Reptile Medicine Flashcards
What is the vagovagal reflex?
Applying pressure to the eyes can lead to a reduction in the heart rate and response to external stimulation
How should a reptile appear when you are examining it on the table
Lizards should be bright alert and lifting their bodies off the table. Snakes should impart a feeling of strength when handled and be able to grip the sides of the table. Observe for mobility, ability to maintain a normal stance, alertness, eyes should be bright and open in lizards and clear in snakes. respiration should be noticeable but without exertion.
Describe the clinical examination of chelonians
Start at the front and work backwards. Check for head abrasions, beak eformities, A dremmel too can be used to correct these. Check ear drums and eyes for swellings. Check shell for any loose scutes, fractures, erosions, reddening and compressibility. Palpate the pre femoral fssa. You may feel eggs or bladder stones.
Describe the clinical examination of lizards
Check the eyes for any ulceration, coonjunctivitis, oedema, exudates. Check the nares and mouth for any discharges or swellings. Wait for a breath and observe the movement of the glottis and listen for any noise. Assess the effort required to open the mouth. check the teeth for any damage or infection. Check the skin for any areas of dysecdysis, swellings, parasites, scars, wouds, retained secretions. Check al limbs for trauma, normal range of movement and obvious swellings. Check cloaca and tail for any signs of damage or prolapses. In larger lizards cloacal palpation of the kidneys is possible. Palpate along the length of the coloemoic cavity. Cardiac function is best assessed using a doppler probe.
What should the hospitalisation environment of a reptile be like?
Use shredded paper as a substrate as it can be easily leaned and faecal and urinary output can be meaasured. There is no need to offer water, just bathe daily or provide fluids via stomach tube. Wear disposable gloves when handling.
What are the zoonotic risks with handling reptiles?
There is a risk of zoonotic diseases being spread to staff. Salmonella species are the most common. Most reptiles (particularly fresh water species) will be shedding salmonella or campylobacter. Testing faecal samples is of little use as faecal excretion is intermittent. This rarely cause clinical disease in reptiles.
Describe fluid therapy which should be given to reptiles
Fluid maintenance requirements are 30mls/kg per day. You can give approximately 1% of bodyweight at any given time. Fluids can be given by a variety of routes. Through bathing, oral, Intra coelomic, intraosseous, IV. The most useful are intra coelomic fluids, bathing, stomach tubing.
What fluids should be used in reptiles?
Administration of lower osmolarity fluids is recommended by some clinicians (diluted 1:10 with sterile water for injection). Practically the use of mammalian preparations is fine.
What is refeeding syndrome?
Sick reptiles require fluid, electrolytes and energy. although there may be elevated plasma electrolytes there is infact a total body deficit. Cellular ion concentration is reduced due to the lack of concurrent transport when glucose and ions are absorbed into the clls. Providing energy sources before body electrolytes are replaced can lead to a life threatening reduction in palsma electrolytes. This in particular leads to hypokalaemia and hypophosphataemia. We should aim to return the osmolarity of the reptile back to within the normal rage anticipated for that species, taking into account the seasonal effects in differing species. Terrestrial chelonians have elevated osmolarity just after hiberation, lizards have elevated values in the dry period. Fresh water aquatic species have reduced osmolarity just after hibernation. They do this by altering blood electrolyte levels. Sodium and urea values can give a good indication of hydration status and osmolarity. Aim to keep sodium below 1400mmool/L. well hydrated chelonians have a urea value of less than 2.1 mmol/l. Individuals with values up to 20mmol/L have responded to bathing aloone.
What are the recommendations for administering fluids and electrolytes?
Use standard mammalian solutions up to 3% body weight per day by the epicoelomic route. Stomach tube with water 1% body weight two or three times daily. Bathe twice a day in water for 20 minutes. Start adding electrolytes to fluids used for stomach tubing and bathing after 24 hours. Once successfully rehydrated the tortoise will start producing urine. At this stage supportive nutrition can begin as the risk of refeeding syndrome will be reduced. Up to 1% of bodyweight can be given by stomach tube of commercially formulated preparations. Keep the reptile warm before and after tubing to allow it to digest its meal.
How can your reptile patient be monitored?
