How do you know if a fish is sick?

We’ve already established that fish get sick, so how can you recognize when something is wrong? Signs of illness can be broken down into two categories: physical and behavioral.


These indicators of illness can be very easy to spot. Physical signs of disease include:

  • Changes in coloration
  • Bumps/lumps
  • Asymmetrical body shape
  • Misshapen fins
  • Wounds
  • Ulcers
  • Etc, etc etc

Most of the times, these changes are fairly obvious, but especially in the case of coelomic tumors, subtle changes can be very hard to spot. Here are some examples of physical signs of disease:


Behavioral signs of disease are harder to spot. If you don’t check your fish out every day, these signs can be very difficult to spot. A 5-minute fish viewing session twice a day is recommended at bare minimum. Behavioral signs of disease include:

  • Incorrect body position
  • Negative/positive buoyancy
  • Avoiding areas of tank/pond
  • Hiding/unsocial (species-specific)
  • Swimming behavior
  • Flashing
  • Non-seasonal change in appetite/feeding behavior
  • Etc

In order to recognize “normal” behavior, you may need to look outside your home pond/tank. What may be “normal” in your pond may be very obviously not normal if you watch other fish of the same species in a different environment. Call up the neighbors and arrange a pond/tank social hour at a different home each week/month!

If you have a behavior that you cannot identify as normal or abnormal, CALL A PROFESSIONAL. Our office number is (831) 278-1081. It is better to be certain than let a unknown behavior slide for too long.

For more information on spotting sick fish, including some behavioral indicators, watch our webinar:


Spring Koi Checkup Package

Just like your cats and dogs, your pet fish can benefit from a yearly wellness exam. By bringing your vet in before you notice any issues, health problems can be caught earlier and treated more effectively. The spring months are the most common times of year when problems with koi occur. Save yourself the stress of trying to guess your koi issues and get it straight from the best trained source in California & Nevada.

Our Spring Pond Package for 2019 will have some new benefits for all pond owners. To schedule, call (831) 728-7000.

Tumor Screenings for Female Koi

With the increased incidence of gonadal sarcomas, we usually do not catch them in time, given their sneaky, lack-of-external, appearance. By implementing regular screening, we can find these tumors much earlier and fish can undergo life-saving surgery.

Watch a full tumor removing surgery.

Recommended Products for Koi Owners

With the closing of our store, the Fish Vet Store, we want to be able to provide our clients with all our best product recommendations. All Spring Pond Package clients will receive a 20oz bag of UltraBalance Maintenance koi food, an API Freshwater Master Test Kit + kH test kit, an infrared thermometer and a signed copy of Dr. Sanders’ book, Healthy Koi Made Easy.

Water Quality Screening

Fish health is directly linked to water quality. Our spring pond checks include full assessment of fish water quality parameters. If there’s an issue, our veterinarian will make recommendations to correct them quickly and easily.

Call (831) 728-7000 to schedule your Spring Pond Checkup today.

How Do Fish Undergo Surgery?

How Do Fish Undergo Surgery?

One of the most common questions we get asked is how do fish undergo surgery? Yes, even surgical treatment is available to fish. It can be a simple lump removal all the way through to a full open abdomen procedure. It is simply amazing how well a fish improve from a simple corrective surgery.

Are they awake for the procedure?

Absolutely not! Just like people, cats and dogs are sedated for surgery, so are fish. Rather than using an aerosolized anesthetic, fish are sedated using a water-based anesthetic. Our office uses a compound called MS-222 or Tricaine-S (tricaine methanesulfonate). Other fish vets may use eugenol or clove oil. These compounds produce a safe plane of anesthesia to operate with the fish happily in dreamland. Recovery using clean water usually occurs within 10-30 minutes.

Surgery on the stomach of a shovelnose catfish

Are the fish underwater when you operate?

No again. For simple external procedures, the fish will lie on one side with the surgical site up in the air. Usually we have an assistant or net hold the fish partially submerged. For open abdomen procedures, we have a specially crafted, acrylic V-shape that fits over a 10-gallon aquarium. An aquarium pump moves water from the reservoir below, through a tube to the fish’s mouth, which then flows over their gills and back down. It is a very simple closed circulation system that works extremely well. (Modified through the amazing work of Drs. Harms & Lewbart). There is one person assigned to this job for the entire surgery and monitors the fish’s anesthetic depth through gill movement and heart rate.

Our specialized surgical rig

What is the craziest surgery you have ever done?

Well, we do a lot of procedures that are very odd for the general veterinary practitioner. Given the specialty of our service, we see nothing but “odd” cases. Some of our favorites include our fish friends Rocky, Lemon and Sparky. Read all about their cases here.

