Hind Leg Degeneration In Pet Rats: The Complete Guide

Whether it’s in their cage or in free roam area you’ve set up for them, pet rats love to move around and explore all the nooks and crannies. As they get older though, their bodies become less and less able to do so, which is a normal sign of ageing. Just like humans, older pet rats can suffer with diminished mobility and it’s important to know how to take care of them properly.

The most common issue older rats face is Hind Leg Degeneration (HLD), which basically means that the back part of their body is slowly becoming paralysed to the point, where your pet rats can completely lose the ability to control it. This particular disease generally occurs earlier in males, rather than females, due to a few key factors.

  • Size. Males are usually bigger in size than females and have a higher tendency to being overweight, which can put more strain on their bodies.
  • Kidney function. Male rats are more prone to kidney failure due to their size and diet.
  • Laziness. It’s a well known fact that boys tent to be more lazy than girls, that’s why is extra important to get your pet rats moving about more.


Hind Leg Degeneration is a gradual process, but if you know your rats well, you can definitely notice slight changes in the way they move and behave. Here’s a few things to look out for.

  • It usually starts with a slight shuffling of the back legs and your rattie walking on flat feet, instead of his/her heels off in the air.
  • You will also be able to feel the back part of your rat’s body lose muscle and be a bit bony to the touch.
  • He/she can occasionally stumble or lose balance and his/her tail can become floppy and drag behind them.
  • Over time, they will experience the loss of ability to control the back part of their body, including dragging their legs behind them or even pooping and peeing without realising.

Even though Hind Leg Degeneration can look scary for their owners, pet rats are hardy animals and, after the initial struggle and confusion, can adapt to the circumstances and still live a happy rest of their rattie life.

What Causes Hind Leg Degeneration In Rats?

HLD is widely associated with old age, but there are three different types of it and specific health issues that cause each type.

  1. Nerve degeneration. This is by far the biggest cause of HDL in pet rats and other animals. As they get older, their spine nerves become worn out and start to fail in sending electrical signals needed for the rats to properly move their back legs and tail. That results in weakening of their muscles and deterioration of general ability to control them. Unfortunately, once this process sets in, there’s no way of curing it, but there are steps you can take during your rat’s life to prevent it as much as possible. We will discuss those further down the article.
  2. Arthritis. Although it’s not quite HDL, arthritis can cause very similar symptoms and therefore be often misdiagnosed as Hind Leg Degeneration in pet rats. This type of degeneration in hind legs is mostly caused by wearing out of the joints. As the soft part of your rattie’s joint, which cushions and absorbs shock and movement, wears out, the area becomes inflamed and swollen, leading to pain when your rat is trying to walk. The main difference between arthritis and Hind Leg Degeneration is that the former can be treated with anti-inflammatory medication and greatly improved by appropriate treatment. That’s why is important to properly diagnose your rat’s condition before taking any other steps.
  3. Kidney failure. Kidneys play a vital role in absorbing calcium by your rat’s body and digesting protein, which is the main muscle food. Once the kidneys start failing, the calcium deficiency causes your rattie’s bones to release their supply of calcium and that often leads to its crystallisation in the joints, which in turn can simulate arthritis symptoms. The hind legs and tail are also the first areas to be hit by muscle degeneration if there’s not enough protein in your rat’s system. So if the kidneys give out, it’s highly likely that symptoms similar to Hind Leg Degeneration will start occurring.

How To Prevent Hind Legs Degeneration

  • Exercise, exercise and exercise! It has been proven by countless scientific studies that regular and life-long activity can significantly help rats in staying healthy and mobile for longer. Especially when it comes to the first type of Hind Leg Degeneration connected to the nerve damage, exercise can make a huge difference.

To achieve the best results in keeping your rat healthy you should introduce physical activity early on and make sure it’s constantly in your rat’s life. Short and spontaneous burst of exercise won’t have the same result as an active lifestyle and can actually lead to more oxidation in your rattie’s body, which causes faster ageing and cell degeneration.

