The Rural Voice, 1993-07, Page 16(*,ILLAGHE.I Fencing
We use Red
Pine pressure-treated posts.
• Sales • Installation • Free estimates
4:4% Canadian
4* tt► Distributor
for
ti♦ Pennwood's
Equine Supreme
From Weaning Through Maturity
A special blending of vitamins, minerals,
amino acids and electrolytes formulated to
bring out your horses' full potential.
"IVA'•
Polydome calf hutches - always in stock
• Farm Gates - all sizes • Hay Feeders
CARSON'S FEED & FARM SUPPLY
Hwy. 86 E, Listowel
519-291-1094 Fax (519) 291-5065
UNCHAIN YOURSELF
Hydra -Spread frees you from all the
mechanism (and breakdowns) of chain
type spreaders. Manure will not freeze
to our polyethylene box.
Available In 295 bu., 365 bu. and
465 bu. slzes at great prices
/agedor ,1� N. E.
y Hagedorn
& Sons Limited
Paisley 519-353-5642
Established 1928
"Farm Equipment Is
Our Only Business"
12 THE RURAL VOICE
Diagnostics
Johne's disease
by Dr. AJ. Rehmtulla
Veterinary Laboratory Services
Huron Park
A serious debilitating infectious
disease essentially of domestic and
wild ruminants, Johne's disease, also
called paratuberculosis, is a bacterial
intestinal ailment caused by
Mycobacterium paratuberculosis.
These bacteria belong to the same
general group as
tuberculosis organisms, but
unlike TB, they are not
communicable to human
beings. They can, however,
persist in pasture and barn
environments for long
periods and hence can be a
source of infection to
susceptible cattle, sheep
and goats.
Johne's disease is a chronic illness
which has a long incubation period.
Hence, clinical signs are seen in
animals at around two years of age or
older, even though infection by the
causative bacteria occurred much
earlier in life, when they were several
months old or even before. Calves
become infected by consuming water
and feed contaminated with feces
from older animals excreting these
organisms. These "shedders" are
carrier animals as they do not show
any overt signs of clinical disease.
Many calves, thus infected, in turn,
also become shedders, thereby
perpetuating bacterial spread and
contaminating the environment for
months before clinical signs appear in
some animals (usually in less than
five per cent) while most of the
remaining animals are either
incubating or have developed
resistance to infection.
In susceptible animals, the
infective bacteria invade the wall of
the intestine where they multiply and
provoke intense reaction. Over time,
the intestinal wall becomes
chronically inflamed and gets
progressively thickened. This
compromises its function of nutrient
absorption and permits excessive
fluid loss. The ensuing diarrhoea and
fluid/electrolyte loss further
aggravates the protein/energy losses
due to malabsorption. The affected
animals, however, continue to eat and
drink, have no fever and do not
appear "sick". The relentless
diarrhoea and dehydration eventually
results in muscle wasting, drop in
milk yield, shedding of wool, etc.,
until animals become visibly
emaciated as if they were starved.
The diarrhoea, in cattle, is profuse,
very watery but without
any blood or tissue debris.
These symptoms often go
on for weeks or months as
animals continue to
deteriorate, become very
thin, weak, dehydrated,
depressed and die or have
to be destroyed.
Johne's disease is
diagnosed at post-mortem
examination by presence of thickened
and corrugated intestine and swollen
associated lymph nodes. The
diagnosis is confirmed by
demonstrating classical microscopic
lesions and detecting the causative
bacteria by special stain. Since these
organisms are unique and slow-
growing, cultures can only be
undertaken by specialized
laboratories and this can take several
months. It is important to obtain an
accurate diagnosis as the disease can,
particularly in younger animals,
resemble other conditions such as
viral diarrhoeas, Salmonellosis,
Coccidiosis, parasitisms or
malnutrition.
Since Johne's infection spreads
slowly, has a long incubation period,
with cases occurring only
sporadically, and also because of the
rather resistant nature of the causative
bacteria and lack of a single reliable
test to detect diseased animals,
antibiotic treatment of individuals or
herds is not a viable option. Johne's
disease is not a reportable disease,
hence its control is strictly on a
voluntary basis. It requires the
producer and the veterinarian to
devise a plan suitable for that
particular operation in order to
contain the disease by instituting
rather major changes in management.
The use is made of a battery of
um1'larts
Catch\
can
John
tse
ase