Dendroworld:
FAQ:
Disease
|
|
Chytrid is a fungal infection which affects many different species of amphibians. Some species act as carriers and appear to be unaffected, whereas the disease is lethal for others, including dendrobatids. Chytrid has recently been detected in the UK and is present in amphibian collections in Europe and North America.
The chytrid fungus attacks keratin in the skin and irritates the frogs so they show excessive skin shedding and wiping of the skin with the hind limbs. They also spend prolonged periods in water bodies or beneath running water as well as becoming very lethargic.
Chytrid can only be identified by a vet or a scientific laboratory and although there are experimental treatments, opinions differ as to their effectiveness. If you buy frogs from an unknown source, e.g. at a 'frogday', quarantine them well away from other frogs for at least a month. Please be aware however that chytrid can take longer than a month to appear in frogs.
Facts on Chytrid:
B. dendrobatidis is susceptible to a broad range of chemical and physical treatments (Berger 2001, Johnson et al. 2003). The most effective solutions for field use contained the quaternary ammonium compound, didecyl dimethyl ammonium chloride (DDAC), 0.1% dilution for 30 sec (Table 3). Sodium hypochlorite was effective at concentrations of 1% and above. Also effective was exposure to 70% ethanol, 1 mg/ml Virkon or 1 mg/ml benzalkonium chloride for 20 seconds. These chemicals can be used for disinfection in the laboratory, in amphibian husbandry, and in field work. For example, alcohol wipes can be used to disinfect scissors, calipers and other instruments between animals. Cultures of B. dendrobatidis did not survive complete drying, but in practice persistence of water in droplets allows survival of the pathogen up to 3 hours after drying (Johnson et al. 2003). Heating to above 37°C for four hours resulted in death. Ultraviolet light used routinely for killing bacteria, fungi and viruses was ineffective. A combination of heating and drying is a safe method for disinfection for many objects, such as clothing and some equipment.
No-one like killing frogs but in some circumstances, e.g. SLS
(see below), this is the best option for a deformed or severely injured animal.
Freezing is *NOT* a humane method of killing for any amphibian. Although
the frogs becomes
torpid, it remains conscious and dies in agony as ice crystals slowly rip it's
muscles and organs apart. Likewise CO2 is not appropriate for amphibians,
which can survive under severe oxygen debt.
Acceptable Methods:
The (U.S.) National Research Council on Pain and Distress in Laboratory Animals
(Wright KM and Whitaker BR. 2001. Amphibian Medicine and Captive Husbandry.
Krieger Publishing Company) recognizes a number of chemical methods
(tricaine methanesulfonate (MS-222), pentobarbitol, benzocaine), none of which
are available to hobbyists in the
UK. The available approved method uses sedation in a bath of 5% ethyl alcohol
(ethanol) followed by immersion in a stronger bath after the amphibian has
been anesthetized.
Pure ethyl alcohol is also not available, but vodka is an acceptable substitute
(usually 40% ethanol, but check the label). Sedate the animal in 5% ethanol
(e.g. 1/8 vodka, room
temperature)
until it
stops moving, then place in 40% ethanol (neat vodka).
The Pet Animals Act, 1951 says:
6.2: Any sick or injured animal must receive appropriate care and treatment without
delay. Inexperienced staff must not treat sick animals unless under appropriately
experienced supervision. Care and treatment may include euthanasia
but under no circumstances may an animal be euthanased other than in a humane
and effective manner. In case of doubt, veterinary advice must be sought.
Nose injures occur when stressed frogs rub against vivarium furniture of glass. Eliminate all sharp/rough objects from the vivarium. If the frog constantly rubs against a particular part of the vivarium, cover this up or move the frog to a different cage. Isolate the injured frog on a substrate of clean damp paper towels and remove sources of stress. Healthy frogs should recover in a few days/weeks although a scar may remain. If the wound shows signs of infection, consult an experienced amphibian veterinarian (if you can find one): http://www.rcvs.org.uk/Templates/InternalHome.asp?NodeID=89659
Frogs affected by internal parasites usually appear listless and underweight. There are many different types of internal parasite (e.g. nematode worms, protozoa, amoebae, etc) and no one medication works against them all. Treating an already sick frog with an inappropriate medication is likely to stress the animal further and may lead to it's death.
Internal parasites are diagnosed by faecal examination. Place the animal on a "sterile" substrate of clean damp paper towels and collect a fresh faecal specimen (not dried out). This must be examined under a microscope to identify parasite. In practice, it is best to consult an experienced amphibian veterinarian (if you can find one): http://www.rcvs.org.uk/Templates/InternalHome.asp?NodeID=89659
A condition where froglets metamorphose with weak and/or deformed front legs.
One or both front legs may be affected. Affected limbs are thinner than healthy
front legs, may fail to support the weight of the froglet or may be held stiffly
at odd angles. The cause(s) of SLS are not known: http://dendroworld.co.uk/BDGarchive/spindleleg.html
It is probable that there are several conditions which give rise to this outcome,
including:
It would appear that a combination of genetic susceptibility (from the parents) and an environmental trigger is necessary for development of SLS. Thus tadpoles from some pairs of frogs but not others may develop SLS under certain conditions, and a particular pair of frogs may produce tadpoles with SLS at some times but not at others. The only way to find a "cure" for SLS is to find and eliminate the cause(s), something which is not easy to do.
Sugar-water or saline solutions act as isotonic preparations that can help with oedema (bloat)/water retention if caught early but the mixture is very specific. It can also aid sick frogs by relieving stress caused by life in an isotonic imbalances. In practice, results of this treatment are variable and it is best to consult an experienced amphibian veterinarian (if you can find one): http://www.rcvs.org.uk/Templates/InternalHome.asp?NodeID=89659
There are few books accessible to hobbyists which deal with amphibian medicine in any detail. The best is "Amphibian Medicine and Captive Husbandry": http://www.amazon.co.uk/exec/obidos/ASIN/0894649175
See Food.
Dendroworld: FAQ:
Disease
|
|