Johne’s Disease Paratuberculosis Johne’s Disease Paratuberculosis is a chronic infection, involving the small and large intestines.. The joints most commonly attacked are the stifle, hip
Trang 1A disease of adult sheep, first recognised in South
Africa (See PULMONARY ADENOMATOSIS.)
Jack
A male donkey
Jack Beans
Jack Beans may cause poisoning if fed raw
(See LEGUME POISONING.)
Jack Russell Terrier
A small, lively dog, having a white coat with
brown or black patches Originally a
cross-breed, it now breeds true Prone to patellar
luxation, it may inherit ataxia, lens luxation and
Perthe’s disease
Jacobson’s Organ
Also known as the vomeronasal organ, this is
associated with the detection of flavours such as
those of food, but is thought also to be able to
detect pheromones The organ has 2 small tubes
which extend from the floor of the nasal cavity
to the level of the 2nd/4th cheek tooth It is
active in most mammals, but even more highly
developed in certain reptiles, especially snakes
Janet
A female mule
Japanese B Encephalitis
This disease is present in Nepal and other
regions of Asia
CauseA flavivirus The disease is transmitted
by mosquitoes from avian species which act as
reservoirs of infection but are themselves
asymptomatic
SignsIn horses, the sight is affected first Later
they become drowsy Many die, and the
recov-ery of others is seldom complete Pigs are also
susceptible; abortion and stillbirths result from
infection
The disease is a zoonosis, and for its
preven-tion in people a vaccine has been used
Japanese Bobtail
A breed of cat of ‘foreign’ conformation with a
rudimentary tail The hind-legs are longer than
the fore-legs but are kept angled so that the back is level There are similarities with the Manx, but there does not appear to be the same frequency of defects as occurs in that breed
Japanese Tosa
A breed of dog raised in Japan for fighting Importation into the UK is banned under the Dangerous Dogs Act
Jaundice
Jaundice is a yellowish discoloration of the visi-ble mucous membranes of the body (eye, nose, mouth, and genital organs) The discoloration
is caused by bilirubin, an orange-yellow pig-ment produced following the breakdown of erythrocytes due to liver disease or obstruction
of the bile flow from the liver and gall-bladder The symptom of jaundice (icterus) may also follow the destruction of red blood cells
by parasites, such as may occur in cases of biliary fever and surra in the horse; red-water
in cattle; malignant jaundice (canine babesio-sis); it is seen also in leptospiral jaundice (see LEPTOSPIROSIS), and canine viral hepatitis
In cats, jaundice is seen in the dry form of feline infectious peritonitis, toxoplasmosis Jaundice may indicate an incompatibility between the blood of sire and dam causing haemolytic jaundice of the newborn foal or piglet
When bile cannot enter into the small intes-tine by the bile-duct from the liver in the usual way, it becomes dammed back, is absorbed by the lymphatics and the blood vessels, carried into the general circulation, and some of its constituents are deposited in the tissues (See GALL-STONES, also under GALL-BLADDER; CIR-RHOSIS; LIVER, DISEASES OF; EQUINE BILIARY FEVER.)
It may be seen during poisoning with copper, mercury, phosphorus, chloroform, or lead, and after some snakebites Aflatoxins may cause jaundice
(See also LEPTOSPIROSIS; JAUNDICE; FOALS,
DISEASES OF; and BILIARY FEVER.)
