Unfortunately, it can be challenging to know if something is wrong with your guppy. Fish can’t tell you when they’re feeling ill. In order to diagnosis your guppy, you’ll need to notice the signs of a sick fish.
Some of the signs that your guppy is sick are:
- Spots on the body
- Decreasing appetite
- Swollen bodies
- Dull coloring
- Water issues in the tank
There are more signs to tell if your guppy is under the weather. This article will provide visual signs as well as other signs of having a sick guppy.
1)White Spots on the Guppy’s Body, Fins, and Tail
White spots on your guppy or any other fish in your aquarium are a sign of ich. The white spots will be fairly noticeable since the white spots are very bright and small. Spotting ich is a lot easier than finding lice on a human head.
What’s ich?
Ich, or ichthyicphthirius Multifilis, is a parasite that burrows into your guppy. It is incredibly contagious. If one fish has it, the rest of your tank is at risk.
Ich can be super hard to clear out from a tank, so it’s important to spot it early and treat it as fast as possible. Ich can go away on its own, but you should make sure that the water temperature is at appropriate levels. You can also buy medication at your local pet store to treat the tank.
2) A Tail That Looks Like It’s Missing Pieces
If you have any aggressive fish in the tank with your guppy, this might be the result of a fight. But, missing tailpieces can also mean fin rot.
If the tail is missing pieces or looks like it’s stuck together, your guppy might be suffering from fin rot. Fin rot is a bacteria that can be found in tanks with poor water quality. In order to remove fin rot from a tank, you’ll need to change the water and clean off all rocks, plants, and decorations.
3) A Guppy Struggling to Breathe
If you notice that your guppy is struggling to breathe, this is one of the signs of gill flukes. Gill flukes are parasites that burrow into your fish’s gills. These parasites are typically found when water quality is poor.
If your fish is struggling to keep its gills open, the culprit is likely gill flukes. You’ll need to buy a treatment for the entire tank to cure your guppy. Medications for gill flukes are available in your local pet store.
4) Guppies Aren’t Eating
Like all other animals, a loss of appetite is a huge warning sign that you have a sick pet. If you notice that the fish food is not being consumed and is just disintegrating into your water, it could mean one of two things. The first is that you’re feeding your fish too much. The second could mean ich.
If you decrease the amount of food and your guppy still isn’t eating, you’ll need to look for other warning signs to ensure that this is ich and then treat accordingly.
How often should you feed your guppy?
Feed your guppy at least two different times throughout the day. Your guppy should be eating fish food that is high in protein. You can also supplement some vegetables into your guppy’s diet, such as peas or lettuce. If there is a lot fo extra food, you’re feeding your guppy too much.
5) Guppies are rubbing their bodies up against rocks, plants, and decorations.
If you notice that your guppy has been trying to scratch itself on the different tank decorations, it could be either ich or gill flukes. Since ich is a parasite, it’s incredibly uncomfortable for your guppy. Your guppy will rub its entire body over whatever it can to try and remove the ich.
If your guppy is primarily rubbing against its own gills, the culprit is likely gill flukes. So, it’s important to note where your guppy is rubbing because ich and gill flukes have different treatments.
6) A Swollen Body with Raised Scabs
A swollen fish body with raised scabs usually means dropsy. Dropsy is a bacterial infection. Although it isn’t contagious, it’s best to remove the affected fish from the tank so you can focus on trying to mend your guppy back to health.
Dropsy, unfortunately, is hard to cure. You’ll need to keep the fish well-fed with the highest quality food and provide medicine. And, it’s also a good idea to change out the water in the big tank to prevent any other fish from developing this disease.
7) Gills that appear like they’re bleeding.
If your guppy’s gills look like they’re bleeding, it’s a sign of gill flukes. Thankfully, gill flukes have very pronounced symptoms that make it one of the more manageable diseases to catch early on.
By the time the gills look like this, you’ll also notice other symptoms of gill flukes, such as your guppy struggling to breathe. Gill flukes have a lot of signs, so once you see all of them, the diagnosis will be quit.
