C.h.d disease, referred to as CHD for short, is a common disease with abnormal hip development or growth in middle and large dogs. The exact etiology and pathogenesis of CHD are determined by many factors. At present, it is generally believed that polygenic inheritance, environment and nutritional status are the main reasons that affect the formation and occurrence of the disease.
Self-network of bone contour materials of German shepherd dog
This is a detailed picture of the dog's side skeleton. The area circled by orange circle is the joint of pelvis and hind legs, and it is also the "hip joint" of congenital heart disease.
To understand CHD and read and understand this article smoothly, we need to understand several noun concepts through the following figure.
Hip augmentation material self-network
As you can see, the dog's hip joint consists of two parts: acetabulum and femoral head. The femoral head at the top of the femur is embedded in the acetabulum on the hip bone, and there is a strong ligament (not shown) and cartilage layer between the two parts. The close combination of these structures ensures that the joint can bear a lot of weight and move flexibly at the same time.
When these structures go wrong, it will lead to poor joints between the femoral head and acetabulum, and the root cause lies in the ligament and cartilage between them. When there is a problem between ligament and cartilage, the tight chimerism of hip joint no longer exists.
Next, we will learn more about coronary heart disease from the following contents.
Self-network of cartilage and ligament materials
Ligament tissue
Location: Center and periphery of femoral head.
Function: Pull the femoral head into the acetabulum with strong pulling force.
Problem: The ligaments of dogs with congenital heart disease will relax, which will make the femoral head and acetabulum loose and slip.
Cartilage tissue
Location: outer layer of femoral head and acetabulum.
Function: Ensure smooth sliding between joints.
Problem: This layer of cartilage in dogs with coronary heart disease has been destroyed and eroded, and the joint operation has changed from "cartilage to cartilage" to "bone to bone friction".
To sum up, due to the abnormal ligaments and cartilage between joints, the normal structure has been eroded and subluxation has occurred, resulting in unnatural friction and collision between femoral head and acetabulum.
What does coronary heart disease bring to the body?
Normal &; Abnormal contrast agent self-network
Femoral head changes
Due to unnatural friction caused by abnormal structure, the originally smooth and round femoral head is ground or proliferated all over the body.
Acetabular changes
The acetabulum that just can accommodate the femoral head will also become thicker and shallower.
Inflammation and pain
All * * * work together to form synovitis, joint capsule gradually becomes thinner, perichondrium overgrows to form spur, and the whole hip joint becomes weird and twisted. With the development of time, inflammation and pain will have more and more influence on dogs.
The process of CHD leading to the above structural changes takes time, or months or years, and the situation of each sick dog is affected by practical comprehensive factors.
Which dogs often suffer from coronary heart disease?
Dogs of any breed and constitution may suffer from coronary heart disease, but most of them are big and fast-growing puppies, and adult dogs with normal weight below 1 1- 12KG rarely suffer from coronary heart disease. Varieties with a normal weight of more than 27 kg will have a higher possibility and severity of coronary heart disease.
Official data: According to the statistics of OFA (Animal Orthopedic Foundation) in the United States, the following dogs are most likely to suffer from coronary heart disease according to the incidence from high to low.
In China, due to people's differences in foreign dog breeds, the common dog breeds will be different. According to the statistics of clinical cases in China, retriever, Labrador, Alaska, German Shepherd, Samoyed and Rottweiler are the most common coronary heart diseases.
Self-network of dogs with high incidence of coronary heart disease in China
In addition to large dogs, bulldogs, pugs and so on. It is also a variety that is often affected by coronary heart disease. Because of the particularity of bone structure, they are very susceptible to coronary heart disease. However, the development speed of coronary heart disease in these breeds of dogs is usually not fast, and even if it happens, it often takes several years to appear obvious abnormalities.
Manifestations of coronary heart disease
The clinical symptoms of C.h.d vary widely, ranging from a few months to several years old, and the degree of symptoms ranges from very mild discomfort to severe claudication.
Hip dysplasia in early puppies, no serious degenerative joint disease and wear, not very painful. Once degenerative arthritis occurs, painful symptoms will begin to appear; Adult c.h.d is serious, and there are also symptoms of body center of gravity shifting to forelimbs. The common clinical manifestations of coronary heart disease are as follows:
behavioral abnormality
1 The hind legs are X-shaped when standing, with thin thighs and lack of muscles.
Poor jumping ability, hind legs jump like rabbits.
3 strange walking posture, three-legged jumping posture running.
If you hesitate to refuse to climb the stairs, you will deliberately avoid using your hind legs.
Touch a part and express pain by barking and whimpering.
Abnormal activity
1 When I was young, I didn't want to move, and my activity decreased.
When you recover from your rest, you seem to hesitate to get up slowly.
Intermittent or persistent claudication often occurs to varying degrees.
4 lick your hair to distract your energy. In severe cases, lick some places for baldness.
Because of lying down for a long time, bedsores and calluses appear on elbows and buttocks.
