Download Strangles

Merrist Wood College
National Certificate in Horse
Studies
Equine Science
Mechanical Systems Failure
Beccy Manley
09.12.2001
Table of Contents- and Figures and Tables
Table of Contents
Figures and Tables ........................................ i
Acknowledgements ......................................... ii
Introduction .............................................. 1
Skeletal system ........................................... 2
Respiratory system ........................................ 3
Cardiovascular system ..................................... 4
Renal system .............................................. 5
Diagnostic decision tree .................................. 6
Strangles ................................................. 7
Conclusion ................................................ 8
References and Bibliography ............................... 9
List of Figures and Tables
Illustration of skeleton .................................. 2
Illustration of synovial joint ............................ 2
Illustration of respiratory system ........................ 3
Illustration of heart ..................................... 4
Table of arteries and veins ............................... 4
Illustration of kidneys ................................... 5
Illustrtion of Strangles .................................. 7
For picture credits see reference page.
i
Acknowledgements
I should like to express my thanks to E. Manley and H.
Manley for their help and ideas in developing the content
of this report.
ii
Introduction
Horses suffer from many common ailments often easily caught
infections that can prove fatal.
Horses need to be fit and well to do their job. If the owner
doesn't recognise the first signs of illness in their horse
then the animal may suffer; never reach its full potential;
ever return to work; cost the owner large vets bills.
This report sets out to describe the basic function of four
main systems in the horse making them easy to understand and
interesting to read.
It also sets out to help owners to find out what may be
wrong with their horse using a diagnostic decision tree.
Lastly it sets out to create a fact file on one common
disease from the decision tree to highlight the importance
of knowing the first signs of illness in horses.
1
Skeletal system
The horse has an endoskeleton, which means skeleton under the skin.
A normal horse has 205 bones but it can have 206 depending on whether it
has 7 or 8 coccygeal vertebrae.
Function
To protect and
support the body.
Locomotion: for
locomotion we need to
have attachments
consisting of bone,
ligament, bone:
muscle, tendon bone.
Bones
• Long bones:
contain marrow for
the manufacture of
red blood cells. They
have compact bone on
the shaft allowing for strength and support and spongy bone at the
head making them light.
•
Irregular bones: these are found in most joints and along the spine.
They have protrusions and projections to allow for muscles, ligaments
and tendons to be attached.
•
Flat bones are found in the skull and the scapula (shoulder).
Joints
Joints are formed when two or
more bones come together and
are held together by bands of
flexible fibrous tissue, known
as ligaments.
There are three main types of
joints:
•
Immovable, these are found
in the junctions between
the skull.
•
Slightly movable, these are
found in the vertebrae
forming the spinal column.
•
Freely movable:
1
Hinge type joint e.g. Fetlock
2
Plane type joint, where flat surfaced bones glide over each other
2
3
Pilot joint: this allows turning, (as in Atlas and Axis).
4
Ball and socket e.g. hip.
Each freely movable joint is enclosed in a fluid filled joint
capsule.
3
Respiration system
Function


Takes air to the lungs which then supplies oxygen.
Diffusing oxygen in to the blood stream and carbon dioxide from the
blood to the lungs.
 Regulates water and temperature.
There are two types of respiration:
Internal: metabolic break down of
compounds e.g. carbohydrates this
happens through the cells of the
body.
External: The transfer of gases
between the environment and the
blood, this takes place in the
lungs.
Upper tract


(A) Buccal cavity
(B) Nasal Cavity (open
to pharynx)
(C) Inferior maxillary
sinus
(D) Superior maxillary
sinus
(E) Frontal sinuses
(F) Guttural pouch
(G) Pharynx
(H) Trachea
(I) Bronchus
(J) Alveolus
(K) Lungs
(L) Larynx
The nostrils: Take oxygen in and
out and have hair to filter dirt.
The horse cannot breath through
its mouth.
 Nasal cavities: Warm and clean
the air with cilia (hair like)
and they have tiny bones which are covered in mucus membranes.
Pharynx: is used of respiration and digestion with the soft palate
separating the mouth from the nasal cavities and the epiglottis
acting as a stopper covering the oesophagus when it breathes and
the larynx when it eats.
 Larynx: is in the entrance of the trachea and contains the vocal
chords, as air goes over they vibrate and make a noise.
 Trachea: This goes form the larynx to the lungs and is held open
by rings of cartilage. It is also part of the lower tract.
Lower tract

