Bone Fracture
A bone fracture, medically referred to as a fracture, is a structural interruption in the continuity of a bone. In our pets, dogs and cats, fractures can affect various bones and occur in different forms. Fundamentally, we distinguish between closed fractures, where the skin remains intact, and open fractures, where the bone penetrates the skin, thus posing an increased risk of infection. Furthermore, fractures are classified according to their shape: transverse, oblique, spiral, comminuted, and splintered fractures describe the various fracture patterns. In growing animals, special fractures of the growth plates can also occur, which require particular attention as they may affect further growth.
The bone structure in dogs and cats is fundamentally similar to that in humans, but there are species-specific differences in resilience and healing tendencies. While cats often suffer less severe fractures due to their lower body mass and higher flexibility, dogs can exhibit more complex fracture patterns depending on breed and size. Bone healing occurs in several phases: initially the inflammatory phase, followed by the formation of a soft callus, which is then converted to hard bone tissue, until finally the remodeling phase completes the healing process.
Causes
Bone fractures occur due to severe trauma or limbs getting caught. Veterinary assistance is essential.
Bone fractures in pets mainly result from external force. Traffic accidents are the most common cause, especially for free-roaming cats and unsupervised dogs. Falls from great heights, particularly cats from windows or balconies (known as “high-rise syndrome”), often lead to multiple fractures. In dogs, collisions with other animals or people, as well as accidents during play or romping, can also cause bone fractures.
Besides traumatic events, pathological factors can also contribute to fractures. These include bone tumors that weaken the bone and can lead to so-called pathological fractures, where even minor stress is sufficient to cause a break. Metabolic diseases such as hyperparathyroidism or kidney failure can reduce bone substance due to calcium imbalances. In older animals, osteoporosis can weaken the bone structure, while in young, rapidly growing dogs of large breeds, a calcium-phosphorus imbalance can lead to brittle bones.
Breed-specific predispositions also play a role. Small dog breeds like Chihuahuas or Yorkshire Terriers have relatively thin bones and are prone to limb fractures. In sighthound breeds like Greyhounds or Whippets, stress fractures occur more frequently due to their high running speeds. Certain breeding lines may also have genetically determined bone diseases that increase the risk of fractures.
Symptoms
With bone fractures in the legs, the animal can no longer use this limb. It shows great pain. The affected limb appears deformed. If the skin is cut, severe bleeding may occur.
The clinical signs of a bone fracture vary depending on location and severity but are usually clearly recognizable. The most noticeable symptom is a sudden lameness up to complete non-weight bearing of the affected limb. With fractures of the spine, neurological deficits such as paralysis or coordination disorders may occur. Pain is expressed through vocalizations (whining, yelping, screaming), aggression when touching the affected area, or general restlessness.
Externally visible changes include swelling, abnormal mobility of the affected body region, and malposition of the limb. In open fractures, the skin is injured, and bone parts may be visible. Bruising of the surrounding skin is also frequently observed. The animal typically shows altered behavior such as reduced activity, loss of appetite, or withdrawal behavior due to pain.
With fractures of the skull or pelvis, additional specific symptoms may occur. Skull fractures can lead to disturbances of consciousness, balance problems, or bleeding from the nose or ears. Pelvic fractures often manifest as a characteristic “duck walk” or difficulties with urination and defecation. With rib fractures, breathing may be impaired, manifesting as shallow, rapid breathing or even respiratory distress.
First Aid
- If there is a very strong, pulsating bleeding, try to stop it.
- Cover the wound with a clean cloth and apply pressure to the wound.
- Apply a bandage (—> Bleeding).
- Do not try to bring the bone into the correct position.
- If bones are protruding, do not try to push them back.
- After applying a provisional bandage, you may be able to attach a splint to immobilize the injured leg.
- Do not manipulate too much. This and defensive movements of the animal can lead to further damage to blood vessels, nerves, and surrounding muscles.
- If necessary, just wrap your pet in a blanket and drive to a veterinarian.
- If you suspect further injuries to skull bones or internal organs, move your pet as little as possible.
Diagnosis
The diagnosis of a bone fracture begins with a thorough clinical examination by the veterinarian. First, a medical history is taken, where the owner is asked about the circumstances of the accident or injury. During the general examination, vital parameters such as heart rate, respiratory rate, and body temperature are checked to assess the animal’s overall condition and recognize possible signs of shock.
Diagnostic imaging is crucial for the precise assessment of the fracture. X-rays in at least two planes (lateral and ventrodorsal/anterior-posterior) are the standard procedure and allow determination of fracture type, location, and extent. For more complex fractures, especially in the area of joints, spine, or skull, advanced imaging techniques such as computed tomography (CT) or magnetic resonance imaging (MRI) may be necessary to obtain more detailed information.
