Always remember that by the time even the most experienced keeper suspects illness in a reptile, there is a very good chance that the animal is more ill and has been sick for longer than either owner or veterinarian can know. This is not the fault of either, it is simply a reflection of the evolution of reptiles, which has made them masters at hiding disease. So, get to know your species as thoroughly as you can, through publications and clubs and your veterinarian. Records will help you to assess your pet's health objectively, but there is no substitute for careful and regular observation of your pet. If your instincts tell you that his behavior has changed, or if your records show a trend, which you cannot explain, you do not need to wait for overt signs of illness before consulting a veterinarian. Regular well-pet examinations will build a good relationship with your reptile veterinarian and expand your knowledge of reptile health and husbandry. Building your knowledge of your pet in health is the surest way to prevention and early detection of disease.

Signs, which warrant a veterinary visit:

Swollen or shortened lower jaw

Swollen or lumpy limbs (for those who have them)

Muscle tremors

Reluctance to move

Paralysis

Abnormal gait or lameness; uncharacteristic slithering in snakes; abnormal posture, e.g. "star gazing" in snakes.

Seizures

Parasites: internal and external, these are a common and unnecessary burden on your pet

Trauma such as broken tails, bite or scratch wounds, burns. Open wounds can rapidly become infected, leading to septicemia (blood poisoning). Cat bites, and those from other reptiles can be particularly dangerous. Do not underestimate the level of aggression that can exist between reptiles; few species should be housed together and in many cases it is inappropriate to house together individuals of the same species.

Changes in stool or urine production

Inappetance or anorexia

Vomiting or regurgitation

Skin lesions: sores, swellings, moist that which should be dry, soft areas that should be hard

Eye or nose discharge

Changes in respiration: open mouth breathing; labored breathing, which may be characterized by an extended head and neck, and in the case of snakes, resting the head against the tank wall; whistles or wheezes as the animal breathes; foam in the mouth.

Weight loss

Changes in behavior such as unusual docility or aggression