What’s Ailing Your Fish?
The number one reason people seek medical attention for their fish is poor husbandry. Since fish eat, breathe, and poop in their water, it’s easy to fall behind on their care.
Fish rely on nitrifying bacteria to help clean their water, this is known as the Nitrogen Cycle. Once fish eat food and create waste, nitrifying bacteria convert the waste to less toxic substances that then bubble out of the water into the atmosphere. The problem fish owners run into is when fish are overfed or if there are too many fish in an environment creating waste. Then, the good nitrifying bacteria can’t keep up causing a collapse of the Nitrogen Cycle. What follows then is stress on the fish’s immune system and secondary diseases like bad bacteria, parasites or molds take over causing illness and sometimes death.
Where do veterinarians come in?
Some veterinarians are trained to see fish. At Conejo Valley Veterinary Hospital, when fish come in for an exam, we have owner’s bring in their fish in a secure transport container with an air pump that bubbles oxygen into the water for transport. Since fish don’t do well with big changes, we ask that you bring in an equal amount of tank water in a separate container in case we need to anesthetize the fish and to freshen up the water for the ride home.
How can you help?
Determining what ails patients that can’t talk requires excellent sleuthing skills. You can help us by providing the fish’s environmental history such as the tank or pond size, most recent water chemistry levels (pH, Nitrates, Nitrites, Ammonia, Temperature), history of new introductions into the enclosures, frequency of water changes, sudden fluctuations in water chemistry levels and temperature. Capturing photos of the tank or pond and video of a fishes behavior whether normal or abnormal can provide clues to fish health.
There’s a Fish in the OR…Say What?
Yes, you heard it right, even fish need surgery! Since most fish absorb oxygen in the water from their gills, you can actually take a fish out of water to perform surgery. This might sound crazy, but if you maintain a constant flow of oxygenated anesthetic water over their gills and keep their body moist, then they can spend quite a long time out of water.
We start the sedation process by placing our fish patients into an oxygenated anesthetic bath. Most fish become sedated within 3 minutes. They will lose their buoyancy and often start to swim on their side. When a fish doesn’t respond to a tail pinch, an indication that they don’t feel pain, then we know we’ve reached an adequate anesthetic plane.
Once the fish are sedated, they are removed from the anesthetic bath, weighed so that we can properly dose medications and quickly moved to the operating table. There they receive continuous oxygenated anesthetic water over their gills through a soft rubber tube. Their anesthetic plane is constantly assessed by monitoring movement of their gill covers (operculum) and a Doppler to monitor heart rate. If opercular movement and heart rate decrease then we dilute the anesthetic water to lighten the anesthetic plane. To make sure we don’t overdo it, we monitor with a periodic tail pinch.
For long procedures we have to run water over the fish’s body to make sure they stay moist. Surgeries that are on the outside of the body tend to heal quickly and rarely require sutures. A surgery where we have to open their belly (celiotomy) will require sutures for closure. Those patients with sutures will have to be re-sedated 3 weeks later since sutures don’t dissolve in fish.
Once surgeries have concluded, fish are given antibiotic injections and anti-inflammatory/pain medication and placed in a recovery tank of oxygenated non-anesthetic water. Since the fish are usually pretty groggy, they are gently supported with gloved hands until they have adequate opercular movement, can achieve buoyancy on their own and are capable of swimming without assistance.
And there you have it folks, even fish can have surgery!