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CLINICAL BIOLOGY AND CARE OF THE ELEPHANT

Based on the work of Dr Shelton Atapattu

A-1.  NATURAL HISTORY

Elephants are in the order Proboscidae, with two species: Elephas maximus, the Asian elephant; and Loxodonta africana, the African elephant.

In Sri Lanka the elephant in the wild is now mainly confined to areas of dry deciduous forests, where vegetation is mainly thick, thorny, impenetrable acacia species. The wild population was estimated to be 1 800 to 2 000 animals in 1990. The Asian bull elephant can reach 3.3 m in height at the withers (shoulder), and a body weight of 5 500 kg. The females can reach 2.7 m at the withers, and a body weight of 4 000 kg. In Sri Lanka, the average adult male elephant reaches a height of 3 m at the withers, with a weight of 4 000 kg. Females vary between 2.0 and 2.5 m at the withers, with a weight of 2 500 to 3 500 kg.

The Asian elephant has a convex-shaped back, a trunk with one finger, ears much smaller than those of the African elephant, and does not have a smooth skin. No females have tusks, and only about 5-7% of bulls have tusks, depending on the sub-species. Some Sri Lankan bulls and cows have rudiments of tusks, called _tushes_.

Thermoregulation is a problem for elephants, and they need adequate shade during the greater part of the day, and live in areas where there is a plentiful and perennial supply of food and water. They prefer to have large foraging areas, and keep on expanding their foraging space by pushing down, breaking or debarking trees, which ultimately degrades wooded areas. Elephants spend about 70% of their time foraging, consuming about 150 kg daily of a mixture of foliage and grasses. Typical sources of fodder and forage are tamarind (Tamarindus indicus), jak or jackfruit (Artocarpus hetero-phyllus), pota (Pothos scandeus), dadep (Erythina variegata, [syn. E. indica]), sugar cane (Saccharum officinarum), wood apple (Limonia acidissima [syn. L. elephantum]), banana and plantain (Musa spp.), coconut (Cocos nucifera), and breadfruit (Artocarpus altilis), but grasses form the bulk of their food. Their feeding rate varies with the type of foliage available. Thus succulent, luscious sugar cane is consumed faster than any other type of vegetation.

An adult elephant drinks an average of 180 to 270 l/day of water (40 to 60 gallons), but this is more in higher ambient temperatures. Twice daily watering is ideal for an elephant.

In Sri Lanka, owners of elephants do not give any concentrates to their elephants. They are fed mainly with tree foliage and grasses.

Wild elephants invade the naturally occurring salterns in the Southern Province of Sri Lanka from time to time to obtain salt.

A-2.  REPRODUCTION AND LIFE CYCLE

Wild cow elephants attain puberty between the ages of 14 and 17 years, but domes-ticated elephants with good nutritional status could attain puberty at the comparatively early age of 8-10 years. Males mature more slowly, becoming sexually mature in domestication by the age of 10-12 years at the earliest. Male elephants can mate at any time during the year. A female in oestrus mates with several males. The average gestation period is 22 months ±1 month. Diagnosis of pregnancy in wild elephants is extremely difficult. However, during the last three months of pregnancy the mammary glands become enlarged and with some milk secretion even before parturition.

After birth the mother looks after the calf for nearly 3 years, and it is during this period that the calf matures, learning the routes to water holes and foraging areas. A female usually produces a calf every 5-7 years, and some of them can continue calving to 55 years old. This pattern of breeding occurs only if the entire family group is left undisturbed, without extraneous factors to disrupt their normal life styles.

In domestication, an elephant is most productive between 20 and 50 years of age, and after the age of 50 they are gradually transferred to lighter tasks, and retired at 60, when the only work expected of them is to fetch home their fodder from harvest sites and periodically to be used for ceremonial work.

The life span of an elephant is up to 100 years, comparable to that of man. In Sri Lanka, most domesticated elephants die when they are about 40-50 years of age, especially amongst the timber logging elephants. This is commonly due to tuberculosis.

Bull elephants exhibit _musth_ annually if in good health. It indicates good physiological condition and sexual preparedness. During this period, usually lasting from 1 to 3 months, the temporal glands become inflamed and swollen, accompanied by intense pain. There is an excessive, oily secretion of fluids from the pores of the temporal glands. A bull elephant in musth is aggressive in behaviour, restless, dribbles urine, and uncontrollable. They are kept away from all work and ceremonial functions, and kept securely tethered (Figure 16), well fed and bathed, and certain herbal oils are applied in the region of the temporal glands to relieve the pain.

