Bruising and Bleeding in Cats

Overview of Feline Bruising and Bleeding

Abnormal bruising and bleeding arises with disorders of hemostasis (clotting). Clotting abnormalities are also called coagulopathies, because they reflect the inability of the blood to coagulate or clot. In cats, bleeding from clotting disturbances may occur into the skin, the mucous membranes, and various internal organs, tissues, and body cavities. When the bleeding occurs into the skin, the membranes of the mouth, nose, eyes and external genitalia it may become visible to the owner. Bleeding into the intestinal tract may appear as hematochezia (fresh blood in the stools) or melena (dark, tarry stools). Bleeding into the urinary tract may be detected as blood in the urine (hematuria).

The impact of such bleeding on the affected individual may be mild or severe depending on the degree of blood loss. Unexpected or unexplained bruising warrants examination of the animal by your veterinarian in order to determine if a clotting abnormality exists. Many clotting abnormalities are serious because they may predispose the animal to a life-threatening episode of bleeding.

Causes of Bruising and Bleeding in Cats

The causes of bruising and bleeding can be classified as platelet disorders, vessel wall disorders, or clotting factor disorders. Platelets are small particles in the blood that begin the formation of a blood clot by clumping together at the site of any break in the blood vessel wall. Clotting factors are proteins in the blood that are responsible for further development of a clot after the platelets have initiated the process. Fortunately, clotting abnormalities of all three types are uncommon in the cat.

Platelet Disorders

Platelet disorders can arise when platelet numbers are decreased, or platelets fail to function properly. Platelet numbers are decreased when they are not produced adequately in the bone marrow, when they are destroyed, or when they are prematurely removed from the circulation. Dysfunction of platelets can occur as an inherited, congenital disorder, or may develop as an acquired condition later in life.

These disorders cause a decrease in the production of platelets:

• Drugs toxic to the bone marrow
• Infection of the bone marrow with certain bacteria and viruses
• Immune mediated destruction of the bone marrow (rare in the cat)
• Cancer of the bone marrow
• Myelophthisis and myelofibrosis, which are scarring and disappearance of bone marrow cells

These disorders result in increased platelet destruction:

• Immune-mediated destruction of platelets (rare in the cat)
• Certain drugs
• Certain viral infections

These disorders cause increased removal of platelets from the circulation:

• Vasculitis
• Certain parasites
• Certain disorders of the spleen

Disorders that affect the function of platelets include the following:

• Congenital platelet function disorders (Chediak-Higashi syndrome in cats)
• Certain drugs
• Some infections
• Kidney failure
• Liver failure
• Certain leukemias

Vascular Disorders

Vascular disorders usually result in abnormal bleeding by weakening the walls of the blood vessels. In some instances the underlying disease may also increase blood pressure, which aggravates any bleeding tendency. Disorders that increase the fragility of blood vessel walls include the following:

• Vasculitis – inflammation of blood vessels
• Hyperadrenocorticism – a disease where the adrenal glands produce too much cortisone hormone in the body (rare in the cat)
• Diabetes mellitus – sugar diabetes
• Uremia – an increase in waste products not cleared by diseased kidneys

Clotting Factor Disorders

• Inherited deficiencies of clotting factors that result in hemophilia (rare in cats)
• Toxicity with warfarin or warfarin-like products that antagonize Vitamin K. This is the most common cause of bleeding problems in cats. It often arises when cats hunt and eat rodents that have been poisoned with warfarin type products. It may also arise when cats directly ingest bate containing warfarin or similar toxins.
• Liver disease that prevents the manufacture of clotting factors
• Disseminated intravascular coagulation (DIC), which is widespread bleeding due to the consumption of platelets and clotting factors

What to Watch For

• Blood in the urine or stool
• Nose bleed (epistaxis)
• Bruises or swelling on or under the skin
• Pin point or blotchy hemorrhages on the gums of the mouth
• Pinpoint hemorrhages on the whites of the eyes or the inside of the eyelids
• Bleeding into the front chamber of the eye
• Difficulty breathing with bleeding into the lungs or chest cavity
• Abdominal distension with bleeding into the abdomen
• Weakness, depression
• Pale gums from anemia
• Excessive or unrelenting bleeding from a cut or wound

Diagnosis of Bruises and Bleeding in Cats

There are many tests that may be recommended for the patient with abnormal bruising or bleeding. The following is a list of the tests that are often performed initially:

