Rev. sci. tech. Off. int. Epiz., 1996, 15 (1), 155-169
Husbandry and diseases of camelids M.E. F O W L E R *
Summary: Camels of the Old World and the New World have provided the indigenous human population with meat, milk, fibre and fuel, also serving as beasts of burden to carry loads, for millennia. With the advent of motorized vehicles, the use of camelids became obsolete except in isolated situations. The numbers of camelids diminished dramatically. A reversal of that trend is now occurring, with a recognition that these animals still function in their respective environments better than any other species of livestock Camelids have always been popular animals in zoos. Camels and two of the South American camelids are domestic animals which adapt well to contained management. They have a unique ability to obtain nourishment from harsh forages. Their reproductive physiology is different from that of any other livestock species.
Few diseases of camelids are restricted to these species, and camelids do not serve as a reservoir for any of the major diseases of livestock
KEYWORDS: Alpacas - Camels - Dromedaries - Guanacos - Infection - Llamas - Parasitism - Vicuñas - Wildlife.
I N T R O D U C T I O N
Camelids have served the needs of people for thousands of years. They have provided food (meat, milk), fibre and fuel, and served as beasts of burden, as well as being important in religious and secular ceremonies both in ancient civilizations and to this day. The industrial revolution minimized the value of camelids and numbers declined; but recently there has been a renaissance in both Old and New World camelids. Once again, camelids are of value in their native lands, as well as in North America, Europe and Australia (8).
An important concept to understand when dealing with camelids is that taxonomically they are not ruminants, nor do they share many of the ruminant diseases which are so important in livestock disease epidemiology (Table I). The family Camelidae is classified in the order Artiodactyla, suborder Tylopoda. The Old World species are the bactrian camel (Camelus bactrianus) and the dromedary (C. dromedarius). New World species are the llama (Lama glama), alpaca (L. pacos), guanaco (L. guanicoe) and vicuña (Vicugna vicugna) (8, 18). Camelids evolved in North America, with primitive progenitors dating back approximately 40 million years to the Eocene epoch. At this early date, all Artiodactyla were single-stomached animals. The Tylopoda and Ruminantia then separated to follow different evolutionary
* Professor Emeri tus, Depar tment of Medicine and Epidemiology, School of Veterinary Medicine, University of California-Davis, 427 Cabrillo Avenue, Davis , C A 95616-8737, United States of Amer ica .
156
pathways. Eventually, the Old World camel progenitors migrated westward to Asia, crossing a land bridge over the Bering Straits at a time when glaciation lowered the sea level, and eventually declining to extinction in the Americas. New World camelid progenitors migrated south across the newly-formed Caribbean land bridge (8, 18).
TABLE I
Differences between South American camelids and ruminants Evolutionary pathways diverged 40 million years ago
Parameter South American camelids Ruminants
Blood Red blood cells elliptical and small Red blood cells round and larger (6.5 µ); predominant white blood (10 µ); predominant white blood cell is neutrophil; leukocytes up to cell is lymphocyte; leukocytes up to 22,000/µl 12,000/µl
Foot Toenails and soft pad; second and Hooves and sole; second and third third foot bones horizontal foot bones vertical
Digestive system Parallel evolution: foregut As for camelids fermenter; regurgitation, re-chewing and re-swallowing
Stomach Three compartments, resistant to Four compartments, susceptible to bloat bloat
Dental formula I: 1/3, C: 1/1, PM: 1-2/1-2, I: 0/3, C: 0/1, PM: 3/3, M: 3 / 3 x 2 = 28-30 M: 3 / 3 x 2 = 32
Reproduction Induced ovulation Spontaneous ovulation No oestrous cycle Oestrous cycle Follicular wave cycle No follicular wave cycle Copulation in prone position Copulation in standing position Placenta diffuse Placenta cotyledonary Epidermal membrane surrounding No epidermal membrane on fetus fetus Cartilaginous projection on tip of No cartilaginous projection on tip penis of penis Ejaculation prolonged Ejaculation short and intense
Respiratory system Soft palate elongated; primarily Soft palate short; nasal or mouth nasal breathing breathing
Urinary system Kidney smooth and elliptical Kidney smooth or lobed Suburethral diverticulum in female No suburethral diverticulum
Parasites Unique lice and coccidia; Do not share lice or coccidia with gastrointestinal nematodes shared cattle, sheep and goats, but do share with cattle, sheep and goats gastrointestinal nematodes
Susceptibility to Minimally susceptible to Highly susceptible to tuberculosis, infectious diseases tuberculosis; no known natural bovine brucellosis, and foot and
bovine brucellosis; mild mouth disease susceptibility to foot and mouth disease; no clinical disease with most other bovine viral diseases
I: incisors C: canines PM: premolars M: molars
157
The precise time and location of domestication of the bactrian camel is unknown, but this is thought to have occurred some time prior to 2500 BC on the borders of the Caspian Sea. Domestication of the dromedary had occurred earlier, prior to 3000 BC in the Arabian peninsula. The cradle of llama domestication is in the Andean highlands, probably around Lake Titicaca, in approximately 4000 BC. Alpaca domestication probably took place elsewhere in Peru at about the same time (18).
