39 The Cat That Ate And Ate But Never Gained Weight!

Student Guide

Learning objectives

• Explain why a cat may eat a lot but still lose weight.
• Explain the importance of the thyroid.
• Describe the symptoms of hyperthyroidism.

Review material

Cats have 2 thyroid glands in their neck, one on each side of their trachea or windpipe. These thyroid glands play very important roles such as regulating metabolism and they secrete two important hormones called T3 and T4 which affect every system in the body. In a hyperthyroid cat, the thyroid glands become bigger and start over producing the hormone T4 which increases the cat’s metabolism, making them hungrier. Common symptoms of hyperthyroidism are weight loss, excessive hunger, increased drinking, vomiting, a poor hair coat, and several others.

There are multiple reasons why an animal may lose weight. The five main reasons are lack of input, excessive output, loss of protein or nutrients, maldigestion, and malabsorption. Weight loss associated with hyperthyroidism falls under excessive output. The cat is burning up calories faster than it can consume them. A good metaphor for this is when your expenses outweigh your income. This is why a cat with hyperthyroidism may eat a lot but still lose weight.

Hyperthyroidism is typically seen in older cats. Most often in those over ten years old. The enlarged thyroid glands are caused by a non-cancerous(benign) tumor. The disease is diagnosed by taking blood from the cat and measuring the levels of thyroid hormone in the blood. High levels of the thyroid hormone indicate hyperthyroidism. There are multiple treatment options for this disease including surgery, radioactive iodine, oral medication, and a prescription diet. Cats normally do well with treatment.

The image above shows the weight loss and poor hair coat associated with hyperthyroidism.

Activities

Students will be divided into groups with 3 students in each group. There will be pretzels placed at the center of the table. One student tries to put as many pretzels as he/she can into a bowl while the other two students try to take pretzels away as fast as they can and place them into another bowl. They will have 5 minutes to complete this activity. The activity demonstrates that in cats with hyperthyroidism their body is using up more than what they can consume.

Knowledge check

Each group will take turns explaining to the class what they have learned. Each of the students in the group will cover one of the learning objectives.