Below is the list of health
conditions that affect the Boxer and what health
screening method is used
to check for that particular health condition.
1. Arrythmogenic
Right Ventricular Cardiomyopathy (ARVC):
Test
Used |
Minimum
Age |
Frequency |
Reported
As |
Holter
Monitor |
12
months |
Annually
for Breeding |
date
tested |
Arrythmogenic Right Ventricular Cardiomyopathy (ARVC) was formerly
known as Boxer Cardiomyopathy. ARVC is a genetic disease that runs
in families and causes substantial illness and/or death in Boxers.
It has been reported in humans and recently in cats too. The genetic
defect is transmitted as an autosomal dominate trait. For this reason
it is strongly recommended that dogs with this congenital defect
not be bred. ARVC is a disease of the heart that causes arrhythmias
(abnormal heart beats) beginning in the right ventricle of the heart.
The arrhythmia present is a ventricular tachycardia with premature
ventricular complexes. This means the ventricles are contracting
too rapidly and out of sync with the rest of the heart. This causes
a decrease in blood flow to the body and can lead to episodes of
collapse, unconsciousness, and even death. In some cases the incidence
of the premature heart beats was over 28,000 in a 24 hour period.
ARVC is checked for using a holter monitor
that is left on the dog for 24 hours and testing for this condition
should be done yearly. The most common type of holter used is an
analog cassette holter recorder (monitor) which uses a cassette
tape to record data from the monitor's electrodes that are attached
to the dog. Once the monitoring is complete, the cassette tape is
then sent off by mail to be read at a holter monitoring specialist
company that is equipped to read the tape. The other type of holter
used is a digital holter where a CF card is used to record data
from the monitor's electrodes that are attached to the dog. With
digital you send the data electronically by email to be read at
a holter monitoring specialist company that is equipped to read
digital data. It is recommended that breeders do not make a breeding
decision base on one holter result. In other words, more than one
holter should be done before making a breeding decision.
The following are two excellent places to
have your cassette and/or digital data read:
A. Alba
Medical - this company can read both types of holter
recorders (monitors). You can read about the two types of service
plans and their cost here.
B. VCGL
Canine Holter Monitoring Service - This is a service
offered by board-certified cardiologist, Dr. Kathryn Meurs, at Washington
State University. Dr. Meurs is the leading researcher on ARVC. You
can read about her service plans and their cost here.
More links on Arrythmogenic Right Ventricular
Cardiomyopathy (ARVC):
Arrythmogenic
Right Ventricular Cardiomyopathy
Dr.
Kate Meurs 2005 Report
Familial
Ventrical Arrythmias In The Boxer
Exciting New Discovery In The Fight
Against Arrythmogenic Right Ventricular Cardiomyopathy (ARVC):
Vet
Cardiologist Discovers Gene For Heart Disease
Boxer
ARVC DNA Test
2. Aortic/Sub-Aortic
Stenosis (AS/SAS):
Test
Used |
Minimum
Age |
Frequency |
Reported
As |
Auscultation
& Doppler Echocardiogram |
24
months |
Once |
date
tested |
In aortic stenosis, there is a partial obstruction to the flow of
blood as it leaves the left side of the heart (the left ventricle)
through the main blood vessel (the aorta) that carries blood to
the rest of the body. The obstruction ranges from small nodules
to a fibrous band, most commonly just below the aortic valve ("subvalvular
aortic stenosis"). Due to the obstruction, the heart must work
harder to pump out an adequate blood volume. Clinical signs and
long-term outcome depend on the degree of narrowing, or stenosis.
AS/SAS is checked for by echocardiogram with
color flow doppler and it should be performed by a board-certified
cardiologist. For screening prior to breeding, it is recommended
that Boxers should be at least 24 months or 2 years of age at the
time of testing. The reason for this is that current information
now reveals that Aortic/Subaortic Stenosis (AS/SAS) may develop
upon sexual maturity in dogs that were previously tested clear.
