Working
with Livestock and Poultry.
Newcastle
Disease.
Newcastle Disease is a constant threat to San Diego ranches. A Ramona
ranch was the only one involved this time, the 2003-2004 outbreak, in
San Diego, although the outbreak involved 6 Southern California
counties requiring the destruction of over 1.2 million chickens. In
1971 the disease infected 1,341 flocks in Southern California requiring
the destruction of just under 12 million chickens. In addition to
poultry, cockatiels, budgies, amazons, and cockatoos are highly
susceptible and often carry the virus. At necropsy all birds of these
species are routinely tested for this disease. Undocumented birds of
these species smuggled into California, principally through the San
Ysidro port of entry appear to be almost the exclusive source of the
disease, although other sources are possible such as the movement of
fighting cocks.
Haemoproteus
Lophortyx
Infection in a Bobwhite Quail
During the fall of 1979 the manager of a hunting club in Pine Valley,
California (San Diego County) experienced heavy mortality in their
pen-raised bobwhite quail. In a 2-wk period approximately 700 quail
died,
essentially the entire flock. Dr Mahoney found weight loss, acute
diarrhea, convulsions, torticollis, and lateral recumbency, linear
hemorrhages and many yellowish lesions in all skeletal muscles. She
determined
histologically that the deaths were due to a massive parasitic
infestation of the muscles and red blood cells. Working with Dr.
Chris Gardiner, a renowned veterinary parasitologist, the findings were
published in the Journal of Wildlife Diseases. Although the disease was
first described in California bobwhite quail in 1930, its significance
wasn't appreciated nor widely recognized until this case was published.
The parasites over-winter in the native California quail doing little
damage and are transmitted to bobwhites by insects as the weather warms
in the spring. This parasite is the reason raising bobwhites in
Southern California has been largely unsuccessful.
Duck Viral
Enteritis,
AKA Duck Plague
When
an unusual number of ducks began dying at a lake in San Diego,
poisoning was suspected. A few were brought to our
laboratory. Duck Plague was easily diagnosed by Dr. Mahoney based
on enteric lesions, viral inclusion bodies, and symptoms. This
disease is caused by a duck herpes virus. It is not
contagious to humans, but can be devastating to the wild migratory duck
population that use our lakes as resting and feeding
grounds. Our office quarantined the lake, allowing the Fish and
Game Department personnel to depopulate the lake for euthanasia and
disposal of the ducks. This was also done at our
laboratory.
Herpes viral
inclusions in duck
intestine, Duck Plague
Botulism,
aka
"Limberneck"
Botulism is also
known as "Limberneck" for obvious reasons. Weak
muscles can't
hold the head up. The condition is also known as "Western Duck
Sickness." This occurs when ducks die in the bushes along duck ponds.
The carcasses breed fly larvae that consume the dead rotting flesh and
concentrate the botulism toxin, which in turn is consumed by the ducks.
Seagulls are frequent victims of botulism the same way as ducks. In
addition, washed-up seaweed that is allowed to decompose and rot can
develop anaerobic condition that allows the botulism toxin to be
produced. The bugs or their larvae that feed upon the washed up
seaweed are then eaten. Seagulls, however are quite resistant.
Twenty-four hours of cage rest with fresh water usually results in
complete recovery. Ducks have been shown to withstand four times as
much toxin when provided with fresh water, as when provided with water
of high mineral content such as found in alkaline lakes of western
states.
Cattle have been poisoned from ingesting silage in which a
carcass of a rat has been found.
The anaerobic
conditions of the silage favors the
multiplication of the botulism bacteria from the
digestive tract of the rat. The toxin is then
dissolved into the moist surrounding silage.
Brucellosis
Eradication
Brucellosis is a bacterial disease that causes "Contagious Abortion" in
cattle. In people it causes "Undulant Fever" a disease difficult
to cure with antibiotics. San Diego County was the first major
dairy producing region in the state to eradicate brucellosis from the
dairy industry. This was essentially due to the close
cooperation between the laboratory and Dr. Dan Suther, the state field
veterinary epidemiologist for San Diego County. The County
Veterinarian has always pursued a policy of intergrated
laboratory and field services, using departmental and state field
personnel for a common goal. Office space was provided
for both state and county field personnel so they had ready
access to necessary laboratory support. In the case of
Brucellosis eradication, Dr. Suther collected blood and milk samples
from county dairies for processing by our laboratory. Positive
and suspect samples were set aside for Dr. Suther to repeat the
tests. Besides giving him a keen insight to this aspect of the
eradication program it provided increased credibility of the results,
when he could tell the doubting dairyman that he personally repeated
the tests, and there was no doubt that the particular cow was
infected. The increased confidence this gave the dairy industry
in the validity of the program in our county was a major reason
for its' early success. In spite of the success of this program,
the number of dairy herds has gradually decreased from 135 in 1960 to
9 in 2002, reflecting our increased urbanization.
