Bruising and contusions in dogs – swelling, pain and treatment

Overview

Contusions, bruises and haematomas

A contusion can damage blood vessels in skin, subcutaneous tissue and muscle. Blood leaks from damaged vessels into local tissues. Bleeding beneath the skin appears as a bruise, or skin discolouration. A local collection of blood, called a haematoma, can also form in muscle tissue.

A larger patch-like bruise may be dark red or purple. Small pinpoint haemorrhages are called petechiae. These can occur on mucous membranes such as the gums as well as the skin. Petechiae appearing without an obvious accident particularly prompt investigation of the bleeding cause.

Bruising associated with mild or moderate trauma does not always need separate treatment. Severity and other findings nevertheless determine whether this is only a local soft tissue injury.

Causes

Impact, compression and muscle fibre damage

A blunt impact can bruise muscle. Contusion can also accompany a fracture or occur during surgery. Muscle compression and partial fibre tearing can cause pain and restrict contraction.

Swelling and local inflammation following bleeding are tissue injury responses. If more muscle fibres have torn, a strain may be present alongside the contusion. Distinguishing an overuse injury, strain and contusion depends on the injury mechanism and examination findings.

Not every bruise comes from a contusion

Bruising can also occur spontaneously without known tissue injury. A clotting system disorder is among the possibilities then suspected. Causes include too few platelets, impaired platelet function or a clotting factor deficiency. Current medication and possible toxin exposure are also reviewed. Investigating a spontaneous bruise therefore differs from assessing a local contusion after a clear mild impact.

Risk factors

A road accident, fall or another major impact predisposes to contusions and concurrent internal injuries. An attack by another animal can crush tissues even without a penetrating wound. Muscles around a fracture can be damaged.

Surgery can also cause local bruising. Mild postoperative bruising that settles on its own is often expected. A spreading, swollen, discharging or painful change may instead need checking. Assessment therefore considers the incident, recent procedures and other concurrent signs.

Chemotherapy can reduce bone marrow platelet production and predispose to bruising. In immune-mediated thrombocytopenia, the body's immune system destroys platelets. These cause bleeding into tissues through a different mechanism from a direct muscle impact.

Typical symptoms

A contusion may appear as a local change or difficulty using a muscle. Common observations include:

• Pain or tenderness at the injury site.
• Local swelling.
• A dark red or purple skin bruise.
• Lameness or stiff movement.
• Reluctance to get up or walk.
• Pain when lying down or getting up.

Your dog may whine or seem more subdued than usual. Obvious limb deformity may suggest a fracture or joint dislocation. Lameness does not, however, establish whether the cause is a contusion, fracture, joint problem or tendon injury; examination distinguishes them.

Haemorrhages may also appear on the gums, abdominal skin, armpits, groin or whites of the eyes. Changes appearing at several sites without injury particularly prompt investigation for a bleeding tendency.

Complications and consequences

Scarring and impaired muscle function

Most contusions heal without permanent problems. Strains or tears associated with a severe contusion may nevertheless leave dysfunction. Scar tissue formed during healing can restrict muscle contraction. Extensive scarring can also shorten a muscle's functional length and reduce joint range of movement.

Hidden injury can be worse than the visible contusion

A major impact can cause internal bleeding or organ rupture. Chest trauma can cause lung bruising, pneumothorax or a diaphragmatic hernia. Severe trauma may also involve a clotting disturbance that increases bleeding. More than the colour of a skin bruise is therefore assessed after a major accident.

After a fall, some injuries become apparent only hours or days later. A dog initially moving normally may later become weak or develop breathing difficulties.

Diagnosis at the vet

The injury mechanism and examination of the whole dog

Your vet asks about the accident, possible toxin exposure, medication and other diseases. The location and extent of haemorrhages on skin and mucous membranes are examined. Signs of internal bleeding and other abnormalities are sought at the same time.

In a patient with multiple injuries, airways, breathing and circulation are assessed first. Abdominal palpation checks for pain, swelling and possible hernias. Listening to the chest assesses breath sounds and heart rhythm.

When are blood tests and imaging needed?

Blood and urine tests can investigate the underlying cause of bruising. Platelet numbers can also be checked microscopically on a blood smear. PT and PTT tests assess the blood clotting system. Where needed, investigations address von Willebrand's disease or another clotting disorder.

X-rays and ultrasound can look for internal injuries or another underlying disease. A suspected fracture may prompt X-rays of the injured area. Repeat examination is sometimes necessary because not every consequence of impact is immediately apparent.

After severe trauma, packed cell volume, or PCV, may initially be normal or even increased despite bleeding. Splenic contraction releases red blood cells into the circulation and temporarily maintains PCV. PCV and blood total solids are therefore monitored through repeated samples. Both ongoing bleeding and fluid treatment affect their trends. Emergency blood tests also check glucose and markers of kidney function.