Camels were essential to the Bedouins of the Arabian peninsula and North Africa. Bactrian camels carried goods along the old Silk Route to China. Camels were also cavalry mounts until Europeans introduced the horse. Ultimately, motorized trucks supplanted camels as freight carriers. Camels had all but become mere curiosities in zoos until two decades ago, when serious interest revived in these marvellous animals which are so well-adapted to the harsh environmental conditions of the desert.
A few wild bactrian camels still roam the steppes of the Gobi desert in Mongolia, but essentially all camels are now the product of domestication. In South America, the vicuña and guanaco remain wild species, while the llama and alpaca are domesticated. The evolution of both Old and New World species - and their accompanying infectious and parasitic disease agents - occurred in geographical regions separated from the habitats of domestic ruminants. Table I lists differences between camelids and ruminants.
H U S B A N D R Y PRACTICES
Old World camels inhabited some of the most inhospitable areas of the world: the bactrian camel in the high deserts of Asia, and the dromedary in the hot dry deserts of the Middle East. Camels are famous for their ability to subsist on harsh, dry and sparse vegetation, at least for a time. The hump(s) of a camel provide(s) a good indication of the nutritional status of the animal. The hump consists of fat interspersed with fibrous tissue. During periods of poor energy intake, the camel is capable of metabolizing the fat in the hump, which shrinks as a result. The humps of the bactrian camel are usually more peaked than the hump of the dromedary, and when the animal loses weight the humps flop over to one side. Floppy humps caused by starvation should not be confused with the congenital floppy humps which may be seen in certain well-conditioned camels (6, 8).
Racing of dromedary camels has become a popular pastime in a number of Middle Eastern countries. Camels in training are kept in outdoor enclosures, sometimes with shade provided. Feeding practices are extremely varied, from browsing in the desert to feeding upon freshly-cut alfalfa and concentrate supplements. Dates and milk are fed to racing dromedaries. The rationale for feeding milk escapes this author. Some sheikhs have pioneered in the nutrition and feeding of camels, and have imported European nutritionists to study nutrition and manage rations. Feed mills have been constructed, and complete diet pellets have been formulated.
Camels may be purged prior to a race; the rationale is to empty the stomach to prevent its bulk from interfering with the camel while running. Some desert shrubs are known to have a cathartic effect and, prior to a race, the alfalfa in the diet is substituted by a purgative plant. The purgative action produces projectile diarrhoea, thus depriving the camel of nourishment and, more seriously, water.
158
In zoos, camelids are maintained in a wide variety of enclosures. In general, the only common requirements are that there be sufficient space to move about, shade, shelter from inclement weather, and water for drinking (9). Some zoos provide ponds for bathing. Hay of various types is the primary forage. On facilities with large acreages, camelids may obtain most of their nourishment from pastures. Only rarely is it necessary to supplement the diet with concentrates (6). Camelids may be affected by deficiencies of such nutrients as selenium, vitamin E, copper and zinc. Mineral supplements should be supplied in a granular form, as camelids do not readily chew or lick mineral blocks.
DISEASES
Infections (8, 17)
The prevalence of viral diseases in camelids is unknown. Few clinically-important viral diseases have been described (Table II). The results of serological surveys indicate that camelids are exposed to and respond immunologically to numerous viral agents, without developing clinical disease. With the increased importance of camelids, more attention is being paid to specific diseases. Whether or not camelids are susceptible to a number of important viral diseases of cattle and sheep is unknown at present (8). Rinderpest has not been reported in South American camelids, but neither does the virus occur in South America; to the knowledge of the author, no one has yet experimentally challenged South American camelids with the rinderpest virus. Camels are known to be mildly susceptible to rinderpest infection, and there is reason to believe that all members of the order Artiodactyla are susceptible to this virus, at least to some degree.