Pullorum
and Fowl Typhoid Eradication
Turkey Blood
Testing for pullorum and Fowl Typhoid
In the 1930s and 1940s the Ramona
community of San Diego County called
itself "Turkey Capital of the World." Dr.
W.R. Hinshaw and E. McNeil provided
some of the first poultry medicine in the
county and developed the pullorum and paratyphoid testing program.
Based on
techniques developed by Dr. Hinshaw et. al. for pullorum testing, Dr.
J.W. (Bill) Dunsing and Dr. Marten E. Goetz of this laboratory
developed
Arizona paracolon(now called Arizona hinshawii) testing for turkeys. In
1961 Drs. H.C. Johnstone and Dean J. Thackrey were appointed to
administer the laboratory division. Pullorum and parathyphoid cultures
used to produce antigen for the official
testing of turkey breeders were maintained by serial weekly transfers
to new media. In preparation for the first testing season it was deemed
prudent to have these stock culture organisms re-evaluated. Samples
were
submitted to the National Animal Disease Laboratory in Ames Iowa. They
were found to be too rough to type and probably no longer suitable for
making antigen. New cultures were requested from the state agricultural
laboratory then in San Gabriel. Since their cultures originally came
from us going back to the work of Dr. Hinshaw et. al., both
laboratories
acquired new strains from the National Animal Disease Laboratory.
Turkey bleeding boxes were provided by the Ramona Turkey Grower's
Association.
Originally state bleeders collected the blood. Near the end of the
program our office provided the bleeders, and even built our own
bleeding tables. Now the only turkeys left in the county are those
running for political office.
Mystery of Dying Horses at Bonita
Farms
Dr. Mahoney was the only pathologist on duty when horses started
dying at the Bonita Farms Equestrian Center. One had died and four were
"staggering around." A private veterinarian had done a field necropsy
and brought the vital organs to our laboratory. The presumptive
diagnosis was feed poisoning most likely due to botulism.
However, stomach contents and serum showed no evidence of botulism
toxin. Toxicology laboratories also reported negative findings on
feed and stomach contents, liver, and kidney samples. Help was made
available from both the state veterinarian and the National Veterinary
Disease Laboratory drawing on their vast resources. Finally the
original presumptive diagnosis of poisoning from contaminated feed was
confirmed. While all of the feed being fed at the time of the initial
deaths tested clean, dust vacuumed up from cracks at the bottom of
mangers contained high levels of Rumensin, an enzyme product intended
for cattle feed. It facilitates rumen digestion, but was lethal to
horses with their different digestive system. All told, over 22
horses died at the stable. Before this episode, the toxicity of
Rumensin
to horses was little known, hence this episode made national news both
in the press and in professional and equine publications.
Accidental Poisoning.
Oleander
stops the heart----------------------------------- Bracken Fern
poisoning
There are many causes of accidental poisonings, poisonous plants being
fairly
common in
livestock, especially oleander ingestion. This is usually eaten when
mixed with other yard
clippings and dumped in a location the animals have access to. Death
is rapid and
undigested leaves are usually easily identified in rumen contents.
Braken Fern poisoning
is slower, causing fever, difficult breathing, salivation, nasal
bleeding, and a rash on the visible mucosa.
The plant is generally consumed only when all other
forage is depleted.
Open Range
Program
These are no fenced areas
where livestock have the right of way.
Pursuant to
state law, counties may declare areas that are devoted chiefly to
grazing "open
range". Normally livestock owners build fences to confine their
livestock. That's not the
case with open range. On open range, cattle and other livestock may
roam freely without
fences. Hence it is a fencing law. Livestock have the right of way. You
have to look out for
them. If you don't want them walking across your front yard, you have
to build the fences to
keep them out.
