Foot diseases in captive elephant.
The foot of an elephant is a highly evolved appendage that not only support the enormous weight of the largest terrestrial mammal but also can withstand enormous concussion. It however appears that even though the anatomical structure of the foot is eminently suited for elephants in the wilderness, in captivity foot diseases probably constitute the most numerous and potentially damaging of ailments that torment them.
In the decade since the blanket ban on the timber industry in India's North East by the Supreme Court of India rendered an overwhelming number of the region's elephants engaged in logging jobless, incidences of foot problems in captive elephants have perhaps increased due to neglect and lack of wear.
The practice of keeping elephants in captivity in India's North East, particularly Assam is age-old and inspite of the ban on the timber industry, the single largest occupation of the captive elephant population here for over a century, elephant owners are continuing to earn from alternative engagements. The elephants are an indispensable part of wild life management in the forest departments as they are extensively deployed the anti-poaching patrols, communications, transportation and eco-tourism. Modern day trend of using captive trained elephants as koonkies for driving away the crop raiding wild herds from human habitations is emerging as a promising way of countering human-elephant conflict. What unfortunately remain to change significantly are management practices for keeping elephants in captivity making the elephants vulnerable to numerous diseases and ailments. An overwhelming number of these captive elephants suffer from numerous foot ailments as a result of being tethered in unhygienic surroundings and these afflictions often aggravate due to utter negligence and lack of awareness regarding proper care and treatment. Foot problems are seen in 50 percent of captive Asian elephants at some time of their lives (Csuti et al., 2001).
For instance, pododermatitis which is a very painful chronic condition characterized by proliferative or degenerative lesions in and around the sole of foot of elephants and which is complicated by pyogenic and fungal infections, is widespread among the region's captive elephants. What is of concern is that these affections are either extremely difficult to cure by ordinary means or are not curable at all. Chronic foot problems may also lead to serious disabilities or may even result in death of elephants. It is therefore extremely important to detect these affections at an early stage and then seek proper treatment.
No precise and extensive data regarding the incidence of foot problems of elephants in eastern India, home to perhaps the largest captive elephant population in world, is available as any focused and extensive study embracing the entire population over a significant period of time is yet to be carried out. The authors can however authoritatively claim from the experience of their clinical practice with the region's elephants that incurable foot diseases constitute one of the most frustrating aspects of treating the region's captive elephants and have witnessed several cases of permanent disabilities afflicting working elephants arising out of chronic foot ailments. The most effective way of dealing with this widespread problem is prevention and in order to ensure that, periodic pedicure of elephants in captivity is derigueur and should form an integral part of modern management practices of captive elephants.
The diagnosis and treatment of foot diseases necessitate an understanding of the anatomy of foot and pathogenesis of foot affections that occur following these infections. The present paper is aimed at documenting the findings of a study undertaken under the aegis of the Project Elephant Directorate, Ministry of Environment and Forest, GOI. The incidence of various foot affections were studied in the selected captive elephant populations of the region in respect of the presence, extent and duration with special reference to different keeping conditions viz. zoos, camp elephants of wildlife departments and the logging elephants of the private owners. The type of lesions, clinical symptoms and isolation and identification of the microorganisms causing the diseases were also undertaken.
Materials and Methods
The present study was a survey conducted (2003-2005) in different areas of the region including Assam, Arunachal Pradesh and North Bengal and randomly selected representative elephant populations were screened and various incidences of foot affections and pedicure practices were recorded. Altogether 312 elephants were studied out of which 72 were from North Bengal, 28 from Arunachal Pradesh and 212 from different areas of Assam. In elephant population studied in Assam, 126 elephants belonged to the Forest Department, Government of Assam and deployed in the various parks and sanctuaries and the remaining 86 was privately owned. All the 72 elephants of North Bengal belonged to Jaldapara and Gorumara forest camps and a moving circus and all 28 elephants studied in Arunachal Pradesh were privately owned logging elephants.
Incidence of pododermatitis was studied in relation to its type, age, sex, limbs, season, different keeping conditions (substrate types) and work assignments. The extents as well as the duration of the foot lesions were also taken into consideration. Lesions were classified according to gross tissue changes (erosive/vegetative), appearance (dry/ moist) and location (nail, interdigital space, pad-skin junction or pad).
