Turtle Health & Feeding Guide

This is the page we should have built three years ago. Linda has been answering the same five health questions in our inbox — shell rot, eye problems, refusal to eat, respiratory infections, and metabolic bone disease — on a loop, and we’ve never had one place to send people. Here’s the proper hub, with each section linking out to the full write-up.

Before we get into specifics: every section on this page is a triage guide, not a substitute for a reptile vet. If your turtle is symptomatic and you don’t have an exotics vet in your phone, finding one is task one. The Association of Reptilian and Amphibian Veterinarians has a global locator at arav.org — bookmark it now.

How turtles signal they’re unwell

Reptiles are stoic by evolutionary necessity — a wild turtle that looks sick gets eaten — so by the time the average keeper notices something is wrong, the animal has usually been struggling for a while. Linda’s rule from her vet-tech years: take any visible behavioural change seriously, especially if more than one of these is true at the same time.

  • The turtle stops basking, or bas constantly without ever entering the water (or vice versa).
  • Eating slows or stops for more than five days at proper temperatures.
  • Eyes are sunken, closed, or weeping discharge.
  • Breathing is audibly wet, wheezing, or open-mouthed.
  • Swimming is lopsided — one side floating higher than the other.
  • The shell develops white, soft, or flaking patches.
  • Limbs feel weak or rubbery, or the jaw is misshapen.

The single most useful diagnostic question we ask in our inbox is “what are your temperatures, exactly?” About half the time, the “mystery illness” is downstream of a basking spot 8 °C below where it should be.

The big five: conditions we see most often

1. Respiratory infection

The most common serious health issue we hear about. Symptoms: wheezing, bubbles or mucus at the nostrils, open-mouth breathing, lopsided floating, and lethargy. Almost always triggered by water that’s too cold, an under-powered basking spot, or both.

First-aid steps before the vet visit: warm the basking spot up to species-appropriate temperatures (32–35 °C for most aquatic species), warm the water to 27 °C, and dry-dock the turtle in a shallow warm setup if floating is severe. Reptile RIs need antibiotics — usually injected ceftazidime — and you cannot get those over the counter. Book the vet.

2. Shell rot

White or grey patches on the shell that don’t scrub off, sometimes with a foul smell or visible pitting. Bacterial or fungal in origin; caused by poor water quality, abrasion, or untreated shell injuries. Caught early, it’s manageable at home with daily dry-docking and a topical chlorhexidine or povidone-iodine scrub. Caught late, the rot can erode through to bone and requires surgical debridement.

The first signs are subtle — a small soft patch you can dent with a thumbnail. Don’t wait to see whether it spreads. Pull the turtle, dry-dock 4 hours a day in a warm UVB-lit setup, scrub the affected area with diluted Nolvasan once daily, and re-evaluate at the one-week mark. The dedicated post on Nolvasan for shell rot covers the protocol in detail.

3. Metabolic bone disease (MBD)

Soft shell, rubbery jaw, weak hind limbs, deformed scute growth. Caused by inadequate UVB exposure, dietary calcium deficiency, or both. The damage from an established case is largely permanent — the shell may calcify back but the deformity stays.

Prevention is the entire ball game: a real reptile-grade UVB tube (5.0 or 10.0 depending on species), replaced every 6–12 months whether or not it still emits visible light, plus a varied diet with appropriate calcium dusting. Compact UVB bulbs and household sunlight through glass are not adequate — see our reader-question post on whether UVB passes through glass for the physics.

4. Vitamin A deficiency

Swollen, closed eyes are the classic presentation, usually accompanied by a runny nose and refusal to eat. Common in turtles kept on a pellet-only diet for months. Long-term, vitamin A deficiency causes the cells lining the eyes, mouth and respiratory tract to misdevelop, which then opens the door to secondary infections.

The fix is a vet-administered vitamin A injection plus a dietary overhaul: dark leafy greens (kale, collards, dandelion), the occasional piece of red bell pepper, and a multivitamin once a week. We cover this in more depth in our vitamin A deficiency write-up.

5. Anorexia and slow growth

By far the most common email we get from new keepers: “my hatchling won’t eat.” Check the temperatures first — a turtle below 22 °C will simply stop eating because its metabolism is suspended. Check the lighting cycle (12 hours on, 12 off). Check stress factors (is there a tank-mate? Is the tank in a high-traffic area? Did it just arrive?). Only after those do we start worrying about parasitology.