Herpesviruses are highly evolved, and are usually well-adapted to one or more hosts. Interestingly, no herpesviruses unique to camelids have been identified. When herpesviruses infect a non-adapted host, serious disease or death is likely to result, which has occurred in both llamas and alpacas infected with equine herpesvirus type 1 (EHV-1). The clinical syndrome is characterized by blindness (caused by retinal degeneration) and encephalitis (14).
Three proliferative infections of the skin of camels are camelpox (Orthopoxvirus), camel contagious ecthyma (Parapoxvirus) and papillomatosis (Papillomavirus) (13, 17). Of these, camelpox is the most widespread, severe and debilitating disease, causing high mortality in young camels. A new vaccine is currently being used to minimize the effects of the infection (17).
Fungal and bacterial diseases of camelids are listed in Table III. The major clostridial diseases of domestic animals and humans are ubiquitous and would be serious threats to livestock production if vaccines were not available. Camelids acquire some of these diseases, and in some cases the diseases have had a serious impact on a herd. Clostridium perfringens types C and D are found throughout the world and may pose problems at the regional level. C. perfringens type A produces a distinct disease in racing camels and high mortality in neonatal camelids in South America (8).
159
TA
BL
E
II
Vir
al d
isea
ses
of
cam
elid
s
Susc
eptib
ility
Dis
ease
nam
e in
Eng
lish
Oth
er l
angu
age
equi
vale
nts
Org
anis
m
Synd
rom
e C
amel
So
uth
Am
eric
an
cam
elid
s
Rab
ies
(E)
rabi
a (F
) ra
ge
(D)
Tol
lwut
Lys
savi
rus
(Rha
bdov
irid
ae)
Enc
epha
litis
Y
es
Yes
Foo
t an
d m
outh
dis
ease
(E
) fi
ebre
aft
osa
FM
D v
irus
O
ral
vesi
cles
Y
es
Mild
dis
ease
(F
MD
) (F
) fi
èvre
aph
teus
e (D
) M
aul-
und
Kla
uens
euch
e (P
icor
navi
rida
e)
Ves
icul
ar s
tom
atit
is (
VS
) (E
) es
tom
atit
is v
esic
ular
(F
) st
omat
ite
vési
cule
use
(D)
vesi
kulä
re S
tom
atit
is
VS
viru
s (R
habd
ovir
us)
Ora
l ve
sicl
es
Exp
erim
enta
l Y
es
Bor
na d
isea
se
Bor
na d
isea
se v
irus
(N
ot c
lass
ifie
d)
Enc
epha
litis
Y
es
Yes
Rin
derp
est
(E)
pest
e bo
vina
(F
) pe
ste
bovi
ne
(D)
Rin
derp
est
Rin
derp
est
viru
s (P
aram
yxov
irid
ae)
Seve
re g
astr
oent
erit
is
Yes
N
R
Ret
inal
deg
ener
atio
n E
quin
e he
rpes
viru
s ty
pe 1
R
etin
al d
egen
erat
ion
and
ence
phal
itis
N
R
Yes
Con
tagi
ous
ecth
yma,
(E
) ec
tim
a co
ntag
ioso
E
cthy
ma
viru
s E
pide
rmal
pro
lifer
atio
n Y
es
Yes
so
re m
outh
, or
f (F
) ec
thym
a co
ntag
ieux
(D
) D
ecth
yma
Kon
tagi
os
(Par
apox
viru
s)
Blu
eton
gue
(E)
leng
ua a
zul
(F)
lang
ue b
leue
(D
) D
ürch
enzu
ng b
laus
ucht
Blu
eton
gue
viru
s (O
rbiv
irus
) P
anvi
raem
ia
SO
SO
(E):
Spa
nish
(F
): F
renc
h (D
): G
erm
an
NR
: no
t re
port
ed
SO:
sero
logi
cal
resp
onse
onl
y
160 T
AB
LE
III
Fun
gal
and
bact
eria
l di
seas
es
of
Cam
elid
ae
(1,
2, 4
)
Dis
ease
nam
e in
Eng
lish
Oth
er l
angu
age
equi
vale
nts
Org
anis
m
Synd
rom
e
Susc
eptib
ility
Sout
h C
amel
A
mer
ican
ca
mel
ids
Der
mat
ophy
losi
s, (E
) tin
a Tr
icho
phyt
on v
erru
cosu
m,
Alo
peci
a, d
erm
al t
hick
enin
g,
Yes
Y
es
ring
wor
m
(F)
teig
ne
T. m
enta
grop
hyte
s va
r.
