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HEALTH
The American Staffordshire Terrier is a relatively healthy
breed, though it is affected by some unpleasant disorders.
Congenitial Heart Disease
The common heart diseases in Amstaffs are as follows:
The Normal Heart
Patent ductus arteriosus (PDA) :
The problem is the failure of the ductus arteriosis to close
shortly after birth and thereby allows continued flow of blood
between the aorta and pulmonary artery.
This was originally thought to be the most frequently
encountered congenital cardiac defect in all dogs. It is now
believed by cardiologist that aortic stenosis is the most
common. Usually this condition presents itself at 6 to 12 weeks
of age and is more common in females. Signs of heart failure are
usually absent. Often a prominent pulse may be noted in many
unusual areas on the body (ie.gums). A continuous murmur is
present.
Prognosis:
Treatment for PDA is via surgical correction or coil occlusion.
In the hands of a skilled surgeon the survival rate is 90%.
Without surgery, it is estimated, though not substantiated, that
60% will die by 1 year.
Aortic Stenosis (AS)
AS is the most common congenital cardiac defect and most
difficult to diagnose in the dog. The stenotic lesion may occur
in the subvalvular position, valvular position or supravalvular
position. The subvalvular is the most common in dogs.
This has been documented in many breeds, including Bull
Terriers. It should be noted this is the most common condition
that causes the exploding hearts in Amstaffs. The genetic
factor(s) of AS are not known as of yet. It is believed to be
polygenetic, and therefore very difficult to eliminate from the
gene pool. Only through the testing of all breeding stock and
strict culling of positive animals and producers of positive
animals are there hopes to eventually eliminate this condition.
AS can be present at birth or develop up to one year of age. It
has not been documented to develop in dogs over 1 year. It can
be present as adults with an incidental murmur. Signs of heart
failure are rare. Dysrhythmias with pulse deficits may be noted.
Systolic heart murmur is located over left heart base and
radiates of the neck and to the right hemothorax. Definitive
diagnosis can be done via Doppler echocardiography or Cardiac
catheterization. EKG will show normal and diagnosis for AS is
inconclusive. A presumptive diagnosis can be done via
ausculation of a left systolic heart murmur with a weak femoral
arterial pulse.
Treatment includes beta blockers (though they are controversial)
or very limited surgical options. Though heart failure is rare,
it is more likely to occur in cases of moderate and severe AS if
concurrent mitral valve insufficiency is present and severe.
Prognosis
• Most cases of AS of marked severity result in sudden death.
• Mild cases of AS live a full life (both normal quality and
duration)
• Even cases of moderate stenosis can anticipate a life of
normal length and quality.
Work with Doppler echocardiography has revealed that if the
velocity of flow across the left ventricular outflow is less
than 4 m/s by the time the dog is mature, it appears that the
dogs can anticipate a life of normal length and quality. If the
velocity is greater than 5 m/s it will likely succumb to this
disorder.
Progression of AS is very slow in mature dogs.
It has been reported that if dogs survive with AS beyond 3
years, they usually do not have AS severe enough to produce a
marked effect on left valve performance.
Pulmonary Stenosis (PS)
PS is the third most prevalent cardiac disorder in the dog. A
stenotic lesion may occur in subvalvular, valvular or
supravalvular position. The valvular disorder is the most common
in dogs. Symptoms include fatigue and exercise intolerance. A
definitive diagnosis for PS is via the Doppler echocardiography
or Cardiac catherization test. EKG provides insight into the
disorder. A presumptive diagnosis can be made via ausculation of
a left basilar systolic heart murmur with a normal femoral
arterial pulse. Dilation of the main pulmonary artery on
thoracic radiographs may be seen.
The treatment of choice for severe PS is surgical correction.
However the efficacy of surgical intervention remains to be
substantiated. Medication to control dysrhythmias and fluid
around the heart may also be an option.