Additionally, laboratory tests can be conducted to assess the general health status and identify possible underlying diseases. A complete blood count can provide indications of inflammation or blood loss, while biochemical parameters such as calcium, phosphorus, and alkaline phosphatase can provide information about bone metabolism. If pathological fractures are suspected, specific tests for tumor markers or metabolic diseases may be indicated.
Further veterinary measures
Bone fractures are usually treated surgically (Fig.).
Depending on the location of the fracture and the type of bone break, various methods and materials are used.
To achieve a stable connection between the bone fragments immediately after surgical treatment, screws, plates, intramedullary nails, wires, and external fixators made of metal are used. Nevertheless, immobilization for about 5 months is necessary for the fracture to heal.
The materials inserted to stabilize the fracture must sometimes be removed after the healing process is complete.
Supplements
The treatment of bone fractures depends on the type, location, and severity of the fracture, as well as the general condition of the animal. Basically, a distinction is made between conservative and surgical therapeutic approaches. Conservative treatment is considered for stable fractures with no or minimal displacement and includes immobilization through bandages, splints, or casts. This method is particularly suitable for fractures in young animals with high healing potential or for certain fractures of the forefoot or toes.
Surgical treatment is the method of choice for most fractures. Various osteosynthesis procedures are available: Plate osteosynthesis provides stable fixation and is often used for fractures of long bones. Intramedullary nails are inserted into the medullary cavity and are particularly suitable for shaft fractures. External fixators consist of pins that are guided through the bone and connected outside the body with rods – a good option for open or infected fractures. Lag screws or Kirschner wires are used for small fragments or joint fractures.
Perioperative management includes pain therapy, antibiotic administration for open fractures, and fluid therapy if necessary. For pain treatment, mainly opioids, NSAIDs (non-steroidal anti-inflammatory drugs), or local anesthetics are used. The choice and combination of analgesics depend on the pain intensity and the individual patient. For open fractures, careful wound care with thorough cleaning and debridement is necessary to prevent infections.
Prognosis and aftercare
The prognosis for bone fractures depends on various factors. Generally, simple, closed fractures have a better chance of healing than complex or open fractures. The age of the animal also plays a crucial role: in young animals, bone fractures typically heal faster and with fewer complications than in older animals. The location of the fracture significantly influences the prognosis – joint fractures often have a poorer prognosis than shaft fractures, as they are more likely to lead to arthritis. Timely and adequate treatment is also an important prognostic factor.
Follow-up care includes regular check-ups with X-rays to monitor the healing process. In the first weeks after surgery or applying a bandage, strict movement restriction is necessary to avoid compromising the stability of the fracture. The duration of this immobilization varies depending on the type of fracture and chosen treatment method, but usually lasts 4-8 weeks. Afterwards, a gradual increase in activity follows.
Physiotherapeutic measures play an important role in rehabilitation. These may include passive movement exercises, controlled weight-bearing exercises, underwater treadmill training, or massages. The goal is to prevent muscle atrophy, promote blood circulation, and maintain or restore joint mobility. Additionally, heat applications, ultrasound, or TENS (transcutaneous electrical nerve stimulation) can be used. For aftercare at home, an adapted environment should be ensured – non-slip floors, no stairs, and possibly aids such as harnesses with carrying handles can facilitate mobility.
Summary
Bone fractures in dogs and cats represent a common emergency situation in small animal practice. They primarily occur due to traumatic events such as traffic accidents or falls, but can also be facilitated by pathological changes in bone structure. Clinical signs include lameness, pain, swelling, and abnormal mobility or misalignment of the affected body region. Diagnosis is made through clinical examination in combination with imaging techniques, with X-rays being the most important diagnostic tool.
Treatment options range from conservative measures such as bandages and splints to various surgical techniques of osteosynthesis. The choice of appropriate therapy depends on the type and location of the fracture as well as the general condition of the patient. The postoperative phase and aftercare are crucial for healing success and include movement restriction, pain management, and possibly physiotherapeutic measures.
With correct diagnosis and adequate treatment, the prognosis is good in most cases, with the healing process monitored through regular check-ups. Special attention is required for complications such as delayed bone healing, infections, or implant failure. Through modern treatment methods and comprehensive aftercare, most patients can achieve complete functional restoration.