Jaundice, Leptospiral
(see under LEPTOSPIROSIS for the appropriate animal)
Java Bean Poisoning
The Java beans, Phaseolus lunatus, were once
imported in large amounts The beans are of varying origin, and differ in colour, thus: Java beans are as a rule reddish-brown, but they may
be almost black; Rangoon or Burmah beans are
J
Trang 2smaller, plumper, and lighter in colour
(so-called ‘red-Rangoons’ are pinkish with small
purple splashes)
The active poisonous agent in the beans is a
substance called phaseolunatin, which is a
member of a group of cyanogenetic glucosides
SignsThese are exactly the same as those given
under HYDROCYANIC ACID
Jaw
The upper jawbones are 2 in number and are
firmly united to the other bones of the face
The lower jaw – mandible or coronoid process
– is composed of a single bone in horse, pig,
dog, and cat, but in the ruminants the fusion
between right and left sides does not occur
until old age Each of the jaws presents a
num-ber of deep sockets or ‘alveoli’ which contain
the teeth (See DISLOCATIONS; FRACTURES;
MOUTH; TEETH; also MUSCLES, DISEASES OF;
ACTINOMYCOSIS (LUMPY JAW)
Jaw, Diseases of
For overshot and undershot jaws, see under
TEETH,DISEASES OF
‘Lion jaw’ (craniomandibular osteopathy): a
disease seen mostly in West Highland terriers
Eating becomes difficult; mouth-opening,
painful
(See‘BOTTLE-JAW’.)
Jejunum
Jejunum is the central portion of the small
INTESTINE
‘Jeckyll and Hyde’ Syndrome
Also known as ‘rage syndrome’, this is a
condi-tion seen in cocker spaniels, especially those
of a golden or dun colour For no apparent
rea-son a quiet dog will suddenly become very
aggressive The dog then returns to its normal
behaviour
Jenny
A female ass
Jequirity Poisoning
This is caused by the red and black seeds of the
climbing plant Abrus precatorius, which grows
in Australia, Asia, and South America It gives
rise to cyanosis and pinpoint-sized
haemor-rhages from the skin, as well as diarrhoea
Jersian
Also known as a F–J hybrid, this is a beef cross
obtained from a Jersey bull on a Friesian cow
(In New Zealand, the reverse cross is used.)
Jetting
Jetting is a technique developed in Australia, involving the application of insecticide under pressure by means of a jetting gun – a handpiece with 4 needle jets for combing through the wool The pressure used is 10 to 14 kg/cm2(60 to 80
lb per sq in), which can be achieved by an ordi-nary medium/high-volume agricultural sprayer Jetting has not displaced dipping to any extent in the UK, where spraying has been found inefficient in the control of sheep scab
Jigger Flea
(see under FLEAS– Tunga penetrans)
Jill
A female donkey or ferret
Johne’s Disease (Paratuberculosis)
Johne’s Disease (Paratuberculosis) is a chronic infection, involving the small and large intestines It affects cattle particularly, but sometimes sheep, goats, and deer, and is char-acterised by the appearance of a persistent diar-rhoea, gradual emaciation, and great weakness The infection has been set up experimentally in the rabbit It may occur naturally in the pig, and post-mortem findings may at first suggest tuberculosis
CauseMycobacterium johnei (M paratubercu-losis).
Experimentally, sheep can be infected with as
few as 1000 M johnei bacilli These then
mul-tiply in the intestinal mucosa for the first 2 or 3 months after infection Some animals are able
to overcome the infection completely; others become carriers, with the bacilli remaining in the intestinal mucosa and lymph nodes Some
of the carriers eventually become clinically ill with Johne’s disease
SignsThe disease is very slow in onset Cattle that have become infected may not show symp-toms for as long as 2 years after the last case occurred on that farm
Pointers to the disease are an unexplained drop
in milk yield (often months before other symp-toms appear); and diarrhoea in an individual adult animal
Loss of condition, general unthriftiness, a harsh, staring coat are then seen, with diar-rhoea The temperature fluctuates a degree or two above normal Appetite is variable In the last stages emaciation becomes very marked, and the animal becomes progressively weaker
In sheep, diarrhoea is not a major symptom
Johne’s Disease (Paratuberculosis) 383
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Trang 3Treatment When well established, Johne’s
disease is invariably fatal, and no treatment is
effective or worthwhile
PreventionAttention should be paid to the
prevention of infection in other animals,
espe-cially calves Pastures that are suspected of being
heavily infected should be left without stock for
4 or 5 months All infected litter should be
stored in a dung-pit which is not accessible to
other animals, and should be used for
cultivat-ed land Loose-boxes, shcultivat-eds, etc., that have
