According to the American Heartworm Society, coughing, difficult breathing, fatigue, vomiting and loss of appetite are common symptoms of heartworms in cats. Cats can die suddenly after being infected with heartworms eve... More » Pets & Animals Pets Cats

In dogs with large heartworm infections, symptoms include a persistent cough, fatigue and loss of appetite, according to the American Heartworm Society. However, most dogs show no noticeable symptoms in the earlier stage... More »

In the early stages of heartworm disease, a dog displays few symptoms, but as the parasites grow and multiply, it starts to develop a persistent cough, fatigue, decreased appetite and weight loss. It may become reluctant... More » Pets & Animals Pets Dogs

Symptoms of heartworms in dogs include a decrease in appetite, weight loss, fatigue after moderate activity, a reluctance to exercise and a mild, persistent cough, according to the American Heartworm Society. As heartwor... More »

Symptoms of tuberculosis include a loss of appetite, unplanned weight loss, coughing for three or more weeks or chest pain when coughing or breathing, according to Mayo Clinic. Some people with tuberculosis may experienc... More » Health Pain & Symptoms

Some symptoms of a weak heart include difficulty in breathing, general body weakness, irregular heartbeat, nausea, loss of appetite, impaired thinking and swelling in certain body parts. A weak heart normally leads to he... More » Health Conditions & Diseases Cardiac Health

Vitamin D toxicity may cause loss of appetite, fatigue, vomiting, dehydration, constipation, muscle weakness and irritability. An excessive amount of this vitamin causes high calcium levels in the blood, and over time, t... More » Health Medications & Vitamins Side Effects