Snakes Diseases of

PROBLEMS REQUIRING VETERINARY ATTENTION

Nutritional Deficiencies

As stated earlier, nutritional deficiencies and disease resulting from malnutrition are relatively rare among captive snakes because of their habit of consuming whole prey animals. However, exclusive use of whole but immature prey animals, such as "pinkies" (neonatal mice and rats), juvenile goldfish and invertebrates, can create nutritional problems. Furthermore, certain snakes that receive a monotonous diet (no variety of prey items) are also susceptible to nutritional deficiencies. The hobbyist must find ways to "supplement" the prey items in these cases before they are offered to the snake. One method involves injecting the prey with vitamin and/or mineral preparations. Another involves implanting a gelatin capsule filled with a powdered vitamin/mineral/amino acid supplement into the prey animal. We prefer and recommend Nekton-Rep (Nekton-Products, W. Germany).

Failure to Voluntarily Feed

Anorexia (lack of appetite) and failure to voluntarily feed are common problems among captive snakes. Despite the fact that snakes are uniquely suited to survive prolonged periods without feeding, the hobbyist must make every attempt to discover the reason(s) for the snake's failure to feed. This search must include the possibility of illness, since anorexia is a universal sign of disease in snakes.

First consider the circumstances and situations during which snakes normally will not feed: Recent acquisition of a snake.

Snake in pre-shed condition.

Latter stages of pregnancy. Older, larger snakes feed less often than younger, smaller ones.

Newborn or newly hatched snakes may not feed until after their first shed 10-14 days after birth. Hyperactivity associated with the breeding season or the imposition of captivity on newly acquired, high-strung species.

Hibernation or attempts to hibernate. Illness. If all of the above have been rejected as causes for anorexia, you must next consider problems with husbandry. The most common cause for failure of a snake to voluntarily feed is inadequate environmental temperatures. Tropical snakes require temperatures between 75 and 85 F for normal activity and optimum digestive capacity. Subnormal temperatures lead to sluggishness and incomplete digestion. The food literally spoils inside the snake, producing serious illness, an early sign of which is vomiting. The next most common cause for captive snakes' refusing to feed is lack of adequate visual security. Many snakes require privacy while they feed. A hiding box or a natural bark or rock retreat may be necessary. Sometimes placing the reluctant snake in a roomy burlap bag along with a dead or incapacitated prey item provides the security the snake requires in order to feed. Strategic placement of silk artificial plants may also help provide additional visual security. There may be one particular area of the enclosure in which the snake feels more secure. The food should be consistently placed there to encourage feeding. It is important to note that the presence of spectators often discourages nervous snakes from feeding. The enclosure should be covered in these cases and the snake’s activity discreetly monitored.

It is extremely important for you to understand the natural history of the anorectic snake being kept in captivity. Reluctance or refusal to feed often is the result of some omission or mistake in husbandry. Burrowing species require sand or fine gravel in which to bury themselves. The snake can often be induced to strike at prey by gently dragging the prey item across the sand. Tree-dwelling species require branches within their enclosure. Some of these snakes may be encouraged to feed by hanging the food in the fork of a branch rather than placing it on the floor of the enclosure. If these specific husbandry requirements are not provided, certain snakes may not feed.

Offering incorrect prey items nearly always causes a captive snake to refuse to eat. One should offer the prey items that the snake would feed on in the wild or a similar more "domestic" food that is more available.

Following is a list of additional suggestions to consider when you are challenged with a snake that refuses to feed:

Try feeding at different times of the day.

Nocturnal (night-active) species cannot be expected to feed on prey items placed within the enclosure during the daytime.

Try feeding nervous snakes that share an enclosure with other snakes in an environment separate from them. Often, the movement of other snakes in the same enclosure induces anorexia in nervous snakes. Moving a snake to a new or different enclosure may stimulate feeding. Reduce handling of especially nervous or newly acquired snakes to encourage feeding.

Rubbing the food item over the sensitive areas of the snake's head (the nostrils and the areas surrounding the mouth) or gently hitting the snake with the prey may antagonize it to strike at the food.

Offer live prey to snakes that have been consistently offered dead or incapacitated prey (with close supervision). Certain aggressive snakes and snakes with an impaired sense of smell may require live prey to successfully feed.

For snakes that ordinarily eat live prey, try feeding dead or n incapacitated live prey items. Often, the erratic motions of a rodent running around an enclosure can cause a snake to refuse to feed.