Elephants that are unhealthy or whose nutritional status is poor would not come into musth annually.

Figure 16 Bull elephant in musth, and the strong fetters needed to control him

A-3.  REMOVALS FROM THE WILD

In general in Sri Lanka there are no records kept of removals for domestication from the wild herds. However, during 1974, permits were issued to private elephant owners on the payment of a fee to the Department of Wild Life Conservation, licensing capture of elephants taller than 7 ft (2.15 m) from "pocketed herds" for domestication. Issuing permits limiting captures to elephants 7 feet or more in height meant removal from the pocketed herds of the animals that cause most trouble. Some of them even turned out to be man killers.

The allowed method of capture was the traditional one of noosing. The capture of elephants by this method was successful in areas where there were big trees, both to lay the nooses and also to tether the elephants after capturing them.

A major post-capture problem was aftercare. Some adult elephants, in their attempts to break away from the manilla leg ropes, cut themselves badly, and secondary infections developed. Many of the elephants died of blood poisoning. The number of deaths was more than otherwise might have been because the elephant owners preferred to use the local traditional herbal medicines for treatment, on the grounds of cost and that they were considered better than "western" treatments.

Elephant capture using drug immobilization was first tried in Sri Lanka in 1974. Seven adult elephants (_7 ft (2.15 m) high) and one baby elephant (4 ft (1.20 m) high) were captured. The baby elephant was sent to the elephant orphanage at Pinnawela, Sri Lanka, and six of the adults were auctioned. The seventh had to be destroyed.

The drug used for this capture operation was M-99 (Reckitt), but it was found that double the standard dose for an African elephant was needed. Because of the thorny and impenetrable nature of the scrub jungle that was the wild elephants' habitat, it was necessary to use a small bulldozer to track the darted animal through the dense scrub.

A-4.  CARE OF ORPHANS

In Sri Lanka, an average of 30 to 40 wild elephants are killed each year, leaving about 20 orphaned baby elephants. Most of these orphaned baby elephants have been rescued by villagers or by the staff of the Wild Life Department, and handed over to the Pinnawela elephant orphanage. These baby elephants are often in a very poor state of health, with infected wounds, and suffering from malnutrition and gastro-intestinal and respiratory tract infections. During the early years of the orphanage most of the baby elephants died. Problems arose because villagers had fed them with cow or buffalo milk, which are not suitable for baby elephants. Present practice is to use an artificial milk powder formulated for humans.

The attendant preparing the milk must observe good hygienic practices, and all utensils used for the preparation of milk for baby elephants should be kept absolutely clean, as should be the bottle. The feeding bottle can be a normal 75 cl bottle (standard Scotch whisky bottle!) with a 4 cm length of 2 cm diameter rubber hose as a teat.

During the first three months the baby elephants consume at least 3 to 4 lbs (_2 kg) of infant milk powder per day, dissolved in well-boiled water, and given to begin with at 3 to 4 hour intervals. This rises to 6 lb/day (_3 kg/day) by the age of 9 months to 1 year. Some "babies" continue taking milk and depend on it totally for longer periods, going up to nearly 1¾ years. In addition, the babies are given 100 g of rice overboiled into rice gruel, together with some sugar-cane syrup.

Nearly all baby elephants coming to the orphanage in Sri Lanka need treatment for enteritis, for which a kaolin-pectin mixture is used, accompanied by antibiotics and vitamin supplements. This reduces mortality considerably.

The average cost of milk foods and medication in the orphanage at Pinnawela were (1990): SL Rs. 35 000 to 40 000/yr. This ignores staff costs.

Care is taken to allow new entrants to the orphanage to have social contact with the herd. This provides social reassurance due to the suckling reflex (as the sub-adult females allow the babies to suckle their nipples even though there is no milk) and cross inoculation of bacterial microflora from the saliva of the juveniles and sub-adults help develop resistance in the babies to some common bacterial infections.

A number of baby elephants are rescued after falling into gempits or unprotected wells. They usually have wounds of the trunk and mouth. These wounds are cleaned well with soap and water, and finally cleaned with glycerine, followed by a course of antibiotics.

Intestinal colics are frequent in baby elephants, when they suffer from excruciating pain and very often roll on the ground screaming. This requires prompt veterinary attention.

A-5.  COMMON DISEASES AND DISORDERS OF ELEPHANTS

Elephants are susceptible to a number of diseases, the occurrence of many of which can be minimized by regular vaccination. These include rabies, tetanus and anthrax. In Sri Lanka, anthrax is not a current problem, but domesticated elephants and the elephants at the National Zoological Gardens are immunized against tetanus and rabies annually. However, as repeated inoculations may cause anaphylactic reactions, the elephants that are vaccinated have to be kept under observation for the appropriate period after immunization.