8) Dull Coloring
Guppies are known for their bright and beautiful colors. So, if you notice that one of your guppies is starting to look a little dull, you might have a sick fish in your tank.
The color can also fade during times of high stress. You want to keep your guppy’s life as stress-free as possible to reduce any illnesses.
What causes stress in guppies?
- Having too many fish in the tank can be stressful for your guppy
- Having aggressive fish in the tank. Guppies are easy-going, so they aren’t going to get along with super aggressive fish.
- Constant water changes can be stressful.
- Improper water conditions. Guppies are anti to South America, so they thrive in warm, freshwater.
9) Hiding Instead of Swimming Around the Tank
If your guppy is hiding among the plants or within your decorations instead of swimming openly, your guppy could be sick. When guppies don’t feel well, they tend to hide to make themselves less visible to predators. And, just like when you’re sick, guppies don’t feel like doing too much extra work.
Guppies can also hide if they are stressed out about any aggressive tank-mates. If you’ve recently introduced a new fish to the tank and your guppy is hiding, it might not be a good match. Be sure to research before adding a new fish to your tank to ensure everyone will get along.
What kind of fish get along well with guppies?
Guppies are community fish and would love to share their tank with other like-minded fish. Guppies do enjoy being together since they are community fish so you could just have a tank full of guppies
But, variety is the spice of life. You could always add some mollies to the tank. Corydoras are also a great tank mate for any guppy.
Be sure to stay away from Red-Tailed Sharks or any known aggressive fish. And, remember that any tank mate will also have to be a freshwater fish.
10) Hanging Out at the Bottom of the Tank
Guppies love to swim around their entire tanks. Guppies tend to use all the available space for swimming when they’re in good health. If your guppy is hanging out at the bottom of the tank, it’s a clear sign that your guppy is sick or stressed out.
If your guppy seems to be spending too much time at the bottom of the tank, it might be time to check your water levels and ensure that the tank is healthy and thriving. Check the temperature and pH levels to ensure that your guppy’s living space is at optimal conditions.
11) Having a Bulging Belly
If you spot a belly bulge on your guppy, your first thought might leap to an illness, but your guppy might just be pregnant. If you have a male guppy and a female guppy in a tank together, they’re probably going to reproduce.
A bulging belly doesn’t have to mean that your fish is sick. It can often be a good thing – provided you have enough space left in your tank to support the guppies. If you plan on keeping any of the babies, it’s best to move them to a different tank since the mother will eat as many as possible after giving birth.
How Can You Tell the Difference Between Female and Male Guppies?
Female guppies are less colorful than their male counterparts. Their rear fin is triangular. Additionally, females are larger than the males. Females can actually be twice as large as male guppies.
Male guppies are incredibly colorful. And, the males have large and colorful tails. They are much smaller than the females and have a more slender shape.
It takes about a week after a guppy is born to determine its sex.
12) It Came From a Sketchy Store
Always buy fish from reputable stores. If you go into the fish store and all the fish look dull, it might be a bad idea to purchase a fish from there. Dull fish that aren’t swimming around a lot are going to be difficult to introduce to an already existing tank.
If the salesperson seems to have a good bit of knowledge and the fish are brightly colored and swimming around freely, it will be a good place to purchase your fish. Use common sense when buying a fish. If the place feels off, it probably doesn’t take great care of its fish.
13) Wounds From Fights
If there were any aggressive fish in the tank, they could attack your guppies resulting in wounds on your guppy’s body. If you don’t take action and remove the aggressive fish from the tank, this could be bad news for the guppy.
Small wounds typically heal up fast. However, if your guppy is stressed out by mean fish in the tank, it can affect their immune system and make it harder for the cuts to heal up. A weak fish can be a dead fish in an aggressive tank.
14) Protruding Eyeballs
Protruding eyeballs can be the symptom of a disease called Popeye. Don’t let the funny name fool you – it can be difficult to treat. Popeye can affect one or both eyes of your guppy.