Prognosis:
Mild cases can be expected to live a full life with this
abnormality. Severe cases of PS may die suddenly or develop
signs of right heart failure and die in 6-12 months.
Ventricular Septal Defect (VSD)
This abnormality is a defect allowing blood flow between the
left and right ventricle. This defect usually presents itself in
puppies. A large defect will stunt growth and the pup will fail
to thrive. A definitive diagnostic test for VSD is via Doppler
or Cardiac catheterization. A presumptive diagnosis can be made
by ausculation of a right sternal border systolic heart murmur
or radiographic evidence of pulmonary overcirculation. Symptoms
include reduced exercise tolerance, fatigue, possible heart
murmur and jugular distention. Treatment for mild VSD requires
no therapy, whereas severe VSD requires surgical repair.
Prognosis for severe VSD if pulmonary hypertension develops is
very poor.
Mitral Valve Dysplasia
The most common disorder of the mitral valve is the partial
backflow (regurgitation) of blood through the valve.
Regurgitation is usually the result of valvular degeneration,
which occurs most often in older members of the smaller dog
breeds. Severe mitral regurgitation, not only produces
significant increases in the left side of the heart, it is
frequently accompanied by varying degrees of congestive heart
failure.
Tricuspid Valve Dysplasia (TVD)
This valve is located between the right atrium and the right
ventricle of the heart. The purpose of this valve is to control
the backflow of blood during contractions of the heart. During
normal fetal development, the tricuspid valve flaps are adhered
to the wall separating atrium from ventricle. As the fetal
development progresses under normal circumstances the adhesive
bonds holding the valve open will degenerate, allowing the valve
flaps to move into their proper position. One of the primary
causes of TVD is the failure of the bond to degenerate.
Depending on the severity of the malformation, the work on the
right side of the heart increases. Symptoms of TVD are dependent
upon the extent of the malformation, but some of the most common
symptoms re: fluid retention, cool extremities and exercise
intolerance (possibly followed by collapse). TVD in dogs is
usually congenital (present at birth). Due to the fact that this
condition (when it occurs) appears in several littermates, and
tends to be more prevalent in some family bloodlines than
others, it is suspected that the tendency to have this birth
defect is hereditary. It is hoped that through screening of
breeding stock and their lineage (parents, grandparents,
littermates, aunts, uncles, etc) efforts can be made to
eliminate susceptible bloodlines from breeding programs.
Eye Problems
The main eye problems seen in Amstaffs are:
• Hereditary Cataracts or Juvenile Cataracts
• Progressive Retinal Atrophy
• Distichiasis
• Hereditary Cataracts or Juvenile Cataracts
Called "juvenile cataracts" to differentiate them from the "old
age" type cataract or from the degenerative type that results
from injury, inoculation reactions or systemic disease. The eye
with the cataract(s) has a cloudiness of the lens of the eye in
a relatively young dog. The purpose of the lens is to focus the
rays of light so that may form an image on the retina. If the
lens becomes cloudy then less light can enter the eye and the
sight will slowly diminish as the cataract becomes larger. This
type of cataract will show up at an early age and in most cases
is inherited. One or both eyes may be affected and the cataracts
may not appear in both eyes at the same time. At this time there
is no proof that eye color has any bearing on the likelihood of
developing juvenile cataracts. Many dogs with juvenile cataracts
can lead normal lives well into their older senior years before
the cataracts impair their vision dramatically. Unfortunately,
in some instances the cataracts are severe enough to cause
blindness at a young age.
Progressive Retinal Atrophy
Progressive retinal atrophy, or PRA as it is frequently termed,
is a long recognized, hereditary, blinding disorder. It is
inherited as a simple autosomal recessive in most breeds.