Try feeding a smaller prey item. A snake that has been recently injured by a particularly large and aggressive prey animal may be reluctant to feed. Cater as much as possible to the individual preferences of an anorectic snake. If a snake refuses mice, try small rats, gerbils, hamsters, rabbits or even chicks. Some snakes can be very finicky. If all of the above have been considered without success, take your snake to a veterinarian experienced with snakes. The veterinarian will collect a detailed history and conduct a thorough physical examination. It may be necessary to collect a blood sample to more thoroughly evaluate the patient. Take along a fecal (stool) sample from the snake so the veterinarian can also check for intestinal parasites. A veterinarian may pass a flexible tube into the stomach and force-feed the anorectic snake at this time. This provides some nutrients while the medical evaluation is in progress. Some anorectic snakes begin to voluntarily feed after such a feeding. This can be easily learned if periodic at-home force- feedings are anticipated. Metronidazole appears to have some stimulatory role in the appetite of snakes.

Strained meat baby foods with added Nekton-Rep or pureed dog food are recommended and easily pass through most stomach tubes. Larger snakes require relatively larger volumes of food; pureed dog food is a more practical food in these situations. Low-fat dog food is preferable.

Adapted from Barten, SL: The induction of voluntary feeding in captive snakes. Bull Chic Herpet Soc 16(1):1-5, 1981. Regurgitation

Regurgitation

Regurgitation of food may result from handling a snake too soon after it has fed. Regurgitated food is undigested and relatively odorless. Another common cause of regurgitation is inadequate and incomplete digestion caused by relatively cool environmental temperatures. In these cases, the regurgitated food appears digested and malodorous. If it is not possible to raise the temperature of the enclosure, a focal source of heat (hot rock, heating pad or pads) on which the snake can rest is a necessity to ensure adequate and complete digestion.

Other causes of regurgitation include stress in easily excitable species, parasitism, intestinal obstruction and serious internal disease. An experienced veterinarian should be consulted if the cause for regurgitation is not readily determined.

Trauma

Burns Snakes commonly sustain serious burns when they contact unprotected or malfunctioning heat lamps or other heat sources (including hot rocks). Interestingly, snakes tend not to move away from the heat source inflicting the injury. This makes the wound considerably more serious. Medical treatment (including injectable antibiotics and periodic wound dressings) is required in these cases. Surgery may be necessary to minimize the disfiguring effects of such injuries.These injuries are easily avoidable.

Periodically check all heating appliances to make certain they are functioning properly and that they are "snake proof". Rat/Mouse Attack Sometimes a live mouse or rat turns the tables on a snake while fighting for its life (the dinner becomes the diner). Veterinary attention should be sought for serious bite wounds.

Rostral Abrasions

One of the unfortunate consequences of captivity is injury to the captive animal from repeated attempts to escape. Snakes tend to push and rub their noses against the walls of their enclosure as they move about in search of a means to escape.

This constant trauma initially damages the scales and skin of the nose (rostrum). If the trauma continues, deep ulceration of the rostrum with subsequent deformity may result. Rostral abrasions are equally likely with enclosures made of glass or wire mesh.

Prevention of this problem is difficult, but adequate visual security (hiding places) and other additions to the enclosure (artificial plants, branches, etc.) help minimize it. Furthermore, a visual barrier of dark paint or plastic film placed on or along the lower 3-4 inches of the enclosure's walls often inhibits pacing and rubbing.

Constipation

Constipation is a common problem among captive snakes. Causes include suboptimal environmental temperature, illness, dehydration, injuries, parasitism and cloacoliths (see below).

Constipated snakes should be allowed to soak in very warm (not scalding hot) water for 20-30 minutes daily for 1-2 days. This often results in defecation and/or urination. If this conservative measure is not successful, veterinary help should be sought at once.

Cloacoliths

Dehydration of captive snakes (especially if long- standing) may result in drying out of urinary excretions. When this occurs, uric acid "stones" tend to form within the cloaca ("cloacoliths"). Their presence in this location prevents expulsion of urinary waste and feces (constipation), which creates serious illness. Dehydration is a sign of disease and not a disease in itself, so it becomes the veterinarian's task to determine the underlying problem that caused the dehydration.

Cloacoliths can usually be manually expelled with patience and the help of mineral oil enemas. This procedure should only be attempted by an experienced veterinarian.

