Fish Mox for Cats: Treating Cat Illness with Fish Antibiotics

Because cats can be subject to infection by a number of different types of microorganisms, treating illness in your pet cats can become an expensive proposition. When you have a cat or kitten with a recurring infection and you know the solution is a course of antibiotics, you can save money by treating at home using Fish Mox rather than going to the veterinarian.

The purpose of this handy guide is to explain what Fish Mox is and how purchasing amoxicillin and other such antibiotics intended for fish can save you time, money, and hassle when treating known infections in your pet cat or kitten. Make sure that you know what types of infections Fish Mox can treat, how to spot them, and how to properly treat them to get the most out of Fish Mox for your cats’ optimum health.

Bacterial Infections

Bacterium, fungi, protozoa, and viruses are all capable of causing infections in your cat’s body. The bacterium is capable of attacking your cat’s body through a variety of means, including something that the cat eats, an open wound, or even just by being in the environment.

Bacterium comes in a variety of different shapes and sizes, and so they most often need to be appropriately diagnosed by a veterinarian. The veterinarian will determine what is infecting the feline to figure out what is going on so that a cause can be determined.

A single, microscopic one-celled organism is capable of causing a whole host of different illnesses, including:

  • skin infections
  • gastroenteritis
  • urinary tract infections
  • pneumonia
  • and many other feline diseases…

If the infection is not treated quickly and adequately, the bacterium will continue to multiply, and the illness will worsen. If you know what the disease is, you can treat it properly using antibiotics, but if you do not know what it is, a diagnosis will be required.

When your cat becomes sick, the best thing that you can do is take it to a veterinarian to be diagnosed so that the proper medication is diagnosed. However, many types of feline infections are recurring, and so once you know what kind of infection you are dealing with the notion of going back to the veterinarian every time the infection comes back can be costly.

How do Antibiotics Work?

The purpose of an anti-bacterial antibiotic such as Fish Mox is to destroy the bad cells in an animal without causing damage to the healthy cells. Different antibiotics work in different ways, but generally, the purpose of an antibiotic is to prevent the bacterium from creating cell walls, which inhibits reproduction.

Another goal of an antibiotic medication may be to starve out the bacterium. This is done by making it impossible for the bacterium to transform glucose in the body into energy, which is a primary function that all living cells do.

There are a number of popular antibiotic medications, including enrofloxacin, amoxicillin, metronidazole, and clindamycin. Each is generally prescribed for different purposes.

  • Enrofloxacin – Also known as Baytril. Enrofloxacin is often indicated for respiratory infections, skin infections, and urinary tract infections.
  • Amoxicillin – Also known as Clavamox or Clavulanic acid. Amoxicillin is often indicated for feline wounds, respiratory infections, and skin infections.
  • Clindamycin – Also known as Antirobe. Clindamycin is often indicated for gastrointestinal issues, and for periodontal disease and other infections of the mouth.
  • Metronidazole – Also known as Flagyl. Clindamycin is most commonly indicated for bacterial infections, soft tissue infections, bone infections, and feline dental infections.

Over-The-Counter Antibiotics for Cats

When you have a cat or kitten who is suffering from a recurring infection, you may find yourself revisiting the veterinarian repeatedly for the same answer and the same fees and prescription. If this is getting a little overwhelming, then the solution may be to buy over the counter antibiotics.

It is important that you try to find the right antibiotics for your cat, especially if you are buying off-label antibiotics, such as fish antibiotics for cats. Fish Mox for cats is a commonly recommended solution because although it is amoxicillin intended to be used in aquariums, it is the same type of medication that would be prescribed by a veterinarian for use in feline bacterial infections.

If you know how to use it and know that you are dealing with the right type of infection, then you can treat your cat’s infection with Fish Mox and save a significant amount of money by purchasing online from a reputable dealer.

What is Fish Mox and Where to Find It

Fish Mox is a fish medication that is designed to be placed in the aquarium, whereby it dissolves and medicates the water. The drug absorbs into the fish through their scales.

This is the easiest way to medicate fish, since feeding them a medication would be severe. What is interesting about products like Fish Mox, however, is that this broad-spectrum antibiotic (Amoxicillin) comes in the same form that it would typically be administered by a veterinarian for many other types of animals and pets.

What this means is that while Fish Mox is labeled for and sold for aquarium fish, it can also be purchased and used for other animals as well as long as you use it properly. In other words, you can use Fish Mox for cats and kittens who are suffering from certain infections for which amoxicillin would be the proper treatment.

Amoxicillin is an ideal antibiotic for many different illnesses and infections because it halts the multiplication of bacterium, preventing the infection from worsening. This is the most common antibiotic recommended for use in aquariums, although it may not work for every feline infection.

Fish Mox is available online through the manufacturer, ThomasLabs, as well as through a number of pet supply retailers. (Fish Mox is not presently available on Amazon, however other fish antibiotics are available on Amazon.)

