk production as early as in the first lactation. (Significant to both dairy and beef herds.)

• Johnes shortens the productive herd life of cattle.

• Purebred and Dairy operators will increasingly find it necessary to eliminate this disease to remain competitive in the market place.

• Consider adopting a comprehensive Johne’s control plan for your herd.

• Consult your veterinarian - you may adopt a plan and/or modify a plan for your herd.

• The United States Animal Health Association has a recommended Johne’s Certification Program. A copy of this program is included. Read it, visit with your veterinarian, consider starting now.

• JOHNE’S WILL NOT GO AWAY - IT WILL CONTINUE TO CAUSE INCREASING PROBLEMS UNLESS CONCERN AND ACTION ARE TAKEN.

What role will the South Dakota Animal Industry Board play?

• While this is a disease the industry must voluntarily control, the Animal Industry Board will provide help in record keeping and certifying herds. This will facilitate authenticity to Herd Plans and therefore assist the industry in controlling and eliminating Johne’s. Certification of voluntary achievement of herd status will no doubt become important in the marketing of animals in the future.

South Dakota PRRS Certification Program FQAs
 

What is Porcine Reproductive and Respiratory Disease (PRRS)

• once called "Mystery Swine Disease"

• capable of producing catastrophic losses either upon introduction into uninfected herds or as rebreaks in endemically infected herds

• occurs in swine of all ages

• recognized in the US, North Carolina, in the late 1980s

• some avian species, mallard ducks in particular, are susceptible to PRRS

What are the signs of PRRS in swine?

• Clinical signs in adult animals

  • lethargy

  • depression

  • failure to eat

  • feverish

  • sows may abort, commonly in late gestation, > 10%

  • boars, loss of libido, poor semen quality

• Farrowing house

  • stillborn levels may increase to 50% - 70%

  • mummified fetuses may increase to 20% - 30%

  • suckling pigs demonstrate

    • "thumping" or a distinct pattern of rapid, open-mouthed, abdominal breathing which results from respiratory disease

  • sows milk poorly leading to colostrum deprivation which results in increased cases of colibacillosis or starvation

• Nursery clinical signs are

  • respiratory disease

  • meningitis

  • post weaning diarrhea

  • reduced average daily gain of 50% - 75%

  • increased mortality of 10% - 25%

Where does PRRS come from?

• primary transmission from herd-to-herd is the introduction of infected animals

• this virus is highly infectious

• as few as 10 virus particles can cause infection by intramuscular or intranasal routes

• virus is shed in saliva, nasal secretions, urine, semen, mammary secretions and feces

• virus persists in lymphoid tissue such as the tonsil

• virus can cross the placenta and infect fetal pigs

How does PRRS develop?

• virus enters the pig through the nasal mucosa and/or epithelium of the upper respiratory tract

• virus multiplies in the mucosa, lymphoid tissue and blood cells in the respiratory system

• virus spreads via the blood to secondary multiplication sites

• virus can be found in lungs, heart, lymph nodes, tonsils, thymus, spleen, intestine, kidneys, liver, adrenal glands, brain, and testes

How long is the incubation period for PRRS?

• with the virus crossing the placenta, piglets can be born with PRRS disease

• introduced infections can cause respiratory signs in as little as 3 days

• typically, pneumonia is most severe at 10 days after infection

• virulence of different strains of PRRS virus is variable

• swine of all ages are susceptible to PRRS

• speaking broadly, younger pigs are more susceptible than older pigs to PRRS

What breeds or types of animals does PRRS effect?

• investigators indicate breed genetics may influence the severity of the infection

• different breeds may have variable severity of infection shown in different tissues (i.e., pneumonia, meningitis, myocarditis, or serum antibody response)

Is PRRS a new disease?

• PRRS virus entered the domestic swine population relatively recently and spread rapidly thereafter

• earliest evidence of PRRS was from Canada in 1979 where 2 of 51 herds had antibodies to PRRS virus detected

• essentially found today in all hemispheres of the world

• the North American and European strains are distinctly different

• some countries are claiming to be free of the PRRS virus

How do I know if have PRRS in my herd?

• clinical signs of reproductive problems in breeding stock and respiratory disease in pigs of any age

• many similarities with other swine diseases lends importance to diagnostic testing

• a definitive diagnosis of PRRS virus infection requires the isolation of virus, detection of viral antigen or genomic material, and/or detection of antibody

• involve your veterinarian in the evaluation of clinical signs, tissue sampling and collection, and diagnostic test interpretation

Is there a good vaccine for PRRS?

• several vaccines are available in the U.S. today

• vaccination does not stop infection

• the purpose of vaccination is to produce an immune response which will alter the course of infection and protect against clinical signs

• both modified live and killed virus vaccines are available

• development of new vaccine products is currently an area of active research

• management changes are required in conjunction with prudent vaccine use

• vaccinated animals will test positive to serologic tests

How do I get a diagnosis?

• contact your herd veterinarian

• not possible on the basis of grossly visible lesions

• submission of tissue samples for microscopic analysis

• submission of serum samples to detect antibodies (serology)

• frozen tissues for laboratory immunohistochemistry

• tissue samples for virus isolation

• tissue submission for viral genomic material detection

• consult with your veterinarian about lab result interpretation and diagnosis

What are the laboratory tests?

