North American Veterinary Licensing Examination (NAVLE) Practice Test

The presentation of cold hindlimbs, tachypnea, and a left parasternal heart murmur in the cat strongly suggests a diagnosis of a thrombus at the aortic bifurcation. This condition, commonly known as aortic thromboembolism, typically occurs when a blood clot lodges at the point where the aorta bifurcates into the femoral arteries.

In affected cats, the clinical signs can include hind limb ischemia, which presents as cold hindlimbs due to reduced blood flow, and sometimes even paralysis. The tachypnea indicates a potential compensatory response to hypoxia or pain, while the left parasternal heart murmur can be attributed to various cardiac issues, including underlying heart disease that may have contributed to the formation of the thrombus.

Other conditions listed, such as T3-L3 intervertebral disc disease, would more likely lead to neurological deficits rather than the specific circulatory signs observed here. Chlorpyrifos toxicity can cause a range of neurological signs and respiratory distress but is less likely to manifest specifically with cold limbs and a heart murmur. Lastly, lymphoma of the spinal cord would typically present with more generalized neurological signs rather than the acute ischemic signs seen in this scenario.