Investigation of bruising without trauma may include infectious diseases such as tick-borne infections. A bone marrow sample can establish whether the marrow is producing platelets where needed. It can also be examined for signs of cancer or immune-mediated disease.

Treatment

Care targets pain and the type of injury

Mild or moderate local bruising can settle without specific treatment. A painful, lame dog nevertheless needs activity restriction. Your vet may prescribe an NSAID or another pain medicine according to the signs. Medication is not chosen from bruise colour alone.

An underlying clotting disorder may require hospital monitoring or blood and plasma products. Infection-related bleeding tendency is treated according to its cause. These situations are therefore managed differently from a simple impact-related contusion.

Hospital monitoring after severe trauma can include respiratory and heart rates, mucous membrane colour and consciousness. Even a dog initially appearing stable can have a significant hidden injury.

First aid for a mild local injury

Cold therapy can reduce pain and swelling around a contusion. It reduces local blood flow. Different durations are given for individual cold pack applications: 15 minutes or at least 20 minutes. Check the appropriate duration and repetition with your vet because not every swelling is treated as a contusion.

In a hairless or sparsely coated dog, place a thin towel between the cold pack and skin. Cold therapy is only first aid and does not replace investigation of the injury's cause. If a limb instead has a fracture or dislocation, moving it can worsen damage and pain.

Elevating an assessed mild limb injury may reduce bleeding by lowering pressure in local blood vessels. Do not, however, force a painful or deformed limb upwards or bend it.

Rehabilitation and follow-up

After muscle injury, physiotherapy can assess movement restrictions, weakness and reduced weight bearing. Goals may include restoring strength or range of movement. An individual home exercise programme is planned where needed. Some veterinary physiotherapy services require referral or veterinary consent for an ill dog's treatment.

Mild lameness without other warning signs needs veterinary assessment if it lasts more than 24 hours. An expanding bruise showing no improvement within 72 hours is examined. Severe pain, pale gums, breathing difficulty or collapse nevertheless require immediate assessment. Do not wait for the time limits above in these situations.

Prevention

Prevent falls in small dogs even from low furniture because jumping from it can cause injury. In a car, transport your dog in a properly secured crate or seat-belt harness. A collar is not used for vehicle restraint. A deploying front-seat airbag can injure a dog.

A crate must allow comfortable rest without too much empty space around the dog.

A long-term rehabilitation goal is also reducing recurrence of strain injury or pain. Exercise is planned according to the dog's own movement restrictions and strength needs. Any aids are individually fitted.

Important for dog owners

Moving an injured dog

Handle your dog carefully while preparing transport because moving can worsen injury. When carrying a small dog, provide support behind the forelimbs and in front of the hindlimbs. A dog unable to get up can be moved on a rigid surface. With breathing difficulty, allow the lying or sitting position your dog finds easiest. Ask the practice for lifting assistance where needed.

Monitor change, rather than only the bruise's presence

Record the bruise's location and whether it spreads, swells or becomes more tender. Also note when it appeared and the accident involved. Monitor walking, lying down and getting up. Tell the treating vet if signs worsen or previously good general condition changes.

After a fall, monitor your dog for several days for delayed signs. Breathing difficulty, weakness or collapse requires prompt contact. Initially good movement therefore does not end monitoring after a severe impact.

A dog may be in pain despite continuing to play or work. Do not give human pain medicines without veterinary instructions. Follow the agreed activity restrictions and prescribed medication instructions.

Frequently asked questions

Is every bruise a contusion?

A bruise results from blood vessel damage, commonly due to tissue trauma. Bleeding can nevertheless start without known injury, for example because of a clotting disorder. Spontaneous bruising or mucous membrane bleeding therefore needs prompt veterinary examination.

Can an ordinary-looking bruise involve a serious injury?

A major impact can involve internal bleeding, organ rupture or a fracture. After a fall, some injuries appear only hours or days later. The whole event and general condition therefore affect investigation needs. Breathing difficulty, pale gums and collapse are urgent signs.

How long should a cold pack stay on a contusion?

Recommendations for individual applications differ: 15 minutes and at least 20 minutes are both used. In a sparsely coated dog, use a thin towel between the skin and cold pack. Confirm the cause of injury and suitable cold therapy with your vet.

Can mild lameness be monitored at home?

For mild lameness without warning signs, activity is restricted. Lameness continuing beyond 24 hours needs veterinary assessment. Severe pain, breathing difficulty or deteriorating general condition nevertheless requires prompt care. Do not wait for the 24-hour threshold in these situations.

When should a bruise be checked again by a vet?

An expanding bruise that does not start improving within 72 hours needs checking. Swelling, discharge and pain may also indicate a need for reassessment. Pale gums, weakness, breathing difficulty or collapse require immediate assessment. A previous contusion diagnosis therefore does not automatically explain a new change in condition.