Health in the Am Staff
Recommended Health TestingThe American Staffordshire Terrier Club of Canada recommends health testing for the following conditions that affect the American Staffordshire Terrier for your breeding programs:
NCL-A- (cerebellar ataxia) through Optigen
NCL tests registered with OFA.
The ASTCC advises that 2 NCL carriers should never be bred together and that affected dogs should never be bred.
Eye examination by a Board ACVO Ophthalmologist (optional)
Results registered with OFA.
The ASTCC advises that 2 NCL carriers should never be bred together and that affected dogs should never be bred.
Autoimmune Thyroiditis. OFA evaluation from an approved laboratory.
Congenital Cardiac. OFA evaluation with examination performed by a cardiologist
(Must be 1 year old to be in OFA database).
Usually done when evaluated for Hip Dysplasia at 2 years of age.
Must be 2 years old for final results for OFA and 16 weeks for PennHIP
Orthopedic Foundation for Animals: To improve the health and well being of companion animals through a reduction in the incidence of genetic disease.
If a breeder says their dogs are OFA Certified, you can look up their dogs in the Orthopedic Foundation for Animals database to see what health testing was done.
PennHIP: Pennsylvania Hip Improvement Program
PennHIP is a multifaceted radiographic screening method for hip evaluation.
The technique assess the quality of the canine hip and quantitatively measures canine hip joint laxity.
Heart DiseaseThe common heart diseases in Am Staffs are as follows:
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 Am Staffs. 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 ProblemsThe main eye problems seen in Am Staffs are:
- Hereditary Cataracts or Juvenile Cataracts
- Progressive Retinal Atrophy
- 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 AtaxiaOne 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; Am Staffs 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 Am Staff 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 an Am Staff pup, please ask the status of the parents' Ataxia test results.
Hip DysplasiaHip 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
> 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
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 for 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 DysplasiaElbow 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.