Some fish have protruding eyeballs already, so it can be harder to diagnosis in other kinds of fish. But, in a guppy, this is relatively easy to tell when your fish is suffering from popeye.
What causes popeye in fish?
- An injury can result in popeye. If only one eye is affected, it’s likely from an injury.
- Infection can cause popeye. The infection can be bacterial, fungal, or parasitic.
- Poor water conditions can result in popeye.
15) Open Sores
Open sores could be the result of fighting or could be linked to a more serious condition – tuberculosis. Tuberculosis in fish can actually be transmitted to humans if the fish is handled directly. It’s contagious between fish and humans.
Unfortunately, tuberculosis in fish cannot be cured. If the fish doesn’t die immediately from contracting this disease, you’ll need to let your fish go on. You’ll want to do this as fast as possible since it is incredibly contagious. You don’t want your other fish in the tank to catch tuberculosis.
16) Red Streaks Over Fish’s Body
If your fish has bloody red streaks covering its body, fins, and tail, your fish might be affected by septicemia. Septicemia is blood poisoning. It is caused by a bacterial infection.
Guppies can also be affected by blood poisoning if an open wound gets infected. It’s important to reduce the chances of your fish getting hurt as these open wounds can be the source of a lot of diseases.
17) Guppy Being Lethargic
Guppies swim a lot. If you notice a change in your fish’s behavior, this might be a symptom of a disease. Guppies are known to swim around all the time in groups. So, if one of your fish is away from the group and not moving as much, it could be sick.
Be sure to observe your fish regularly so you can tell if one of your guppies is acting out of the normal. If you don’t have an idea for how your fish normally acts, you won’t be able to determine if your guppy is sick.
18) Cold Water
Since guppies are native to South America, they are accustomed to warm water. You’ll need to keep your tank between 74 and 82 degrees Fahrenheit. If the temperature gets cooler than this, it can be a breeding ground for parasites.
There is one particular parasite that primarily affects guppies. When a guppy is affected by this parasite, it is called guppy disease. Other fish can contract this disease, but it’s usually found in guppies.
How do you keep your tank warm?
You’ll need to purchase a heater for your tank. This is especially important if you live in a colder climate. You’ll also need to add a thermometer in the tank to ensure that the water temperature is within the correct levels.
Don’t keep your tank next to a window or a drafty area in your house. A cold tank can cause a lot of issues for your guppies, so this is one of the most important things to keep track of when caring for guppies.
19) Sinking to the Bottom or Floating at the Top
Swim Bladder disorder is typically spotted when the guppy has buoyancy issues. Guppies typically have their heads straight up while they swim when they are affected by this disease. Fish affected by this disease will typically have an extended belly, as well.
The fish community is split over treatment of swim bladder. Some members believe that this is not curable, and the best course of action is to euthanize the fish affected before it spreads to any other fish in the tank. Others believe that this can be cured by heating the water back up to appropriate temperatures.
A home remedy would be to feed the affected fish a cooked and peeled pea. Guppies do enjoy eating peas, so they might see this as a treat. If this doesn’t work, euthanasia is the only viable option since this is painful for guppies.
20) Gold Dots All Over Your Guppy’s Body
Similarly to ich, there is another disease called velvet that can be spotted by gold spots covering your guppy’s body. Fortunately, this disease is not as common in hobby tanks, so you’re not likely to see this disease in your guppies at home.
These gold spots start off incredibly small, so it is a difficult disease to notice at first. Most fish owners only realize that velvet has taken over their tank when the fish start bleeding.
Velvet is cured with a copper treatment. But this can affect other animals in your tank so be sure that all animals in your take can withstand the treatment of this disease.

Hi, my name is Adam and I’m an aquarium enthusiast! I didn’t discover the joys of being an ‘aquarium fanatic’ (as some of my friends call me!) until I was in my 20’s. When I first started out I found it difficult to find all the information I needed so I started this website to compile all the useful information I can think of. Enjoy!
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