CL Goats : (is CL a defect, or not)

[mikey]

Caseous Lymphadenitis (CL) is a chronic contagious disease affecting mainly sheep and goats This disease is also called pseudotuberculosis or often "abscesses," and has been referred to as the curse of the goat industry throughout the world.

CL is an infection of goats, caused by Corynebacterium pseudotuberculosis. It is also referred to as "abscesses", because of the peripheral swelling, rupture, and drainage of pus from affected lymph nodes. The prevalence of CL in the commercial goat herds may be as high as 30%. If abscesses affect more than one lymph node, the carcass will be condemned at slaughter. Decreased body weight and milk production also occurs, and reproductive efficiency is often lower when these animals have developed internal abscesses.

Clinical Signs:

 Most commonly, symptoms are palpable enlargements of one or more of the superficial lymph nodes. The morbidity of the infection rate in goat flocks increase with age, and may approach 70%.

The enlarged lymph nodes have a very thick wall and are filled with thick greenish pus. The most common lymph nodes affected are mandibular (A in figure 1), prescapular (B), prefermoral (C), and supramammary (D) lymph nodes. Less common is involvement of lymph nodes internally in the chest and abdomen. As the animal gets older, abscesses often develop around the lungs, heart, liver, kidney, and spinal cord. They may cause weight loss, pneumonia, and neuoligical signs.

Pathogenesis:
C. pseudotuberculosis is spread in the environment by broken and draining external abscesses. The organism survives in the environment for at least one year and can be spread on such items as shearing blades, fences, and feeders. The organism enters the goats body through small breaks in skin or mucous membranes and eventually becomes localized in a regional lymph node. Heavy environmental bacteria contamination occurs in confinement operations and around feeders, goat dairies seem to have a high prevalence of CL. There is some evidence that the organism can penetrate intact skin and mucous membrane.

Diagnosis:


1. Presence of a firm to slightly soft subcutaneous swelling in the location of a lymph node.
2. Herd history of CL.
3. Culture: aspiration of the swelling and sending it to the diagnostic lab for isolating and identifying the organism.
4. Serology: serologic tests such as bacterial agglutination test and synergistic hemolysis - inhibition test are valuable in identifying goats with early stage of the disease (no abscess yet developing).
Serologic testing may not be accurate due to the presence of antibodies in previously exposed non-diseased or from cross - reactivity of diagnostic antigens with antibodies against other bacteria.

Treatment:


1. Separate and isolate the affective animals.
2. Ripened abscesses lanced and flushed with 7% iodine solution.
3. The pus should be flushed down a drain, or collected and burned.
4. Wear gloves to prevent skin infections in humans.
5. Wash hands well after handling infected animal.
6. Surgical removal of the encapsulated abscess offers the advantages that the treated animals need not be quarantined.
7. antibiotic treatment has not been effective.
Eradication:
Herd eradication requires diligent management.

Purchase animals from known non-infected herds.
Quarantine and monitor new animals at lease 60 days.
Monitor and cull animals with multiple abscessed lymph nodes
Housing free of sharp objects
Clean and disinfect feeders and pens regularly.
Disinfect equipment like de-horners, scalpel blades, tattoo numbers/letters, castrating instruments and other surgical instruments.
Use a new hypodermic needle for each animal.
Cull animals with chronic respiratory and wasting disease.
Bedding cleaned out regularly.
Pus should be collected and burned.
Vaccination:
A vaccine is available and should be considered in management of CL in infected herds. Vaccine should be considered if you're previously described eradication methods haven't worked or failed. Colorado Serum Company is marketing Caseous-DT, an immunoprophylactic product composed of formalin-killed organisms and toxoided culture supernatant fluid. (Also contains toxoids for clostridium perfringens type D and tentanus toxin.) Which has an efficiency of 70-80% in preventing the clinical manifestations of the disease.

The vaccine may cause severe reactions in infected animals, and also interferes with serologic testing for CL.
 