housed a case should be carefully disinfected
and diseased animals should be fed after healthy
ones Ponds and water-courses should be fenced
to prevent fouling by faeces, water for drinking
being pumped out
Calfhood vaccination may prevent clinical
disease but interferes with subsequent tuberculin
tests
Vaccination is being practised in Iceland, the
Netherlands, Belgium, and France
In Norway a vaccination campaign to
con-trol the disease in goats reduced the infection
rate from 53 to 1 per cent Kids are vaccinated
at the age of 2 to 4 weeks
DiagnosisThe disease can usually be
diag-nosed on clinical evidence, with some
confir-mation afforded by microscopic examination of
the faeces Typical clumps of acid-fast bacilli
may be found, and the complement fixation test
is positive in about 90 per cent of cattle with
advanced disease The fluorescent antibody test
is equally useful
Unfortunately, diagnosis of the carrier state
is not possible with any certainty There is no
single test which can conclusively detect the
presence or absence of M johnei, although
laboratory tests can identify the presence of
Mycobacteria spp The complement fixation test
is positive in only a small proportion of carriers
and can give false positive results
The difficulty in identifying ‘carriers’ makes
Johne’s disease a difficult one to control
Johnin
A diagnostic agent derived from M
paratuber-culosis used for JOHNE’S DISEASE Cutaneous
injection results in thickening of the skin
in positive cases While insufficiently sensitive
for individual diagnosis, the test is useful for
identifying infected herds
Joint-Ill
Also called NAVEL-ILLor POLYARTHRITIS, this is
a disease of foals, lambs, and calves, in which
abscesses form at the umbilicus and in some of
the joints of the limbs, due, in the majority of cases, to the entrance of organisms into the body by way of the unclosed navel There are numerous organisms associated with the dis-ease, the commonest of which are streptococci,
staphylococci, Pasteurella, E coli, the necrosis
bacillus, and see under FOALS,DISEASES OF
SignsUsually the young animal becomes dull, takes no interest in its dam, refuses to suckle; the breathing is hurried; the temperature rises from 0.6°to 1.2°C (2°to 4°F) above normal; the foal prefers to lie stretched out on its side, and may have attacks of either diarrhoea or con-stipation If the navel is examined it is found to
be wet and oozing with bloodstained serous material, or it may be dry, swollen, painful to the touch, and hard, owing to abscess formation within In cases that appear later in life there may be no umbilical symptoms In the course
of a day or so, one or more of the joints swells
up The joints most commonly attacked are the stifle, hip, knee, hock, shoulder and elbow, but
it may be seen in any of the others The swelling
is tense, painful, hot, and oedematous There is the danger of a fatal septicaemia
A chronic form of infection resulting in internal umbilical abscesses is sometimes seen The primary infection occurs at, or soon after, birth; but once the umbilicus has sealed over, external signs are not evident, and the umbilical remnant appears normal
The calves are usually presented as unthrifty, depressed and slow in their movements Their temperature invariably normal
PreventionAttention must always be paid to the cleanliness of the foaling-box, the calving-box and the lambing-pen Where climatic and other conditions are favourable, the pregnant females should be allowed to give birth to their young out of doors Lambing-pens should with-out fail be changed to a fresh site every year Investigations undertaken by the Animal Health Trust suggest that thoroughbred foals in the UK suffer severe illness as a result of being deprived of a not inconsiderable volume of blood when the navel cord is severed prema-turely by attendants Severance of the cord, it seems, is always best left to the mare The use of strong disinfectants applied to the stump of the navel cord is likewise deprecated
An application of a sulphanilamide or other antibiotic dry dressing may be safer than iodine solution
When cutting the cord, it is necessary to maintain the strictest cleanliness Scissors should
be sterilised, and tape scrupulously clean
384 Johnin
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Trang 4TreatmentAntibiotics and, if available,
anti-serum for the causative micro-organisms
Surgically, the umbilicus is opened up,
evacuat-ed, and disinfected Isolation and other hygiene
measures are needed
All pails, and other feeding utensils that are
liable to get infected, should be thoroughly
cleaned using boiling water or steamed before
future use, and the pen or box that houses a
case should be occasionally washed out with
disinfectant (See also FOALS,DISEASES OF.)