The cardiologist will "listen" to the dog's heart (auscultation)
using a stethoscope which checks for any murmur present prior to
the ultrasound. A Boxer that has no murmur is usually considered
to not have AS/SAS, however, echocardiography is the only way to
obtain flow rates and it also allows the cardiologist to check for
other abnormalities with the heart that cannot be found by auscultation
alone.
More links on Aortic/Subaortic Stenosis:
Aortic/Subaortic
Stenosis
Louisiana
State University - Aortic Stenosis
Mar
Vista Medical - Subaortic Stenosis (SAS)
Merck
Vet Manual - Aortic Stenosis
SAS
- What it is & why breeders should be concerned
3. Canine
Thyroid Disease:
Test
Used |
Minimum
Age |
Frequency |
Reported
As |
Thyroid
Panel |
24
months |
Annually
for Breeding |
date
tested |
The most common cause of canine thyroid disease is autoimmune thyroiditis
(estimated 90% of cases). Thyroiditis is an immune-mediated process
that develops in genetically susceptible individuals and is characterized
by the presence of antithyroid antibodies in the blood or tissues.
Thyroiditis is believed to start in most cases around puberty, and
gradually progress through mid-life and old age to become clinically
expressed hypothyroidism once thyroid glandular reserve has been
depleted. During this process the animal becomes more susceptible
to immune-mediated or other diseases affecting various target tissues
and organs. The prerequisite genetic basis for susceptibility to
this disorder has been in established in humans, dogs and several
other species.
Canine thyroid disease is checked for by
a blood sample taken at one's veterinary clinic by an Animal Health
Technician (AHT) or by your veterinarian. The blood sample is then
sent off to an accredited laboratory to test for thyroid disease.
It is important to know that a full panel must be done to get accurate
thyroid results. An "in-house" check of the dog's T4 and
TSH does not properly tell you if the dog has canine thyroid disease
or not. The Orthopedic
Foundation For Animals (OFA) requires the blood sample
to be sent to an OFA
approved laboratory as listed on their website if you
want to register your dog's result in their registry. If you do
not wish to register your dog's thyroid results in the OFA database,
the OFA approved laboratories would be highly recommended to have
your vet send your dog's blood sample to for a full panel to be
run. A full panel thyroid test checks for Total T4, Canine Thyroid
Stimulating Hormone (cTSH), Free T3, Free T4, T3 Autoantibodies
(T3AA), T4 Autoantibodies (T4AA), and Thyroglobulin Autoantibodies
(TgAA).
Thyroid testing for genetic screening purposes
should be intitiated once healthy dogs and bitches have reached
sexual maturity. For males this can occur between 10 and 14 months
of age. For females it should be done during the first anestrous
period (the time between each heat cycle) following their first
heat cycle. Once the initial thyroid profile has been done, dogs
and bitches should be rechecked annually.
More links on Canine Thyroid Disease:
Hypothyroidism
OFA
- Hypothyroidism
Mar
Vista Medical - Hypothyroidism
Thyroid
Articles by Dr. Jean Dodds
Thyroid
& Seizures
4. Canine
Hip Dysplasia:
Test
Used |
Minimum
Age |
Frequency |
Reported
As |
Radiograph |
6
months |
Once |
PennHip% |
Radiograph |
24
months |
Once |
OFA# |
Dysplasia comes from the Greek words dys, meaning "disordered"
or "abnormal", and plassein meaning "to form".
The expression hip dysplasia can be interpreted as the abnormal
or faulty development of the hip. Abnormal development of the hip
causes excessive wear of the joint cartilage during weight bearing,
eventually leading to the development of arthritis, often called
osteoarthritis (OA) or degenerative joint disease (DJD). The terms
osteoarthritis and degenerative joint disease are used interchangeably.
Canine hip dysplasia and elbow dysplasia
is checked for by positioning the dog's hips and elbows in a certain
way and then a radiograph (x-ray) is taken while the dog is held
in that position. There are two types of methods to check for Canine
Hip Dysplasia. One is using the method recommended by the Orthopedic
Foundation For Animals (OFA) which can be done with or
without sedation at one's veterinary clinic and the other is performed
by a certified veterinarian using the PennHIP
method that requires the dog to be under sedation. Each method has
it's own grading system.