Infectious diseases of elephants include tuberculosis, haemorrhagic septicaemia, trypanosomiasis, pyroplasmosis, foot and mouth disease, pox, bacillary necrosis, salmonellosis, streptococcosis, babesiosis, helminthiasis and ectoparasitism, in addition to the previously mentioned rabies and tetanus.

There are no known cases of rinderpest; clostridial diseases (other than tetanus) such as gas gangrene, blackquarter or botulism; glandus; pleuropneumonia; actinobacilliosis; actinomycosis; listeriosis; leptospirosis; nor of diseases due to the numerous viruses and protozoa which can infect domestic cattle.

A-5.1  TETANUS

This is caused by an anaerobic, spore-bearing bacillus, Clostridium tetani. This organism lives freely in the bowels of many mammals. The organism enters the body mainly through some injury, especially if the sole of the foot has open wounds.

The clinical symptoms are general dullness; changed gait; and the muscles of mastication are very badly affected, especially of the lower jaw. The slightest disturbance invokes severe muscular contractions.

Adult elephants should be immunized against tetanus by administering 4 000 IU of tetanus antitoxin _ which would give active protection for up to 2 weeks _ at the same time as the toxoid is administered. This is repeated after a month. Annual booster doses of toxoid should be given in order to maintain immunity.

A-5.2  ANTHRAX

Anthrax is an acute infection (caused by Bacillus anthracis) with a high mortality rate. It occurs in enzootic and epizootic forms in tropical countries. This disease is well known in elephants, but has been eliminated from Sri Lanka. However, haemorrhagic septicaemia has symptoms similar to those of anthrax, making clinical differential diagnosis difficult, and blood films have to be examined for definitive diagnosis. Where anthrax is endemic, it is best to immunize regularly.

A-5.3  HAEMORRHAGIC SEPTICAEMIA

Haemorrhagic septicaemia is a common infectious disease, especially amongst wild elephants. In Sri Lanka there have been outbreaks every 2 or 3 years in almost all the provinces of the country during the past 25 years. This disease is caused by a bacterium, Pasturella multicida (Type I). Other serotypes cause an acute septicaemia. Haemorrhagic septic-aemia appears when animals are under stress, such as when rain sets in immediately after a severe drought. Exhaustion and chilling are also precipitating factors. Within a few hours of infection the elephant commences to salivate, rigor sets in and within 24 to 48 hours the elephants die. Wild herds cannot be immunized and so the suscept-ible elephants die, although the mortality rate is usually less than 10% in any given herd. The disease is so acute that clinical symptoms barely develop. Symptoms are: anorexia, frequent yawning, swellings of various sizes _ either circumscribed or diffuse _ on various parts of the body. Swelling is usually noted in the region between the jaws, in the neck, shoulders, under the abdomen, groin and between the hind legs, with lameness. There is respiratory distress, and convulsions precede death by suffocation. The tongue is usually dark in colour and the lining of the mouth is coated with thick saliva. The palate may be dark and with mulberry spots. Urine is very off-coloured, and scanty. Where domesticated elephants are in contact with diseased cattle or buffaloes, it is strongly advised that the elephants be immunized.

A-5.4  TUBERCULOSIS

Elephants are susceptible to the human type of Mycobacterium tuberculosis and therefore attendants should be TB-free. There is no evidence that elephants are susceptible to bovine or avian types of TB.

Tuberculosis is predisposed in elephants by stress resulting from factors such as severe punishment; heavy work without adequate rest, i.e., continuous timber logging; bleeding from wounds; being subjected to regular bouts of thermoregulatory imbalance; drinking polluted water; or undernutrition.

A-5.5  OTHER INFECTIOUS DISEASES

The foot-and-mouth disease virus is said to be recorded in elephants in full living condition. Mortality is nil and no symptoms appear.

Clostridial enterotoxaemia has killed several elephants and baby elephants. Clinically the patient suffers from acute diarrhoea, lack of appetite and a mildly elevated temperature, in the region of 99_-100_F (37.2_-37.8_C). Therapy is based on fluid replacement by administering normal saline drips, coupled with high doses of antibiotics and supportive therapy for full-grown adult elephants.

A-5.6  RESPIRATORY TRACT INFECTIONS

Typical clinical signs, especially in the case of pneumonia, tracheitis and bronchitis, are that the patient develops a copious flow of purulent exudate dripping from the trunk; coughing; laboured breathing; pain; fever; copious lacrimal secretion; and increased respiratory rate.