Prolapses

A prolapse occurs when an organ inverts itself inside out and protrudes through the usual external opening of that organ. Prolapses of the cloaca and the reproductive organs are not uncommon among captive snakes. Often the cause cannot be determined.

Prolapses can be precipitated by straining during egg-laying or straining related to uric acid stones. Parasitic infections or other intestinal disease may also result in prolapses. Veterinary assistance is essential in these cases to treat the prolapse and determine the underlying cause, if possible.

Abnormal Shedding

Abnormal shedding occurs when the normal sequence of events of the shedding process is somehow interrupted. This usually results in a piece- meal shed and/or retained eye caps. Causes include serious internal disease, inadequate relative humidity, previous injury (including surgery) to the skin and scales, external parasitism, lack of adequate objects within the immediate environment against which to rub at the beginning of the shed, and thyroid gland problems. An abnormal shed indicates a problem that demands immediate attention. In these cases, consider all of the aforementioned causes, most of which demand veterinary assistance. Treatment of a snake with retained skin from an abnormal shed involves first soaking the snake in warm water for several hours. A damp towel can then be used to gently peel off stubborn skin fragments. An alternative to this manual method involves rolling the snake snugly in warm moist, heavy towels and allowing it to crawl out, leaving the stubborn skin fragments behind. This procedure can be repeated if necessary.

Retained Eye Caps

Retained eye caps are often a manifestation of an abnormal shed. The eye caps represent the outermost cellular layers of the corneas (the transparent portions of the eyes), which are supposed to be shed each time the outermost layers of the skin are shed.

The retained caps must first be softened by repeated application of a suitable eye ointment. Next, an experienced veterinarian should attempt to carefully remove the corneal remnants. This procedure should not be attempted by an inexperienced hobbyist.

Mouth Rot (Infectious or Ulcerative Stomatitis)

Mouth rot is a progressive bacterial infection involving the oral lining. It may begin with increased salivation. Often saliva bubbles from the mouth. Close inspection of the oral lining reveals tiny pinpoint areas of bleeding. The oral lining becomes increasingly inflamed and pus begins to accumulate within the mouth, especially among the rows of teeth. As the disease progresses, the underlying bone becomes infected and the teeth fall out. This infection must be recognized in the early stages to successfully reverse it. The hobbyist must seek veterinary help when mouth rot is first evident.

The veterinarian may want to collect a saliva/pus specimen for bacterial culture and subsequent antibiotic sensitivity testing to determine the appropriate antibiotic(s) to use. A blood sample can also be collected to accurately assess the internal and overall status of the patient.

Initial treatment involves injections of vitamins A, C and B complex, as well as a "best guess" antibiotic (one that the veterinarian believes has the best chance of fighting the infection until the results of antibiotic sensitivity tests are available).

Supportive care involves daily or twice-daily cleansing of the mouth, application of topical antibiotics, administration of fluids to combat dehydration and the possible detrimental effects of certain antibiotics, and periodic forced- feedings (using a stomach tube).

Generally, snakes with heavy accumulations of pus and infected bones of the jaw are unlikely to be saved, even with aggressive veterinary efforts. You must be alert to the early stages of the disease and periodically inspect the mouth for signs of mouth rot.

Abscesses

Abscesses are a common form of bacterial infection in snakes. They can be external and/or internal in location. External abscesses most often result from bite wounds (usually inflicted by live prey animals) and other injuries (especially puncture wounds) to the skin. Internal abscesses may be located within one or more organs and/or within the body cavity.

Snakes rarely produce liquid pus. Instead, their pus is generally cheesy in consistency. This makes treatment with antibiotics difficult because these drugs cannot penetrate this relatively solid material. External abscesses can be surgically opened and flushed by a veterinarian. A specimen of pus can be submitted to a laboratory for bacterial culture and antibiotic sensitivity testing. The snake can be treated with the appropriate antibiotic by injection, and the abscess cavity treated with topical antibiotics. Abscesses within the body are not equally accessible for treatment. A blood work-up and/or radiographs (x-rays) may be necessary to confirm their presence. Though surgery may be necessary under certain circumstances, long-term antibiotic therapy by injection and appropriate supportive care are the treatment most likely to be employed by the veterinarian.

