Antibiotics for Fish (What Is Best?)
Dealing with sick disease is hard and often overlooked by aquarists. Sometimes it can be hard to identify when a fish is sick and even harder to know if it’s an infection, parasite or something else.
From there, you need to determine if the parasite is external or internal, if the infection is fungal or bacterial. A lot of work is needed to correctly diagnosis your fish and start treatment, but unfortunately, many hobbyists don’t catch these diseases at the right time.
The most crucial step to treating a sick fish is being well prepared. Many of these diseases pop up out of nowhere, leaving a healthy fish gasping for air at the bottom of the tank the following day. It is at times like these that an assortment of medications and a quarantine system and can make treatment effective and quick.
Lot of these medications are antibiotics meant to cure bacterial infections. But how do you know when to start fish antibiotics, and what are the best medications available? How do antibiotics for pet fish work in the aquarium setting, Today’s post is all about answering these questions. Let’s start with the first…
How Do Fish Antibiotics Work?
In order to understand when to use antibiotics, we need to the work behind antibiotics.
It’s very important to understand that fish antibiotics do not magically cure fish of their ailments. Instead, fish antibiotics decrease the growth of bacteria populations until the immune system of the fish is in a position to recover and naturally build resistance.
In other words, fish antibiotics interfere with the reproductive and physiological abilities of bacteria, stopping or slowing spread and growth. There are two main types of bacterial infections you need to be conscious of: gram-positive bacteria and gram-negative bacteria.
Gram-Positive Bacteria vs. Gram-Negative Bacteria
Knowing the difference bacteria can be quite challenging, but it’s essential for accurate diagnosis and treatment. In short, the difference between gram-positive bacteria and gram-negative bacteria is the composition of their cell wall.
- Gram-positive bacteria have a thin cell wall covered by an outer membrane. Gram-positive bacterial infections are rare in the aquarium setting and usually made of Streptococcus spp..
- Gram-negative bacteria doesn’t have an outer membrane but instead they have a thick polymer layers. Most aquatic bacterial infections come from gram-negative bacteria, like Aeromonas spp., Flavobacterium spp., Vibrio spp., and Pseudomonas spp..
The most definitive way to differentiate between gram-negative bacteria and gram-positive bacteria is by performing a gram stain, hence the name. Gram-negative bacteria will stain pink while Gram-positive bacteria will stain blue.
Only physical symptoms can be observed for diagnosis because most hobbyists aren’t able to perform such a test. Gram-negative infections are usually more deadly and aggressive to fish.
Identifying Bacterial Infections
A bacterial infection can be hard to diagnose. They often happen alongside other infections and diseases with similar symptoms, especially fungal infections. However, bacterial infections are much more frequent than true fungal infections as bacteria readily live in aquarium water, waiting to affect a compromised pet fish.
The most common symptoms of a bacterial infection are:
- Inflammation or redness
- Cloudy or swollen eyes
- Bloating
- Irregular mucus/slime coat
- Fragile and frayed fins
Infection is largely a result of injury alongside malnourishment and/or poor water conditions. If the water quality is good and diet is maintained it is very possible for your fish to fight off infection, though sometimes even the strongest pet fish can succumb to harmful bacteria.
It is near impossible to differentiate between gram-negative bacteria and gram-positive bacteria without a gram stain. Since gram-negative bacterial infections are much more frequent (in freshwater), most hobbyists use a fish medication that will target those bacteria first. In marine fish, gram-negative is more common.
Treating Aquarium Fish With Antibiotics
Knowing what to treat is a very important step. Fish antibiotics have exact instructions and the treatment schedule needs to be followed strictly.
How do these antibiotics move from the water into your fish?
How To Give To Your Pets
Treated food is the best way to give your fish antibiotics is through. This saves damage to nitrifying bacteria allows the medicine be administered in more direct, higher doses and. But when you this might be impossible if your pet fish refuses to eat though.
Most fish antibiotics can be dosed directly into the aquarium, and then incorporated into the body of the fish, but how? This involves some physiology.
Fish deal with osmoregulation. Osmosis is the process of a solvent moving from an area of low concentration to an area of high concentration across a semipermeable membrane in order to balance between the external and internal environments. Osmoregulation differs between freshwater and saltwater life.
Freshwater fish are hypertonic, meaning that their internal environment contains more salt than their external environment. Which causes water to flow through the gills and to be absorbed by the body.