prur
itis
(D)
Flec
hte
men
tagr
ophy
tes,
M
icro
spor
um s
pp.
Can
dido
sis,
mon
ilios
is
(E)
cand
idos
is
Can
dida
alb
ican
s G
astr
oint
estit
is
Yes
Y
es
(F)
Can
dido
se
(D)
Kan
dida
myk
ose
Asp
ergi
llosi
s (E
) as
perg
ilosi
s A
sper
gillu
s fu
mig
atus
Pn
eum
onia
, en
ceph
aliti
s Y
es
Yes
(F
) as
perg
illos
e (D
) A
sper
gillo
sis
Coc
cidi
oido
myc
osis
, (E
) co
ccid
ioid
omic
osis
C
occi
dioi
des
imm
itus
Pneu
mon
ia a
nd d
isse
min
ated
N
R
Yes
valle
y fe
ver
(F)
cocc
idio
idom
ycos
e gr
anul
omas
(D
) C
occi
dioi
dom
ycos
is
Tet
anus
(E
) té
tano
s C
lost
ridi
um t
etan
i G
ener
aliz
ed t
etan
y Y
es
Yes
(F
) té
tano
s (D
) T
etan
us
Ent
erot
oxae
mia
C
lost
ridi
um p
erfr
inge
ns
Var
iabl
e ef
fect
s on
cen
tral
Y
es
Yes
ty
pes
A, C
and
D
nerv
ous
and
gast
roen
teri
c sy
stem
s, s
udde
n de
ath
Bot
ulis
m
(E)
botu
lism
o C
lost
ridi
um b
otul
inum
Fl
acci
d pa
raly
sis
Yes
Y
es
(F)
botu
lism
e (D
) B
otul
ism
us
Mal
igna
nt o
edem
a C
lost
ridi
um s
eptic
um
Wou
nd c
ellu
litis
Y
es
Yes
161
Tub
ercu
losi
s (E
) tu
berc
ulos
is
Myc
obac
teri
um b
ovis
, P
ulm
onar
y an
d d
isse
min
ated
Y
es
Yes
, but
not
(F
) tu
berc
ulos
e M
. av
ium
, M.
kans
asii
gr
anul
omas
hi
ghly
(D
) T
uber
culo
se
cont
agio
us
Par
atub
ercu
losi
s,
(E)
para
tube
rcul
osis
M
ycob
acte
rium
E
nter
itis
Y
es
Yes
, bu
t no
t Jo
hne'
s di
seas
e (F
) pa
ratu
berc
ulos
e (D
) P
arat
uber
kulo
se
para
tube
rcul
oisi
s hi
ghly
co
ntag
ious
Ant
hrax
(E
) an
trax
mal
igno
(F
) fi
èvre
cha
rbon
neus
e (D
) M
ilzbr
and
Bac
illu
s an
thra
cis
Pan
sept
icae
mia
Y
es
Yes
Bru
cello
sis,
und
ulan
t (E
) br
ucel
osis
B
ruce
lla
abor
tus
Abo
rtio
n, i
nfer
tilit
y Y
es
NR
fe
ver
(F)
bruc
ello
se
(D)
Bru
zello
se
B.
