In general, a healthy amphibian has bright, alert eyes and moves about his environment with ease. If an amphibian looks healthy, he probably is. Unless he is living in substandard conditions, an amphibian rarely becomes ill.
To recognize illness in your amphibian, observe him regularly. Make written notes about his behavior, eating habits and environment (temperature, humidity and so on), and document any changes. Signs of illness include:
Don't assume that an unusual smell means an amphibian is in poor health. Amphibians emit a wide array of scents, from garlic to vanilla, in order to make themselves unappetizing to predators.
Following is a description of a typical amphibian's anatomy to give you an idea of both what is normal and what is not - and when you need the advice of a veterinarian.
The skin of some amphibians is moist and covered with mucous, while the skin of other amphibians is dry. The skin is permeable and in many species is used for hydration or even breathing. Since an amphibian can absorb water through his skin, it provides little protection from diseases or poisoning. Keeping his environment impeccably clean is vital. Dirty water, or a dirty environment, can be deadly for amphibians.
Just like a reptile, your amphibian will shed his skin regularly - but don't be concerned if you don't find the skin shell. Most amphibians eat the skin they shed. It contains essential nutrients.
Although all amphibians secrete toxins through their skin to some degree, amphibians with brightly colored skin usually secrete more potent toxins - the color serves as a warning to predators. When you handle any amphibian - for example, when you clean his cage - use caution and wear appropriate gloves.
To prevent bacterial infections in your amphibian, handle him only when absolutely necessary. Frequent handling can rub off the protective mucus coating on the skin and invite disease. Handling is especially dangerous to newts, which have very delicate skeletons. When you do pick up your amphibian, moisten your hands first and be very gentle. You can also use either an aquarium net or a plastic cup.
The eyes of a healthy amphibian are bright and alert and appear to sparkle. Most amphibians have yellow eyes, although there are exceptions, such as the Red-Eyed Tree Frog and the Common European Toad, which have copper-colored eyes.
An amphibian's keen eyesight helps him identify and capture his prey. All amphibians need to keep their eyes clean and wet to remain healthy, so they possess a special membrane that cleans and moistens their eyes.
Amphibians have four limbs, and when healthy, move easily and without effort. An amphibian who appears lame or has difficulty moving may suffer from metabolic bone disease, which is caused by a vitamin/mineral deficiency.
Be especially concerned if your amphibian develops red spots on the insides of his thighs; this is a symptom of a very serious bacterial infection called red leg.
Frogs and toads, being tailless, are called anurans (tailless amphibians). A salamander has a long tail, comprising half the size of his body, which he can shed to protect himself from predators. Don't be concerned if this occurs. The tail will grow back, and losing it is not a sign of illness. In general, amphibians, especially salamanders, are better at limb regeneration than reptiles.
Frogs and toads have ear openings, allowing them to hear. Salamanders and newts are silent creatures - they cannot croak or call, and some are deaf.
An amphibian's cloaca is where the urinary, intestinal and reproductive tracts empty. A healthy amphibian will have a clean vent (opening to the cloaca).
A healthy, non-tropical amphibian will want to hibernate. Usually, this occurs only when there is a drop in temperature. Ask your veterinarian whether your amphibian should be allowed to hibernate, and, if so, how to provide optimum conditions. If you notice any behavior changes in your amphibian or any other signs of illness, call your veterinarian for advice and treatment.