The largest artery in the body that is the main “highway” for the propagation of oxygenated blood from the heart to the tissues is the aorta. The feline aorta leaves the heart with oxygen rich blood and courses through the chest and ultimately through the abdomen heading toward the tail. At the level of the pelvis, the aorta splits into two smaller arteries that ultimately supply blood to the tissues of each leg. It is at this split where formed clots can get lodged, leading to a severe medical emergency called a saddle thrombus.
Saddle thrombus is nearly exclusively a feline phenomena (it is reported in dogs rarely), causing a severe situation where the lodged clot cuts off blood supply to the legs. The lack of nutrient rich, oxygen rich blood reaching the tissues of the legs leads to severe pain, disuse of the legs and severe damage to the tissues, blood vessels, and nerves.
Typically, cats that are predisposed to saddle thrombus have underlying cardiac disease that increases turbulence to the flow of blood through the heart. This increased turbulence makes these patients more prone to the formation of clots. Cats with hyper-thyroidism are prone to a cardiac condition called hypertrophic cardiomyopathy. Therefore, saddle thrombus tends to be associated with cats that have hyperthyroidism.
Other conditions such as hypertension or degenerative kidney disease may also predispose cats to the development of saddle thrombus. This is why many veterinarians include blood pressure measurement as part of the routine yearly wellness examinations and recommend yearly senior wellness blood work as an integral component of the yearly visit.
Cats that have formed a saddle thrombus typically appear paralyzed, unable to move the rear legs. They are often vocalizing due to severe pain. When touched, the back legs are often cold and stiff, and sometimes there is panting and trouble breathing.
Due to the time sensitive nature of the irreversible consequences of saddle thrombus, as well as the severe pain that saddle thrombus causes, it is strongly recommended that one seek immediate veterinary care for one’s cat if saddle thrombus is suspected.
Saddle thrombus is diagnosed by a combination of history, presentation, cold/stiff rear legs, and lack of any palpable pulses in the rear legs. Chest x-rays will often indicate evidence of cardiac disease, and even congestive heart failure.
Prognosis is poor for saddle thrombus, even when found early. Treatment is geared toward managing pain and re-establishing blood supply to the legs through the use of IV clot busters such as heparin, or surgical removal of the clot. In many cases, however, the damage to the tissues, blood vessels, and nerves of the rear limbs is too severe and irreversible for treatment to offer a return quality of life, leaving euthanasia the most humane option for the patient.
Although there currently is no officially documented research to study their efficacy, many veterinarians are attempting alternative therapies in management of saddle thrombus in cats. Below are three alternative therapies that have been anecdotally noted to be beneficial ancillary therapy in cases of feline saddle thrombus. Until there is university level, peer reviewed research to study these modalities, their benefit for this specific condition remains questionable.
A hyperbaric chamber creates a pure oxygen environment. It has notable efficacy in the management of burns, contaminated wounds, and many other clinical applications where high levels of oxygen are beneficial in restoring cellular and tissue integrity following trauma or conditions that lead to cellular and tissue damage.
Since saddle thrombus exerts its damage in large measure due to hypoxia (oxygen deprivation) due to the clot obstructing oxygen rich blood flow to the rear limbs, hyperbaric chamber therapy theoretically may help to heal the cells and tissues comprising the rear limbs with abundant oxygen exposure.
Class IV Therapy Laser
Classic IV therapy laser gently infuses low level photons of energy into cells and tissues. The resulting physiological effect at the cellular and tissue level is called photobiomodulation. This process dilates arteries and arterioles to bring oxygen and nutrient rich blood to areas. Arterial blood also brings healing cells to help clean up and remodel damaged cells and tissues.
Photobiomodulation also dilates veins and venules, as well as lymphatic vessels. By stimulating venous circulation, this helps to stimulate the removal of inflammatory debris and stagnant blood in a compromised areas. By dilating lymphatic vessels, we potentially stimulate the drainage and replenishment of interstitial fluid, the liquid medium cells and tissues of the body are housed within.
Therapy laser also stimulates the production of adenosine triphosphate (ATP) within cells. ATP is the powerhouse of the cell by from which it derives energy to perform its physiological functions. By increasing ATP within cells, therapy laser serves to provide cells a jolt of energy in the form of increased ATP to enhance cellular repair and the rebuilding of tissues.
In ancient Chinese medicine, acupuncture via needles placed in strategic points along channels of energy called meridians, restores the flow of a life force called Chi, initiating healing of damaged cells and tissues. From this perspective, restoring the flow of Chi enhances healing, controls pain, and increases recovery rates for any number of diseases.
From the western perspective, acupuncture stimulates nerve conduction and blood circulation. Acupuncture also produces local endorphin release that provides a natural and effective pain management or analgesic effect.
These alternative measures have well documented and proven benefit for burns, chronic or contaminated wounds, post surgical healing, spinal and other central nervous system diseases, and a number of other health conditions. Their efficacy in the management of saddle thrombus in cats remains only anecdotal at this time and more research needs to be done to truly ascertain their benefit.
Roger L. Welton, DVM
Founder and Chief Editor, Web-DVM.net
President, Maybeck Animal Hospital
Article updated 9/2/2017