PRA is a disease of the retina. This tissue, located inside the
back of the eye, contains specialized cells called
photoreceptors that absorb the light focused on them by the
eye’s lens, and converts that light, through a series of
chemical reactions into electrical nerve signals. The nerve
signals from the retina are passed by the optic nerve to the
brain where they are perceived as vision. The retinal
photoreceptors are specialized into rods, for vision in dim
light (night vision), and cones for vision in bright light (day
and color vision). PRA usually affects the rods initially, and
then cones in later stages of the disease. In human families,
the diseases equivalent to PRA (in dogs) are termed retinitis
pigmentosa.
In all canine breeds PRA has certain common features. Early in
the disease, affected dogs are nightblind, lacking the ability
to adjust their vision to dim light; later their daytime vision
also fails. As their vision deteriorates, affected dogs will
adapt to their handicap as long as their environment remains
constant, and they are not faced with situations requiring
excellent vision. At the same time the pupils of their eyes
become increasingly dilated, in a vain attempt to gather more
light, causing a noticeable "shine" to their eyes; and the lens
of their eyes may become cloudy, or opaque, resulting in a
cataract.
Diagnosis of PRA is normally made by ophthalmoscopic
examination. This is undertaken using an instrument called an
indirect ophthalmoscope, and requires dilatation of the dog’s
pupil by application of eyedrops. Broadly speaking, all forms of
PRA have the same sequence of ophthalmoscopic changes: increased
reflectivity (shininess) of the fundus (the inside of the back
of the eye, overlain by the retina); reduction in the diameter
and branching pattern of the retina’s blood vessels; and
shrinking of the optic nerve head (the nerve connecting the
retina to the brain). These changes occur in all forms of PRA,
but at different times in the different breed-specific forms.
Usually by the time the affected dog has these changes there is
already significant evidence of loss of vision.
Distichiasis
Eyelids of dogs can grow abnormal hairs. These hairs grow from
the oil glands (Meibomian glands) of the lids and are called
distichia if the hair protrudes from the oil gland opening onto
the edge of the eyelid. Distichia are often irritating,
especially if the hairs are long and stiff. Ectopic cilia are
also hairs growing from oil glands on the eyelid, but the hair
protrudes from the inner surface of the eyelid and is very
painful, often causing corneal ulcers.
Dogs with distichiasis may or may not show signs of discomfort,
ranging from slight intermittent squinting and/or rubbing of the
eyes, to severe squinting and discomfort. Dogs with ectopic
cilia are always uncomfortable. Most dogs with ectopic cilia are
young adult dogs or older puppies. Both conditions are common in
Shih Tzus. Many other breeds have problems with distichia. At
Animal Eye Care, both conditions are treated surgically under
general anesthesia, with a procedure called cryoepilation. With
this procedure, the abnormal hair follicles are frozen using a
liquid nitrogen probe, and the hairs then removed.
After surgery, the eyelids are swollen for 4-5 days, and the
eyelid margins will depigment and turn pink. Usually, the lid
margins will repigment within 4 months. It is important to
understand that new abnormal hairs can grow from new sites after
surgery, but this is uncommon in dogs older than 3 years old
(unless the dog is a Shih Tzu). With cryoepilation, 85-90% of
the treated hair follicles will not regrow. Repeat surgical
treatment is rarely required, unless the animal is a puppy (and
grows new hairs in new sites) or a Shih Tzu.
Cerebellar Ataxia
One of the most serious disorders from which this breed suffers
is called Hereditary Ataxia or Cerebellar Ataxia. This is a
neurological disorder of a serious nature and as of yet there is
no cure; it seems as if the gene governing the disorder is quite
widespread in the breed and often avoiding the breeding of
affected dogs is difficult due to the late onset of symptoms.
Research to find out the exact mode of inheritance and to find
some kind of treatment is ongoing and owners of dogs with the
disease are encouraged to allow their dogs to participate in
trials and studies.
