Peripheral Edema in Dogs

Edema is characterized by swelling due to an excessive accumulation of tissue fluid within the interstitium, which is a small space, or gap, in the substance of the body’s tissues or organs. This can be localized (focal) or generalized (diffuse) in location.

Peripheral edema can occur in both dogs and cats, with some dog breeds believed to be more susceptible, including the Poodle, Bulldog, Old English Sheepdog, and Labrador Retriever. If you would like to learn more about how this disease affects cats, please visit this page in the PetMD health library.

Symptoms and Types

Dogs that develop peripheral edema will often have a history of allergies, or other immune, cardiac, or organic diseases. Exposure to toxic or infectious agents, such as poisonous spiders or ticks, and traumatic incidents such as car accidents, are also frequent in the histories of animals that have developed peripheral edema.

Overall, visible symptoms are almost impossible to detect early on in the development of this condition. A physical examination may reveal unexplained weight gain. The areas in which excess fluid may become first apparent are generally the throat or abdomen.

Causes

There is a wide range of conditions that can lead to peripheral edema. Localized or single-limb edema may result from injury, such as from a car accident, burns, obstruction in an artery (due to a blood clot), contact with toxic agents, such as a snake bite or bee sting, abnormal tissue growth (known as neoplasia) in the lymphatic tissues of the body, or high pressure in the capillary fluids.

Regional or generalized edema, which is not focused in a single area or limb, may result from infections, such as a severe bacterial infection, congestive heart failure, kidney failure, the tourniquet effect of a bandage bound too tight, or hypernatremia, a disease in which the kidneys retain excessive amounts of sodium.

Diagnosis

Diagnosis of peripheral edema is often determined by fine-needle aspiration of an affected area, by which a fluid-sample is removed via needle for microscopic evaluation. An examination of the affected tissue samples taken by biopsy may also help determine an underlying cause for the edema. Additional diagnostic procedures may include urine analysis, chest and lung X-rays, and an electrocardiogram to measure the heart’s functionality.