CL appears to be in some boer goats now in the Philippines.True,some will manage this problem and some want nothing to do with it.My personal opinion,we want no CL goats in our herd.In larger confinement operations CL appears more common.When a person/s buys a goat/s for breeding stock,one expects to be getting quality stock.In alot of cases CL is introduced into a CL free herd by a carrier goat.Once the bacteria is on your farm the bacteria can survive from 6 months to 5 years.There is some evidence now coming out of the U.S.A. that the bacteria can invade throught intact skin as well as broken skin.A CL goat used for breeding does nothing to improve the breed,it weakens it.I will agree CL goats used for the meat trade is acceptable, providing the abscess not involve more than 1 lymph node.CL goat/s adds more cost to ones operation,time is money.Buyer beware.Educate yourself
 

[mikey]

The Thin Poor Doing Goat
by Kevin D Pelzer DVM. MPVM
Virginia Maryland Regional College of Veterinary Medicine
Periodically goats appear thin or lose condition but generally regain weight. This is pretty normal in most animal production systems. Unfortunately, some goats do not regain the lost weight and may even continue to lose weight. There are a number of reasons that goats may become poor doers, some are management related and some are related to disease agents that have a long term negative effect on the animal.

Extra label usage - drugs listed in this category can only be used under direction of your veterinarian. Need to obtain withdraw periods and directions.


Management Factors
a) Low quality diets or low quantity diets
Goats should have a diet that consists of 8 - 13.5 % CP depending on the stage of production. Energy requirements will vary as well and are the highest during lactation. The best means to evaluate the ration is to have forage analysis performed on the forage. Book values can be used for the common grains.
b) Inadequate feeder space

Ideally more than one feeder should be used.
1.4 to 2 linear feet per head.
c) Inadequate space

Dry lot confinement there should be 35 to 100 sq ft per animal.
Less space increases fighting.
d) bully vs shy animals

French Alpine and Toggenburg breeds tend to be more aggressive.
Nubians tend to be shy and submissive.
e) Age hierarchy


Infectious Agents
a) Parasites
Internal parasites - Haemonchus contortus or Barber pole worm
causes severe anemia
look at the third eyelid
bottle jaw, edema under the jaw
External parasites - Biting and sucking lice

can cause anemia or blood loss along with blood proteins
part the hair and observe little brown dots with white/cream ends
Treatment
Cylence® - pyrethroid Extra label usage
Seven Dust® - carbaryl Extra label usage
sprinkle over back
CO-RAL® powder Extra label usage
Cydectin® pour-on cattle dewormer Extra label usage
Along with topical treatment, injectable treatment with an avermectin may be helpful.
Ivomec or Dectomax Extra label usage
b) Caseous Lymphadenitis


Caused by Corynebacterium pseudotuberculosis
Survives in dark, damp areas, soil, and manure for extended periods of time.

Clinical signs:
Enlarged lymph nodes especially in the throat latch area
Internal abscess, lungs and associated lymph nodes, lymph nodes of the intestinal tract.
May affect the spinal cord and udder causing mastitis.
Transmission
contamination of superficial wounds (shearing) or mucous membranes
indirectly through fomites - feeders, grooming equipment, and bedding
inhalation or ingestion
Diagnosis
culture
appearance of thick green pus
serology/blood test
Treatment
lance abscess and pack with iodine gauze
contaminates the environment - keep isolated
long term penicillin, 30 days rarely successful
cull
Prevention
hygiene, disinfect equipment (trimmers)
cull infected animals.
don't buy infected animals.
blood test, cull positive animals - consult veterinarian
vaccination - using sheep vaccine may cause adverse reactions in goats if the goats are already infected. Best to vaccinate at 2 - 3 months of age and then yearly
c) Johne's Disease

Caused by Mycobacterium paratuberculosis
survives in soil and manure for years



Clinical signs:
chronic weight loss in spite of a good appetite
diarrhea may occur in animals but is generally not seen as it is in cattle
weight loss is noted (brought on) after a time of stress, kidding or breeding
rough hair coat
animals are usually older than 1 year of age.
Transmission
fecal oral, consumed in feed or off pasture
kids are most susceptible to infection
can be acquired through milk or colostrum
can be acquired in utero
Diagnosis
serology/blood test
biopsy of intestinal lymph nodes
Treatment
none
cull
Prevention
hygiene, keep waterers and feeders clean
cull infected animals and off spring of affected animals
don't buy infected animals
blood test, cull positive animals - consult veterinarian
raise kids separated from adults
use colostrum from negative or disease free animals
Chronic Pulmonary Disease - Lungers

Chronic pulmonary or lung disease can be caused by a variety of infectious agents.
Depending on the agent, clinical signs may vary.

