As the popularity of reptiles has grown, so has the demand for quality veterinary care. Today, reptile medicine represents
a viable subset of companion animal practice. Reptiles are stoic and have evolved to mask signs of illness, which makes them
a challenge to diagnose and treat. For veterinarians and technicians who are willing to become proficient, however, reptile
practice offers many rewards.
Capture and Restraint
Snakes are easy to hold because there is only one dangerous part to restrain. When approaching a snake you do not know, the
head may first be covered with a towel. This has the dual effect of blocking his view of the handler and providing him a
sense of security. Restrain by grasping behind the head with one hand and supporting the body with the other.
Snakes do not have complete tracheal rings, so use caution that asphyxiation does not occur. Some colubrid snakes will emit
a musky paste from the scent glands as a defense mechanism. Snakes that are used to being handled are much less likely to
bite. Bites from non-venomous species, if they occur, are generally harmless. Use the buddy system when dealing with giant
or venomous species.
Basic Exam Skills
Weigh the patient (in grams) at every opportunity. A decline in weight may be the only clue that there is a problem developing.
Assess body score by examining the dorsolateral musculature. Check for mites or ticks in the gular groove between the mandibles
and under the edges of scales. Examine the heat pits and eyes for mites. Look for retained skin especially on the head and
spectacles. During the oral exam, look for petechiation and abscessation. Check the tongue and glottis for swelling, symmetry,
and inflammation. Observe snakes for righting reflex and positional nystagmus when the head is moved side to side. Palpate
the abdomen for masses and ova.
Sexing via Hemipenal Probe
Use a lubricated blunt probe (e.g. ball-tipped feeding needle, urinary catheter). Pass the probe cranially under the lateral
edge of the vent flap, then flip the probe to aim it caudally. Direct the probe into a longitudinal canal that runs paramedian
along the tail. If the probe passes 3 caudal scales (into the scent gland) it is female, if it passes 7-10 caudal scales
(into the hemipenal canal) it is a male.
• Ventral tail vein: caudal to the cloaca with the snake in dorsal recumbency. A 5/8-1", 21-25ga needle is angled
at 45° craniodorsally, between caudal scales. Apply slight negative pressure once you are under the skin. If the needle
hits a vertebral body, withdraw slightly and redirect. (Best for large snakes)
• Cardiocentesis: restrain the snake in dorsal recumbency, watch for heart beat, and locate the heart ¼ to ⅓ of
the way down the body. Steady the heart with fingers and advance a 5/8-1.5", 21-25ga needle at a 45° angle craniodorsally,
under a scute, into the apex/ventricle. Blood usually enters the syringe with each beat. (Best for small snakes)
• Palatine vein: paired veins run along the roof of the mouth. Ideal for IV injections while under sedation.
Use a 25 ga., 5/8" needle on a 1 cc syringe. Pre-bend the needle slightly for easier approach. Place pressure on the vein
after withdrawing to avoid hematoma. (May require sedation)
Tracheal wash is the preferred method for sampling of respiratory pathogens. With the snake's head elevated, a sterile urinary
catheter is placed through the glottis while the patient takes a breath. Then, 3-10 ml/kg of sterile saline is injected.
The snake is quickly tilted downward, and the fluid is aspirated back into the syringe. Because of the simple anatomy of
the reptile lung, samples collected in this manner may actually be lung washes. Wet mount cytology of tracheal wash samples
may reveal lung worm (e.g. Rhabdias, pentastomid) larvae or ova. Anaerobic and aerobic culture and sensitivity are also performed.
Maintenance fluid rate for most reptiles is 15-25 ml/kg/day, and up to 5% of body weight may be given in a single dose if
indicated. Subcutaneous or intracoelomic fluid administration is utilized in the majority of cases. In snakes, SQ fluids
can be given along the lateral folds. ICe fluids are given ventrolaterally a short distance cranial to the vent, using care
not to enter the caudal extent of the lungs.
IV catheters can be placed in most reptiles however a cut-down approach is usually necessary. The preferred site for snakes
is the right jugular vein. A cut-down incision is made from 4-7 scutes cranial to the heart, at the junction of the ventral
scutes and lateral body scales. After the vein is isolated, a catheter is placed in the usual manner and secured using tape,
suture, and/or tissue adhesive.
Reptiles are slightly hypotonic when compared to birds and mammals. To prepare "Reptile Ringers Solution", mix 2 parts Dextrose
2.5%/Saline 0.45% with 1 part lactated Ringer's solution (or 1 part Dextrose 5%, 1 part Saline 0.9%, and 1 part Ringer's).
Snakes frequently present for lack of appetite. In some species (e.g. ball pythons) this can be considered a normal, seasonal
occurrence. In others it may be attributed to stress or disease. Often, no abnormality can be found on physical examination
or fecal testing. Force-feeding provides nutritional support for these patients while the clinician seeks to diagnose the
problem and correct husbandry. In the majority of cases, force-feeding will stimulate a snake's appetite. Medications (e.g.
metronidazole, fenbendazole) are frequently added to the mixture to "shotgun" the problem before resorting to further diagnostic
Oxbow Carnivore Care is used for this purpose. Mix to the desired consistency. Give 2.5-5% of body weight using a catheter-tipped
syringe and lubricated 14-fr. red rubber catheter. A snake's mouth can be opened with a rubber spatula or similar speculum.
Its glottis will be located far cranially in the mouth and is easy to avoid. Gently massage the food caudally as it is given.
After feeding, hold the snake's head elevated for several minutes. Once he is moving forwards in a serpentine fashion it
is ok to release him.