Snakes can experience a variety of health problems, but can you have an overweight snake? Perhaps you’ve noticed that your snake doesn’t seem to know when it should stop eating and that it’s grown much larger than other snakes that you’ve owned or have seen at your local pet store.
A snake can gain weight if it eats too much food. Boas and pythons can get very fat because they are largely sedentary snakes. Corn snakes and other more active snakes are less likely to become overweight. You can tell if a snake is overweight because of ‘scale spreading,’ where the snake’s skin shows through the gaps between the scales.
We’ve created reference tables (below) that you can use to make sure that your snake stays within a healthy weight range. Just because a snake is ‘overweight,’ it doesn’t necessarily mean that it’s unhealthy. Some species of snakes are naturally much longer and bigger than others.
Do Snakes Have Body Fat?
Snakes do have body fat because this is how they store energy for later use. They have very slow metabolisms, and can go for weeks or months without eating a meal. These fat reserves are subcutaneous, meaning ‘just under the skin.’ Snakes also have ‘visceral fat bodies,’ which means areas where there is a larger-than-average amount of fat.
However, snakes don’t keep body fat to store heat because they don’t produce body heat. They’re ectothermic, which means that they rely on external sources for heat. There’s no internal warmth for the fat to absorb.
This has many pros and cons. While they use up to 99% less energy than an endothermic animal (animals that produce their own body heat), it also means that they have to go into a period of low activity during the winter. However, snakes do have a thin layer of body fat to store energy.
Can Snakes Get Fat?
Captive snakes are prone to getting fat because they don’t burn off the energy that they get from food. If you overfeed them, their metabolisms are too slow to burn off of the excess energy.
This problem is exacerbated because a snake doesn’t know when it’s eating too much food, so it won’t refuse food. This applies especially to boas and pythons, which are sedentary snakes. Other snakes, like colubrids and elapids, are far more active and so stand less chance of getting fat.
It also depends on the season. According to the American Zoologist, snakes and other reptiles store more body fat just before the winter months. This is natural, but this same biological instinct can also cause the snake to store too much fat from its diet due to overfeeding.
If a captive snake is fat, it’s because the owner has been feeding it too much food. When a snake gains weight, it will add fat stores both under the skin and in pockets around the body. This will make the snake look thick, especially around the middle at first, but then throughout the entire body.
Can Snakes Get Obese?
Obesity is a medically defined term that refers to a body mass index (BMI) of more than 30. Being overweight is defined as a BMI between 25 and 29.9. Since snakes have a different body structure and don’t store fat in the same way as humans, you can’t say that a snake is medically obese in the same way that a human can be classified as obese.
However, it’s clear to see that snakes in captivity can become overweight, perhaps even obese. Again, this is because the snake’s owner has been overfeeding them (too much/often). This can easily be done because a snake’s diet has to slow down a lot once it reaches two years of age.
Snake Average Weight and Length
Snakes of all species follow a pattern as they grow older. They will grow very quickly for the first year or two years of their life, before ‘plateauing’ and growing slowly from there on out.
Members of the same species will hatch and grow at roughly the same rate, although there are always outliers. The only other factor you have to consider is whether the snake is a male or a female, as the two sexes typically differ in size. Female snakes are normally larger than males.
Average Weight and Length of Hatchlings
| Species | Hatch Length (Male) | Hatch Length (Female) | Hatch Weight (Male) | Hatch Weight (Female) |
|---|---|---|---|---|
| Ball Python: | 10-16″ | 10-16″ | 65-100g | 65-100g |
| King Snake: | 8-11″ | 8-11″ | 9-14g | 9-14g |
| Corn Snake: | 10-15″ | 10-15″ | 6-8g | 6-8g |
| Boa Constrictor: | 14-22″ | 14-22″ | 50-60g | 50-60g |
| Milk Snake: | 5-10″ | 5-10″ | 4-8g | 4-8g |
Hatchlings come out at the same length and weight, regardless of sex. It’s only once they start reaching sexual maturity—at between 1 and 3/4 years—that you start to see a difference in size between the sexes.
