NAVLE Practice Test 2025 – Complete Exam Prep Guide

An 8-year-old dog presenting with cough, exercise intolerance, and anemia suggests a significant impact on the dog's health due to heartworm disease. Heartworm disease is classified into different classes based on the severity of clinical signs and the associated effects on the dog’s health.

In the case of Class II heartworm disease, there are moderate clinical signs, which include intermittent cough, exercise intolerance, and potential for measurable changes in blood work, such as anemia. The presence of anemia indicates that the dog's body is struggling to maintain normal red blood cell levels, possibly due to the chronic effects of the heartworm infection.

Class I typically involves mild symptoms or may even include asymptomatic dogs. In Class III heartworm disease, the clinical signs become more severe, including chronic symptoms, and may also include the development of congestive heart failure due to damage caused by the worms. Class IV, also known as caval syndrome, represents a critical condition with extreme clinical signs and potential shock.

The dog's symptoms of cough and exercise intolerance align with Class II, where the infection has begun to seriously affect the dog's quality of life but has not yet escalated to the more severe stages. Thus, this classification captures both the moderate severity of the dog’s clinical signs and the laboratory