• indirect fluorescent antibody (IFA)

• enzyme-linked immunosorbent assay (ELISA)

• serum virus neutralization (SVN)

• virus isolation

• fluorescent antibody test (FA)

• immunohistochemistry test (IHC)

• polymerase chain reaction test (PCR)

• monoclonal antibody analysis can be used to differentiate a commercial MLV vaccine from field isolates

• research continues on developing new laboratory tests

How long does the PRRS virus survive in the environment?

• PRRS virus is a fragile virus which is quickly inactivated in the environment

• at 75 degrees virus does not persist on fomites beyond a day

• standard cleaning and disinfection procedures should be effective for inactivation of PRRS virus in facilities and on equipment

• drying quickly inactivates PRRS virus

How is PRRS virus transmitted in and between herds?

• once a herd is infected, PRRS virus tends to circulate within a herd indefinitely

• PRRS virus persists in clinically normal carrier animals and the continual introduction of susceptible animals either through birth or purchase

• primary herd-to-herd transmission is the introduction of infected animals

• aerosol transmission rarely occurs over a distance of 1 meter

• transmission occurs by close contact between animals

• semen from infected boars can infect susceptible females

TESTS FOR PRRS
 

*Current Serologic Assays Cannot Routinely Differentiate Vaccine-Derived Antibodies From Field Isolate-Derived Antibodies.

What are the costs of PRRS Disease in my herd?

• loss of animals due to death or early culling

• decreased milk production in affected sows and gilts

• decreased average daily gain

• 2 -3-fold increase in number of disadvantaged pigs

• reduction in total profits due to performance losses

• veterinary costs for diagnosis

Are there Laws regulating PRRS Disease?

• No - not other than as with any other disease - clinically affected animals are not eligible to be sold other than for slaughter

How do I control or eliminate PRRS Disease?

• With your veterinarian

  • evaluate the extent of infection

  • set up plan to identify infected animals

  • determine best program for your herd

  • continue testing on a quarterly basis to monitor progress of efforts (record keeping)

  • participate in the Voluntary PRRS Certification Program in South Dakota

What role will the South Dakota Animal Industry Board play?

While this is a disease the industry will voluntarily control, the Animal Industry Board will provide help in record keeping and certifying herds. This will facilitate authenticity to Herd Plans and therefore assist the industry in controlling and eliminating PRRS. Certification of voluntary achievement of herd status will no doubt become important in the marketing of animals in the future.

Cervid CWD Surveillance Identification (CCWDSI) Program
 

Methods for obtaining certified CWD cervid herd status.

Certified CWD cervid herd status must include all cervidae in the cervid herd. They may not be commingled with other cervids that are not certified. A herd may qualify for status as a certified CWD cervid herd as follows:

(1) Purchasing a certified CWD cervid herd: Upon request and with proof of purchase the board shall issue a new certificate in the new owner's name. The anniversary date and the herd number remain the same. If part or all of the purchased herd is moved directly to premises that have no other cervidae, the herd may retain certified CWD status, and the board shall issue a new certification number. The anniversary date of the new herd is the date of the most recent herd certification status certificate;

(2) Upon request and with proof by records, a herd owner shall be issued a certified CWD cervid herd certificate by complying with the CCWDSI program as defined in subdivision 12:68:25:01. (15) for a period of five years.

"Cervid CWD surveillance identification (CCWDSI) program," a CWD surveillance program requiring identification and laboratory diagnosis including brain tissue as directed by the state veterinarian on all deaths of cervids eighteen months of age or greater, including deaths by slaughter, hunting, illness, and injury. The diagnosis shall include examination of brain and any other tissue as directed by the state veterinarian. If tissues associated with a cervid death are not submitted for laboratory diagnosis due to postmortem changes or unavailability, the board shall determine compliance;

(16) "Certificate," an official document issued by the state veterinarian or federal animal health official or an accredited veterinarian at the point of origin containing information on the individual identification of the animals, the number of animals, the purpose of the movement, the points of origin and destination, the consignor, the consignee, and any other information required by the state animal health official for importation or translocation;

(17) "Designated epidemiologist," a state or federal veterinarian who has demonstrated the knowledge and ability to perform the functions required under this chapter and who has been selected by the state veterinarian;

(18) "Group," one or more cervidae;

(19) "Individual herd plan," a written herd management and testing plan that is designed by the herd owner, the owner's veterinarian if requested, and a designated epidemiologist to identify and eradicate CWD from an affected, exposed, or adjacent herd;

(20) "Official cervid identification," an identification eartag that conforms to the alphanumeric National Uniform Eartagging System as defined in 9 C.F.R. Part 71.1 (January 1, 1994) or other identification device which uniquely and permanently identifies each cervid;

(21) "Official cervid CWD test," an approved test conducted at an official laboratory to diagnose CWD.

From South Dakota Legislative Rule 12:68:25:01/18 at http://www.state.sd.us/state/legis/lrc/rules/lrcmenu.shtm

back to top

 

Current Issues  |  News  |  Forms  |  Pamphlets  |  Positions Available  |  Links  |  Contact Us  |  Home  | State Home Page
Disease Control  |  Meat Inspection  |  Livestock Auctions  |  Certification Programs  |  State Import Requirements  |  Animal Disease Traceability