More links on Canine Hip Dysplasia:
Canine
Hip Dysplasia (CHD) & Degenerative Joint Disease (DJD)
Hip
Dysplasia In Dogs
Hip Dysplasia In Dogs: Diagnosis, Treatment & Prevention
Mar
Vista Medical - Hip Dysplasia
Merck
Vet Manual - Hip Dysplasia
5. Degenerative
Myelopathy (DM):
Test
Used |
Minimum
Age |
Frequency |
Reported
As |
DNA
Sample |
None |
Once |
OFA# |
Degenerative Myelopathy is a progressive disease of the spinal cord
in older dogs. The disease has a gradual onset typically between
8 and 14 years of age. It begins with a loss of coordination (ataxia)
in the hind limbs. The affected dog will wobble when walking, knuckle
over or drag the feet. This can first occur in one hind limb and
then affect the other. As the disease progresses, the limbs become
weak and the dog begins to buckle and has difficulty standing. The
weakness gets progressively worse until the dog is unable to walk.
The clinical course can range from 6 months to 1 year before dogs
become paraplegic. If signs progress for a longer period of time,
loss of urinary and fecal continence may occur and eventually weakness
will develop in the front limbs. Another key feature of DM is that
it is not a painful disease.
Degenerative Myelopathy has typically been
diagnosed through a process of elimination. Other causes of the
weakness have been looked for using diagnostic test such as myelography
and MRI. Once other causes have been ruled out, a presumptive diagnosis
of DM is usually made. The only way to confirm the diagnosis of
DM is by examination of the spinal cord under microscope when a
necropsy (autopsy) has been performed as there are degenerative
changes in the spinal cord characteristics for DM that are not typical
for some other spinal cord disease. Keep in mind that other types
of diseases that affect the spinal cord can have similar signs of
loss of coordination and weakness as DM so it is important to check
for other spinal diseases as they may be more effectively treated.
There are no treatments that have been clearly shown to stop or
slow progression of DM.
In July 2008, researchers at the Broad Institute
and the University Of Missouri announced that they had identified
a gene that is a major risk factor for the development of Degenerative
Myelopathy (DM) in dogs. As a result of this research breeders,
pet owners and veterinarians now have a DNA
test available to purchase through the Orthopedic
Foundation For Animals (OFA) website. There are two possible
forms of the gene, the normal form ("N") and the abnormal
form ("n" or "A" as used by the researchers).
Every Boxer has two copies of the gene, one copy comes from each
parent which results in one of the three combinations; two copies
of the normal gene (homozygous normal) which is also referred to
as "Clear" or "NN", two copies of the mutated
gene (homozygous mutated) which is also referred to as "At
Risk" or "nn" or one copy of each gene (heterozygous)
which is also referred to as "Carrier" or "Nn".
It is important to note that having two copies of the mutated gene
does not necessarily result in disease and the researchers recommend
that dog breeders take into consideration the DM test results as
they plan their breeding programs, however, they should not over-emphasize
this test result. Instead, the test result is one factor among many
in a balanced breeding program.
More links on Degenerative Myleopathy (DM):
Degenerative
Myelopathy (DM)
Degenerative
Myelopathy DNA Test: Breeding Expections For Various Combinations
Degenerative
Myelopathy DNA Test
Degenerative
Myleopathy (DM) Test Results Statistics
6. Eye
Disease:
Test
Used |
Minimum
Age |
Frequency |
Reported
As |
Eye
Exam |
None |
Every
12 Months |
CERF# |
While some may believe that eye disorders in the Boxer aren't common,
it should be noted that some of the eye disorders listed below can
be found in the Boxer and some of these eye disorders are considered
to be inherited. It should also be noted that while the Boxer may
not be listed as a breed predisposed to some of the eye diseases
listed, it does not mean the breed should not have regular eye exams.