All the animals were examined thoroughly for any gross foot abnormalities in the standing position and then the animals were allowed to walk to identify any signs of lameness. The affected limb showing lameness or any gross foot abnormalities were examined in detail in recumbent position after proper cleaning of the foot region. The postural changes of the limbs were also examined in the standing position .The sole of the foot was examined for cracks, overgrowth of tissues or over wear. The nails were examined for their overgrowth, ingrowths, splitting and/ or ring formation. The interdigital space was examined for infection, overgrowth of cuticles and abscess.
Samples for investigation of bacteria, fungi or parasites associated with different foot lesions of afflicted elephants were collected from the depth of the lesions with the help of sterile cotton swab, examined and classified following standard methods.
Results and Discussion
Incidence: Percentages of elephants affected by various kinds of foot afflictions in Assam were as follows: Kaziranga-38.00, Orang-27, Manas-30.77, Nameri-25, Pobitora-37.50, Guwahati Zoo-20 and private elephants 78.65. The private elephants of Arunachal Pradesh had a much higher incidence at 82.14% and the camp elephants of North Bengal had lowly 27.77 percent afflictions involving some structure of the foot. Overall, 49.06 percent of the elephants had foot afflictions. Inspite of the near natural living conditions, half of the captive elephant population had foot afflictions and the affected numbers was comparable to that of the western elephant holdings (Csuti et al., 2001).
Substrate wise, the North Bengal elephants has a dry sand and pebbled condition, Arunachal Pradesh elephants live and work in high and hilly rocky mountainous conditions and the privately owned logging elephants of Assam also work in similar conditions except three months break off period where they are shifted to their owner's places in the villages in the plains to live in muddy conditions. Out of the camp elephants of Assam, Manas has conditions similar to that of North Bengal and conditions in the rest of the parks remain muddy for about 8-9 months of the year. Observations from the present study indicated that muddy conditions were more likely to cause foot afflictions. The logging elephants had a much higher incidence of foot afflictions due to greater exposure to injuries from rocks and logs and lack of foot care. In comparison to the departmental elephants, foot care practices were abysmal in the logging elephants of both the states.
Sex wise, males (62 out of 118) had a higher incidence (52.54 percent), compared to the females (95 out of 194) with 48.97 percent of foot afflictions. Healthy male elephants in the middle age group kept on good diets generally develop Musth and had to be kept chained for months, making maintenance of stall hygiene and administration of foot care difficult and therefore, making them prone to foot afflictions more easily compared to females that were generally cooperative to the administration of foot care.
The present study also revealed that advancing age also progressively increased incidences of foot afflictions. Highest incidence of foot affliction was recorded in the elephants of 50 years and above age group (76.92%), followed by 41-50 (76.66%), 31-40 (70.02%), 21-30 (52.38%), 11-20 (37.14%) and least in the 0-10 (22.80%) years age group. A detailed look into the type of afflictions revealed that lesions of infectious origin were more frequent in older elephants and lesions of traumatic origin were frequent in younger age groups. Various organisms, later invaded the injuries that the elephants received while young and when not cared properly led to infections. Obviously, ageing also compromises the tissue resistance to injuries and infections; besides arthritis and reduced activities also make the older elephants prone to foot afflictions (West, 2001). Some interesting observations were made while studying the limb wise distribution of the various foot disorders. Percentage wise, the hind limbs had significantly higher incidences of foot affections (40.35% of all elephants) than the fore limbs (26.63%). In 33.33 percent elephants, lesions were encountered in all the four legs.
Affections like split nails, kari (septic degenerative or proliferative pododermatitis in the sole-heel junction), cracked sole and cracked heel were more frequent in the hind feet. Overgrown cuticle, overgrown sole, ingrown nails and laminitis rings were frequently encountered in the fore feet. Most of the lesions also affected the contra lateral limbs.
Different kinds of foot lesions
A total of 14 different foot lesions were recorded in the study population in the present investigation (Fig.1-9).
