Twisted spleen in dogs – splenic torsion and urgent treatment

Overview

A twisted spleen, or splenic torsion, is a rare, potentially life-threatening circulatory disorder. Blood cannot drain normally from the spleen, so it fills with blood and enlarges. Torsion can occur with gastric dilatation-volvulus, or GDV. However, it may affect the spleen alone without the stomach twisting at the same time.

Without treatment, torsion of abdominal organs can cause severe pain, organ dysfunction and circulatory failure. Nevertheless, a dog recovering from successful spleen removal may regain a normal quality of life.

In a group of 1,480 patients with splenic disease, isolated splenic torsion accounted for 0.5%. In a group of 87 patients with splenic disease requiring surgery, it accounted for 3.4%.

Causes

The spleen attaches to the greater curvature of the stomach through a broad fold of tissue. This attachment allows it to move relatively freely within the abdomen. The exact mechanism of primary, or isolated, torsion is not fully understood. Congenital or acquired laxity of its supporting ligaments may predispose the spleen to excessive movement.

When the vascular pedicle twists, venous return is almost or completely blocked. Arterial blood flow into the spleen may also be partly or completely blocked. Congestion and oxygen deprivation cause inflammation and tissue damage that can progress to cell death, or necrosis. Slower-onset symptoms may result from only partial vessel obstruction.

Previous stomach dilatation can stretch the spleen's supporting ligaments and increase the possibility of later torsion. As the spleen enlarges, the ligament between it and the stomach may tighten and impair normal stomach function.

Risk factors

Large and giant breeds with deep chests are most commonly affected. Recognised predisposed breeds include German Shepherd Dogs and Great Danes. Isolated splenic torsion also occurs in English Bulldogs.

In a group of 102 operated dogs, 23.5% were German Shepherd Dogs. Great Danes accounted for 14.7%. English Bulldogs accounted for 11.8%. Together these breeds made up 50% of cases in that patient group.

Previous abdominal surgery, trauma or GDV may be associated with acquired ligament laxity. The anatomical attachment between the stomach and spleen links disease of the two organs.

Small size does not rule out torsion, as an isolated case has also been identified in a Boston Terrier.

Typical symptoms

Severe abdominal pain and a sharp deterioration in general condition may dominate acute torsion. In a prolonged case, signs may be milder and resemble other abdominal conditions.

• Abdominal pain comes in waves or your dog resents its abdomen being touched.

• Your dog vomits without an obvious known cause.

• Appetite decreases or meals are left entirely uneaten.

• The abdomen looks larger than usual or tense.

• Weight gradually falls during prolonged illness.

• Drinking and urination may increase compared with before.

• Urine may become reddish or dark because of blood or red blood cell pigment.

The mechanical effect of an enlarged spleen on the stomach can also resemble abdominal illness caused by a foreign body. A dog may simply seem subdued even though splenic circulation is already impaired.

Complications and consequences

Interrupted blood flow and surgical risks

Prolonged circulatory obstruction can destroy splenic tissue, so treatment delays threaten the organ's viability. Twisted splenic tissue is usually free of bacteria, but infection with gas-producing bacteria can also occur. Uncontrolled untwisting can release clots and substances affecting blood pressure and heart rate into the circulation.

Possible problems during or after surgery include arrhythmias, bleeding, pancreatitis and infection. Pre-existing septic peritonitis, bleeding during surgery and postoperative breathing difficulty are associated with poorer survival.

Untreated torsion may involve a widespread clotting disorder in which small clots form throughout the body. Release of red blood cell pigment may also be associated with kidney tubular damage. Early spleen removal and supportive care reduce these risks.

The outlook is often favourable after successful treatment

Of 102 dogs operated on for isolated splenic torsion, 93, or 91.2%, survived to hospital discharge. This describes the hospital phase of operated patients, rather than the outlook for untreated torsion. Histopathology in the same patient group found no splenic neoplasia.

GDV can also develop after spleen removal. Reported GDV rates were 4% after splenectomy and 1% after other emergency surgery. However, the difference between the groups was not statistically significant.

Diagnosis at the vet

General condition, blood tests and abdominal examination

The vet first assesses circulation, pain and general condition before detailed imaging. Abdominal palpation may identify pain and direct investigation towards abdominal structures. Blood and urine samples may be needed to assess the dog's situation and readiness for surgery.

With prolonged torsion, blood tests often show anaemia, increased white blood cells and red blood cell pigment released into plasma. Findings associated with red blood cell breakdown can resemble immune-mediated haemolytic anaemia, or IMHA. These conditions can therefore be difficult to distinguish from symptoms and routine laboratory findings alone.

Urinalysis can identify haemoglobin, the red blood cell pigment, helping investigate unusually dark urine.

Imaging assesses splenic position and blood flow

Radiographs may show a markedly enlarged spleen displacing neighbouring organs. However, accumulated abdominal fluid can make the spleen's outlines harder to identify. An enlarged spleen may resemble a mass, so size alone does not always reveal the cause.