On the other hand, saltwater fish are a hypotonic fish, meaning that their internal environment contains less salt than their external environment. Which push the water to leave their body. In order to make up for this loss, saltwater fish need to actively drink water and conserve it by sending some to their digestive tract.
In an aquarium setting, this is makes an advantage to saltwater species. Because saltwater fish actively take water into their bodies, soluble antibiotics tend to enter the internal bloodstream in the marine environment immediately.Yet giving them soluble antibiotics. Freshwater fish can also be given, though feeding them which is much more effective.
There are only two ways to administer fish antibiotics for both saltwater and freshwater fish. In case if your fish is suffering from an external infection, then we recommend you with bath treatments, even though they can sometimes be ineffective. But if your fish is showing signs of internal infection, then you should use food treatment is the way to go.
Bath Treatments
Bath treatments are the best choice for treating external infections when the fish refuses to eat or there are other limitations.
Bath treatments are most favorable when there is no access to a quarantine system that allows for fish antibiotics to be directly dosed into the aquarium. This could be a result of invertebrates and sensitive corals or where there is large biological filtration that could be affected.
The problem with bath treatments is that not all the medicine actually enters the bloodstream of the fish. In addition, the constant transferring of the fish can cause stress and injury; if the fish dies during this transfer, then there was probably little hope for it to live in the first place.
Antibiotic-Treated Food
Food mixed with fish antibiotics is the best treatment for bacterial infections is. but you will need a binding factor, like Seachem Focus, so that no food is leaked out of the fish antibiotics .
The advantage of this method is that it allows the medication to be administered in large doses. However, it requires that the fish is still actively eating.
Lastly, injection is a possible option t, though many hobbyists do not have this option available to them.
Generally an injection is the most effective method of treating infections and expensive fish, like koi or oscars, but is often unattainable for the average hobbyist.
The Most Populaire antibiotics
Different fish antibiotics are effective depending on the type and severity of the infection. Most of these fish antibiotics can be used in freshwater, saltwater and brackish systems and but it is recommended to read all instructions closely.
1. Thomas Labs Cephalexin (Keflex)
Thomas Labs Cephalexin make two grades of fish antibiotics: Thomas Labs Fish Flex and Fish Flex Forte. Even though this antibiotic is labeled as ornamental fish antibiotics, lot of hobbyists have actually found it to be most effective against invertebrate bacterial infections, especially those found in anemones.
This is a very broad fish antibiotics and needs to be administered in a quarantine system or bath for 5-10 days.
2. Thomas Labs Ciprofloxacin
Thomas Labs also provides two grades of this antibiotic: Thomas Labs Fish Flox and Fish Flox Forte.
This product is regularly used to treat anemones and other invertebrates, and it is more effective than cephalexin.
Specifically, this medicine can be dosed in a quarantine tank or a bath or in for gram-negative bacterial infections over the course of 5-7 days.
3. Thomas Labs Amoxicillin
Amoxicillin is a very popular antibiotic for other animals and human use as well. But amoxicillin isn’t commonly used in the aquarium as a viable course of fish antibiotics. Regardless, Thomas Labs carries Thomas Laboratories Amoxicillin Fish Mox Forte and Fish Mox.
If for anything, amoxicillin is one of the few fish antibiotics, alongside ampicillin and penicillin, used for gram-positive bacterial infections treatment. These fish antibiotics and should be administered in a quarantine tank or bath treatment for 5 days should not be used with invertebrates. Still, hobbyists prefer other fish antibiotics first.
Can You Use Amoxicillin In The Aquarium?
Never put antibiotics made for human consumption in the aquarium and vice versa. Medications should always be dosed carefully and seriously. Aquarium brands have specific formulas for making ornamental fish drugs that are not made for human consumption.
While you can use aquarium brand amoxicillin in the aquarium, lot of hobbyists prefer other options first. Amoxicillin is also known for treating animals and humans but is generally useless in the aquarium setting. Treating fungal infections in the eyes is One of the only ailments hobbyists have found amoxicillin to be useful for.
4. Thomas Labs Clindamycin Hydrochloride
Thomas Labs Clindamycin Hydrochloride is an antibiotic that exerts a bactericidal action on some gram-negative and gram-positive bacteria in fish. It is effective for control of some common bacterial diseases in fish, including ones caused by bacteria such as Pseudomonas, Aeromonas and Mycobacterial (Gill diseases and Chondrococcus).