Coronary heart disease examination
In pet hospitals, doctors often use three test methods to diagnose CHD of hip joint diseases, namely Ortolani, PennHip and OFA.
Otullani Outla test
This method is often carried out when the dog 10- 12 weeks old. This is a relatively simple palpation, which can be performed without special equipment, but its accuracy has no clear value for diagnosis and prognosis.
Detection method: generally let the dog lie on its side, stretch its hind legs backwards and try to turn the thigh root to see if the dog is in pain. In addition, the doctor may ask you to take the dog for a few steps. If the dog has coronary heart disease, there may be audible and visible changes in the hip joint.
Ortolani test graph self-network
PennHip
This is a method of early diagnosis by X-ray. By calculating segregation index (DI), the degree of hip joint relaxation in puppies can be judged, and 4-month-old dogs can be screened for congenital heart disease. This detection method was invented by Pennsylvania of Pennsylvania Animal College.
Detection method: A qualified veterinarian needs to take three accurate X-rays, namely, joint relaxation, stretching and squeezing. The smaller the difference between the three, the higher the joint stability-the lower the chance of suffering from coronary heart disease.
PennHip test chart from the network
carcinoembryonic antigen
This method is a subjective hip joint scoring method, which is carried out when the dog is 24 months old with high accuracy. OFA technology has a high authority in the diagnosis of coronary heart disease, but in clinic, the diagnosis of 2-year-old adult dogs is very late, and the morphological structure of hip joint has been formed.
Detection method: Two standard X-ray films (ventral dorsal position and ventral dorsal frog position) were taken, and the dogs were graded by three OFA experts according to the position relationship between hip joint and femoral head and the degree of joint inflammation. The results were divided into seven grades, namely, normal (excellent, good, qualified), possible or stunted (slight, moderate, severe and extremely severe).
OFA scoring standard material self-network
At present, X-ray examination can only tell us whether dogs have joint diseases to some extent, but generally speaking, if the X-rays taken at the age of 2 have not shown signs of coronary heart disease, then the probability of scientifically raised dogs suffering from coronary heart disease in the future will not be too high. In addition, the commonly used method to judge CHD by X-ray is Norberg angle diagnosis, which is a method to quantitatively evaluate hip joint relaxation, so I won't repeat it here.
In the evaluation of X-ray, the shooting position is very important. Most dogs are inevitably nervous, scared and moving when taking X-rays, so they need a shot to calm themselves down when taking X-rays to ensure more accurate results.
Treatment of coronary heart disease
At present, the treatment of coronary heart disease is divided into three ways: conservative treatment, early interventional treatment and late treatment.
conservative treatment
Conservative treatment is a non-surgical treatment method. At the initial stage of detection, measures such as weight control, exercise restriction, impact protection, warmth and cold protection are taken to reduce the pressure on the hip joint and prevent the further development of dislocation of the hip joint.
At the same time, cooperate with the medicine prescribed by the doctor to relieve the joint pain of dogs. When conditions permit and necessary, reasonable physical therapy methods can be used to cooperate with the treatment, such as hip massage and hydrotherapy.
Self-network of conservative treatment materials
Early intervention treatment
Early interventional therapy is the interventional therapy after surgical treatment in puppy period and evaluation of joints and hip joints by Otaola's test and imaging. If it is found that dogs may have severe hip dysplasia, surgical intervention at the right age can achieve a high cure rate.
At the age of 3.5 to 4.5 months, pups were subjected to pubic symphysis anastomosis (JPS).
At the age of 5-8 months, double pelvic incision (DPO) can be performed.
Self-network of x-ray films after PDO operation.
Late treatment
Post-treatment includes femoral head and neck resection (FHO) and total hip replacement (THR) in dogs.
FHO is an operation that removes the femoral head to protect the hip joint from wear and pain. FHO is not suitable for dogs weighing more than 20 kg, and it takes more than half a year to recover their mobility after surgery.
Self-network of FHO surgical graphic materials
THR surgery can be performed at any stage of the dog. For dogs with severe coronary heart disease and weighing more than 20 kg, hip replacement is the only choice. The success rate of this operation is about 95%, and the joint prosthesis can be used for more than 15 years, which can basically meet the needs of dogs for a lifetime. However, the difficulty of THR operation lies in the high cost and the scarcity of doctors. Doctors who can do hip replacement for dogs in China are generally orthopedic experts.
THR surgical graphic material self-network
In short, all treatments should be carried out in time and effectively, and only in this way can dogs be helped to stay away from the pain of coronary heart disease as soon as possible.
Be a qualified scientific breeder
Coronary heart disease is a disease controlled by polygenic genetic factors. We know that breeding relatively healthy dogs through genetic eugenics will greatly reduce the incidence and severity of this disease.
However, it is a complex systematic project to correct this disease from breeding, and it is difficult to completely avoid or prevent serious hip dysplasia in future generations through breeding. Our first task is to select puppies with potential coronary heart disease for early intervention and correction through comprehensive early diagnosis, and strive to improve their quality of life.
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