• Complete blood count (CBC)
• Platelet count
• Biochemical profile
• Urinalysis
• Thoracic (chest) and abdominal radiographs (x-rays)
• Fecal tests
• Coagulation studies that measure how long it takes for the blood to clot
• Serologic tests for infectious diseases that can affect clotting
• Abdominal ultrasonography
• Bone marrow aspiration and cytology
• Assays of clotting factors

Treatment of Bruising and Bleeding in Cats

There are several things your veterinarian might recommend to treat the patient with bruising/bleeding symptomatically while the diagnostic work up is underway. These supportive measures include the following:

• Discontinue any medications that may cause a bleeding problem.
• Minimize activity to reduce the risk of even minor trauma.
• If an animal is severely anemic or weak from excessive bleeding, it may be necessary to hospitalize the patient for the administration of intravenous fluids, transfusions of blood products, and institution of other stabilizing measures, such as oxygen therapy, vitamin K therapy, and administration of antidotes to toxins.

Home Care

Any sign of bruising or bleeding should be evaluated in a timely fashion by your veterinarian. Administer only medications that your veterinarian has recommended and do not allow your pet to have exposure to rat poison and other toxins that can cause bleeding.

In-depth Information on Bruising and Bleeding in Cats

Inappropriate bruising or bleeding arises in animals for many reasons, including disorders associated with platelets, clotting factors, or the vessels in which blood travels. These disorders are rare in the cat, but can occur in any age or breed of cat.

Bruising or bleeding may occur in association with many systemic illnesses or disorders. Clinical signs may be mild and subtle, such as a small bruise on the skin, or signs may be severe and life threatening. Unexplained or abnormal bruising or bleeding should never be ignored. Examination by a veterinarian should be sought immediately in pets that appear to be pale, lethargic, weak, or in distress.

When evaluating an animal with abnormal bleeding, it is important to establish a definitive diagnosis as to the type of clotting abnormality present, and to identify any underlying causes. The therapy of coagulopathies varies, and must address not only the underlying cause, but must also treat the specific defect in clotting.

Causes of Bruising and Bleeding in Cats

There are many causes of bruising and bleeding. Although it is not unusual for a normal cat or dog to have a small bruise or an occasional fleck of blood in the stool, it is not normal or acceptable for bleeding to be widespread, prolonged, severe, or recurrent.

Platelet disorders can arise when platelet numbers are decreased or when platelets fail to function properly. Platelet numbers are decreased when they are not produced adequately in the bone marrow, when they are destroyed, or when they are prematurely removed from the circulation. Thrombocytopenia is defined as a decreased platelet count. Generally speaking, animals with platelet counts less than 25,000 may bleed spontaneously and are at risk for life-threatening hemorrhages.

Dysfunction of platelets can occur as an inherited, congenital disorder, or may develop as an acquired condition later in life.

Disorders that Decrease Platelet Numbers or Function

• Immune mediated destruction of circulating platelets or the cells of the bone marrow that form platelets (rare in cats)
• Various disorders of the cells of the bone marrow, such as cancer, myelophthisis and myelofibrosis
• Viral infections – feline leukemia virus, feline immunodeficiency virus, panleukopenia virus
• Bacterial infections – Salmonella
• Certain parasites – heartworm disease, Plasmodium infection
• Neoplasia (cancer) in the body
• Drugs that alter platelet production or function – chloramphenicol, griseofulvin, chemotherapeutic drugs, etc.
• Disorders of the spleen
• Vasculitis (inflammation of the vessels)
• Disseminated intravascular hemolysis (DIC), a complex, life threatening hemostatic defect that occurs secondary to many systemic diseases
• Congenital platelet function disorder, namely Chediak-Higashi syndrome in the cat
• Kidney disease
• Liver disease
• Vaccination with modified live viruses

Vascular Disorders

• Vasculitis – inflammation of blood vessels
• Hyperadrenocorticism – a disease where the adrenal glands produce too much cortisone hormone in the body (rare in cats)
• Diabetes mellitus – sugar diabetes
• Uremia – an increase in waste products not cleared by diseased kidneys

Clotting Factor Disorders

• Inherited deficiencies of clotting factors that result in hemophilia (rare in cats)
• Toxicity with warfarin or warfarin-like products that antagonize Vitamin K. This is the most common cause of bleeding problems in cats. It often arises when cats hunt and eat rodents that have been poisoned with warfarin type products. It may also arise when cats directly ingest bate containing warfarin or similar toxins.
• Liver disease that prevents the manufacture of clotting factors
• Disseminated intravascular coagulation (DIC), which is widespread bleeding due to the consumption of platelets and clotting factors

