Category Archives: Diseases

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Swollen Eyes in Red Eared Sliders and other Aquatic Turtles

Swollen, inflamed eyes are commonly seen in a wide variety of captive turtles.  Strangely, the hardy Red Eared Slider seems especially prone to this annoying and potentially life-threatening condition (as we’ll see, popular feeding practices may partially explain this).  From childhood through my career as a herpetologist, standard wisdom has blamed the condition on a Vitamin A deficiency. Today we also know that poor water quality is responsible for many, if not most, of the eye problems seen in Sliders, Cooters, Painted Turtles and similar species.  In this article we will look at the symptoms, causes, prevention and treatment of various turtle eye maladies.

HAIDEN , TURTLE, CLOSESymptoms

Most eye problems first manifest as a slight but noticeable puffiness of the eyelids.  Vitamin A deficiencies and fungal/bacterial infections can cause tissue within and around the eyes to degrade.  As a result, epithelial cell “debris” collects along the eye rims and under the lids. Pressure and irritation causes the lids and tear ducts to swell. Read More »

Turtle and Tortoise Eggs – Knowing When She is Ready to Lay

In the course of my work, I am often contacted by turtle owners whose pets cease feeding and become unusually restless.  The behavior appears suddenly, sometimes after many uneventful years – a Common Musk Turtle did so after 22 years in my collection – and seems to have no external cause.  A normally placid turtle may begin frantically paddling or wandering about, trying to climb the sides of the terrarium and escape.  Food, once the focus of the creature’s existence, is ignored.

Common Snappers hatching

Uploaded by Frank Indiviglio

It surprises some folks to learn that turtle and tortoise eggs may develop even if the female has never mated, and that mated animals may retain sperm and produce fertile eggs years later.  Unfortunately, gravid (egg-bearing) turtles can be very choosy when it comes to nesting sites…a ½ acre exhibit failed to satisfy some I’ve cared for at the Bronx Zoo!  If the eggs are not deposited, blockages due to over-calcification and life-threatening infections invariably result.  Fortunately, there are ways to “convince” your pet to lay her eggs; failing this, several effective veterinary options are available.

What To Do

If your female turtle or tortoise suddenly stops feeding and begins to act as described above, first check that something has not gone wrong in the environment.  Overheating, Lysol poured into the tank by a mischievous child (actual story), or cage-mate aggression can all cause similar behaviors.

If you suspect eggs, your best option would be to have radiographs done by a veterinarian (please post below if you need help in locating an experienced vet).  Your vet can determine how many eggs are present, approximately how far along they are in their development, and if problems related to unusual size or over-calcification can be expected.  Also, other health issues that may cause similar symptoms can be investigated. Read More »

Snake Fungal Disease – Conservationists Fear Emerging Disease Epidemic

Recently I reported on a study that documented declines of 50-90% in 17 populations of 8 snake species (please see article linked below).  These findings brought to mind the global amphibian decline that was first uncovered in 1990.  Since then, an emerging disease caused by the fungus Batrachochytrium dendrobatitis has likely caused the extinctions of over 100 frog species.  Researchers seeking to avoid a similar crisis among the world’s snakes have now identified an emerging illness, Snake Fungal Disease, as cause for serious concern.  Associated with a newly-described fungus, Chrysosporium ophiodiicola, the disease has been found in several species in 9 states (USA), but is likely much more widespread.

Timber Rattler

Uploaded to Wikipedia Commons by Rkillcrazy

New Victims of a New Fungus

The global snake declines mentioned above first came to light in the late 1990’s, but explanations remain elusive.  In 2008, herpetologists became alarmed when Eastern Massasaugas (or Swamp Rattlesnakes) in Illinois and Timber Rattlesnakes in New Hampshire showed evidence of an unusual fungal infection.  A fungus (Chrysosporium sp.) that had previously been isolated from captive snakes, but never in the wild, was identified from head lesions on the Timber and Swamp Rattlesnakes.  All of the snakes submitted for study expired.

In April of 2013, the USGS National Wildlife Health Center announced the discovery of a fungus new to science, Chrysosporium ophiodiicola.  This fungus has been implicated in an emerging disease that is now afflicting snakes in the Eastern and Midwestern USA.  Increasing numbers of snakes showing evidence of infection have been found by USGS biologists, who fear that the disease may devastate snake populations. Read More »

The Best Terrarium Cleaning Products and Methods

During a long career zoo career that found me working with animals ranging from ants to elephants, I’ve had many occasions to review veterinary and pathology reports.  In doing so, I’ve come to understand that zoonotic diseases – those that can pass from animals to people – are a potential concern in the keeping of any pet.  Most people associate Salmonella, the best known zoonotic, with reptiles, but nearly any animal, including dogs, cats and birds, may harbor this bacterium. Fortunately, Salmonella and other infections can be avoided by following a few relatively simple rules.

Note: This article is not meant to replace a doctor’s advice, nor is it intended to discourage pet ownership.  By observing a few simple precautions, the most commonly-encountered problems can be effectively managed.  Please post your questions and concerns below, and be sure to consult your doctor or veterinarian for specific information concerning disease prevention and treatment. Read More »

Amphibian Declines – Pollution Worsens Disease and Parasite Attacks

Deformed FrogIn 1990, the IUCN’s Declining Amphibian Populations Task Force, to which I belonged, was one of the few large scale efforts addressing what is now known as the “Disappearing Amphibian Crisis”.  Today, with legions of biologists and hobbyists at work on the problem, we still do not fully understand why nearly 200 species have become extinct in the last 20 years – a rate 200x that of what might be “expected”.  But we do have some insights, one of which was highlighted in a recent journal article (Philosophical Transactions of the Royal Society (Biology) .  It appears that stress, much of which is in response to what we are doing to amphibian habitats, is worsening the effects of normal pathogens and diseases.

Parasites and Insecticides: a Confusing Scenario

As the reality of worldwide amphibian declines became apparent, herpetologists and private citizens began noticing increasing numbers of deformed and dead frogs. In 1995, school children in Minnesota made headlines when they found dozens of deformed frogs in a local pond. Since several chemicals are known to cause growth abnormalities, researchers began focusing on pollutants. At the Bronx Zoo, I worked with a veterinarian who studied African Clawed Frogs, and was amazed to see ovaries develop in males that had been exposed to Atrazine (a common insecticide). Read More »

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