What is a Fish Veterinarian?

If your dog or cat is sick, you are likely close to one of the more than 58,000 veterinary hospitals in the United States. However, when your fish is unwell, the situation becomes more complicated. You can’t take your Koi or Goldfish to a regular veterinarian, as even those who specialize in exotic pets typically do not have the training to treat fish.

Instead, you will need to find an aquatic veterinarian who specializes in animals that live primarily in water, including fish, marine mammals, invertebrates, reptiles, and amphibians. Aquatic veterinarians often work at aquariums, zoos, fisheries, and research universities. However, some fish specialists treat aquatic animals in clinics or make house calls.

A fish doctor graduated from veterinary school with a particular specialty in aquatics. There is no board certification specifically for fish medicine. However, aquatic veterinarians complete competency courses on marine life in addition to standard veterinary courses. Veterinary school typically requires four years of intensive coursework in anatomy, physiology, pharmacology, and pathology.

Why Are Fish Vets Uncommon?

If you are a seasoned Koi or Goldfish enthusiast, you might find the lack of aquatic vets puzzling. Your pond and its inhabitants play a significant role in your life. However, there are very few specialists in aquatic care, with only 0.2% of all veterinarians trained to treat fish.

Unfortunately, many people view fish as disposable pets, which limits the demand for specialized care. Even pond owners often do not pursue veterinary help. When their fish get sick, they either recover on their own or perish.

Some people regard fish as lesser pets because they don’t display emotions or seek affection in the same way that other animals do. However, despite not being cuddly, fish can still be highly engaging and social companions. Among Koi varieties, those from the Kawarimono class, particularly Chagoi, are likely to become close friends with their owners. They often show excitement at the sight of their owners, especially when they associate them with being fed.

Cost is an additional barrier to seeking veterinary care for fish. Often, a consultation can be more expensive than the fish itself. Koi and Goldfish are an investment, and it’s important to consider all associated costs when deciding to bring a pet into your home. If you plan to invest in a Koi or Goldfish pond, make sure to include veterinary care among your potential expenses.

When Does My Fish Need a Vet?

Many experienced Koi hobbyists have dedicated lots of time and energy to learning how to create favorable pond conditions that keep their fish happy and healthy. But, sometimes, despite all the attention and care, your fish may display signs of illness that require the attention of a trained professional.

Most Common Illnesses in Koi and Goldfish

Poor water quality, environmental stress, and exposure to sick fish are the most common causes of illnesses in Koi and Goldfish. Unfortunately, these factors can lead to a snowball effect, where the initial parasite or bacteria that triggered the infection pave the way for additional opportunistic infections. Therefore, it is crucial to address these issues promptly.

Parasites

Parasites commonly enter a pond with new fish or plants, making proper quarantine measures essential. Once a parasite infestation is introduced to your pond, it can multiply quickly and negatively impact the entire population. Koi can be affected by both internal and external parasites. The five most common parasites that affect Koi and Goldfish are flukes, costia, chilodonella, trichodina, and ich. Since all of these parasites are microscopic, your veterinarian will need to take a sample and examine it under a microscope.

While parasites typically do not directly kill Koi, they can be fatal due to the various secondary infections they cause. If left untreated, parasites can damage a Koi’s immune system, increase its susceptibility to illness, harm the gills, and infect the skin around the wounds where the parasites are situated.

Unfortunately, there is a parasite for every season; some thrive in warm water, while others appear when temperatures drop. Treatments vary depending on the specific parasite, but in general, eradicating them takes time. It is crucial to break the parasitic cycle, which involves killing both the adult parasites and their larvae and eggs. 

Bacterial Infections

Bacterial fish diseases are common, yet they are among the most challenging health problems to deal with effectively. However, with a basic understanding of how bacteria cause disease and how to recognize bacterial infections, it is possible to deal successfully with the majority of problems. 

Bacteria are always present in ponds. If your pond is clean and your Koi are relatively stress-free, their presence shouldn’t cause problems. Koi have a natural protective slime coat, but issues with bacteria can easily arise if it becomes damaged. Parasitic infestations, predator attacks, poor water quality, and stress can increase the susceptibility of Koi to bacterial infections.

Pathogenic bacteria can spread disease throughout a fish’s body if they enter through the gills, gut, or skin. This is known as a systemic infection. There are also bacterial infections that cause localized surface diseases, such as fin rot and ulcers. If these localized infections are not treated, they can lead to a systemic infection. In general, there are four types of bacterial infections that Koi keepers should be aware of:

• Fin Rot – typically caused by environmental stress.
• Bacterial Body Ulcers – open lesions on the fish’s body that can range from shallow to deep.
• Bacterial Gill Disease – gills are the primary target of the infection.
• Systemic Bacterial Disease – bacteria invade the fish’s body and damage its internal organs.

Signs of Illnesses in Koi and Goldfish

If your Koi get sick, it’s helpful to quickly identify and treat the problem before it worsens and spreads to other fish. Though your Koi and Goldfish can’t tell you when they’re feeling unwell, they often exhibit atypical behaviors that indicate something is bothering them. 

