Osteoporosis

What is osteoporosis?

Osteoporosis literally means "porous bone". Bone is a living tissue that is constantly being broken down and rebuilt. This process is known as bone remodeling. In a healthy dog, bone remodeling is balanced, i.e. just as much bone substance is broken down as is newly formed. In a dog with osteoporosis, this process is disturbed, meaning that more bone substance is broken down than is newly formed. This makes the bone thinner, weaker and more fragile.

What are the causes of osteoporosis?

Osteoporosis can have various causes, which can be either congenital or acquired. Congenital causes include genetic defects or developmental disorders that lead to reduced bone formation or increased bone resorption. Acquired causes include

• Poor diet: an unbalanced diet that is low in calcium, phosphorus or vitamin D can affect bone health. Calcium and phosphorus are important minerals for bone formation, while vitamin D promotes the absorption of calcium from the intestine.
• Nutrient deficiency: A lack of certain nutrients such as protein, zinc or copper can also lead to reduced bone formation or increased bone resorption.
• Age: With increasing age, the body's ability to form new bone substance decreases. In addition, hormone production, which also plays a role in bone metabolism, decreases.
• Disease of the bone marrow: The bone marrow is the soft tissue inside the bones that is responsible for the formation of blood cells. A disease of the bone marrow such as leukemia or lymphoma can lead to a reduced production of blood cells, which in turn can affect bone metabolism.
• Hormonal disorders: Some hormones have an influence on bone metabolism. For example, parathyroid hormone promotes the release of calcium from the bone into the blood, while thyroid hormone inhibits the breakdown of calcium from the blood into the bone. An over- or under-function of these hormones can lead to an imbalance in the calcium balance, which reduces bone density.
• Prolonged cortisone therapy: Cortisone is an anti-inflammatory drug that is used to treat various diseases. However, prolonged use of cortisone can also have negative effects on bone metabolism. For example, it inhibits the formation of new bone substance and promotes the resorption of existing bone substance.
• Lack of exercise: Exercise stimulates the formation of new bone substance and strengthens the muscles that support the bone. A lack of exercise can therefore lead to reduced bone density.

What are the symptoms of osteoporosis?

Osteoporosis does not initially cause any obvious symptoms. Only when the bone is so weakened that it breaks under normal stress does the disease become noticeable. The most common symptoms of osteoporosis are

• Lameness: Lameness is the most noticeable symptom of osteoporosis. It can occur suddenly or gradually and can vary in severity depending on the bone affected. Lameness can also be intermittent, i.e. it comes and goes.
• Pain: A bone fracture is very painful and can lead to a change in the dog's behavior. For example, he may play, eat or move less. He may also react aggressively or anxiously if you touch him in the affected area.
• Swelling: Swelling may occur at the site of the fracture, caused by inflammation or bleeding. Swelling can also lead to deformation of the bone.
• Fever: An infection at the site of the fracture can lead to an increase in body temperature, known as a fever. Fever is a sign that the body is fighting the pathogens.

How is osteoporosis diagnosed?

To diagnose osteoporosis, the vet must first carry out a thorough medical history and clinical examination. He will ask about possible causes, risk factors and symptoms and examine the dog for lameness, pain and swelling. However, to confirm the diagnosis, the vet will need to perform an X-ray examination.

X-ray examination

An X-ray examination is the most important method of diagnosing osteoporosis. X-rays are sent through the dog's body and visualized on a film or screen. The X-rays are absorbed to different degrees by different tissues, so that the structure and density of the bones can be seen on the X-ray image.

In a dog with osteoporosis, a reduced bone density can be seen on the X-ray image, which shows up as increased transparency or reduced density. You may also see bone fractures or deformities. The X-ray examination can also help to rule out other diseases that can cause similar symptoms, such as a bone tumor.

How is osteoporosis treated?

Unfortunately, osteoporosis cannot be cured, but there are various ways to treat the disease and improve the dog's well-being. The treatment depends on the cause, the severity and the general condition of the dog. Possible treatment options include

• Dietary changes: a balanced diet is essential for bone health. The dog should receive sufficient calcium, phosphorus and vitamin D, but not too much, as this can also be harmful. The vet may recommend a special dietary food or prescribe supplements.
• Medication: There are various medications that can affect bone metabolism. For example, bisphosphonates can inhibit bone resorption and thus slow down bone resorption. Other drugs such as calcitonin or parathyroid hormone can promote bone formation and thus accelerate bone formation. However, these drugs must be taken under strict veterinary supervision as they can also have side effects.