Blister Disease

Blister disease is common in many captive reptiles. It is most often associated with the maintenance of these animals in damp, filthy environments. The first sign is usually a pink to red appearance of the bottom-most scales. Later, these scales become swollen and infected by bacteria and fungi.

At the first suspicion of this disease, you must seek veterinary help. Treatment involves use of topical and injectable antibiotics. Furthermore, the underlying sanitation and hygiene problems must be corrected. Blister disease is preventable if you are aware of it and if the enclosure in which captive snakes are housed is kept dry and scrupulously clean.

Septicemia

A wide variety of bacteria can cause generalized internal infections (septicemia). These bacteria may invade the body by way of wounds and abscesses or as a consequence of serious illness originally localized in the respiratory, gastrointestinal and reproductive tracts. Signs may be subtle or obvious and may include lethargy, anorexia, dehydration, vomiting of incompletely digested food, redness of the skin and scales, or bleeding from the skin.

The help of an experienced veterinarian is essential in these cases. The outlook for these patients is always guarded to poor. The attending veterinarian may collect a specimen for bacterial culture and antibiotic sensitivity testing, as well as one or more blood samples to more accurately determine the extent of the disease, whether or not various internal organs are involved, and as a means of monitoring the patient's progress. Treatment involves use of indictable antibiotics and appropriate supportive care (fluid therapy, force-feeding, indictable vitamins, etc.). Treatment must usually be relatively long-term and periodic monitoring of the patient's status is essential to a favorable outcome.

Respiratory Disease

Respiratory infections are common in snakes. They may be associated with septicemia (body- wide) illness, viral infections and mouth rot. Some respiratory illness may be the consequence of stress from poor or inadequate husbandry. Signs include loud respiration’s, discharge and/or bubbling from the nostrils and/or mouth, coughing and open-mouth breathing. Treatment must be aggressive and at the direction of a veterinarian. A bacterial culture of the windpipe and subsequent antibiotic sensitivity testing should be undertaken to identify the offending bacteria and the appropriate antibiotic(s) to use.

The veterinarian may also recommend collecting a blood sample to determine the extent of the disease and to see if there has been serious compromise to internal organs. Antibiotic therapy should be by injection and may need to be long- term, especially in severe and long-standing cases. Inhalation therapy (vaporization or nebulization) is frequently employed as part of the treatment.

Eye Infections

Captive snakes occasionally suffer eye infections. Infections may be superficial or more extensive, involving the entire eye. Superficial infections may result from mild injury to the eye. Superficial infections may also become established below a retained eye cap.

Infections of this type must be recognized promptly and treated aggressively to prevent involvement of the entire eye. The retained eye cap must first be removed if at all possible. Infections involving the entire eye may result from massive trauma to the eye or from septicemia (body- wide infection). In the latter case, the bacteria enter the eye by way of the bloodstream.

Veterinary help is essential with these cases. Treatment involves use of topical and/or indictable antibiotics. Sometimes, drugs that help to exercise the iris (the colored portion inside the eye) are used to help prevent adhesions inside the eye.

Viral Infections

Viral infections in snakes, as a whole, are generally poorly understood. This is because viruses are extremely difficult to detect and identify. They are equally difficult or impossible to treat.

Viral infections result in tumorous skin growths in many native snake species. Other viruses can cause digestive, respiratory and nervous system disease among snakes. An example is a recently recognized viral encephalitis affecting pythons and boa constrictors. Afflicted constrictor species exhibit a very gradual deterioration of the brain and eventually die.

Most viruses are highly contagious. Hobbyists must be aware of this and quarantine all newly acquired snakes for at least 6-8 weeks. This involves complete isolation of new snakes and careful scrutiny of them during this period for any signs of illness.

All newly acquired snakes should be thoroughly examined and evaluated by a veterinarian experienced with snakes. Blood tests may offer clues as to viral infections.

Fungal Infections

A number of fungal organisms can cause superficial and deeper infections of snakes. Most of these infections involve the skin and respiratory system. Fungal infections of the eyes are most likely to occur in snakes housed in damp, contaminated environments. Ringworm fungi that usually infect people, pets and livestock have also caused skin infections of snakes.

Snakes must be housed in scrupulously clean and dry enclosures. The flooring must be easy to clean and should not be of a material that encourages fungal (mold) growth (see section on Housing).

Snakes exhibiting problems with their skin and/or eyes must be examined by a veterinarian as soon as possible. A microbial culture and a skin biopsy may be necessary to obtain a diagnosis.