mel
iten
sis
? Y
es
Lis
teri
osis
(E
) lis
tere
losi
s (F
) lis
teri
ose
(D)
Lis
teri
ose
Lis
teri
a m
onoc
ytog
enes
E
ncep
halit
is
Yes
Y
es
Col
ibac
illos
is
(E)
coli
baci
losi
s (F
) co
liba
cill
ose
(D)
Kol
ibaz
illo
se
Esc
here
chia
col
i M
etri
tis,
mas
titi
s, s
epti
caem
ia,
endo
toxa
emia
Y
es
Yes
Nec
roba
cillo
sis
(E)
necr
obac
ilosi
s (F
) ne
crob
acill
ose
(D)
Nec
roba
zillo
se
Fus
obac
teri
um n
ecro
phor
um N
ecro
tizi
ng l
esio
ns o
f th
e fa
cial
bo
nes
Yes
Y
es
Act
inom
ycos
is,
(E)
acti
nom
icos
is
Act
inom
yces
sp
. A
bsce
sses
N
R
Yes
lu
mpy
ja
w
(F)
acti
nom
ycos
e (D
) St
rahl
enpi
lz-k
rank
heit
en
Stre
ptoc
occo
sis
(E)
estr
epto
coco
sis
(F)
stre
ptoc
occo
se
(D)
Stre
ptok
okko
se
Stre
ptoc
occu
s sp
p.
Sept
icae
mia
, ab
sces
ses
Yes
Y
es
Noc
ardi
osis
(E
) no
card
iasi
s (F
) no
card
iose
(D
) N
ocar
dios
e
Noc
ardi
a as
tero
ides
A
bsce
sses
, se
ptic
aem
ia
NR
Y
es
NR
: n
ot r
epor
ted
(E):
Spa
nish
(F
): F
renc
h (D
): G
erm
an
162
Tuberculosis is not a major disease of camelids, but these species do occasionally develop the disease. Both natural and experimental infections have been reported for the four major species of acid-fast staining mycobacteria (Mycobacterium bovis, M. tuberculosis, M. avium and M. paratuberculosis) (3). Most infections have occurred when camelids have lived in close association with other infected livestock or infected humans. The use of intradermal tuberculin as a means of evaluating an individual camelid or a herd for the presence of tuberculosis has proved less than satisfactory. Both false-positive and false-negative reactions have been described. A recent study, conducted on llamas in Argentina, correlated intradermal testing with a panel of serological tests. Preliminary reports on the study indicate that more satisfactory testing procedures may be available.
Actinomyces (lamae) causes a bacterial infection unique to South American camelids. The disease usually manifests as a thick-walled abscess in the throat region, lungs or liver, but the organism has also been recovered from apical dental abscesses. This organism may be under-reported, as it is a Gram-positive, short rod which may be mistaken for a coccus. Abscesses caused by streptococci, micrococci and corynebacterium heal permanently if surgically incised, drained and irrigated, whereas actinomyces abscesses temporarily heal only to reappear, unless long-term (4-6 weeks) antibiotic therapy is administered.
Parasitism (11, 15)
The major parasitic diseases of camelids are listed in Table IV. A brief discussion of a few important parasitic diseases of camelids is presented below.
Three types of mange have been reported from camelids: sarcoptic, psoroptic and chorioptic (8). Of these, sarcoptic mange is the most common and troublesome. The true identity of the mite must be established to institute effective therapy and to determine whether or not the case must be reported to regulatory authorities. Psoroptic mange (scab) is a reportable disease in the United States of America, and all forms of mange are reportable in certain states. Sarcoptic mange and trypanosomosis are the most important parasitic diseases of camels.
The sarcoptic mite burrows into the epidermis causing hyperaemia, papules and pustules, which become encrusted. The skin becomes thickened in affected areas and loses its vitality, becoming susceptible to secondary bacterial infection, with subsequent exudation. Pruritus is common. Lesions are usually found on the limbs, between the toes and on the medial thighs, ventral abdomen, chest and axilla, on the perineum of the female and on the prepuce of the male.
The parasites which are important in camelid herds or flocks in South America have been studied intensively. Those of lesser importance are rarely investigated. The lack of reported instances of parasitism from major taxonomic groups may simply reflect a failure to observe, identify or report. To date, only seventy-five species of parasites have been reported as causing clinical disease in South American camelids. South American camelids share no nematode genera with equids.
Two parasitic diseases of South American camelids warrant additional comment, as the llama or alpaca serves as an aberrant host and the parasitism may be lethal. The deer nasopharyngeal bot, or deer nasal bot (Cephenemyia spp.) is ubiquitous wherever cervids are found (10). The adult fly is approximately 14 mm in length. First instar
163
larvae are approximately 1 mm long, and progress to third instar larvae which vary from 12-40 mm. A third instar larva removed from the nasopharynx of a llama was cream-coloured, 2.5 cm long and approximately 0.7 cm in diameter (10). In the llama or alpaca, the irritation of only a single larva may stimulate production of a granuloma which obstructs the nasal airway. Llamas and alpacas are obligate nasal breathers, and this malady can therefore be lethal if not diagnosed and treated appropriately.