Joints
Joints fall into 2 great divisions, namely
mov-able joints and fixed joints In a movmov-able joint
there are 4 main structures Firstly, there are the
2 bones whose junction forms the joint;
sec-ondly, there is a layer of smooth cartilage
cover-ing the ends of these bones where they meet,
which is called ‘articular’ cartilage; thirdly, there
is a sheath of fibrous tissue known as the ‘joint
capsule’, which is thickened into bands of
‘liga-ments’ which hold the bones together at various
points; and finally, there is a closed bladder of
membrane, known as the ‘synovial membrane’,
which lines the capsule and produces a synovial
fluid to lubricate the movements of the joint
Further, the bones are kept in position at the
joints by the various muscles passing over them
This type is known as a diarthrodial joint
Some joints possess subsidiary structures such
as discs of fibro-cartilage, which adapt the bones
more perfectly to one another where they do not
quite correspond, and allow of slightly freer
movement, e.g the stifle-joint In others,
mov-able pads of fat under the synovial membrane fill
up larger cavities and afford additional
protec-tion to the joint, e.g the hock-joint In some the
edge of one bone is amplified by a margin of
car-tilage which makes dislocation less of a risk than
otherwise, e.g the hip and the shoulder-joints
In the fixed joints a layer of cartilage or of
fibrous tissue intervenes between the bones and
binds them firmly together (synarthrodial
joint) This type of joint is exemplified by
the ‘sutures’ between the bones that make up
the skull Classified among these fixed joints are
the amphi-arthrodial joints, in which there is a
thick disc of fibro-cartilage between the bones,
so that, although the individual joint is capable
of only limited movement, a series of these, like
the joints between the bodies of the vertebrae,
gives the column, as a whole, a very flexible
character In this connection it is noticeable
that the movement in the region of the neck
may be much more free than in some of the
true movable joints, such as between the small
bones of the hock or carpus
Varieties Apart from the division into fixed and movable joints, those that are movable are further classified Gliding joints are those in which the bones have flat surfaces capable only
of a limited amount of movement, such as the bones of the carpus and tarsus In hinge-joints like the elbow, fetlock, and pastern, movement can take place around one axis only, and is called flexion and extension In the ball-and-socket joints, such as the shoulder and hip-joints, free movement can occur in any direction There are other subsidiary varieties, named according to the shape of the bones which enter into the joint
Joints, Diseases of
Arthritismeans inflammation which involves all the structures of the joint – viz synovial membrane, capsular ligaments, cartilages, and the ends of the bones that take part in the for-mation of the joint Arthritis is a general term which includes osteoarthritis and rheumatoid arthritis Arthritis often begins as a synovitis (see
below), but the degree of inflammation is severe enough to extend to the structures around the synovial membrane Its causes, symptoms, and treatment are similar to those given for synovi-tis, but it sometimes leads to ankylosis and fix-ation of the joint (See CORTISONE.) The joints that are most often affected are the stifle, hock, knee, and fetlocks, but the shoulder, hip, elbow, and the lower joints of the digit are not infre-quently the seat of disease as well Among dis-eases that are associated with joints, and which are treated separately, are NAVICULAR DISEASE;
SLIPPED SHOULDER;SLIPPED STIFLE;HYGROMA;
CAPPED ELBOW;CAPPED HOCK;KNUCKLING OF THE FETLOCK; JOINT-ILL; see alsobelow and BUR-SITIS; ANKYLOSIS; FRACTURES; DISLOCATIONS;
GLASSER’S DISEASE; HIP DYSPLASIA IN DOGS;
SWINE ERYSIPELAS
impor-tant in the dog, and may occur at any age from
2 years Symptoms may be vague at first; the animal appears depressed, with a poor appetite and often some degree of fever, but with no lameness Eventually the latter symptom appears, sometimes involving several joints, sometimes affecting only one limb and then shifting to another There may be crepitus – a grating sound – when the limb is moved Diagnosis depends upon radiography and –
as in human medicine – there are certain laboratory tests, the results of which provide additional criteria for deciding whether the condition really is rheumatoid arthritis or not
