Plus-Hex CLINICAL
Considerations when working with amphibian species
Laws protecting the common toad
The common toad is a biodiversity priority species under the Natural Environment and Rural Communities Act 2006 due to its recent population decline [ 3 , 7 ] . It is protected from sale and trade under the Wildlife and Countryside Act 1981 .
Handling and environment
Moistened , powder-free vinyl gloves should be worn when handling all amphibians [ 8 , 9 ] . Special consideration should be given to the source of water used because amphibian skin is incredibly sensitive , and absorption of chemicals from the environment through the skin can be harmful . Due to the presence of harmful chloramines and chlorine , tap water should be avoided . Rainwater , distilled water , reverse osmosis filtered water or aged tap water can be used for amphibians in captivity [ 10 ] .
Overheating is another concern for amphibians , with an optimal environmental temperature of 14 – 18 ° C being preferred [ 9 ] . Whitaker and Yaw [ 11 ] recommend that the examination room be no warmer than 21 – 24 ° C . Care should also be taken when handling toads , due to the risk of heat transfer from the palm of the hand . There is limited literature on the preferred optimal temperature range for the common toad , but Meek and Jolley [ 12 ] found that active common toads had a body temperature range of 11.7 – 18.9 ° C .
When handling and releasing amphibians , another important consideration is biosecurity . There is a risk of spreading amphibian diseases such as ranavirus and chytrid fungus , which could have devastating effects on amphibian populations in the UK [ 13 ] . To reduce the risk of spreading diseases , handling amphibians should be avoided unless absolutely necessary . If possible , individuals should be released where they were found to prevent the accidental spread of local disease . Appropriate use of personal protective equipment ( PPE ) and disinfectants will also help reduce the spread of amphibian disease . More information on biosecurity can be found in Amphibian Disease Precautions : A Guide for UK Fieldworkers [ 13 ] .
Health and safety
The common toad produces a poison , which is an irritant and works as part of its defence against predators in the wild [ 1 , 14 ] .
At present , there is no evidence to suggest that amphibian diseases found in the UK present a hazard to human health [ 9 , 13 ] .
Patient signalment
The patient was a male common toad , weighing 24 g , which was presented to the practice with a hindlimb injury , involving degloving and traumatic amputation of the left hindfoot , which was likely to have been the result of a gardening or road accident .
Triage
Before commencing treatment , it is the veterinary team ' s responsibility to triage patients , including determining whether a wildlife casualty needs immediate euthanasia or whether it has a good chance of release [ 14 ] .
Following triage of the toad , analgesia ( meloxicam 0.4 mg / kg intramuscularly ( IM )) [ 15 , 16 ] was administered immediately on admission ( Table 1 , page 54 ).
Prior to further treatment , research into the success of anurans following limb amputation was reviewed , to ensure that this individual would have a good quality of life in the wild . If this literature had stated otherwise , then humane euthanasia would have been elected as the best option for this patient [ 4 , 17 ] . Findings from the literature indicated that , unlike frogs , toads have a ‘ crawling ’ gait and tend to spend less time in bodies of water , which gave this toad a good chance of recovery and release [ 4 , 17 ] . Had the forelimbs been wounded or amputated , the outcome may have been different due to the natural mating behaviour of toads , which involves the male using its forelimbs to grip the female tightly [ 18 ] .
After administration of meloxicam , anaesthesia was induced to facilitate the cleaning , debridement and suturing of the wound .
Medication and anaesthesia
The use and efficacy of analgesic drugs in amphibians is not well understood [ 19 , 20 ] . Amphibians ' response to treatment with non-steroidal anti-inflammatory drugs ( NSAIDs ) is particularly poorly documented . However , Minter et al . [ 20 ] found evidence of anti-inflammatory effects when administering meloxicam to North American bullfrogs IM every 24 hours at a dose of 0.1 mg / kg .
A comparison study by Koeller et al . [ 21 ] suggested that analgesia could be provided successfully by administration of buprenorphine ( 50 mg / kg intracoelomically ) and bathing in 0.5 mg / l butorphanol in a recovery tank . Analgesia using these methods was effective , with the rapid return of normal behaviours ( eating , seeking shelter ) when compared with control groups .
Other options that have been found to provide good analgesic effects include morphine ( 30 mg / l in water ) and dexmedetomidine ( 0.6 mg / kg IM or intracoelomically ) [ 22 ] .
Volume 39 ( 4 ) • August 2024
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