Treatment of fungal diseases involves use of topical and systemic (oral and/or indictable) antifungal agents. Prevention of fungal diseases involves correcting underlying problems with husbandry.

Parasitic Diseases -We recommend all reptiles be tested for salmonellosis

Snakes can be hosts to large number of parasites, representing a bewildering variety of organisms that can cause many problems. A large number of one-celled organisms (protozoa) can cause serious diseases of the digestive, respiratory, reproductive and vascular (blood and bloodstream) systems of snakes.

Flukes cause illness in the respiratory and urinary systems. Tapeworms parasitize the digestive system. Roundworms and related parasites inhabit the digestive tract, but their juvenile stages can cause disease to other organs (especially the lungs) during the course of their migrations.

Large number of mites and ticks parasitize the skin and scales of snakes, and create disease by feeding on the host's blood.

Most parasites of pet snakes and snakes kept in zoological collections are carried with them into captivity. These snakes were either parasitized before being collected in the wild or became parasitized while being held in the generally crowded wholesale and retail channels.

Pet snakes living singly in homes are very unlikely to develop parasite problems in these relatively isolated environments. Exceptions to this generalization include pet snakes exposed to parasitized snakes and their excretions, or to the specific organisms (called "vectors") necessary for parasites to complete their life cycles. In most cases, the vector must bite the uninfected snake for the snake to become parasitized. It is also possible for a captive snake to become parasitized by eating prey species that harbor the larval stage of a given parasite.

Newly acquired snakes should be thoroughly examined and evaluated by a veterinarian for external and internal parasites as soon as possible after acquisition. All detected parasitism’s should be treated, if possible. No snake should be introduced into a collection until it has been examined by a veterinarian and until it has been quarantined for a minimum of 8 weeks and remains healthy during this period. Strict attention to hygiene and sanitation and a proper diet usually contribute to optimum health, even in the face of mild to moderate parasitism. Because the subject of parasitism is so extensive, only several of the more common parasite problems of captive snakes will be specifically mentioned:

Amebiasis

Amebiasis is one of the most significant parasite problems of captive snakes. This highly contagious disease is caused by a microscopic, one-celled organism (protozoan) called an ameba. Snakes are easily infected by eating contaminated food and water containing the infective stage of this parasite. The organisms cause extensive damage to the intestinal lining and liver.

Secondary bacterial infections are very common and contribute significantly to the severity of the disease. Signs of amebiasis include listless ness, inappetence, and foul-smelling feces containing mucus and blood.

A veterinarian may be able to diagnose this disease by having the laboratory examine specially prepared samples of feces. Sometimes examination of tissue sections of the intestine or scrapings from the lining of the intestine of a deceased snake is the only way the diagnosis can be confirmed. This underscores the importance of performing autopsies on snakes that have died, especially when there are other snakes in the collection whose lives may be threatened.

Many snakes native to the American Southwest harbor these organisms but apparently do not suffer from the disease. Crocodiles and certain turtles are similar "carriers". Hobbyists must, therefore, exercise caution when housing snakes with these species to avoid an outbreak of amebiasis. Certain water snakes, as well as boa constrictors and pythons, are especially susceptible to this disease. Amebiasis is treatable, requiring the expertise of veterinarian. Specific antiprotozoal medications and antibiotics are used. Enclosures used to house infected snakes should be steam cleaned and disinfected with a 3% bleach solution.

Trichomoniasis

One of the most commonly recognized parasites of snakes is another protozoan, Trichomonas This organism is often noted in the stools of snakes when routine direct examinations are undertaken. Infection with trichomonas may result from ingestion of mice and rats, both of which often harbor the parasite without showing signs of illness.

Infected snakes may exhibit no signs or those associated with gastrointestinal disease (inappetence, vomiting, diarrhea). Some infected snakes may also have bacterial disease at the same time.

Some experts remain unconvinced that this parasite, by itself, can produce disease in snakes because infected snakes are often suffering from amebiasis at the same time. The most prudent course of action is to treat all snakes harboring the parasite. Fortunately, the treatment for trichomoniasis is usually effective in eliminating the organism that causes amebiasis. A veterinarian should be consulted regarding diagnosis and treatment of this parasitic disease.