Joints, Diseases of 385
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Trang 5386 Joule
Intractable arthritis of the hip-joint in dogs,
as in human beings, may be overcome by major
surgery involving removal of the top of the
femur and replacement of the ball part of the
ball-and-socket joint with a plastic prosthesis
Synovitisis the name given to any
inflamma-tion of the membrane lining a joint cavity It
may be acute, sub-acute, or chronic
Generally this is not a separate condition
but occurs during the course of rheumatism,
rickets, gout (in poultry), severe sprains and
bruises, and in a variety of specific infections
such as brucellosis, swine erysipelas,
tuberculo-sis Tubercular joint disease often produces a
chronic synovitis in the neck bones of the horse,
which leads to an arthritis later
Conditions such as wind-galls, curb, bog
spavin, etc., are really only synovitis that have
become chronic or are complicated with other
pathological conditions
The synovial membrane becomes inflamed,
thickened, and secretes an excessive amount
of fluid into the joint As a result the joint
becomes hot, swollen, and painful The animal
goes lame in greater or lesser degree according
to the extent of the inflammation When at
rest, the joint is usually kept flexed with the toe
of the affected leg just resting on the ground If
it is a simple condition, such as a mild sprain,
these symptoms last for a few days and then
gradually pass off In more severe cases, such as
in joint-ill, there may be pus formation,
septi-caemia, and death In the chronic type the
swelling persists The animal is able to use its
limb as usual, but the accumulated fluid in the
cavity does not disappear (e.g bog spavin,
wind-galls, etc.)
Open jointis a condition in which, by
acci-dent or other trauma, the inside of the joint is
exposed to infection
The seriousness of an open joint is not so
much due to the initial injury as to the danger of
infection This may cause tissue destruction
with-in the jowith-int, and even lead to a fatal SEPTICAEMIA
The most striking signs of open joint are,
first, the excessive degree of pain that seems out
of all proportion to the visible amount of
dam-age that has been inflicted; secondly, the great
amount of swelling that is usually seen; and
thirdly, the discharge of a thin, straw-coloured
or blood-stained sticky synovia which has a
tendency to coagulate around the skin opening
Veterinary advice should be sought at once
Prompt treatment with antibiotics, and surgery
if required, is necessary to prevent or limit infection
Dislocations(seemain dictionary entry)
Bursitis, an inflammation of a bursa, com-monly occurs in the region of a joint The prominences of the hock, elbow, knee, stifle, etc., are protected by bursae – lined on their insides by synovial membrane These sometimes become inflamed and lead to the formation
of fluctuating swellings which have a tendency
to become chronic Capped elbow, capped hock, and hygroma of the knee, are of this nature (See also OSTEOARTHRITIS;MAST CELLS;
OSTEOCHONDROSIS;RHEUMATISM.)
Joule
A derived SI unit of metabolisable energy (See CALORIES and STARCH EQUIVALENT, which it replaced; also SI UNITS.)
Jugular Veins
Jugular veins carry the blood back to the chest from the head and anterior parts of the neck The jugular vein is often used for taking blood samples and for intravenous injection The jugular furrow is the groove between the tra-chea and the muscles of the neck, in the depths
of which lies the jugular vein
Jungle Fowl
(Gallus gallus) A native of the rain forests of
South-East Asia, it is the species from which the domestic fowl originated In its normal environ-ment it prefers hot, humid, shady conditions with frequent rain showers A broiler-producing company has replicated the climate found in the rain forest in its broiler houses Mortality was very low and lameness almost non-existent, although the birds took a little longer to reach market weight
Juvenile Cellulitis
Also known as ‘puppy strangles’, this condition affects pups between 3 weeks and 4 months of age The cause is unknown but a hypersensitiv-ity reaction may be involved Clinical signs are cellulitis on the face and head, prepuce and anus, accompanied by lethargy, anorexia and, possibly, raised temperature There may be lymphadenopathy Steroid and antibiotic
thera-py is indicated; affected parts may be bathed
in aluminium acetate solution Permanent scarring may result