This condition involves the cerebellum, a very important part of
the brain; it’s located at the base of the brain, just above the
brainstem and spinal cord. The most important function of the
cerebellum is the coordination of movement. It takes information
regarding the position of the body and its muscles and
integrates it with pathways coming from higher structures of the
brain that involve movement commands. Based on the body’s
position, the cerebellum is able to control movements with a
high level of precision; the cerebellum is constantly working to
maintain posture and muscle tone. If this area is damaged, the
individual will have great difficulty moving and often swaggers
and sways; there may even be cognitive damage as well.
Hereditary ataxia is a condition in which there
is widespread degeneration of the cerebellum. While the signs
resulting from hereditary ataxia could be indicative of a wide
variety of diseases or problems that affect the cerebellum, this
particular disease is characterized by a certain order and rate
of appearance of signs. First, you’ll see your dog behave
somewhat clumsily and he could begin to sway occasionally.
Clumsiness worsens over time with the progression of the disease
and soon the dog will constantly fall over, losing his balance.
You may also notice rapid eye and head movements and walking
will become much more difficult; weight loss is often seen in
dogs suffering from hereditary ataxia. These symptoms usually do
not occur in dogs younger than two years of age.
Exactly how the disease develops is still poorly understood and
it actually seems to be different in different dogs. Signs are
slow to develop in some dogs, while they develop rapidly in
other dogs. As of now, this is a fatal disease as there is no
cure and a normal life is impossible; Amstaffs with hereditary
ataxia are more often than not humanely euthanized by the time
they are 7 or 8 years old. There are no diagnostic tests at the
moment to specifically detect hereditary ataxia; confirmation of
the presence of the disease comes only through an autopsy, after
death. If you see your Amstaff exhibiting strange signs, you
must immediately take the dog to a veterinary neurologist who
will perform a wide variety of tests to rule out any other
possible condition that could lead to the same signs.
Cerebellar Ataxia is inherited as a autosomal
recessive trait, which means a dog must have two defective
copies (one from each parent) to be affected. A dog once tested
will be classified as one of the following three
classifications:
Clear - 2 normal copies of the implicated gene - the dog does
not have ataxia, is not a carrier for ataxia and cannot produce
carrier or affected offspring.
Carrier - 1 normal copy and one defective copy of the implicated
gene - the dog is not affected by ataxia but is a carrier of the
gene. He can pass the gene onto his offspring.
Affected - 2 defective copies of the implicated gene - the dog
has ataxia, and will pass the gene onto offspring.
The approximate breakdown rate of breeding a clear, carrier and
affected dog is as follows:
• Clear to Clear - 100% Clear
• Clear to Carrier - 50% Clear, 50% Carrier
• Clear to Affected - 100% Carriers
• Carrier to Carrier - 25% Affected, 25% Clear, 50% Carriers
• Carrier to Affected - 50% Affected, 50% Carriers
• Affected to Affected - 100% Affected
It should be noted if 2 Clear dogs are bred together, the
resulting pups are clear by parentage and do not require
testing. If you are purchasing a Amstaff pup, please ask the
status of the parents Ataxia test results.
Hip Dysplasia
Hip dysplasia is caused by a subluxation in the hip joint. This
creates abnormal wear and erosion of the joint and as a result
arthritis and pain develop. The disease process is fairly
straightforward; the controversy starts when we try to determine
what predisposes animals to contracting the disease
What is happening?