The easiest way to get your Boxer's eyes examined by a board-certified
ophthalmologist is at Canine
Eye Registration Foundation (CERF) eye clinics which
are frequently hosted by All Breed Kennel Clubs or Breed Clubs throughout
the year. These clinics are usually held at the same venue as the
host club's dog show but not always. Some clinics are not held on
the same weekend as a dog show and some specialist veterinary clinics
also have a board-certified ophthalmologist on staff for eye exams
throughout the year.
A. Cataracts
- A cataract is any opacity or loss of transparency of the lens
of the eye. The opacity may be confined to a small area of the lens
or capsule, or it may affect the whole structure. A complete cataract
affecting both eyes will result in blindness, whereas small non-progressive
cataracts will not interfere with vision. Primary cataracts occur
in some breeds; in other breeds the cataract may develop secondarily
to another inherited disorder such as progressive retinal atrophy
or glaucoma
B. Cherry
Eye - The third eyelid is a triangular shaped structure
in the inner corners of your dog's eyes that you may notice sometimes
partly covers the eye. It consists of a t-shaped cartilage to provide
support, and a tear gland. The third eyelid is important in protection
of the surface of the eye, and in tear production. It is also called
the nictitating membrane (or membrana nictitans) and haw. In Boxers,
a prolapse of the gland or "cherry eye" occurs when the
base of the gland (embedded in the cartilage) flips up and is seen
above and behind the border of the third eyelid. The prolapsed gland
becomes swollen and inflamed. The condition frequently occurs in
both eyes and is most common in young dogs.
C. Corneal
Dystrophy (Epithelial Erosion) - Corneal dystrophy is
an inherited abnormality that affects one or more layers of the
cornea. Both eyes are usually affected, although not necessarily
symmetrically. Chronic or recurring shallow ulcers may result, depending
on the corneal layers affected. The type of Corneal Dystrophy that
affects Boxers 7 to 8 years and older is called Epithelial Dystrophy
which causes shallow painful erosions/ulcerations in the cornea.
D. Distichiasis
- Distichiasis is when extra eyelashes grow from abnormal follicles
located on the inside edge of the eyelid. They may be singular or
multiple.
E. Ectropion
- Ectropion is a defect of conformation in which there is a sagging
or rolling-out (eversion) of the eyelids. This results in abnormal
exposure of the eye, which often leads to irritation. Ectropion
is most commonly seen in dogs with exaggerated facial features where
it is often a breed characteristic.
F. Entropion
- Entropion is the inward rolling of the eyelid, most commonly the
lower lid. This irritates the surface of the eye (the cornea) and
may ultimately cause visual impairment.
G. Glaucoma
- Glaucoma is a leading cause of blindness in dogs. It is the result
of increased fluid pressure within the eye (elevated intraocular
pressure or IOP). If the pressure can not be reduced, there will
be permanent damage to the retina and optic nerve resulting in visual
impairment. Complete blindness can occur within 24 hours if the
IOP is extremely elevated or can occur slowly over weeks or months
if the the elevation is mild. Glaucoma is usually very painful.
Glaucoma may be primary (inherited) or secondary to a number of
eye disorders including luxation of the lens, tumours of the eye,
and uveitis (inflammation of the eye).
H. Progressive
Retinal Atrophy (PRA) - The cells of the retina receive
light stimuli from the external environment and transmit the information
to the brain where it is interpreted to become vision. In progressive
retinal atrophy (PRA), deterioration of the retinal cells causes
blindness. The term progressive retinal atrophy covers several types
of inherited degeneration (deterioration) of the retina. Sub-classifications
of PRA are based on the age at which dogs show signs of the disease
and the type of retinal cell which is affected.
More links on Eye Disease:
Cataracts:
A Common Ocular Disease In Dogs
Inherited
Disorders Of The Eye
Mar Vista Medical - Corneal Ulcers & Erosions
Merck
Veterinary Manual - Ophthalmology |