Clinical signs:

may or may not have a temperature, may go and come
persistent cough
noticeable movement of the chest with effort to expel breath, little grunt
slightly depressed and poor appetite or intermittent anorexia
exercise brings on clinical signs
Causes:

Lung worms
Diagnose by fecal exam
treatment of animals with severe signs is unrewarding
Mycoplasma mycoides
Treatment
Long acting tetracycline Extralabel usage
-- these infections can be very difficult to treat
Pastuerella hemolytica or Mannheimia hemolytica
Treatment
Naxcel®
Nuflor® Extralabel usage
adjunct treatment
Vit C/100 lbs Extralabel usage
BoSe/100 lbs, may not want to use in pregnant goats as may produce an allergic type reaction. Extralabel usage
Caprine Arthritis and Encephalitis Virus

Lamenesses
Degenerative Joint Disease
Caprine Arthritis and Encephalitis
Caused by CAE Virus - retrovirus, similar to AIDS virus


Clinical signs:
chronic weight loss
swollen joints, especially the knees (carpus) usually a year of age or older
may have swelling just behind the poll
contracted tendons
rough hair coat
lung problems
Note* Many animals may be affected but do not show clinical signs. Most infections are acquired around birth but clinical signs do not develop for years.


Transmission
exposure to body fluids - milk, saliva, nasal secretions
kids are most susceptible to infection
can be acquired through milk or colostrum
can be acquired in utero
can be transmitted by blood

Diagnosis
serology/blood test

Treatment
none
cull

Prevention
Pasteurize colostrum and milk (heat milk to 134F for 30 minutes
cull infected animals and off spring of affected animals
don't buy infected animals
blood test, cull positive animals - consult veterinarian
raise kids separated from adults
use colostrum from negative or disease free animals, colostrum substitute - Lifeline®
Mycoplasma arthritis
Mycoplasma mycoides
Clinical signs - similar to CAE
Transmission
acquired through infected milk and colostrum
kids develop a joint infection but recover but some damage has been done to the joint surfaces which takes some time before noticeable arthritis occurs.
Diagnosis - difficult
Treatment
antiinflammatory drugs - Aspirin
Adequan® Extralabel

Foot rot
Caused by 2 bacteria
Bacteroides nodosus (Dichelobacter nodosus)
Fusobacterium necrophorum
Clinical signs:
under run hoofwall separated from the hoof
swollen joint above hoof is common in severe cases
necrotic smell, black tarry dirt in the overgrown hoof
Transmission
organisms picked up from the soil
spread via hoof trimmers
Diagnosis
clinical signs
Treatment
trim feet, remove all separated hoof wall
soak feet in 10% sodium sulfate foot bath
Long acting tetracycline or Penicillin
Vaccinate
Prevention
keep feet trimmed
keep out of wet damp environments
vaccinate
Return to Maryland Goat Conference.

[mikey]