• Loosely fitting hip joints cause stretching of the joint
capsule and abnormal cartilage wear
• Inflammation and pain result from the altered joint mechanics
and cartilage destruction
• Arthritis and reformation of the hip bones progress over time
• Clinical signs you might notice in your pet
• Stiffness of the hind legs upon rising, particularly after
long periods of rest
• Reluctance to climb stairs or jump
• Tiring easily with play
• Resting more than other dogs of similar age and breed
• "Clunking" noise when walking
• "Bunny hopping" to gain speed when trotting or running
Diagnosis
• Careful orthopedic examination to determine which joint(s) are
affected
• Sedated examination to determine the degree of hip looseness
and severity of cartilage damage (degenerative joint
disease/arthritis)
• Precisely positioned x-rays are taken to document the degree
of hip looseness and severity of bone reformation related to
cartilage wear
Surgical treatment
• Depending on patient age and diagnostic findings, recommended
surgical options may include:
• Rearrangement of the angle at which the components of the hip
meet (triple pelvic osteotomy/TPO)-most commonly used for young
dogs without significant cartilage wear (arthritis) or bony
reformation
• Replacement of the components of the hip (total hip
replacement)-most commonly used for older dogs or those with
significant arthritis or bony reformation
• Alteration of the hip joint to prevent painful bone contact
(femoral head and neck ostectomy/FHO)-most commonly used for
smaller dogs
Special postoperative care
• If a triple pelvic osteotomy or total hip replacement was
performed:
• Patient activity is strictly limited until adequate healing
occurs, usually 6-12 weeks
• X-rays will be taken at specific intervals to evaluate healing
at the surgery site
• If femoral head and neck ostectomy was performed, physical
therapy will be initiated within several days of surgery, and is
usually continued 4-8 weeks
Expected results after surgery
• If a triple pelvic osteotomy was performed, pain is generally
relieved, limb use becomes more normal, and the patient does not
develop significant hip arthritis
• If a total hip replacement was performed, pain is relieved,
limb use becomes more normal, and arthritis is permanently
relieved
• If a femoral head and neck ostectomy was performed, a mild
limp will likely remain, but pain and arthritis are relieved
Elbow Dysplasia
Elbow dysplasia is a general term used to identify an inherited
polygenic disease in the elbow of dogs. Three specific
etiologies make up this disease and they can occur independently
or in conjunction with one another. These etiologies include:
• Pathology involving the medial coronoid of the ulna (FCP)
• Osteochondritis of the medial humeral condyle in the elbow
joint (OCD)
• Ununited anconeal process (UAP)
Studies have shown the inherited polygenic traits causing these
etiologies are independent of one another. Clinical signs
involve lameness which may remain subtle for long periods of
time. No one can predict at what age lameness will occur in a
dog due to a large number of genetic and environmental factors
such as degree of severity of changes, rate of weight gain,
amount of exercise, etc. Subtle changes in gait may be
characterized by excessive inward deviation of the paw which
raises the outside of the paw so that it receives less weight
and distributes more mechanical weight on the outside (lateral)
aspect of the elbow joint away from the lesions located on the
inside of the joint. Range of motion in the elbow is also
decreased.
Luxating Patella
The patella, or kneecap, is part of the stifle joint (knee). In
patellar luxation, the kneecap luxates, or pops out of place,
either in a medial or lateral position.
Bilateral involvement is most common, but unilateral is not
uncommon. Animals can be affected by the time they are 8 weeks
of age. The most notable finding is a knock-knee (genu valgum)
stance. The patella is usually reducible, and laxity of the
medial collateral ligament may be evident. The medial
retinacular tissues of the stifle joint are often thickened, and
the foot can be seen to twist laterally as weight is placed on
the limb.
Thyroid Dysfunction
Hypothyroidism is a common problem in dogs, but rarely occurs in
cats. The thyroid gland has a number of different functions, but
it is most well known for its role in regulating metabolism.
Hypothyroidism is the condition that occurs when not enough
thyroid hormone is produced. Hypothyroidism causes a wide
variety of symptoms, but is often suspected in dogs that have
trouble with weight gain or obesity and suffer from hair loss
and skin problems. Hypothyroidism is easy to diagnose with a
blood test that checks the level of various thyroid hormones
including T3 and T4. Most hypothyroid dogs respond readily to
treatment with synthetic thyroid medication such as Soloxine.
Many dogs suffer from a low thyroid hormone level for years
without treatment.
Other Disorders
The breed may be vulnerable to skin allergies, urinary tract
infections (UTI), and autoimmune diseases. Spondylosis and
osteoarthritis are common in older dogs.
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