The meningeal worm (Parelaphostrongylus tenuis) of the white-tailed deer (Odocoileus virginianus) is well adapted to the primary host, in which little or no clinical disease develops. In aberrant hosts, such as the llama or alpaca, migration of the larvae through the spinal cord produces neurological defects commensurate with the location of the larvae, including lameness, ataxia, stiffness, circling, blindness, hypermetria, paralysis and death (8).
The following gastrointestinal nematodes are found in racing camels in the United Arab Emirates (listed in order of prevalence) (12):
- Haemonchus - Trichostrongylus - Nematodirus - Oesophagostumum - Strongyloides - Camelostrongylus - Marshallagia - Trichuris - Bunostomum - Ostertagia.
Similar findings have been reported from Iraq, Tunisia, Ethiopia, Saudi Arabia, Egypt, Sudan and India (12).
Old World camels are highly susceptible to infection with a number of species of Trypanosoma. Camels are seldom used in Africa in the region called the 'tsetse fly belt'. Illness and death due to nagana - the disease caused by T. brucei - may be the key factor in the absence of these animals from the area. T. evansi is the major trypanosome affecting camels, causing a disease called surra. 'Surra' in the Marathu language (India) means 'rotten'. T. evansi may have some significance in South American camelids (see below). Any biting or blood-sucking insect or tick may serve as a vector. Mechanical transmission via contaminated hypodermic needles is also possible.
The geographical distribution of T. evansi is extensive. This parasite causes disease in North Africa, Asia Minor, the former Soviet Union, Pakistan, Afghanistan, India, Burma, Malaya, Indochina, southern China, Indonesia and the Philippines. Trypanosomosis has not been reported in South American camelids in Central and South America, despite the presence of the organism. Acute surra is characterized by fever, depression, weakness and oedema. The presence of pulmonary oedema may contribute to the development of secondary pneumonia. Females may abort, and the milk of lactating females may become caseous. Large numbers of trypanosomes may be seen in peripheral blood samples. Death may occur within a few weeks of infection.
164
TA
BL
E IV
Sele
cted
par
asiti
c di
seas
es
of
cam
elid
ae
(5,
7, 1
6)
Susc
eptib
ility
Dis
ease
/com
mon
nam
e O
rgan
ism
L
ife c
ycle
Sy
ndro
me
Cam
el
Sout
h A
mer
ican
ca
mel
ids
Pedi
culo
sis,
lic
e D
amal
inia
bre
vice
ps
Mic
roth
orac
is c
amel
i C
ompl
eted
on
the
host
A
lope
cia
and
prur
itis
Yes
Y
es
Man
ge
Sarc
opte
s sc
abei
P
soro
ptes
spp
. C
hori
opte
s sp
p.
Com
plet
ed o
n th
e ho
st
Thi
cken
ed,
crus
ty s
kin
Yes
Y
es
Try
pano
som
osis
Tr
ypan
osom
a ev
ansi
(sur
ra)
Tryp
anos
oma
spp.
Sp
read
by
bitin
g in
sect
s A
naem
ia
Yes
Y
es
Coc
cidi
osis
E
imer
ia s
pp.
(uni
que
to c
amel
ids)
D
irec
t E
nter
itis,
diar
rhoe
a Y
es
Yes
Tox
opla
smos
is
Toxo
plas
ma
gond
ii Fe
ed
cont
amin
ated
with
cat
faec
es
Var
iabl
e de
pend
ing
on t
he
orga
n af
fect
ed
Yes
Y
es
Liv
er f
luke
s F
asci
ola
hepa
tica
Fas
ciol
oide
s m
agna
In
term
edia
te h
osts
are
aqu
atic
sn
ails
H
epat
ic i
nsuf
ficie
ncy
Yes
Y
es
Hyd
atid
dis
ease
E
chin
ococ
cus
gran
ulos
a Pr
imar
y ho
st i
s a
carn
ivor
e V
aria
ble
depe
ndin
g on
the
or
gan
affe
cted
Y
es
Yes
Tap
ewor
ms
Man
y sp
ecie
s (e
.g. M
onie
zia
expa
nsa)
In
term
edia
te h
osts
are
or
abat
id m
ites
Wei
ght
loss
and
dia
rrho
ea
Yes
Y
es
165
Stom
ach
wor
ms
Tric
host
rong
ylus
spp
. O
ster
tagi
a sp
p.