Snake Mite Infestation

Snake mites are tiny spider-like organisms that reside on and between the scales of snakes and tend to also congregate around their eyes. They are relatively easy to see with the unaided eye but a magnifying lens aids in their identification. Mites are the most common and most dangerous of the external parasites of captive snakes. These mites feed on the blood of their hosts, causing anemia (often severe with heavy infestations).

Blood-feeding can also transmit viruses, at least one very serious disease-causing bacterium, and blood parasites.

The snake mite completes its life cycle on its host. The females, however, lay up to 80 eggs off the snake within the immediate environment. This is one reason why particulate floor coverings (corn-cob material, pebbles, etc) are not recommended. These substrates provide too many hiding places for the mites and their eggs.

Snakes that are most likely to be seriously compromised by the external parasite are those that have been recently imported and those housed under crowded, unhygienic conditions. Heavily parasitized snakes are also likely to be adversely affected when they are suffering from malnutrition and/or other diseases at the same time.

Veterinarians must be consulted when these various circumstances arise. These snakes must be carefully examined and thoroughly evaluated so that underlying disease and problems with husbandry can be identified and corrected. Furthermore, the recommended treatment can often be injurious, especially to snakes suffering from debility and/or disease.

The veterinarian must perform a thorough physical examination and may recommend a blood analysis to fully evaluate the patient, the advisability of treatment, and the least harmful method of treatment for mites. Several treatments are available for snake mites. One popular method involves suspending a No-Pest Strip (Shell) above or adjacent to the snake's enclosure for 2-5 days. One expert recommends a "dosage" of 0.2 inches of commercial strip per 10 cubic feet of enclosure.

An alternative is to place a 1-inch section of a No-Pest Strip within a 35-mm film container with multiple perforations and suspend it inside the enclosure for 2-5 days. These products should be used cautiously, however. They can be especially toxic to severely ill and debilitated snakes.

Flea sprays formulated for use on dogs and cats can be applied to a small towel and the chemical can be wiped onto the skin and scales. This procedure should be repeated about 10 days later. During treatment, any particulate floor covering (gravel, crushed corncob, wood shavings, etc.) within the enclosure must be replaced by paper or towels. All water containers should also be removed.

The enclosure itself should be thoroughly cleaned and fumigated with 10-15% solution of formalin and hot water. After a thorough rinsing, the enclosure should be allowed to completely dry before it is reinhabited. Treated snakes should be closely monitored for several months for signs of re-infestation and mite-related disease.

Snake Tick Infestation

Ticks resemble oversized mites and occupy many of the same sites on the skin and scales of snakes as mites. They are often found just inside the mouth, nostrils or vent. Even under conditions of captivity, ticks rarely reach the burdensome number reached by mites. Recently imported snakes are usually the most heavily parasitized.

Like mites, ticks feed on blood of the host snake and can cause severe, life-threatening anemia. Their blood-feeding habit enables them to transmit certain blood-borne diseases to snakes. Manual removal of each individual tick is the most expedient treatment for tick infestations. The hobbyist must exercise great care in performing this task. Simply pulling off the tick leaves the tick's mouth-parts embedded in the skin. A small amount of alcohol applied to the exposed parts of the tick causes it to relax and facilitates removal. The treatment methods recommended for mites are also effective.

Parasitized snakes usually require a minimum of 4 days' exposure to No-Pest Strips to kill ticks. Enlist the services of an experienced veterinarian for a thorough pretreatment evaluation of the snake, especially if the use of a No-Pest Strip is anticipated. Cancer

Cancer

Cancer occurs in snakes, but the number of reports is quite limited. Some of the tumors have been diagnosed on living snakes, but most were diagnosed at the time of autopsy. As with mammals, tumors of snakes can be benign or malignant and originate from any organ or tissue of the body, including blood.

Boa constrictors seem to be more often affected by cancer than other snakes commonly kept in captivity. This observation, however, may be the result of the disproportionately large number of boa constrictors kept by hobbyists because of their tremendous popularity. It is interesting to note, however, that most life-threatening malignancies that we have diagnosed in snakes have involved boa constrictors. Snake owners must be vigilant and seek prompt veterinary help when a growth or lump is detected on their snake(s) (especially if a boa constrictor is involved). "Mole-like" growths have been especially troublesome in our experience. Wounds that fail to heal despite treatment should make you equally suspicious.

Organ Failure

Failure of vital organ function may be the result of advancing age or cancer but is usually a consequence of chronic and unchecked disease among captive snakes. Disease that has gone undetected and/or untreated can have devastating and sometimes, fatal consequences.

