Veterinary Technician Practice Exam 2025 - Free Veterinary Technician Practice Questions and Study Guide

The clinical signs of heartworm disease primarily manifest as a deep cough and irregular heartbeat due to the presence of heartworms in the pulmonary arteries and heart, which can cause damage and lead to compromised cardiac function. As the infection progresses, the worms can obstruct blood flow, resulting in inflammation of the blood vessels and lungs, leading to coughing as a response to increased pressure in the pulmonary arteries. Furthermore, the irregular heartbeat occurs as the heart struggles to cope with the obstruction and the stress of the infection. These cardiovascular changes are critical in diagnosing heartworm disease, as the animal's respiratory and circulatory systems are significantly impacted.

In contrast, the other options list signs that are not typically associated with heartworm disease. For example, vomiting and diarrhea may suggest gastrointestinal issues rather than cardiovascular problems. Excessive barking and lethargy do not specifically indicate heartworm infection, as they can result from various other conditions or behavioral factors. Lastly, weight gain and increased appetite are not signs related to heartworm disease; rather, animals suffering from heartworm disease often experience weight loss and decreased appetite due to the overall decline in health associated with the infection. Understanding these specific clinical signs helps veterinary professionals diagnose and manage heartworm disease effectively.