What diseases are Chihuahuas prone to?

1. Eye problems: The Chihuahua’s large, protruding eyes make them prone to eye injuries, including scratched corneas, proptosis, displacement of the eyeball out of the socket, corneal ulcers, and dry eye.

1. Legg-Calve-Perthes: This condition causes the head of the femur (located in a dog’s hind leg) to spontaneously degenerate, which, over time, leads to erosion of the hip joint and arthritis. A Chihuahua suffering from Legg-Calve-Perthes will become lame, limp while walking, and experience pain when moving the hip joint. Surgery is the most effective treatment for the disorder.

1. Patellar Luxation: Also known as “slipped kneecaps,” patellar luxation occurs when slight abnormalities cause the knee joint to slide in and out of place. This common problem in many dog breeds can cause pain and occasional lameness. Surgical treatment is available for severe cases, although many dogs lead normal lives without treatment.

1. Portosystemic Shunt: Portosystemic shunt (PSS) is a hereditary issue that obstructs proper blood flow to the liver. Since the liver is responsible for detoxifying the body, PSS sends the toxins in unfiltered blood to the heart, brain, and other body parts. Signs can include but are not limited to behavioral changes, loss of appetite, hypoglycemia (low blood sugar), jaundice, urinary tract problems, vision problems, and stunted growth. PSS can be life-threatening if not treated early. Antibiotics and diet changes can help in the short term, but surgery is the only permanent treatment for the problem.

1. Open Fontanel: Much like human babies, Chihuahuas are born with a soft spot on the top of their heads. In most puppies, the soft spot will close as they mature, but sometimes the skull does not form properly, and the spot does not close fully. This leaves a vulnerable spot on the dog’s head into adulthood. Chihuahuas with open fontanel can lead normal lives, but extra care should be taken as an accidental blow to that spot could result in death.

1. Pulmonic Stenosis: Pulmonic stenosis is a heart defect that occurs when a malformation of the pulmonic valve (the structure that connects the pulmonary artery to the right ventricle) prevents blood from flowing properly through the heart. The poor blood flow may create an obstruction and make the heart work harder, which often causes the heart to become enlarged and leads to heart failure.

• Hypothyroidism, a thyroid malfunction that results in low hormone production and could cause obesity, low energy, and a brittle coat. 

• Tracheal collapse, where the trachea (or windpipe) flattens and makes it difficult for air to enter the lungs properly. 

• Hypoglycemia, a treatable but potentially fatal disease that causes low blood sugar.

• Mitral valve disease, a condition where the valve directing blood from the left atrium to the left ventricle begins to fail and eventually leads to heart failure

• Periodontal disease.

• Epilepsy, a neurological disease that Chihuahuas are at high risk of because of their domed skulls.