5. Thomas Labs Hyclate
Thomas Labs Hyclate is an antibiotic that apply a bactericidal action on gram-positive and some gram-negative bacteria in fish. Used to control some common bacterial diseases in fish, including Fin and Tail Rot, Septicemia, Mouth Rot.
6. Thomas Labs Fluconazole
Thomas labs provide an antifungal medication used for systemic fungal and topical infections in fish. It is very effective against fungus that is susceptible to Fluconazole, such as hoferi , Ichthyophonus and Saprolegnia fungus.
7. Thomas Labs Metronidazole
Thomas Labs Metronidazole is an antibiotic that can be used for bacterial infections and parasitic. It is has high effectiveness against anaerobic bacteria (bacteria that grow only where there is no oxygen).
8. Thomas Labs Ketoconazole
Fish Fungus™ (Ketoconazole) from Thomas Labs is a broad-spectrum antifungal medication used to cure systemic and topical fungal infections in fish. made for use in aquariums, this fish medication is effective against fungus that is susceptible to Ketoconazole.
9. Thomas Labs Penicillin V Potassium
Fish Pen™ (Penicillin V Potassium) is an antibiotic that exerts a bactericidal action on gram-positive and some gram-negative bacteria in fish. It is useful for control of some common bacterial diseases in fish, including diseases caused by bacteria such as fin and tail rot and Flexibacter infections.
10. Thomas Labs Sulfamethoxazole/ Trimethoprim or SMZ-TMP
Fish Sulfa Forte® (Sulfamethoxazole/ Trimethoprim or SMZ-TMP) is an antibiotic that exerts a bactericidal action on gram-positive and some gram-negative bacteria in fish. It is useful for control of some common bacterial diseases in fish, including diseases caused by bacteria such as Aeromonas, Pseudomonas, and Mycobacterial (Gill diseases and Chondrococcus).
Which Are Safe?
All medications that are have “for aquarium use” are safe for your aquarium. However, you should always follow the instructions carefully to avoid any overdose on some medication.
There is one thing you should stay away from, and that’s ‘natural’ medications.
Avoiding ‘Natural’ Antibiotic Forms And Medications
While several reputable aquarium brands offer great products to their consumers, others take advantage of branding treatments. Some of the latest trends in the aquarium hobby have arisen from medications and ‘natural’ fish antibiotics and which end damaging the fish more than helping them. Some of these organic alternatives include natural oils and tannins.
Tannins can add lot of benefit to aquatic systems and can lead to healthy fish, however, they don’t help with bacterial infections directly. Research has shown that tannins can only be effective at combatting bacteria at very high concentrations,much more than is reasonable for any tank size.
Natural oils, like those found in PimaFix and MelaFix and are also damaging to the health of your fish. Though these oils might have a medicinal smell and look, it has been shown that they are linked to swim bladder damage and they are ineffective at low concentrations. Similarly, aloe vera also increases available sugars for bacteria to feed on and inhibits your fish’s ability to exchange oxygen.
Though it might seem like a good idea to stay as natural as possible when it comes to treating fish diseases, it is usually easier and safer to use true and tried fish antibiotics.
Can You Give Your Fish Over-The-Counter Human Types?
You should never give your Fish medications intended for human consumption. Even though the chemical makeup may be similar between medicines, factors like efficacy, solubilities and dosages cannot be known.
Some fish antibiotics have become hard to find recently. Though you may not be able to get the antibiotics of your choice, there many aquariums brands such as Seachem and API that provide many alternatives. This makes treating your fish fast, easy and safe.
Can Humans Take Fish Meds?
Where To Buy
It’s actually getting harder these days to buy fish antibiotics as regulations get tougher from states (and the food and drug administration). Supplies have also gotten tighter. Here are a few places you can find the fish med you are looking for.
Final Thoughts
There’s probably a lot more to fish antibiotics than you might think. Identifying a bacterial infection in your fish can a difficult step, but treatment doesn’t need to be complicated.
First, understand how to distinguish between gram-positive and gram-negative infections. Then pick a course of fish antibiotics and a method for administering them. Keep up with water parameters and water changes and keep your fish eating.
The infection should start to heal and your fish will get back to normal in the very soon.