The program was, and still is,
assigned to the director of the county road department, with
the County Veterinarian determining that the area was primarily used
for grazing of
livestock. The road department has the main responsibility because they
maintain the roads
and post the signs "Open Range", "Beware of Livestock" etc. as
appropriate. The person
requesting the declaration fills out a request form provided by the
road
department which provides a "Board Letter" requesting an ordinance with
that
designation. The County Veterinarian concurs that the area is devoted
chiefly to grazing. While this is
basically a land use designation, in the early days of San Diego County
Government, the areas involved were un-zoned, and such ordinances could
not be included
in zoning laws
because they didn't exist in those areas. Hence, the
County Code of
Regulatory Ordinances was used, the livestock portion of which was
assigned to the
Livestock Inspector (now called the County Veterinarian). The
transportation portion was
assigned to the County Engineer (subsequently called the Director of
Transportation).
Because of the increased urbanization of the county, it is unlikely for
additional areas to be
so designated. Since the entire county is now zoned, the County
Veterinarian's portion of
the program could be assigned to the zoning department, who may not
want it, because I
suspect their zoning authority does not apply to Indian Reservations,
nor to forestry areas,
where many open range areas exist. It would still remain primarily a
problem for the road
department, which should maintain the primary control of the program.
The County
Veterinarian has always been happy to assist all other departments
whenever he or she can. Because this
problem comes up so seldom, and because the County Engineer or Director
of
Roads has such a volume of paperwork and change of staff, they have, on
occasion, been
unable to retrieve their old records, which the County Veterinarian has
readily provided. All areas
declared open range are listed in the County Code of Regulatory
Ordinances. The
most recently declared area, as of 9/04, is listed as section 62.1108.
Regulation of Garbage Feeding Hog
Ranches
Infectious
Swine Diseases
Feeding garbage to hogs was the original recycling program in San
Diego County, long before reuse of newspapers and aluminum cans was
even considered. Originally garbage disposal was the primary job,
and hog feeding was incidental. I remember being admonished just after
World War II
that Americans wasted enough food to feed half the starving children of
Europe and that I should "clean my plate," to which I responded "who
wants to eat garbage?" Well, the hogs sure did. Hog feeders soon
realized the economic value of table scraps and edible waste material
from homes, food plants, and large institutions. What was once an
expense to dispose of, became an economic asset as hog ranchers bid on
garbage hauling contracts. One ton of garbage produced 50 pounds of
pork. This was before the term "value added" was invented. In 1954 San
Diego County had far more garbage feeding operations (41) than any
other county in California. The second largest number was in Los
Angeles County (29), which showed the superiority of our garbage, the
best of
which was supplied by the U.S. Navy. One County Supervisor expressed
concern over our county being rated number one on the basis of garbage
quality. In 1954, when cooking of garbage became compulsory and
enforcement came
under our office, ranches became a rich source of silverware and dishes
discarded with the garbage. Many of these items are still in use in our
lunch room. The largest garbage feeding operation was in Fontana, CA.
which received garbage from Los Angeles City by the train load. There,
one could purchase entire sets of matched silverware, some of it
sterling silver. Alas, San Diego was a poorer community and our
silverware is very mis-matched. When you visit our laboratory and are
offered a cup of coffee, think of the rich history that cup itself
represents. One could say the cup was "steeped" in history. The
installation of garbage disposers in newer Navy commissaries eliminated
much of the supply. By 1977 these ranches had dropped to 11 in number
and to only seven by 1981.
Vesicular Exanthema (VE)
San Diego County had the distinction in
1932, of introducing into the U.S., Vesicular Exanthema, a viral
disease of swine, clinically indistinguishable at that time from Hoof
and Mouth Disease. By 1959 Vesicular Exanthema was eliminated from the
U. S. by the passing of compulsory garbage cooking laws, but only after
it spread to all of the 49 adjacent states. Although the disease first
appeared in California, California was the last state to require
cooking of garbage prior to being fed to swine.
No! that's not
a rectal thermometer for
an elephant.
It was used to record the cooking temperature of garbage. Garbage was
often collected in dump trucks with steam pipes welded to the bed. When
connected to a steam boiler, super heated steam was used to bring the
garbage to boiling temperature. Temperatures were recorded in several
areas to insure uniform heating. After World War II most of the
unincorporated areas of the county were
unzoned and therefore not covered by the county zoning ordinance. The
County Code of Regulatory Ordinances was used to control garbage
feeding operations.