Treatment of infections of the respiratory tract involves parenteral administration of broad-based antibiotics and supportive therapy.

A-5.7  DISEASES OF THE FEET

Foot rot is common in domesticated and wild elephants, where the sole of the foot gets worn and bacterial infection sets in. Treatment consists of keeping the elephant under clean conditions, washing the soles of the feet daily with a 5% copper sulphate solution, a 10% formalin solution and finally painting the affected area with Stockholm Tar. This is reinforced by a broad-based antibiotic administered parenterally.

Other precipitating factors for foot rot are overgrown soles, cracked soles, cracked heels, overgrown nails and split nails.

A-5.8  DISORDERS OF THE DIGESTIVE SYSTEM

These include colics, diarrhoea, dental abscess, caries, constipation, foreign body ingestion, intussusception and hepatitis.

If there is improper development of the molars, mastication of food is impaired and the general physical condition of the elephant deteriorates. Therefore measures have to be taken to correct the malformed molars.

Colics in baby elephants being fed milk are often the result of unhygienic milk preparation.

In juveniles, sub-adults and adults, colics are very often caused by sudden changes in diet _ especially of concentrates _ or consumption of unusually rich food.

Clinical signs of colic are abdominal posture, frequent micturition, biting of the tip of the trunk, nystagmus (in very acute cases) and excruciating pain.

Treatment includes liberal amounts of soap water enemas, and administration parenterally of an analgesic. As signs of relief appear, standard food should be commenced, in small quantities until digestion returns to normal. All rancid concentrates should be removed.

There are many instances where elephants have died of asphyxia due to a large object _ such as a husked coconut _ being lodged in the pharynx. In such instances the patient has to be anaesthetized and the obstruction removed.

Elephants that have eaten large quantities of earth and gravel can suffer from intestinal colic as a result. Again, large quantities of soap water enemas are given and an analgesic.

Diseases of the liver are fairly common at all ages. Icterus is often the clinical indication of liver dysfunction. Liver function tests should be done to assess the extent of liver damage, and blood smears examined for any protozoa that may affect the liver.

A-5.9  INFECTIONS OF THE URINOGENITAL SYSTEM

Infections of the urinogenital system are quite common, and include urethritis, nephritis, neoplasia of the reproductive tract, and post-partum metritis.

Clinical signs of urethritis are obvious pain when urinating, and urinary incontinence. Definitive diagnosis requires culture of a urine sample, and examining it for the presence of pathogenic micro-organisms. If any are found they should be screened for antibiotic sensitivity and antibiotic therapy adjusted accordingly. However, immediate therapy to provide relief consists of large doses of broad-based antibiotics.

By the time the culture report is obtained more than 80% of patients will have responded to this therapy. Where response is good, it should be continued for at least a week.

Post-partum metritis can occur in domestic elephants that have otherwise had a normal delivery. To help evacuate the pus from the uterus, it is douched with a 5% potassium permanganate solution to which antibiotics are added. Parental administration of high doses of antibiotics combined with corticosteroids and other supportive therapy are essential for the successful treatment of such cases. Treatment should be carried out for at least 14 consecutive days, or until all clinical signs vanish, whichever is the longer.

A-5.10  PARASITIC AND TICK-BORNE DISEASES

Babesiosis

Animals suffering from babesiosis have a mildly elevated body temperature of about 37.8_C (100_F) _ compared with the usual 36.6_-37_C (98.0_F-98.6_F) _ loss of general condition, loss of appetite, anaemia and haemoglobaemia. Transmission is by various ticks, including Boophilus annulatus, Bunicoplus spp., Ixodes spp., Ricinus spp. and Ripicephalus spp.

Surra

This disease of elephants is caused by a blood parasite _ Trypanosoma evansi _ which is carried by biting fleas and mosquitoes. It is a wasting disease: however much the elephant eats it never puts on weight. Oedema appears in the dependent parts of the body, there is muscular weakness, and finally paralysis. The elephant has slow, lethargic movements; gets exhausted easily; and has intermittent diarrhoea and fever.

Filariasis

Filariasis, caused by the parasitic nematode Indofilaria patta biramani, is common amongst domesticated elephants. It causes a haemorrhagic dermatitis. Clinically multiple abscesses appear through the body. Blood smears are the only means of confirm the diagnosis. Anti-filarial drugs, such as diethyl carbamazine citrate administered parentally, combined with anti-histamines parentally for 2 weeks usually cures the condition. High doses of antibiotics (e.g., procaine penicillin, 6 000 000 units, and streptomycin, 8 g, should be given intravenously daily for 10 days to combat secondary infection of the multiple abscesses.