Over grown nails: A very high incidence (20.57%) of over grown nails was recorded. Over grown nails were generally due to lack of wear, which was mostly due to inadequate exercise and wet substrate conditions. The nails became oddly shaped, roughened having a layered appearance. Fowler (1978) observed over grown nails extending as far as 12 to 25 cm beyond the foot level. Over growth of the nail led to the splitting of the nails.
Overgrown cuticle: Overgrown cuticles appeared as a roughened area of skin over the coronary band proximal to the nails. In some cases, the cuticles appeared between the toes causing impediments in the locomotion and resulting in lameness. The percentage of overgrown cuticle was 13.54% and was more frequent in the fore limbs. Over growth of cuticle was painful to the elephant. Elephant feet without cuticle trimming developed fluid pockets behind the overgrown cuticles. It appeared that when the sweat gland, which sit around the curve of the nails are covered by an untrimmed cuticle they became locked and small pockets of clear fluid accumulated. After cutting of excess cuticle and drainage of the pockets the elephants recovered.
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Split nails: Breaking of a stride over the elongated toe nail put undue strain over the toe and led to its splitting. Generally middle toe of the hind leg was affected with this condition (11.19%) and bilateral involvement was more common. The split which started at the free border, extended upwards and even reached up to the coronary band into the sensitive laminae causing severe pain in several cases. The split was filled with mud and grass and were nidus for infections and pain. An effective technique was trimming of the smaller side of the crack so that it did not bear weight (Balasko, 1997). To decrease weight bearing, the side of the crack needs to be rasped and trimmed every 14 to 30 days with an equine hoof knife.
Cracked sole: Cracked sole condition occurred in 9.38% of total affections in the present study. This condition was observed more frequently in the older age group. Contrary to the observation of Fowler (1978), the cracked sole condition was more common in the dry substrate. Those animals affected, had cracked sole involving all the four feet (33.33%), which also indicated the fault with the substrate. Dry conditions associated with the loss of elasticity of solar tissues in older elephants were probably responsible for cracked sole condition.
Pitted sole: An interesting appearance of the sole that could be described as pitted sole was occurring in 9.11% out of the total affections. This condition did not cause any lameness and was mostly seen in elephants of the forest department and in both dry and moist substrate. Perusal of available literature revealed that no previous workers have reported this condition. It appeared that the gyri would only be bearing the weight of the animal and the unequal weight distribution might lead to some complications in the long run. The foot pads of elephant in the wild are not smooth or manicured; they have deep grooves and cracks. Excessive trimming or slicing the pad of an elephant foot is a common practice in the western facilities. The deeper the trim the lighter the sole of the foot becomes. Sufficient pad needs to be left intact. The elephant should not feel pain when walked on hot ground and rocks.
Septic pododermatitis (Kari): Though this disease occupied a relatively low percentage of the affections (8.33%), it was the most dreaded and worst kind of foot problem. It is a very painful condition characterized by proliferative or degenerative lesions in and around the sole of the foot of working elephants, which was frequently complicated by pyogenic and fungal infections. These affections were also difficult to treat by ordinary means. Most of the affections in the present investigation were recorded from the moist substrate and history revealed that the beginning was generally after the flood season or after an episode of musth. Higher incidences of kari could be correlated to dirty substrates particularly of elephant excreta origin. Hind limbs were more frequently affected (65.62%). The reason for the hind limbs being more susceptible was probably the way the male elephants are hobbled during musth at the hind legs over the same place for a considerable length of time without provisions for cleaning the excreta. Microbial examinations of the lesions revealed involvement of several bacteria and fungi.
Overgrown sole: Out of various foot affections, overgrown sole occurred in 7.29% of the cases. Inadequate and uneven wear, faults in weight distribution due to faulty conformation, complementary lameness, moist substrate and lack of exercise (walking) were the reasons for the occasional overgrown sole. The soles appeared ragged, irregular, and layered similar to the observations of Fowler, 1978. The overlapping layer formation led to lodgment of small pebbles and hardened coal tar between the layers and was the cause of lameness, pruritis, fissures, secondary infections and abscessation and complementary over worn sole in the healthy part.