A displaced spleen may form a reverse C shape on a lateral radiograph. Nevertheless, radiography alone does not always confirm torsion. On ultrasound, the spleen may look mottled or lace-like because of tissue congestion.

Doppler ultrasound assesses whether blood flows within the enlarged spleen and its veins. Tissue may sometimes retain a normal ultrasound appearance despite torsion. A bright triangular area of fat at the splenic hilum may support suspicion.

A mottled ultrasound texture can also result from another circulatory infarction without torsion. Blood flow is therefore assessed with Doppler alongside tissue appearance to detect possible loss of flow.

With gas-producing bacterial infection, radiographs may show gas outlining vessel-shaped structures within the spleen. Fine-needle samples may appear normal even when imaging and surgery demonstrate torsion.

The splenic veins may also be markedly dilated when normal drainage is blocked.

Contrast-enhanced computed tomography can clarify the situation when radiographs are inconclusive. In some cases, the final diagnosis is only confirmed during exploratory abdominal surgery.

Treatment

Circulation is stabilised and the twisted spleen removed

Your vet prescribes the necessary supportive care before and after surgery.

Fluid therapy begins before surgery, and blood products are given if needed. A dog with acute abdominal pain may also need supplemental oxygen and pain relief. Once circulation is stabilised, diagnosis and surgery proceed without delay.

The usual corrective procedure is complete spleen removal, called splenectomy. The surgeon ensures that the twisted vascular pedicle does not untwist in an uncontrolled way during the procedure. This aims to prevent clots and substances affecting circulation from being released into the body.

In a large surgical group, 101 dogs underwent complete splenectomy. Only one dog's spleen was untwisted and left in place. Attaching the stomach at the same time may be considered to prevent later gastric twisting.

Additional risks of stomach fixation include longer anaesthesia, altered stomach motility and rare leakage of stomach contents into the abdomen.

Heart monitoring and quiet recovery

Postoperative care includes heart rhythm monitoring because splenic disease can cause arrhythmias. Pain relief and other supportive care are tailored to recovery. Exercise is usually restricted for 2 weeks after spleen removal. Wound licking is prevented with a protective collar or shirt where needed.

Hospital monitoring after spleen removal often lasts 24–48 hours to assess heart rhythm and blood volume. Arrhythmias are sought using an electrocardiogram, or ECG, and some need specific treatment. Most surgery-associated arrhythmias settle within 24–48 hours. During the first 2 weeks of recovery, outings are limited to short lead walks.

Prevention

The cause of isolated splenic torsion is not fully understood, so no reliable everyday preventive measure has been demonstrated. Stomach fixation, or gastropexy, prevents free gastric twisting, but this differs from preventing splenic torsion. Evidence is insufficient to support routinely performing it in every splenectomy patient. The additional procedure's benefits and risks are weighed individually.

A definite causal relationship between spleen removal and later GDV has not been demonstrated. The same body-conformation factors may predispose a dog to both conditions.

Important for dog owners

Before the appointment, record when signs began and whether abdominal problems have been continuous or intermittent. Mention previous abdominal surgery, injuries and episodes of stomach dilatation. Bring details of current medicines and recent eating. After surgery, follow the exercise restrictions and wound-care instructions. Ask for discharge guidance on when to return to an emergency vet, a follow-up plan and arrangements to discuss histopathology results.

Post-splenectomy pancreatitis may appear at home as new vomiting, for example, which needs veterinary assessment.

The possibility of arrhythmias, ongoing bleeding or infection makes assessment of a new deterioration urgent. A normal, good quality of life can be expected after complete recovery.

Frequently asked questions

Can a dog live without a spleen?

A dog fully recovered from splenectomy and any complications can have a normal quality of life. However, surgery-related arrhythmias, bleeding and other complications influence the outlook. Among dogs operated on for isolated torsion, 91.2% have survived to hospital discharge.

Is splenic torsion the same as GDV?

They involve different organs, but can occur at the same time. The spleen attaches to the stomach's greater curvature through a tissue fold. Stomach dilatation may stretch the ligaments supporting the spleen and predispose it to later torsion.

Can a twisted spleen cause symptoms for a long time?

Yes: prolonged illness can occur as well as sudden, severe torsion. Signs may include intermittent abdominal pain, vomiting, reduced appetite and weight loss. A slower course may result from partial circulatory obstruction, but torsion can still damage splenic tissue.

Can the spleen simply be untwisted?

The usual treatment is surgical spleen removal. Untwisting can release clots and substances affecting blood pressure and heart rate into the circulation. The surgeon therefore handles the twisted vascular pedicle particularly carefully during splenectomy.

Does an enlarged spleen mean cancer?

Enlargement can result from torsion blocking blood drainage and does not itself mean a tumour. In the patient group operated on for isolated torsion, no splenic tumours were found on histopathology. Imaging and, where necessary, exploratory surgery are used to clarify the situation.