Endoparasites in general

The drug of choice in the treatment of internal parasites in elephants is the anthelmintic thiabendazole (40 mg per kg body weight). In the case of milk-feeding baby elephants, it is preferable to use piperazine citrate, 100 mg per kg during the first few months of life. It is preferable to use fractional dosing in milk-feeding baby elephants.

Ectoparasites

Ectoparasites of elephants include mange mites, ticks, and elephant louse. Clinically, with ectoparasitic infestation the entire body surface becomes irritated, with acute pruritus and inflammation. The patient is generally restless, rubbing its body on trees, which in turn causes abrasions and secondary infection sets in if proper treatment is not given. Treatment involves administration of an analgesic (e.g., promethazine hydrochloride, 500 mg parentally twice a day for 10 days), an anti-inflammatory agent (e.g., dexamethasone, 90 mg intravenously twice a day for 10 days), broad spectrum antibiotic (e.g., procaine penicillin, 6 000 000 units intramuscularly once a day for 10 days), and a commercial, organo-phosphorus-based agricultural anti-parasitic dip applied to the skin (e.g., Neguvon-Bayer, but at half the strength recommended for domestic cattle).

Certain mange mites in elephants cause severe irritation of the tail, which can become so unbearable that the elephant hits its tail against trees. This can lead to such extensive trauma that necrosis sets in and the caudal vertebrae fall off one by one, thereby shortening the tail.

Treatment involves washing the tail well, using soap and water, twice a day; cleaning the affected areas with hydrogen peroxide; administering high doses of antibiotic, such as penicillin; and anointing the tail twice daily with a mixture comprising iodoform  (75 g [_3 ozs]); camphorated oil (225 g [_8 ozs]); turpentine (225 g [_8 ozs]); and an organo-phosphorus insecticide, such as Negnum-Bayer) (50 g [2 ozs]).

A-5.11  PHYSIOLOGICAL DISORDERS

Dependent oedema is a common clinical sign of a very poor physiological state. Fluid accumulates in the external genitalia, which become obviously swollen. Frusemide 600 mg given intramuscularly twice a day with other supportive therapy is helpful.

Elephants are very susceptible to heatstroke due to thermoregulatory imbalance. If exposed to high temperatures for long periods they can die of heatstroke.

Clinically, elephants suffering from heatstroke exhibit a staggering gait, rigor, depression and sudden collapse.

The animal must be immediately provided with shade. Administer hydrocortisone succinate, 600 mg, intravenously together with normal saline drips, 500 ml × 20, plus 50% dextrose, 20 ml × 20, immediately. Give chloramphenicol, 10 g, intravenously, and follow up with symptomatic treatment.

A-5.12  WORK-RELATED INJURIES

Common accidents affecting working elephants include:

 _  Trunk injuries, such as crushing, foreign body penetration, lacerations, or damage to motor nerves. These occur when timber logs are being loaded, unloaded, or during tree felling. Trunk paralysis may occur in some cases due to nerve injuries. Secondary bacterial infections are a problem in trunk injuries, requiring antibiotics in high doses, corticosteroids and analgesics.

 _  Tusk injuries. If the tusk breaks over the root canal, there is haemorrhage and pain, and with the danger of secondary infection leading to loss of the entire tusk. Treatment is as follows: sedation of the elephant with Chlorpromazine hydrochloride; analgesics such as Votaren (Diclofenac); and high doses of broad spectrum antibiotics. If the nerve is exposed it may lead to death of the nerve, and ultimately loss of the tusk, if not treated properly. The simplest way to minimize risk of loss of the tusk is to flush the exposed nerve with a general-purpose antiseptic, such as cetrimide, and to cover the wound with an antibiotic ointment, coupled with parenteral administration of large doses of antibiotics.

A-5.13  MISCELLANEOUS PROBLEMS

Some elephants, such as juveniles that had been rescued and brought to be admitted to the elephant orphanage, have died either of a "broken heart" or "sudden death syndrome" due to the fact that they had been transported in isolation in a lorry, and the isolation had been a terrifying experience. The "broken heart" reaction may be avoided by providing other elephants as travelling companions. This is a common experience with rescued elephants, and can be reduced if these rescued elephants are quickly brought to the orphanage and allowed to mix with the other inmates _ adults, sub-adults and babies.

In the wild state, several of a group of elephants have died instantaneously due to fear caused by thunderstorms. Actual death is caused by the continuous discharge of the sympathetic nervous system, which induces ventricular fibrillation.



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