There is also a huge variance in the size and weight of hatchlings, even outside the ranges described above, so don’t think that your snake is ‘abnormal’ if they aren’t as described above.
For the first year of a snake’s life, they’re going to grow very quickly, so much so that you will notice the difference week by week if not day by day.
Average Weight and Length Snakes (1-Year-Old)
| Species | Yearling Length (Male) | Yearling Length (Female) | Yearling Weight (Male) | Yearling Weight (Female) |
|---|---|---|---|---|
| Ball Python: | 30-40″ | 30-50″ | 500-800g | 500-1000g |
| King Snake: | 24-30″ | 24-30″ | 250-300g | 250-300g |
| Corn Snake: | 24-40″ | 24-40″ | 35-80g | 50-100g |
| Boa Constrictor: | 36-50″ | 36-50″ | 800g-1KG | 800g-1KG |
| Milk Snake: | 15-40″ | 15-40″ | 100-500g | 100-500g |
At this point, females start to get longer and heavier than males. After two years, you should stop feeding for growth and start feeding them for sustenance. That is, unless your snake is underweight and a problem feeder, in which case you should keep feeding the snake to try and get it to full adult size.
Average Weight and Length Snakes (2-Year-Olds)
| Species | Adult Length (Male) | Adult Length (Female) | Adult Weight (Male) | Adult Weight (Female) |
|---|---|---|---|---|
| Ball Python: | 40-50” | 50-60” | 1300-1700g | 1400-1900g |
| King Snake: | 35-37” | 39-41” | 300-600g | 700-900g |
| Corn Snake: | 40-60” | 30-50” | 500-700g | 700-900g |
| Boa Constrictor: | 60-90” | 70-100” | 8-12kg | 10-15kg |
| Milk Snake: | 20-60” | 20-60” | 300-1300g | 300-1300g |
Any variance in the size and weight of a snake species is normal. Milk snakes are a perfect example. There are two dozen different milk snake subspecies, and some grow much bigger than others do.
Some snakes are bigger than others because of their genetics. If you know for a fact that you’re feeding your snake a normal diet, and you can’t spot any signs of your snake being overweight for its length, then it’s likely that there’s no problem.
How to Tell If Your Snake Is Overweight
Scale spreading is a term that refers to your snake’s scales moving further apart so that you can see the skin below. This happens when the snake gets so large around the middle that the scales aren’t big enough to cover the surface area of the snake’s skin.
A small amount of scale spreading is normal after a snake has a large meal. However, if scale spreading occurs but doesn’t go away, this is a sure sign that the snake is overweight. In the worst cases, you will also notice scale spreading elsewhere on their body, like behind their head. Scale spreading itself isn’t much of a problem, it’s a symptom.
Snake Obesity Symptoms
A snake that’s overweight will also display other symptoms:
- Large around the middle. This is normal after a large meal, but if overweight, it will have excess weight around its gut.
- Softer and heavier. Snakes usually feel quite firm and muscular when you hold them. An overweight snake will quite literally feel heavier, but will also feel softer than a snake of average weight.
- Inactivity. This is a cause and symptom of obesity. This is most evident during handling when most snakes are quite active.
Snake Overeating Health Problems
If a snake eats too much, it will have similar health problems to an obese person. Its arteries can become clogged with fat, and it can have liver and kidney problems because of excess fat.
These issues shorten the life expectancy of a snake considerably, so it’s wise to do something about the problem before it gets out of hand.
Weight Differences Between Snakes
Some snakes are naturally thinner than other snakes. A ball python is normally quite thick around the middle. A corn snake, by contrast, is thinner. A green snake is thinner still.
What to Do If Your Snake Is Obese
If your snake is obese, put it on a controlled diet. If you have a feeding schedule, adjust it so that you are feeding your snake less regularly. To help your snake lose weight, you should halve the amount that you feed your snake or double the amount of time in between feeds.
Add something to your snake’s enclosure that it can climb. Branches work well, as do non-natural plastic items. These encourage your snake to move around more which will help it to burn off extra fat. In the same way, handling your snake more often will encourage it to move about more.