Caseous abscessation of lymph nodes and internal organs caused by Corynebacterium pseudotuberculosis occurs worldwide and is widely distributed throughout North America. It is an important endemic infection in regions with large sheep and goat populations. Economic losses result mostly from condemnation and trim of infected carcasses and devaluation of hides. Caseous lymphadenitis is also a cause of ill-thrift and sudden death in animals with internal abscesses. However, producers often report that the major impact in the flock is from disagreeable aesthetics, which may result in loss of breeding stock sales as well as early culling. Although principally an infection of sheep and goats, sporadic disease also occurs in horses and cattle ( see Corynebacterium pseudotuberculosis Infection of Horses and Cattle), camelids, water buffalo, wild ruminants, primates, pigs, and fowl. It rarely causes regional lymphadenitis in humans.
Etiology and Pathogenesis:
The small gram-positive rod is a facultative intracellular parasite that is found on fomites and in soil and manure contaminated with purulent exudate. Two biotypes have been identified based on the ability of the bacteria to reduce nitrate: a nitrate-negative group that infects sheep and goats, and a nitrate-positive group that infects horses. Isolates from cattle are a heterogeneous group. All strains produce an antigenically similar exotoxin with enzymatic activity (phospholipase D) that appears to be leukotoxic and that can damage endothelial cells and promote spread from the initial site of infection to regional lymph nodes and visceral organs. The chemical composition of its cell wall (high lipid content) enables the organism to resist being killed by phagocytes and to maintain chronic infection despite a good immune response.
Infection occurs after C pseudotuberculosis penetrates through unbroken or abraded skin or through mucous membranes. Most infections occur through wounds contaminated with purulent exudate from ruptured external and pulmonary abscesses. Contaminated dipping vats and shearing, handling, and feeding equipment are responsible for spread of the organism, along with confinement housing at high stocking densities. The pus contains large numbers of bacteria that can survive for months in hay, shavings, and soil. The disease is most often introduced into a flock by entry of an apparently healthy carrier from an infected flock, by contact on shared pastures, or via contaminated fomites such as shearing equipment.
 
Clinical Findings:
Caseous lymphadenitis is a chronic, recurring disease. A slowly enlarging, localized, and nonpainful abscess may develop either at the point of entry into the skin or in the regional lymph node (superficial or external form), from which it may spread via the blood or lymphatic system and cause abscessation of internal lymph nodes or organs (visceral or internal form). Initial infection may cause no clinical signs or may be accompanied by high fever, anorexia, anemia, and cellulitis at the infection site. Superficial abscesses enlarge and may rupture and discharge infectious pus. In sheep on range, most superficial abscesses develop in the prescapular and prefemoral region, with transmission probably occurring when the flock is gathered for group treatments such as shearing. In housed goats and sheep, superficial abscesses develop mainly in the head and neck region, likely due to transmission by contaminated feed, feeders, and other fomites. Animals with superficial abscesses show no obvious ill effects unless the location of the abscess interferes with functions such as swallowing or breathing. Abscessation may recur at the same site. Internal abscesses should be considered as a potential diagnosis for “thin ewe syndrome,” in which an adult small ruminant loses condition in the face of adequate nutrition. The visceral form is usually more extensive in sheep than in goats, mostly involving abscesses of the pulmonary parenchyma and mediastinal lymph nodes. Other less common manifestations include caseous bronchopneumonia, arthritis, abortion, CNS abscessation often occurring in the pituitary gland, abscessation of a vertebral body causing paresis or paralysis, scrotal abscessation, and rarely, mastitis. Scrotal (inguinal) abscesses can cause temporary infertility in rams. The incidence of abscesses steadily increases with age; clinical disease is more prevalent in adults, and up to 40% of animals in a flock can have superficial abscesses. 
     
   
   
   
   
   
 
 
 
   
 Caseous lymphadenitis kidney lesion, goat
 
 
 
 
 
 
 
     
   
   
   
   
   
 
 
 
   
 Caseous lymphadenitis, goat
 
 
 
 
 
 
 
Lesions: The typical gross lesion is a discrete abscess distended by thick and often dry, greenish yellow or white, purulent exudate. In sheep, the abscess often has the classically described laminated “onion-ring” appearance in cross section, with concentric fibrous layers separated by inspissated caseous exudate. In goats, the exudate is usually soft and pasty.
 