Cam
elos
tron
gylu
s sp
p.
Hae
moc
hus
spp.
G
raph
inem
a sp
p.
Spic
ulop
tera
gia
spp.
Dir
ect
Gas
triti
s Y
es
Yes
Whi
pwor
ms
Tric
huri
s sp
p.
Dir
ect
Ente
ritis
, di
arrh
oea
Yes
Y
es
Inte
stin
al n
emat
odes
N
emat
odir
us s
pp.
Oes
opha
gost
umum
spp
. N
umer
ous
othe
r sp
ecie
s
Dir
ect
Ente
ritis
Y
es
Yes
Lung
wor
ms
Dic
tyoc
aulu
s sp
p.
Dir
ect
Bron
chiti
s, pn
eum
onia
Y
es
Yes
Men
inge
al w
orm
P
arel
apho
stro
ngyl
us t
enui
s In
term
edia
te h
osts
ar
e te
rres
tria
l sn
ails
and
slug
s A
taxi
a, p
arap
legi
a, p
aral
ysis
NR
Y
es
Abe
rran
t ho
st
•Hoo
kwor
ms
Bun
osto
mum
spp
. D
irec
t A
naem
ia,
diar
rhoe
a Y
es
Yes
Lam
anem
a ch
avez
ii D
irec
t La
rvae
mig
rate
to
the
liver
and
lu
ng
Hep
atop
athy
, en
teri
tis,
repo
rted
onl
y in
So
uth
Am
eric
a
NR
Y
es
NR
: no
t re
port
ed
166
Chronic surra is characterized by intermittent episodes of fever, anaemia, pendant oedema and emaciation. Between episodes of fever, the parasite may be absent from peripheral blood vessels. A camel may live for three or four years, depending on the care provided.
Coccidia spp. tend to be host-specific and, in the case of camelids, a few species of the genus Eimeria have been described. To the knowledge of the author, camelids do not host any species of Coccidia except those for which they are unique hosts.
Nematode species are the most numerous and detrimental of the camelid parasites. Most of these parasites are located in the gastrointestinal tract. Species identification of the gastrointestinal parasites of South American camelids in North America has never been reported. Thus it is not known whether these parasite species are the same as those found in cattle, sheep and goats, or different species from the same genera. In general, it is assumed that camelids and ruminants share the same gastrointestinal nematodes. Although taxonomic information is important from an epidemiological standpoint, this will not be available until a classical taxonomist of parasites takes an interest in camelids. Many aspects of gastrointestinal parasitism are similar, regardless of which species of parasite is involved. Most gastrointestinal parasites produce a protein-losing gastroenteropathy. In severe cases, hypoalbuminaemia may develop. Enteritis will induce changes in the secretory status of the gut. Appetite and utilization of the feed consumed is reduced, depriving the body of vital nutrients. Absorption of calcium and phosphorus is depressed, causing arrested skeletal development in the young animal. Selenium uptake is also retarded. Young animals are at greatest risk when affected by parasitism, as no resistance has been developed to the invading organisms. There are peracute, acute and chronic forms of most parasitisms. Death may be caused by overwhelming invasion of an organ or system, but parasitism usually results only in varying degrees of debilitation. Over a period of time, the body loses the ability to resist minor infectious agents, and a secondary infection may cause death. Some degree of ill thrift usually accompanies parasitism. The fibre coat may lack lustre.
Diarrhoea is the most prominent sign of enteritis but need not always be present in parasitism, especially when larvae invade such tissues as the liver or lungs. Anaemia may be observed during heavy infestations, even with parasites which are not blood-suckers. The cutting mouthparts which the parasite uses for attachment may result in leakage of plasma and cells from capillaries. In adult animals, production and quality of fibre and milk will be depressed. Thus a juvenile may be doubly jeopardized, both by its own parasite load and by lack of nourishment as a result of the effect of parasitism on the mother.
Lamanema chavezi is one of the more important nematode parasites of camelids in South America. Fortunately, no instances of parasitism outside South America have been reported.