Our dedicated post My hatchling isn’t eating works through the full triage.

Feeding fundamentals

Diet drives most of the health problems above. Here’s the framework we use ourselves, by species group.

Aquatic turtles (sliders, painted, map, cooter, musk)

These are omnivores whose protein/plant ratio shifts with age:

  • Hatchling to year 1 — roughly 70 % animal protein. Bloodworms, krill, soft-soaked pellets, the occasional small earthworm.
  • Year 1 to year 4 — transition gradually to 50/50.
  • Adult — around 60 % plant matter (collards, dandelion greens, romaine, aquatic plants like duckweed and anacharis), 40 % protein.

Feed adults every other day to manage waste output and prevent obesity. Hatchlings can be fed daily. Never feed iceberg lettuce (essentially no nutrition), avocado (toxic), or anything from the onion / garlic family.

Box turtles (semi-aquatic, semi-terrestrial)

Roughly 50/50 plant and protein lifelong. They love earthworms, snails, slugs, the occasional pinkie mouse (rare treat only). On the plant side, leafy greens, berries, melon, the occasional tomato. A box turtle that won’t eat usually wants live moving food — box turtles are visual hunters and respond to wriggle.

Mediterranean tortoises (Hermann’s, Greek, Russian, Marginated)

High-fibre, low-protein, low-fruit. Weeds and dark leafy greens are the bulk of the diet — dandelion, plantain (the weed, not the banana), clover, hibiscus leaves and flowers. No fruit beyond rare treats. Calcium dust three times a week, multivitamin once a week. Iceberg, peas, beans and bread can all cause real problems in this group.

Tropical tortoises (red-foot, yellow-foot, hingebacks)

The one group that genuinely wants fruit regularly — mango, papaya, melon, banana — alongside greens and a small protein component (a hard-boiled egg or a piece of cooked chicken once or twice a month). Higher humidity, warmer temperatures, and softer substrate than Mediterranean species.

Sulcata, Aldabra and Galapagos tortoises

Grazers. Their diet should look like a horse paddock: grass hay, fresh grasses, the occasional weed. Almost no fruit, almost no high-protein anything. The classic sulcata problems — pyramiding shell, kidney issues — trace back to too much fruit and too little fibre in juveniles.

Supplements: what and when

  • Calcium powder without D3 — dust food two to three times per week for animals that get adequate UVB. Without UVB, the animal can’t synthesise vitamin D3 and so can’t metabolise the calcium properly.
  • Calcium with D3 — use sparingly (once a week) for animals with limited UVB exposure, but understand that this is a workaround. UVB is the proper answer.
  • Reptile multivitamin — once a week, dusted on food. Choose one with vitamin A (retinol) listed, not just beta-carotene.
  • Cuttlebone — leave a piece in tortoise pens at all times. They self-regulate.

Setting up a quarantine tank

If you keep more than one turtle and one of them gets sick, separate them. Set up a simple quarantine tank: a plastic tub with a small water dish, a heat lamp, a UVB tube, and paper-towel substrate. Paper towel makes waste and uneaten food visible — you want both for diagnostic purposes — and is easy to swap daily.

Keep the quarantine setup for a minimum of 30 days after symptoms resolve, and use separate equipment (nets, gloves, towels) for the quarantine tank to avoid cross-contamination.

When you absolutely need a vet

Some things cannot be treated at home, period. Get to a vet, ideally same day, if:

  • The turtle has a visible shell crack or trauma from a fall or pet attack.
  • Blood is visible at the mouth, vent, or any wound.
  • The turtle is lying motionless on its back and not righting itself.
  • A respiratory infection has progressed to the point of lopsided floating.
  • The turtle is straining to defecate or pass eggs and hasn’t for several days.
  • Any neurological signs — head tilting, circling, twitching.

Reptile vets are not GPs — you may need to drive an hour or two. Plan for that now rather than at 9 pm on a Friday.

External resources we trust

  • ARAV vet locator — find a herp-experienced vet in your area.
  • Tortoise Trust — the deepest free archive on tortoise nutrition, MBD prevention and outdoor husbandry.
  • British Chelonia Group — species-specific veterinary care sheets, particularly strong on UK-keeper concerns.

Related on Turtle Times

— Linda, with Tom and Priya on edits. If you’re reading this in the middle of an active health emergency and not finding the answer, the Contact form goes straight to our shared inbox and we answer health questions first.

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