Diagnosis:
The diagnosis can usually be based on clinical signs and flock history. For definitive diagnosis, an aspirate of an intact abscess should be submitted for bacteriologic examination; C pseudotuberculosis can easily be isolated, although it may be recovered in mixed culture with other pyogenic organisms. Suppurative lymphadenitis and abscesses can also be caused by various other pyogenic organisms, such as Arcanobacter (Actinomyces) pyogenes , Staphylococcus aureus , Pasteurella multocida , and occasionally anaerobes such as Fusobacterium necrophorum . Scrotal abscesses may be confused with orchitis due to A pyogenes or with epididymitis due to Histophilus sp , Brucella ovis , or other pyogenic organisms. The differential diagnosis for emaciated animals also should include ovine progressive pneumonia (maedi, visna), caprine arthritis and encephalitis, paratuberculosis (Johne’s disease), dental disease, and parasitism.
Serologic testing is available commercially. Most tests detect antibodies to the phospholipase D exotoxin. A positive test should be interpreted as exposure to the exotoxin and may indicate active infection. Infected animals may have a false-negative result, likely because the infection is well walled off in abscesses, or if they are severely debilitated. Colostral titers usually disappear by 3-6 mo of age, so serologic testing of lambs or kids <6 mo old should be interpreted with caution. Vaccinated animals will test positive and should not be included in a serologic program. Goats tend to have higher titers than sheep.
 
Treatment and Control:
Although the organism is susceptible to penicillin, treatment with antibiotics is usually not attempted because the formation of abscesses limits their penetration and effectiveness. Therefore, prophylactic and therapeutic treatment will not eliminate C pseudotuberculosis from infected flocks or individuals. Abscesses frequently recur after draining or attempted surgical excision. The practice of injecting abscesses with formalin should be discouraged as this practice is painful to the animal and may leave a residue of a carcinogenic compound in a food-producing animal.
Prevention is based on reducing transmission of the organism from infected to susceptible animals. Emaciated animals and those with recurring abscesses should be culled. When animals are too valuable to cull, those with developing abscesses should be isolated, and the abscesses lanced and flushed with an iodine solution. Any lancing of abscesses should be done so that the purulent material can be collected and environmental contamination prevented. Young animals should be raised in isolation from older, infected animals. Older animals and those with abscesses should be shorn last, and equipment should be disinfected whenever it is contaminated with draining exudate. Skin wounds from shearing or fighting should be treated topically with iodine and sutured if necessary.
Commercial vaccines, currently only licensed for use in sheep, reduce the incidence and prevalence of caseous lymphadenitis within a flock, but they neither prevent all new infections nor cure animals already infected. Currently, all contain phospholipase D toxoid, and some also contain killed whole bacterial cells. Usually, Clostridium tetani and C perfringens type D, along with other clostridial antigens, are included in the vaccine. Vaccination should start in young stock after colostral immunity has waned (~3 mo of age). Colostral immunity can be improved by administering a booster to pregnant ewes and does 1 mo prior to lambing/kidding. A primary series (2 injections, 4 wk apart) is required in young stock or previously unvaccinated adults; repeat vaccination at least annually will help reduce the prevalence of disease. Vaccination will not cure existing infections, so it is important to ensure that animals are well vaccinated prior to exposure. Evidence suggests that increasing the frequency of vaccination to every 4-6 mo may be of benefit in flocks where exposure is high (eg, confinement housed for at least part of the year). These vaccines should be used with caution in potentially infected goats, as adverse reactions are sometimes reported.
An effective control program must involve vaccinating, culling, and reducing exposure to potentially contaminated fomites, such as shearing blades, dipping fluids, feeders, and feed. Eradication is difficult and requires strict biosecurity and vaccination protocols and rigorous culling of all infected animals. Once the disease is at a low prevalence, vaccination should be stopped and all seropositive, nonvaccinated animals culled. Prevention of disease entry into a clean flock is based on serologic screening and isolation of incoming animals. Seropostive unvaccinated animals should not be accepted into the flock.
If management allows, removal of young stock at birth and rearing separately from the infected flock has been shown to be an effective means of eradication. The infected flock is then culled as quickly as economics allow. Prevention of caseous lymphadenitis in an uninfected flock involves shearing biosecurity and purchase only of uninfected replacement stock. Producers should purchase their own shearing equipment and not share it with other flocks. Shearers should arrive at the flock wearing clean footwear and clothing. Wool bags, shearing boards, moccasins, hands, clothing, and all parts of clippers can be a source of bacteria. If there is a break in biosecurity, disease usually shows up 1-3 mo after exposure, or longer if the initial abscesses are internal or are missed.
 
Taken from the  Merck Veterinary Manual