A guppy rarely lives alone, breeds quickly, and lives a short life, so the records a new vet needs are colony records. One fish may be the reason for the appointment, but its group, its water, and its breeding history explain far more than a close look at a single small fish in a bag. Build the handover around the colony and then narrow to the individual.
Start With Colony Size, Balance, and Births
Write down how many guppies you keep, roughly how many are male and how many female, and whether fry are being raised in the same tank, a breeder box, or a separate nursery. Record when the last births happened and whether numbers have been climbing, steady, or falling. If you raised this fish from fry, say so, and note any recent losses — how many, over what period, and whether they shared signs — because a pattern across several fish points the vet in a very different direction from one fish fading alone. Say where the colony began: a shop, a breeder, or fry raised from your own adults, and whether new guppies have been added recently and from where.
Bring Water Readings Suited to Guppies
Guppies generally do best in harder, more alkaline water than many soft-water tropical species, so bring actual readings rather than assuming 'tropical tank' says enough: pH, hardness if you test it, ammonia, nitrite, nitrate, and temperature. Note your water-change rhythm, whether you use tap water with conditioner or adjust it in any way, and any recent swing — a filter failure, a long gap between changes, or a sudden restock that raised the waste load. If a heater or filter was replaced, record when. Small fish in a busy colony tank feel water changes quickly, and the timeline of readings often lines up with when fish began to look unwell.
Show Colour, Tails, and Body Condition
Bring recent photos or short video of this guppy in the tank, where its colour, tail spread, and swimming can be seen among the group. Note changes you have spotted: colours dulling, tails clamping or splitting, a belly that looks swollen or hollow, or a fish separating itself and hovering in a corner or at the surface. Record what the colony eats — flake, micro-pellets, baby brine shrimp or other fry foods — how much, and how often, including whether fry get extra feedings. Write down this fish's approximate age if you raised it, since a young adult and a guppy near the end of its natural span call for different expectations.
Add Treatments Given to the Whole Tank
Because guppy treatments are usually given to the whole tank, list anything added to the shared water, when, and what changed afterwards, including remedies aimed at a different fish. Note plants, snails, shrimp, or other species sharing the tank, and whether a quarantine or hospital tank is available at home, as that affects what the vet can suggest. Finish with your contact details and any previous vet information. Keeping colony counts, births, and water notes together in KinsLe's Pet Passport gives the vet the full breeding-tank picture behind one small patient.