Regular psychical activity will significantly improve your rat’s muscle mass and keep their tail tendons younger and more flexible for longer. It can also help with shedding any excess weight your rat might accumulate on their body and therefore reduce the strain on their heart, kidneys and other vital organs.

  • Nutritious Diet. Overfeeding has a direct link to obesity in rats and is making them less physically able. Studies show that rats fed a restrictive diet – about 80% of the standard food allowance – are more alert and active even in their old age. Their cells are less degenerated and fat deposits on their organs are much lower, leading to less stress on the muscles, tendons and bones. A balanced diet including daily intake of good oils like omega or linseed will be also beneficial to ensuring healthy joints, as well as keeping kidneys working properly and therefore reducing the possibility of your ratties developing Hind Leg Degeneration.

If your rat is showing signs or arthritis, you can treat him/her with anti-inflammatory drugs any vet can provide. B vitamin supplements can also help with your rat’s nervous system and even slow down Hind Leg Degeneration caused by the damage in the spine nerves.

What To Do If Your Rat Has HLD?

First, don’t panic! If your rattie is not suffering from pain and extreme discomfort, there’s no reason why they can’t live out their life in piece of their own home.

Of course, they won’t be able to climb to the top of the cage and sleep in their favourite hammock. They might not even be able to get inside a hideaway or make it to the litter tray before they poop, but isn’t it the same with humans? Old age affects everyone and there’s no escaping it, but you can easily make adjustments to suit your rat’s elderly needs.

  • Assess your rat’s abilities. If your rat is in the early stages of HLD, they might still want to spend time with their cage mates and pile up in the same hammock. A few more ledges and ramps can help them to be social and move around the cage in a comfortable and safe manor. But remember, if you notice that your rat is having difficulty with climbing or even accessing food and water, it’s time to make some serious changes.
  • Provide disabled access. Making the cage safe is the most important thing when taking care of a rattie with Hind Leg Degeneration. If your rat can’t move very well, but still enjoys the company of other rats, there’s no problem with leaving them together in one cage. As long as you make sure that the bottom of the cage is arranged on one level with easy access to a comfortable bed, food and water and a toilet, your rat will be perfectly content with these living arrangements.
Rat on a ladder
Source: @rachaelsrats Instagram
  • Move him/her to a retirement home. HDL can progress quickly, so it’s extremely vital that you assess the situation daily and make further changes, when needed. You might think that moving your elderly rat into a separate cage with no mates is cruel, but in this situation it’s the best option to keep him/her comfortable and stress free. Once the disease reaches the point, when your rattie can’t move around at all and other rats just simply start to annoy him/her, it’s time to make a move. The best way to do it is to have a small cage (or even a cat carrier) set up, where he/she can live out the rest of their life in piece. Make the floor nice and soft with some paper substrate and a blanket or a house your rattie can lay in. Put some food down and hang a bottle of water directly next to him/her, so you can monitor how much he/she eats and drinks a day.
  • Do a daily clean-up. It’s tremendously important that you clean out your elderly pet rat’s cage every day. If they can’t move and pee/poop around themselves, you need to make sure their area is clean and disinfected daily to prevent infections and further sickness. Change the blankets or houses and give your rat a scrub, especially in their belly and genitals areas. As they can’t clean there themselves, it needs to be your job to help them out in this department. It might be a bit gross at times, but your pet rat will be grateful for your efforts.

Love Them Until The End

In most Hind Leg Degeneration cases euthanasia is not required, but it’s ultimately the pet owner’s responsibility to make sure their animals don’t suffer unnecessarily and over prolonged period of time. If you decide to care for your elderly pet rats at home until they pass away naturally, you can still enjoy each others company for some time, although it’s different for every rat.

Even though HLD doesn’t cause death directly, the gradual increase in overwhelming paralysis can be the last straw before passing. All you can do in any advanced cases of HLD is to provide safe and loving environment. You will probably notice your pet rats being more needy and cuddly, so use this time to comfort him/her as much as possible and know, that you’ve done everything you could for them.

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