Ingested larvae penetrate the intestinal wall and migrate to the liver and lungs. The most serious damage occurs in the liver. Ultimately, maturation of the larvae is completed, with migration back to the small intestine via the trachea.
Whipworms (Trichuris spp.) are significant parasites of camelids, and are resistant to treatment with the usual doses of anthelmintics which are effective for other gastrointestinal nematodes. These parasites are characterized by long, slender anterior segments and a thicker posterior segment. Adult parasites are found in the caecum and
167
large intestine. Trichurids identified from camels include T. globulosa, T. cameli and T. skrjabini. Whipworms cause a marked enteritis, leading to diarrhoea, dehydration and weight loss.
Zoonoses
Infectious zoonoses include rabies, encephalomyocarditis, contagious ecthyma, Rift Valley fever, numerous viruses spread by ticks, in addition to anthrax, plague, salmonellosis, leptospirosis, colibacillosis, dermatophilosis, brucellosis and tuberculosis. Camelids are not major carrier hosts for any of these diseases. Parasitic zoonoses include trypanosomosis and sarcoptic mange.
Diseases of camelids acquired from other species
Gastrointestinal nematodes may be shared between ruminants and camelids. South American camelids have become infected with EHV-1 and two parasite species, namely Cephenemyia spp. and Parelaphostrongylus tenuis. Camelids may also acquire numerous bacterial diseases from other species.
*
ÉLEVAGE ET PATHOLOGIE DES CAMÉLIDÉS. - M.E. Fowler.
Résumé : Depuis des millénaires, les hommes de l'Ancien et du Nouveau Monde utilisent les camélidés pour leur viande, leur lait, leur laine et leur graisse, et en tant que bêtes de somme pouvant porter de lourds fardeaux. Depuis l'apparition des véhicules motorisés, l'utilisation des camélidés est devenue obsolète, sauf dans certaines situations exceptionnelles. Le nombre de ces animaux a donc considérablement diminué. Cette situation s'inverse actuellement, car l'on a finalement admis que les camélidés ont une meilleure utilité dans leur environnement naturel que n'importe quel autre animal domestique. Les camélidés ont toujours été très appréciés dans les parcs zoologiques. Les chameaux, ainsi que deux espèces camélines d'Amérique du Sud, sont des animaux qui supportent très bien la captivité. Ils montrent une capacité exceptionnelle à se nourrir de fourrages épineux. Les caractéristiques de ces espèces en termes de reproduction les distinguent également des autres animaux de rente.
Peu de maladies des camélidés leur sont spécifiques ; les camélidés ne constituent un réservoir pour aucune maladie grave du bétail.
MOTS-CLÉS : Alpagas — Chameaux - Dromadaires — Faune sauvage — Guanacos - Infection - Lamas - Parasitisme - Vigognes.
*
CRÍA Y PATOLOGÍA DE LOS CAMÉLIDOS. - M.E. Fowler.
Resumen: Los camellos del Viejo y del Nuevo Mundo constituyeron durante milenios fuente de carne, leche, fibra y combustible para las poblaciones humanas indígenas, además de servir como bestias de carga para el transporte.
168
Con la llegada de los vehículos de motor, el empleo de camellos se volvió obsoleto, salvo en ciertas situaciones muy particulares. El número de camellos menguó de forma espectacular. Hoy esta tendencia se está invirtiendo, pues se ha constatado que estos animales son mucho más eficaces, en su entorno natural, que cualquier otra especie de animales de renta. Los camélidos siempre han sido populares en los zoológicos. Los camellos, junto con otras dos especies de camélidos sudamericanos, son animales domésticos que se adaptan con facilidad al manejo en espacios limitados. Poseen una capacidad única para alimentarse con forrajes extremadamente ásperos. Su fisiología reproductiva es distinta de la de cualquier otra especie doméstica.
Pocas de las enfermedades de los camélidos son exclusivas de estas especies. Los camélidos no son reservonos para ninguna de las enfermedades importantes del ganado.
PALABRAS CLAVE: Alpacas - Camellos - Dromedarios - Fauna salvaje - Guanacos - Infección - Llamas - Parasitismo — Vicuñas.
* * *
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D.H. Snow & F.J. Wade, eds). Dubai, United Arab Emirates, 2-6 February. R and W Publications, Newmarket, United Kingdom, 85-87.
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