Weight change is one of the most useful parameters to measure. Weight increases will initially be dramatic as the reptile changes from empty to full. Once rehydrated and with a bowel full of food , the output = input and the weight will stabilise. It is this weight that should be maintained once returned home and off supportive care. Further dramatic weight gains are not going to happen. The tortoise fills its bladder with fluid ) changes can be up to 25% of bodyweight) soo tortoise weight changes can be dramatic. Monitoring urine output and its SG and pH are useful guidelines to the metabolic state of a chelonian. A bladder aspirate can be taken if you are impatient. Aim for a pH of 7.5 and a SG of 1.003-1.012 in herbivorous terrestrial chelonians. Fresh water species will have a lower SG and if omnivorous a pH of 6.5. Dehydrated chelonians may have a SG up to 1.034.
Why can faecal burdens build up quickly in reptiles?
Reptiles generally inhabit the same environment for their lifetime. this is likely to be a small area. They are messy feeders and contaminate their food sources with faecal material. Heavy parasite burdens can build up quickly in captive reptiles as may parasites have a direct life cycle. Invertebrates if left in the tank run about and contaminate themselves with faecal material prior to ingestion.
How can you reduce parasite burdens in reptile
Provide an easy to clean substate that allows removal of all faecal material. remove all uneaten food promptly after feeding. Run a faecal sample to check for parasites. Parasites can build up on a particulate substrates and a complete substrate change may be required. Ensure all reptiles have a negative faecal sample prior to going onto particulate substrates. Monitor faecal samples at least anually to check for the need for anti parasitic drugs.
Why should you not worm reptiles routinely?
Toxic effects of deworming products are becoming well known. febendazole toxicity causes radiomimetic lesions with ulcerated, haemorrhagic bowels, Ivermectins kill chelonians as they enter the CNS and cause flaccid paralysis. Efficiency is actually increased by dosing over a few days.
What techniques can be used for faecal analysis?
Wet preparation - for motility and general impression of numbers evident. Floatation - to identify smaller numbers of parasites. Concentrate -to identify even smaller numbers. Quantification via mcmasters technique. tog et an egg cout. Iodine stained preparation for parasitic cysts. Generally the first three are sufficient. If no sample - can use a cloacal flush of 1% bodyweight of warmed saline. In some squamates manipulation will induce the passing of a faecal sample. This is preferable as it is more cocentrated. Pass catheter into colon and slowly infuse saline. Draw back on syringe and collect sample and anything else voided afterwards.
What are the common parasites seen in reptiles?
Coccidiosis - direct life cycles, bearded dragons and snakes. Toltrazuril daily for three days by stomach tube. repeat faecal check.
Ascarids - commonly found - Direct and indirect life cycles. Large worms can cause impactions. Fenbendazole as treatment daily for three days by stomach tube.
Oxyurids - faecal analysis positive in 75% . Can build up to massive level due to direct life cycle. Many species, particularly beardies. May have a role in mixing ingesta.
Ciliates - most are commensals such as nycotheries and balantidium. High levels may be secondary to other diseases.
Treatment in the critically ill chelonian may be required.
Cryptoosporidium - protozoal with direct life cycle in lizards and snakes. 80% of oocysts reinfect the host within the host. 20% immediately infective when passed in faeces. Cause regurgitation, anorexia and stomach swellng in snakes. Emaciation due to SI disease in leopard geckos.
Describe how you select antibiotics in reptiles.
Culture samples an be taken from any lesion, faecal samples or from swabs or washes. up to 50% of reptile bacterial infections include anaerobes. Many can be secondary invaders. Generally a culture sample will grow organisms. Most will be gram negative and have multiple resistance. Only one antibiotic is licensed for use in exotic species - enrofloxacin. This is bactericidal and is effective against aerobic bacteria only. Its efficacy against gram negative species is high including pseudomonas. Synergism with other bactericidal antibiotics can improve effective kill further. Ceftazidime is a third generation cephalosporin. Its bactericidal and has excellent activity against gram negatives including pseudomonas sp. Pharmacokinetic studies in snakes and tortoises demonstrated that 20mg/kg every 72 hours is appropriate. Metronidazole also can be used. Indigo snakes and king snakes have shown toxic signs with doses over 40mg/kg. Ticarcillin is also highly effective against anaerobes. it is an antipseudomonal penicillin. Available in combination with clavulanate.