Diagnostic In-depth

There are many tests that may be recommended for the patient with abnormal bruising or bleeding. The following is a list of the tests that are often performed initially:

• Complete medical history (including travel history, toxin exposure, housing and environment) and thorough physical examination
• A complete blood count (CBC) to evaluate for the presence of systemic infection or inflammation. This test may reveal anemia secondary to bleeding, and may show changes in other cell lines such as the white blood count that might be indicative of other or concurrent disorders.
• Platelet count to accurately count the number of circulating platelets
• A biochemical profile to evaluate kidney and liver function, electrolytes (such as potassium and calcium), total protein, and blood sugar. The biochemistry profile is very helpful in identifying potential underlying causes of the bruising and bleeding.
• A urinalysis to evaluate the kidneys, hydration status of the patient, and confirm the presence of blood
• Thoracic (chest) and abdominal radiographs (x-rays). Although they may be within normal limits, x-rays may reveal evidence of lymphadenopathy (enlarged lymph nodes), liver and/or splenic enlargement, bleeding into the chest and abdomen, etc. In addition, x-rays are helpful to rule out other diseases that cause similar clinical signs (such as weakness, pallor, lethargy, difficulty breathing, abdominal distention, etc.).
• Fecal tests for blood and parasites
• Coagulation (clotting) studies to measure the time in which it takes blood to clot. A number of tests are available to assess blood clotting and 2 – 3 tests are often run at the same time.
• Serologic tests to detect infectious diseases that can affect clotting, especially tick titers in dogs
• Heartworm test
• Abdominal ultrasonography to evaluate the abdominal organs, including the liver, kidneys, lymph nodes and spleen
• A blood pressure test to detect hypertension
• A bone marrow aspirate in the patient with unexplained thrombocytopenia, alterations in white blood cells, or persistent anemia.
• Von Willebrand’s factor assay to measure the amount of this factor in the blood
• Measurement of other clotting factors in the blood

Depending upon the animal’s clinical signs and the results of the above tests, your veterinarian may recommend additional tests to insure optimal medical care. These ancillary tests are selected on a case-by-case basis, and include the following:

• Endocrine testing and assays of certain hormones
• Protein electrophoresis for animals with abnormally high circulating protein levels
• Platelet function tests, which must often be sent to very specialized laboratories
• Cytologic examination of any abnormal body fluids
• Bacterial culture of abnormal body fluids, blood, or bone marrow for some suspected bacterial infections
• Biopsy of any abnormal tissues, organs, or masses

Therapy In-depth

As a diagnostic work-up is progressing treatment of serious bleeding and clinical signs may be needed. Supportive care of seriously ill animals usually requires hospitalization and may involve the following:

• Intravenous fluids and treatment of shock if present
• Transfusions with blood or other blood products
• Oxygen therapy
• Confinement in a small, soft-padded area to minimize movement and trauma
• Protective/adsorbant medications to coat and protect the lining of the gastrointestinal tract
• Antibiotics for fevers or suspected infections

Supportive and nonspecific therapies are not a substitute for definitive treatment of the underlying disease responsible for your pet’s condition. It is important to determine any underlying or contributing causes and to address those specifically. For example:

• Discontinue any medications that may cause bleeding or bruising.
• Begin corticosteroids for immune-mediated diseases.
• Institute Vitamin K therapy for clotting disorders associated with rodenticide toxicity and severe liver disease.
• Begin antibiotics for any rickettsial diseases or known bacterial infections.
• Remove or treat any contributing cancers or tumors.
• Return hormone levels to normal.
• Start specific treatments for heartworm disease, kidney disease, liver disease and any identified blood parasites.
• Begin treatment for DIC if it is diagnosed.

Follow-up care for Cats with Bruising and Bleeding

Optimal treatment for your pet requires a combination of home and professional veterinary care. Follow-up can be critical, especially if your pet does not rapidly improve. It is important to note that bruising or bleeding may lead to life-threatening consequences.

It is important to monitor your pet very closely and note the frequency, severity, or intensity of bruising and/or bleeding.

Administer all prescribed medications as directed. Alert your veterinarian if you are experiencing problems treating your pet. Never use medications that your veterinarian has not recommended. It is important to use the medication only at the dosage and frequency recommended.

Return for follow up visits as directed by your veterinarian. Repeated measurement of platelet counts and clotting tests may be of utmost importance in some cases.

Avoid any medications or substances that may be cause or exacerbate (worsen) bleeding and other clinical signs.

Do not breed animals with inherited bleeding disorders.