Over worn sole: Over worn sole constituted 5.97 percent of the feet maladies in the present investigation in the affected elephants. The elephants when made to work in moist substrate constantly and forced to work on hard abrasive surface might cause over wear of sole.
Cracked heel: Cracked heel was generally found in elephants of the middle age (7.03%). It was mostly seen from the dry substrate. In the elephants of the private owners the incidence was more. Cracked heel can be attributed to constitutional causes and it is a serious unsoundness owing to its liability to recur every rainy season. The junction between the sole and the skin in the hind part of the foot becomes dry and starts cracking. Discharge may also come from the cracks. These cracks usually lead to infection from the ground, which become chronic in nature if remain untreated.
Ingrown Nails: Ingrown nails (3.19%) were generally seen in elephants suffering from chronic laminitis. The distal phalanges get rotated and the nails grow in different direction. Elephants especially those working in muddy substrate were liable. The ingrown nail also caused pain and lameness. The nails generally grew obliquely downward. These nails can be trimmed with the help of a short pointed knife and its presence reflected lack of even minimum of foot care.
Laminitis: Both acute laminitis causing severe pain with lameness and chronic laminitis with rotation of toes were recorded. Laminitis rings were seen on the nails of many middle aged and older elephants. Cases of acute laminitis could be connected to long road marches on rocky surfaces without sufficient rest particularly in unconditioned elephants. High fever, increased heat around the footpad was noticed and in a severe case, the elephant used his knees to progress.
Injury: Injuries to the foot of the elephant was not very uncommon (2.30%). Several types of injuries were recorded; some sharp objects like a nail or a sharp piece of bamboo, shoot of burnt birina grass (Vetiveria zezonoid) or even a shed antler caused penetrating injuries to pad of the sole.
Abscess: Abscess was commonly seen in many captive elephants, and their causes are usually not obvious (Roocroft and Oosterhuis 2001). In the present study incidence of abscess was found in only 0.78 per cent. Abscesses can also occur in pad of the foot. These could be caused by a puncture from a sharp object, abscessation of the foot is common sequel to injury or poor foot care, due to the thickness and toughness of normal or overgrown sole; many abscesses of the foot are readily observable externally as a fluctuant swelling (Fowler, 1978). Untreated infections could result in the sloughing of one or more nails, or the entire sole.
Arthritis: Arthritis of the limb joints is another condition that can lead to foot problems. The soreness in an elephant's joints would result in decreased joint flexibility. This will lead to an altering of the elephant's gait and, abnormal pressure on the nails and pads. However, in the present study the incidence of arthritis was found to be very low (0.52%). It might be due to the fact that the study population get sufficient exercise; their diet contains low energy when compared to that of their counterparts in the western facilities. So, they are not over weight and the exercise keeps their joints in a healthy state.
Ascertaining Infectious Agents
In the present study, large numbers of commonly found bacteria were isolated from elephant's foot affected with pododermatitis. Most common isolates were Staphylococcus, Bacillus, Pseudomonas, Corynebacterium and Streptococcus. Dicholobacter nodusus was stated to be mostly involved with foot diseases in ruminants was also isolated from two cases in elephants. West (2001) isolated Proteus mirabilis, Enterobacter and Bacteriodes from the foot lesions. Chakraborty et al. (1991) recorded Staphylococcus aureus and Streptococci pyogenes from the foot of the elephants of Assam. Barn and yard cleanliness was important in preventing the build up of bacteria as well as removal of debris directly from the elephant feet. Schmidt (1986) observed that elephant in the west usually developed bacterial infection in the foot during the winter because the elephants are generally kept inside the barn during the winter season. The urine keeps the area moist, which allow bacteria to colonize on the skin that can initiate the development of foot rot. The bacteria are generally soil origin. Injury on the foot region lead to discontinuity of the skin and bacteria get the chance to invade into the deeper tissues.
Antibiotic sensitivity test
The bacteria isolated were resistant to most of the antimicrobial agents. In the present study, enrofloxacin was found to be most effective against almost all the bacterial isolates, in conformity to the observation of West (2001).