Pineconing

Pineconing is a visual effect where the body appears rounder than usual due to a swollen abdomen. This distension occurs because of fluid accumulation within the body cavity. Pineconing can be a sign of various health issues, including infections and organ failure. To diagnose the underlying problem, a fish veterinarian can perform an ultrasound and take a sample of the fluid.

Flashing/Scraping

Flashing is a behavior exhibited by Koi and Goldfish in which they turn on their sides and swim rapidly, often scraping their bodies against rocks or other hard surfaces. Flashing usually indicates that the fish are experiencing discomfort and are trying to scratch it away. Parasitic infections are often the primary cause of this behavior, but other factors, such as bacterial infections or water contaminants, can also contribute. An aquatic veterinarian can help identify the cause of the flashing and recommend appropriate treatment.

Jumping/Gasping

Jumping above the water’s surface is a typical and playful behavior for Koi. However, if this behavior becomes frequent, it could indicate that they are seeking relief from gill irritation due to an environmental factor. Fish that hang out at the water’s surface and look like they are gulping for air could also be trying to take in oxygen from outside the pond. If the water contains insufficient oxygen, your fish will surface to try to breathe.

In such cases, a veterinarian will first check the oxygen levels to determine whether they fall within a healthy range. If normal, he will measure other water parameters, including pH, ammonia, nitrite, and nitrate levels.

Clamped Fins

If Koi or Goldfish swim with their pectoral fins held tightly against their bodies instead of moving them normally, they are likely experiencing stress due to some discomfort. Bacterial or parasitic infections often cause this behavior. If a quick physical examination does not reveal the issue, the veterinarian may need to perform a skin scrape to examine under a microscope.

Hiding/Lethargy

Aside from their winter dormant period, Koi and Goldfish should generally remain active. If a fish is lying at the bottom of the pond and not responding to stimuli, it is likely experiencing stress. This behavior can often indicate poor water conditions or an unsuitable temperature. The veterinarian will assess the water temperature to ensure it is within the optimal range of 65 to 75 degrees and will check that the pond is properly aerated. Additionally, he will test for diseases and bacterial infections that may cause fish to become lethargic.

Loss of Appetite

Koi love to eat, so if one or more of your fish is eating less or not at all, there likely is an underlying environmental or physical condition. Check for water quality, as high nitrate levels can affect a Koi’s appetite. 

How Do I Find a Fish Vet?

To find an aquatic veterinarian near you, you can consult the American Association of Fish Veterinarians. Additionally, the World Aquatic Veterinary Medical Association offers an international database to help you locate a qualified professional.

Home Visit

Your visit with the aquatic veterinarian will involve an environmental assessment, water testing, and the examination of sick fish. The veterinarian will evaluate your pond’s size, filtration system, and maintenance routine. He may also discuss your experience level with maintaining a Koi or Goldfish pond to determine the best starting point. It is essential to document any prior interventions you have tried. Additionally, the veterinarian may ask about the source of your water, as the approach to assessing your pond may vary depending on whether it comes from a well or a municipal system.

Next, the veterinarian will test your water parameters. It is helpful to measure these yourself before the visit so that you can compare your results with those obtained by the professional. Water parameters are considered the vital signs of a pond or aquarium, much like how a doctor checks your blood pressure, oxygen levels, and body temperature before an examination. In this case, the vital indicators include the water’s pH, ammonia, nitrate, and nitrite levels.

Before the veterinarian can examine the fish, he must first catch it. It would be helpful if you pre-isolate the sick fish to minimize stress. To catch your Koi, use a pan net (a shallow net resembling a frying pan) and approach slowly and deliberately. Stay calm and quiet while approaching, and do not chase the fish around the pond. Never force a skittish Koi into the net, as this can damage its scales or fins. 

Finally, the veterinarian will inspect your Koi or Goldfish. Typically, he will perform a skin scraping, a fin clip, and a gill biopsy, which he will review under a microscope to look for evidence of parasites, bacteria, or fungi. He may also take blood samples to send to a diagnostic laboratory, which could require sedating your fish. In rare cases, the veterinarian might need to transport your fish back to the clinic for X-rays.

Transporting Your Koi or Goldfish to an Aquatic Vet

Sudden changes in a fish’s environment can induce acute stress, especially if the fish are already sick. Therefore, we recommend finding a veterinarian who makes house calls. If that’s not possible, it’s essential to transport your fish in the safest way possible to minimize stress. 

For this purpose, it’s advisable to use a double-bagging technique. Choose bags that are 4 mm thick to withstand transportation stress. Fill the inner bag with water from the pond, ensuring that the water level completely covers the fish and rises above its gills.

The bags should be large enough to provide at least six inches of space, allowing for sufficient oxygen. Aim to fill at least half of the bag’s volume with air. If you are placing two Koi in the same bag, ensure there is enough room for them to fit comfortably side by side without touching.

Secure each bag with two new rubber bands to ensure it is properly closed. Keep the bags horizontal during transport. A large ice chest or cooler is a sturdy and well-insulated option for transporting the bagged Koi, which can also help lower their temperature to reduce stress during the journey.