How to Use Fish Mox for Cats and Kittens

Although Fish Mox is labeled and originally intended to be for fish, it can also be used for cats and kittens. What is essential to know is that it is the same medication as what you would receive from the veterinarian but more cost-effective because it is available online without a prescription.

There are a number of important considerations when it comes to using Fish Mox for your cats and kittens, however. Keep these considerations in mind when making your purchase as well as administering Fish Mox to your pets.

1. Make sure that you have a good idea of what infection you are dealing with. Some infections are going to be more apparent cut than others, such as urinary tract infections and upper respiratory infections. Other infections may be more challenging to diagnose.

Take care to ensure that you have a good understanding of the symptoms your cat or kitten is experiencing and do some research to determine the proper diagnosis before you begin treatment. Although amoxicillin is a broad-spectrum antibiotic, it will not treat every type of infection.

2. Make sure that amoxicillin is the proper antibiotic to treat the infection. As noted above, amoxicillin is not going to handle every type of infection. Fish Mox will be most useful in treating:

  • bacterial skin wounds and other skin infections
  • respiratory infections including upper respiratory infections and pneumonia
  • ear infections
  • dental infections
  • bladder infections
  • and urinary tract infections.

If your cat is suffering from another type of infection, the Fish Mox may not be beneficial. This is because different types of antibiotics work on different bacterium in different ways. You may need to try a different type of antibiotic to get results.

3. Make sure that you purchase Fish Mox from a reputable source. When you do decide that Fish Mox is the answer, make sure you are purchasing it from a reputable dealer. Because this is not a prescription medication, you will want to buy quality medication from a trustworthy source.

There are many pet products suppliers with names that you can rely on to deliver trustworthy products. Do not be afraid to shop around until you can find a product supplier you can trust to buy your pet antibiotics.

4. Double-check the dosage and administration requirements before giving the medicine to your cat. Most pet products suppliers who deal in Fish Mox for use in cats recommend 5-10 mg of the product for each 1 pound of feline every 12-24 hours. Each capsule of Fish Mox contains 250mg of amoxicillin.

You will need to break up the capsules and measure out the contents depending on the size of the cat. In other words:

  • 1 lb cat: 5-10mg every 12-24 hours.
  • 2 lb cat: 10-20mg every 12-24 hours.
  • 3 lb cat: 15-30mg every 12-24 hours.
  • 4 lb cat: 20-25 mg every 12-24 hours.
  • 5 lb cat: 25-30 mg every 12-24 hours.
  • 6 lb cat: 30-35 mg every 12-24 hours.
  • 7 lb cat: 35-40 mg every 12-24 hours.
  • 8 lb cat: 40-45 mg every 12-24 hours.
  • 9 lb cat: 45-50 mg every 12-24 hours.
  • 10 lb cat: 50-55 mg every 12-24 hours.
  • 11 lb cat: 55-60 mg every 12-24 hours.
  • 12 lb cat: 60-65 mg every 12-24 hours.
  • 13 lb cat: 65-70 mg every 12-24 hours.
  • 14 lb cat: 70-75 mg every 12-24 hours.
  • 15 lb cat: 75-80 mg every 12-24 hours.

It is more vital that you achieve an adequate dosage than anything. Achieving proper dosing is important to make sure the antibiotics work correctly for your cat.

5. Only give one antibiotic at a time. Giving more than one type of antibiotic at a time can cause a severe reaction or an overdose reaction. Only give one antibiotic to your pet at a time unless your veterinarian directs otherwise.

6. Avoid giving an overdose of amoxicillin. Make sure that you follow the dosage instructions carefully. Signs of overdose can include nausea and vomiting, abdominal pain, diarrhea, acute renal failure, and hematuria.

If you believe that you may have given your cat too much amoxicillin and an overdose response is occurring, consult your veterinarian immediately.

7. If you have questions, don’t be afraid to ask for help. Information is available online through reputable sources, and there are also veterinarian information phone lines that you can call if you have questions.

It is not uncommon today for people to use fish antibiotics for their pets, so there are many resources available if you have questions or concerns.

6. When in doubt, take your cat to the veterinarian. If you feel like the antibiotics are not working, the infection is not responding to the medicine, or that your cat may have an infection that is outside the capabilities of Fish Mox, visit your veterinarian.

You should also feel comfortable calling your veterinarian with questions. Your veterinarian should always be a resource when you have questions or concerns about the health of your pets.


If you are a seasoned cat owner and you become acquainted with certain infections, you can save a significant amount of money on veterinary fees by treating at home using Fish Mox for your cats. It is important to purchase your Fish Mox from a reputable supplier and to measure out the dosage accurately. Once you learn how to do this, you will find that it is easy to treat your cat or cats at home without going to the veterinarian every time an infection arises.

Amoxicillin is a valuable and useful broad-spectrum antibiotic that can be extremely useful when your cat comes down with a serious infection. If you know what to look for and how to respond when your cat becomes sick, then you can easily treat your cat at home using fish antibiotics instead of going to the veterinarian every time an infection surfaces.

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