Different types of fungi were isolated from the chronic lesions of the foot. The most commonly found fungi were Aspergillus, Phycomycetes and Trichophytons. Candida, and Blastomycetes. Yeast was also found in some cases. Chakraborty et al. (1991) recorded fungus from the foot affected with chronic infection, like Trichophyton terrestre and Aspergillus niger. Steel (1885) identified fungal infection usually occurring round the rim of the back feet, at the edge of the hoof slipper, which he attributed to imperfect removal of urine and fasces from the picketing ground. This problem was controlled when the elephant was allowed to spend more time outdoors.
Unidentified pathogenic mites and filarial parasites were isolated from the foot lesions. Chatterjee (1984) also recovered parasites from the foot lesions of the elephant. Chakraborty (2002) recorded filarial parasites from the foot lesions of elephant of Assam. The mite would have been in its transitory phase.
Summary and conclusion
Majority of the captive elephants of eastern India are engaged in various kinds of commercial activities and live in primitive facilities. The area is characterized by high rainfall and humid conditions. Most of the elephant facilities have muddy substrate conditions and lacks in foot hygiene and foot care. The management attaches minimum importance to foot care and the mahouts administer some primitive pedicure at irregular intervals. The knowledge of foot anatomy, care and pedicure techniques are pathetically low.
A total of 312 randomly selected captive elephants of the region were studied for various kinds of foot affections during 2003-2005. Out of the study population, 123 elephants belonged to various elephant camps and zoos of Assam, 72 were camp elephants of North Bengal, 98 were privately owned logging elephants from Assam and 19 were from Arunachal Pradesh. Fourteen different kinds of foot affections were recorded; half of the elephant population of the region was affected with foot diseases in their total life. Males were relatively more affected because of their low tolerance for foot care particularly during the period of musth. Hind limbs were more susceptible and lesions were also severe in the hind limbs. Advancing age made the elephants more susceptible. Remarkably higher percentage of privately owned elephants was affected with foot affections. A host of bacteria and fungi were isolated from the foot lesions. No bacteria or fungus was singularly responsible for causing foot affections. Unidentified mites and filarial worms were also isolated from foot lesions. Most of the Kari (septic pododermatitis) cases began after incarceration for musth or rainy season. Moist substrate was worse in terms of foot health. Training the elephants to accept foot care is essential. The present investigation proved that even adult elephants could be easily trained for cooperation during foot care. Foot protection shoes were very useful in the treatment of chronic foot affections.
Project Elephant Directorate, Ministry of Environment and Forests, Government of India, New Delhi for supporting the study.
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Chakraborty, A. (2002). Helminth parasites of Indian elephants (Elephasmaximus) in India. In: Helminthology in India, Edn. Sood, M.L., International Book Distributors, Dehradun, India. pp 263-84.
Chatterjee, A. (1984). Association of Stephanofilaria indistinguishable from S. assamensis with lesions on the feet of Indian elephants (Elephas maximus). Indian J. Anim. Hlth. 23: 29-35.
Csuti, B., Sargent, E.L. and Berchert, U.S. (2001). The Elephant's Foot. 1st Edn., Iowa State University press., 2121 South State Avenue, Ames.
Fowler, M.E. (1978). Zoo and Wild Animal Medicine, Ch. 4; pp. 29.
Steel, J.H. (1885). A Manual of the Diseases of the Elephant. Madras, India: Lawrence Asylum Press.
West, G. (2001). Occurrence and treatment of nail /foot abscess, nail cracks, and sole abscesses in captive elephants. In: The Elephant's Foot; 1st Edn., edited by Csuti, B., Sargent, E.L. and Bechert, U.S., pp. 93-98. Ames Iowa, USA, Iowa State University Press.
K.K. Sarma (1), S. Thomas, D. Gogoi, M. Sarma (2), D.K. Sarma (3)
Department of Surgery and Radiology College of Veterinary Science Assam Agricultural University Khanapara Guwahati--781022 (Assam)
(1) Corresponding Author E-mail: firstname.lastname@example.org
(2) Associate Professor, Department of Anatomy and Histology
(3) Veterinary Assistant Surgeon
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|Title Annotation:||Research Article|
|Author:||Sarma, K.K.; Thomas, S.; Gogoi, D.; Sarma, M.; Sarma, D.K.|
|Date:||Jul 1, 2012|
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