Bronchi: they divide in to each lung and are held open by rings
of cartilage. Once in each lung they divide into a bronchiole
tree.
 Narrow tubes with mucus membranes.
 Alveoli: alveoli are sacs found at the tip of ducts. They made
up of lung tissue and cover a huge surface area. They have a
very thin surface area so that the cells from the pulmonary artery
can make a gaseous exchange.
Gaseous exchange
The de-oxygenated blood is found in capillaries, close to the surface of
the alveoli.
The carbon dioxide found in the blood diffuses into the air in the
alveoli and expelled. Oxygen taken in from the air into the alveoli
diffuses into the capillary walls and combines with the haemoglobin in
the blood.
4
Cardiovascular system
Functions



Circulates blood throughout the body.
Transports energy substrates,
electrolytes and hormones to tissues.
Removes waste products,
thermoregulation, lactate, Carbon
dioxide and water.
Blood




White cells: Immune system, fight
germs, make antibodies, remove germs
and dead cells.
Red cells: Carry oxygen and give blood
its colour.
Platelets: Clotting agent.
Plasma: 90% water, straw colour, anti bodies, carbon dioxide,
enzymes, hormones, amino acids salt and fibre
(A) Anterior vena cave from head.
that helps the healing process,
(B) Aorta to body and head.
(C) Pulmonary artery to lungs.
(D) Pulmonary veins from lungs.
(E) Left atrium.
(F) Left ventricle.
(G) Right ventricle.
(H) Right atrium.
(J) Posterior vena cava from body
The Heart
How it works: Oxygenated blood from the lungs
goes to the Pulmonary vein into the left atrium
in diastolic phase (relaxed). Then it goes in to
the left ventricle until it is full, this causes
pressure which pushes the blood out through the
aorta into the body, this pressure is called
systolic phase.
The deoxygenated blood enters the right atrium through the vena cava in
diastolic phase; it goes into the right ventricle until it reaches
systolic phase then it goes through the pulmonary artery to the lungs.
This is called the cardiac cycle.
Facts




The heart weighs 4kg.
The average horse's heartbeat is 30-40 beats per minute.
Reasons for the heart rate to increase are spooking, feeding, excess
noise, posture, exercise, stress and illness.
For illness the heart rate goes up because the body needs more blood
to make antibodies.
Blood vessels, arteries, veins and capillaries
Arteries
 Carry blood from the heart to
the body (oxygenated)
 Not Pulmonary Artery
 Blood carried at high pressure
 Thick walls
 No valves
Veins
 Deoxygenated blood from body to
heart
 Not Pulmonary vein
 Blood carried at a low pressure
 Thin walls
 Valves to stop back flow
5
Capillaries
These are tiny tubes which connect the arteries to the veins, they allow
material to go between the tissues.
6
The Renal system
This system can be
divided into two
subdivisions they are:

Kidneys, the
manufacture of urine

Excretory passages,
all the structures
of collecting urine
and draining it out
of the body, the
Ureter, bladder and
Urethra.
The Kidney



Controls the flux of
ions out of the body
Conserves water
Excretion of nitrogenous wastes
There are two parts to a kidney, the Cortex with urine producing
nephrons and some tubules. The medulla is the deeper region, composed
entirely of tubules.
Renal blood supply

The kidney is the place where blood is filtered

Blood flow is the force behind urine formation.

Blood enters the kidney via the renal artery and is distributed
through smaller vessels.
Ureter


Thick muscle wall with two layers of muscle, one inner longitudinal
one and an outer circular one. These act as a valve and prevent back
flow.
Conveys urine from renal pelvis to bladder.
Urinary bladder

Temporary storage organ for urine.