Permits were required from the Livestock Inspector (later renamed
County Veterinarian)
that covered location, construction, equipment and sanitation. New
operations could not be located within one mile of any incorporated
city or any closely settled unincorporated area, public park,
recreation center, or school, etc. Permits in turn had to be approved
by
the Board of Supervisors. In 1975 a dairyman in north county, who had a
rather small operation, but the cleanest garbage feeding facility in
our county, applied for a premise permit for a large operation.
Unfortunately the desired location was adjacent
to the city limits of Oceanside, with drainage into the San Luis Rey
River, and immediately below some very expensive homes, all of which
prohibited the issuance of a permit. Even if issued, the permit would
not have withstood the public hearing phase. Since this was a land use
decision, the applicant questioned why the County Veterinarian was
involved. This led to the removal of the County Veterinarian from the
permit process. By this time, L.C. (Limited Control) zoning had been
established in all previously unzoned areas of the county. The County
Zoning Department simply adopted the existing restrictions into the
zoning ordinance. The hog ranch never developed. The California Bureau
of Animal Health enforced the cooking requirements and associated
sanitation thereafter.
Hog Cholera
Hog Cholera
Viral Inclusion in lymphatic tissue & lymphocytic cuff
of blood vessel in brain
What was probably the last case of Hog
Cholera in the U.S. occurred in a garbage feeding operation in San
Diego. Dr. Thackrey of the San Diego County Veterinary
Diagnostic Laboratory diagnosed the case on the basis of gross and
histologic
lesions including specific inclusion bodies in lymph nodes and the
spleen. The case was reported to the state veterinarian who, because of
partial state indemnity, wanted it confirmed by the state laboratory.
However, this was a national eradication program and considered a
foreign animal disease, and the federal veterinarian for California
required a second reconfirmation by the National Animal Disease
Laboratory. Everyone has to protect their own turf. Since the national
laboratory is the final authority, we decided to send our specimens
directly to them and bypass
the middle man and save one to two weeks in turn around time. At that
time Mexico was using live virus vaccine made in China, while
vaccination had ceased in this country. Personnel on this ranch moved
freely across the border as the national boundary fence consisted of a
few strands of barb wire. The strain of virus was never determined. All
this was before immunologic diagnostic methods were available. The
owner was also observed driving his truck across the border at his
ranch. The Mexican vaccine must have been very good as no other cases
occurred.
Salt
Poisoning
One of the last garbage feeding operations in the county was a small
operation where garbage from a fast food restaurant was used. Dr.
Mahoney determined the pigs were coming down with salt poisoning and
the operation was terminated as unprofitable.
Lymphocytic
and
eosinophilic cuff of blood vessel in brain
The Baby
Albino Gorilla that went "Oink"
May we see the baby albino gorilla? The what? The baby albino
gorilla. We haven't got
any albino gorilla! Such went the conversation at our front counter one
Friday morning.
Two high school age boys were at our front door upon opening. They were
on a student
summer work program assisting our custodian, and insisted we had a baby
albino gorilla
in our animal holding room. The receptionist, who had no idea what was
going on, thought
that was all she needed to screw up another day, but dutifully took the
boys back to our
animal room. Whereupon a young pig presented itself with a loud "oink,"
and the boys
exclaimed "Wait until we get even with that guy." It turned out that
the custodian,
knowing full well what we had, told the boys we had a baby albino
gorilla. Of course they
were skeptical until he told them to go and pound on the rear door of
our holding room.
Upon doing so the pig made the usual pig noises convincing the "city
boys" we had in fact a
baby albino gorilla.
Many
organizations and individuals utilize our services. Where else can one
get a horse lung?
The physiology department of the U.C. Medical School in San
Diego requested a large preserved lung for teaching purposes. Our
necropsy service provided a horse. Their veterinarian removed and
prepared the lung at our laboratory by inflation with a vacuum cleaner
and air drying, a very simple process. Our laboratory provides many
unique services unavailable elsewhere.
Horse lung
being prepared for U.C. medical student demonstration
When an animal dies, blood gravitates to the downward side as
illustrated by the red
coloration on the lower half of the lung as
pictured above. This phenomenon is used by
forensic pathologists to determine if a body
has been moved or relocated after death.
Tapeworm cysts
in muscle of
rabbit Myxomatosis, mosquito transmitted
viral disease
Ear mites,
rabbit
Visceral gout, (white urates) , duck
Twisted umbilical cord caused abortion, equine