Watch some of our procedures on our YouTube site: Eyeball Removal, Abdominal Tumor Removal

Have more questions? Check out our Fish Surgery FAQ

Fish Surgery FAQ

Fish Surgery FAQ

Surgery? On a fish? As odd as that may sound, fish surgery is a common occurrence in our veterinary practice. From the simple “lump-ectomy” to a fully-invasive abdominal explore (ceolom explore for professionals), fish can undergo surgery just like you or your furry pets. We have some of these posted on YouTube for you to get a better idea of what they entail.

Abdominal Explore – Tumor Removal in a Koi

Wen Trim – Oranda (Goldfish) Haircut

Still want to know more? Here are some of our most frequently asked questions:

Our in-house surgical setup
Our in-house surgical setup

1. Is the fish anesthetized?

Absolutely! Even most of our routine physicals are performed under sedation. Unlike a cat or a dog, manually restraining a fish is a fruitless endeavor. They are very slippery and have no limbs to hold on to! For surgery, we want to make sure the fish hold perfectly still, so we anesthetize them to the point where they can still breathe on their own, but they can’t feel us cutting or stitching. I usually have my surgical assistant monitor the patient’s breathing while I mess around with the rest of the body. We use a drug called MS-222, also known as Tricaine or Finquel. It is commonly used in fish medicine and has a very rapid recovery rate.

2. Do you stitch them up after surgery?

It depends on the surgery, but in the case of a large abdominal incision, we absolutely stitch them back up! Before cutting them open, we remove the scales along our incision site, revealing their underlying skin. Trying to cut into the skin without removing the scales would dull a dozen scalpel blades before we were able to get in there! Upon completion of the procedure, we stitch them up using regular suture material through their skin. We can use absorbable or non-absorbable suture in fish, and it’s usually up to the veterinarian’s discretion. I prefer a non-absorbable suture material, therefore ensuring I have to check the fish about 10-14 days later to remove the sutures and check in his progress.

Me on surgery day
Making the incision

3. How long do they need to recover?

For most of our procedures, fish will fully recover from anesthesia within 10-15 minutes. Some fish are more sensitive than others and will need more time. Others wake right up as soon as they go back in their home tank/pond. If there is an incision that needs to heal, fish in warm water (>65 F) will heal within 10-14 days. Colder water leads to longer healing time, since a fish’s metabolism is directly correlated to the water temperature. Lower metabolism = lower immune function = slower healing.

4. How does fish surgery differ from cat/dog surgery?

Between the land and water, the actual procedures are remarkably similar. Anatomy, however, is a different story. They all have the basic structures, kidneys, spleen, liver, heart, intestines, etc., but they are in very different places and can look very odd. Specialized training is certainly required to recognize a cat kidney from a fish kidney. Anesthesia is another key difference for surgery. Dogs and cats require inhalant anesthesia for most procedures, that is taken into the blood through the lungs. Well, fish don’t have lungs and can’t breathe air, so we dissolve the anesthetic in the water that passes over their gills and into their blood.

Courtesy of Dr. J Sanders
Simple eyeball removal (with tumor!)

5. What is the most common surgical procedure you perform?

They most common aquatic veterinary surgery I perform are eye removals, or enucleations. When eyes get damaged or have large growths on them, treating the globe itself is very hard with the fish having to live underwater. Most of the time, the best course of action is to simply remove the eye. Removing the eye has very minimal impact on a fish’s quality of life. They can still sniff out their dinner and use their lateral line system to tell where they are swimming and where their friends are. Fish living in groups that have vision issues or an eye removal will sometimes form a close attachment with another fish in the pond. They follow their buddy constantly and use them as a “seeing eye fish.”

6. What is the cost for surgery?

For relatively simple procedures, such as a wen trim or eye removal, the total cost for a visit is approximately $280-320. This includes everything your fish may need during the procedure. A more complicated procedure, such as a abdominal tumor removal, can run $600-700.

One year post eyeball removal
One year post eyeball removal

7. Do you use any pre-operative or post-operative drugs or antibiotics?

Again, it depends on the type of surgery. For simple lump removals or fish haircuts, no additional drugs are needed. For an invasive tumor removal, we often administer an intramuscular antibiotics and NSAID pain medication.

8. Where does the fish recover?

If the home tank/pond water has good water quality, the fish can recover in their own water. We certainly prefer if they can go right back into an environment they are familiar with that has all their fish family. If the water quality is not great, we can bring the fish to our hospital facility to recover for a few weeks in our heated quarantine tanks.

If you have any additional questions, we are happy to answer them! Please email or call (831) 346-6151

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