It is made up of three layers of smooth muscle and elastic
connective tissue.

The lining is folded and puckered in a relaxed state (epithelium).

Stretches.
Urethra



Conveys urine from bladder to exterior.
In males it does two jobs, urinary tract and reproductive system.
Urine release into urethra controlled by external sphincter.
7
8
Strangles
Strangles is a common worldwide disease in horses and can be fatal. It
is a disease of the upper respiratory tract and the lymph nodes of the
head. It rapidly spreads from horse to horse through coughing, or by the
horse eating or drinking infective droplets.
Cause: It is caused by a bacterium called Streptococcus equi.
Signs: Within 3-8 days of becoming infected, the horse will show a
fever. The throat and larynx become inflamed and it becomes painful of
impossible to swallow. There will be a typical yellow discharge from one
or both nostrils and it may cough.
The lymph nodes of the head become swollen and painful and may
eventually burst with thick yellow pus.
Infection in a few cases, spreads to other organs in the body and is
called Bastard Strangles, it is usually fatal.
Control: the best way to control strangles is to isolate the infected
horses and disinfect all of the equipment that goes near it to avoid
spreading it.
Treatment: Penicillin is used to treat it. The abscesses may need to be
opened and drained.
9
Recovery: Most horses do recover but it can be three months before they
are fit enough to go back to work.
10
Conclusion
Many things happen in the horse's body every day that people don’t think
about, their body systems are like a humans. This makes them hard to
look after the way we use them because there are so many risks involved
in everything they are made to do.
Decision trees are an easy way to find out if your horse has the
symptoms of a common ailment, but there is also a bad side to it because
someone could try and treat their horse without ringing the vet, to save
money and the horse may be suffering from something worse.
Strangles is a very infectious disease and is air borne so it is easily
caught.
Horse owners have to careful about how they handle infections and make
sure that the horse is isolated.
11
References
Skeletal system
Text:
Merrist Wood lecture
Picture 1: Southwest Pony Club (1999) skeletal system [referenced in www
document]
http://www.websouthwest.co.uk/ponyclub/pages/respiratory_2.htm
(accessed 28.11.01)
Picture 2: C. Wayne McIlwraith, BVSc, PhD (?) Anatomy and Physiology of
Equine Joints [referenced in www document]
http://www.colostate.edu/depts/equine/graduate/orthopedics/ques
tions/anatomyjoint.html (accessed 29.11.01)
Respiration system
Text:
Merrist Wood lecture
Picture:
Southwest Pony Club (1999) respiratory system [referenced in
www document]
http://www.websouthwest.co.uk/ponyclub/pages/respiratory_2.htm
(accessed 28.11.01)
Cardiovascular system
Text:
Merrist Wood lecture
Picture:
Southwest Pony Club (!999) cardiovascular system [referenced
in www document]
http://www.websouthwest.co.uk/ponyclub/pages/respiratory_2.htm
(accessed 28.11.01)
Renal system
Text:
Dr. Thomas Caceci (?) urinary system [referenced in www
document]
http:education.vetmed.vt.edu/cirriculum/VM8054/Labs/Lab23/lab23
.htm (accessed 02.12.01)
Picture:
University of Bristol (05.09.00) Kidneys [referenced in www
document] www.bris.ac.uk/Depts/Anatomy/calnet/potdse/page2.htm
(accessed 02.12.01)
Diagnostic decision tree
Text:
Southwest Pony Club (1999) diseases [referenced in www
document]
http://www.websouthwest.co.uk/ponyclub/pages/respiratory_2.htm
(accessed 28.11.01)
Strangles
Text:
(?) (?) OHAHS Health FAQ [referenced in www document]
http://www.ohahs.org/strangles.html (accessed 28.11.01)
Picture:
Southwest Pony Club (1999) diseases [referenced in www
document]
http://www.websouthwest.co.uk/ponyclub/pages/respiratory_2.htm
(accessed 28.11.01)
12