Outlook on current research
Research in the field of fracture treatment in small animals is continuously evolving. A promising approach is the application of biological therapies to support bone healing. Platelet-rich plasma (PRP) and mesenchymal stem cells show positive effects on healing speed and quality in initial studies, especially for complicated fractures or pseudarthroses. These autologous procedures utilize the body’s own resources to promote regeneration and can be used as a complement to conventional treatment methods.
There are also significant advances in implant technology. Bioactive coatings on osteosynthesis materials can improve osteointegration and reduce the risk of infection. Resorbable implants made of polymers or magnesium alloys offer the advantage that no secondary surgery is necessary for implant removal, and they reduce the risk of stress-shielding effects. 3D printing technology also enables the production of patient-specific implants that are precisely adapted to individual anatomy – particularly valuable for complex fractures or reconstructions.
Minimally invasive surgical techniques are also gaining importance in veterinary medicine. Percutaneous plate osteosynthesis and arthroscopically assisted fracture care can reduce soft tissue trauma, thereby decreasing complications and shortening rehabilitation time. The further development of imaging techniques such as intraoperative 3D imaging or augmented reality support during operations promises more precise placement of implants and thus better treatment outcomes.
Frequently asked questions (FAQs)
- How can I tell if my pet has suffered a bone fracture?
Typical signs include sudden lameness, pain, swelling, abnormal mobility, or visible misalignment of the affected body region. The animal usually does not put weight on the injured limb and shows pain reactions when touched. - Is a bone fracture always an emergency?
Yes, any suspicion of a bone fracture should be considered an emergency. Even if there is no open wound, complications such as vascular or nerve injuries can occur. Timely veterinary care significantly improves the chances of healing. - How do I transport my pet with a suspected bone fracture to the vet?
Move the animal as little as possible. Small animals can be transported in a stable box. For larger dogs, ideally use a firm surface like a board. Only immobilize the injured limb if it can be done without resistance. - How long does it take for a bone fracture to heal in a dog or cat?
The healing time varies depending on the age of the animal, type and location of the fracture, and chosen treatment method. On average, it takes 4-12 weeks, with young animals healing faster than older ones. - What complications can occur during healing?
Possible complications include infections (especially with open fractures), delayed bone healing or non-union (failure to heal), implant failure, malposition, and secondary arthritis in fractures near joints. - Does my pet need to wear a special bandage after surgery for fracture treatment?
This depends on the type of surgery. With internal fixation using plates or intramedullary nails, an additional bandage is often not necessary. External fixation or certain fractures may require supportive bandaging. - How can I help my pet at home after fracture treatment?
Strictly follow movement restrictions, provide a non-slip environment, avoid stairs and jumps. Ensure correct medication administration and monitor the surgical wound for signs of infection. - Can my pet fully recover after a bone fracture?
With uncomplicated fractures and adequate treatment, complete recovery is usually possible. Complex fractures, especially in joint areas, may result in movement restrictions or chronic pain. - Are certain dog or cat breeds more susceptible to bone fractures?
Small dog breeds with thin bones (e.g., Chihuahua, Yorkshire Terrier) and sighthound breeds with high running speeds have an increased risk. In cats, no clear breed predispositions are known, but certain genetic diseases can weaken bone structure. - What preventive measures can I take to avoid bone fractures?
Keep dogs on a leash near busy streets, secure windows and balconies for cats, provide a balanced diet with adequate calcium intake, and avoid excessive romping on slippery floors or uneven surfaces.
Literature
- Diehm, M. B.: Fractures of the extremities in dogs and cats – a retrospective study in the years 2010 – 2013, Veterinary University, Diss., 2016
- Löwe, G. and Löwe, O. (2021). Emergencies in Dogs and Cats – A Veterinary Guide. Kynos-Verlag. 208 p.
- DeCamp CE, Johnston SA, Déjardin LM, Schaefer SL. Brinker, Piermattei, and Flo’s Handbook of Small Animal Orthopedics and Fracture Repair. 5th Edition. St. Louis: Elsevier; 2020.
- Montavon PM, Voss K, Langley-Hobbs SJ. Feline Orthopedic Surgery and Musculoskeletal Disease. 2nd Edition. Philadelphia: Elsevier; 2022.
- Pozzi A, Risselada M, Winter MD. Fracture Fixation Techniques for the Small Animal Practitioner. Veterinary Clinics of North America: Small Animal Practice. 2020;50(1):67-84.
- Nolte DM, Fusco JV, Peterson ME. Incidence of and predisposing factors for nonunion of fractures involving the appendicular skeleton in cats: 18 cases (1998-2002). Journal of the American Veterinary Medical Association. 2019;236(11):1267-1273.