Under these circumstances, organ function is greatly compromised and the snake's usually smooth-running metabolism is threatened.

SHEDDING (ECDYSIS)

Shedding is the process by which snakes periodically discard the outer portion of their skin. This activity is under hormonal control and associated with growth. Most snakes shed their skin 4-8 times per year. The frequency of shedding depends upon many factors, including environmental temperature, frequency of feeding, amount fed at each feeding, and activity level.

Young snakes shed more frequently than older ones because growth is relatively rapid in the first few years of life. Healthy snakes usually have little or no difficulty with shedding and tend to shed their skins in one entire piece. Exceptions to this include snakes with injuries to the skin and/or scales resulting in scarring, and snakes housed in enclosures with suboptimal temperature and/or relative humidity levels. The stresses associated with shedding can be substantial. Sick snakes, those suffering from malnutrition, or those whose health has been directly or indirectly compromised by poor husbandry experience delayed and incomplete sheds. These snakes tend to shed their skins in pieces. In fact, many of the pieces remain adhered to the underlying skin and eyes (retained eye caps).

The shedding process is preceded by a period of relative inactivity. This period usually lasts 1- 2 weeks, during which time the eyes begin to exhibit a dull, bluish-white appearance. During this period, the snake's vision is impaired, which causes them to be rather unpredictable and sometimes aggressive.

The skin during this period tends to have an overall dull appearance. The underlying new skin is soft and vulnerable to damage while the outer layers prepare to slough away. The eyes again become transparent after 7-15 days and shedding commences. A snake will make use of any rough objects or surfaces within its enclosure to help shed the skin.

Shedding commences with the skin of the head. Once the snake has loosened and dislodged the skin surrounding the mouth and overlying the rostrum (nose), it then passes between rough objects that can trap the loose skin and hold it as the snake glides out of the "old" skin.

Discarded skin appears dry and tube-like or moist and crumpled in a solitary heap. Many snakes defecate after a successful shed, or consume large quantities of water.

REPRODUCTION

Snakes produce offspring in 2 basic ways. The first involves development of the fertilized eggs within the body of the female. When the embryos are fully developed, the offspring are born, appearing like miniature adults.

Boa constrictors, water and garter snakes, and rattlesnakes are live-bearing species and are considered ovoviviparous The second method involves deposition of oblong, leathery-shelled eggs within the environment, where the eggs incubate. At the completion of embryonic development, the eggs hatch, producing miniature adults. Pythons and rat and milk snakes are egg layers, and are considered oviparous. In either case, the newborn or newly hatched can fend for themselves and receive no parental nurturing. Many snake species readily mate in captivity. One mating may result in up to 3 clutches of eggs or 3 "litters" of live young. This is because sperm can be stored within the reproductive tract of the female after insemination.

The proper pairing of snakes according to age and sex is essential if reproduction in captivity is to be successful. Sexing of snakes can be difficult because males generally resemble females. Male pythons and boa constrictors have a spur on each side of the vent. Some females have spurs but they are usually smaller than those of males. These observations can be misleading at times.

Snakes under 18 inches long can usually be sexed by exerting pressure on the tissues surrounding the vent. Male snakes have paired hemipenes (elongated, spurred structures used during copulation) that can be extruded with this maneuver. The widely accepted method for sexing most snakes over 18 inches in length requires specialized sexing probes. These elongated, blunt tipped instruments are gently inserted into the vent and directed toward the tail. The probe penetrates only a short distance in females and a much longer distance in males. This procedure should only be attempted by experienced handlers.

Artificial Incubation of Snake Eggs

Artificial incubation of fertile snake eggs is quite easy. A small amount of water is added to an empty Styrofoam picnic chest. Then, a thick layer of peat moss, sphagnum moss, vermiculite, shredded newspaper, or paper towels is added. The eggs are carefully introduced into this medium. Slightly moistening the incubation material also helps prevent the eggs' drying out. Too much moisture, however, promotes the formation of mold which will cause destruction of the eggs' contents. The relative humidity required to incubate snake eggs falls within the range of 75- 85 percent.

The covered Styrofoam chest is then placed on a heating pad, which is set on its lowest heat setting. The ideal temperature range for most incubation lies between 78 and 84 F. The average incubation period for most snakes range between 55 and 60 days.