bustard preventive medicine programmes for captive breeding … · 2019-05-24 · 4. monitor causes...
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Bustard Preventive Medicine
Programmes for Captive Breeding
and Rehabilitation Projects
Dr Tom Bailey
International Wildlife Consultants, Wales, UK.
Dubai Falcon Hospital, Dubai, UAE.
National Avian Research Center, Abu Dhabi, UAE.
Bustard Preventive Medicine Programme
Health is of paramount importance for projects
releasing captive bred birds.
Disease problems in CBRPs include:
– Pink pigeons (low resistance to viral pathogens)
– Mauritius kestrels (adenovirus)
– Whooping cranes (equine encephalitis)
– Californian condors (lead toxicosis)
– Waterfowl (TB)
Health management and disease investigations are
integral part of IUCN guidelines for Re-introduction
and Rehabilitation Projects.
See J. Avian Med & Surg 1996: 10; 268-277
Design of a Preventive Medicine Programme
Breeding flock health essential component of CBRPs
Understanding the ‘disease profile’ of a species is
necessary to design flock health recommendations
At NARC we established a disease profile for bustards
and designed a flock health programme following;
– 1. Morbidity and Mortality surveys.
– 2. Serological surveys.
– 3. Consideration of endemic diseases in poultry and wild
species that birds in CBRP come into contact with (e.g. doves).
Biomedical Research
Program
2. Establish clinical
parameters in health and
disease
1. Establish laboratory
diagnostic parameters in
health and disease
4. Monitor causes of
morbidity and mortality 5. Establish optimal
medical treatment
regimens
6. Establish
biomedical studies
on free-living
populations
Outline of the core objectives of the houbara bustard
biomedical research programme of NARC.
3. Establish
biomedical
reference
collection
Biomedical Research
Program
2. Establish clinical
parameters in health
and disease
1. Establish laboratory
diagnostic parameters in
health and disease
4. Monitor causes of
morbidity and mortality
5. Establish optimal medical
treatment regimens
6. Establish colateral
biomedical studies on free-
living populations
Microbiology Parasitology
Haematology
Serology Biochemistry
Anatomy and physiology studies
Growth and development studies
Reproductiv
e studies
Nutritional studies
3. Establish
biomedical
reference
collection
Pathological investigations Serological surveys
Post-mortem examination
Vaccination trials
Pharmacological trials
Dead birds Live birds
Anesthetics trials
Database
analysis
Microbiological screening
Documentation
One outcome of the
biomedical research
programme initiated at
NARC in 1993 was the
documentation and
publication of a
significant volume of
biomedical information
primarily on Houbara and
other bustard species.
Research compiled in a
multi-author book in
2008
Summary of Conditions of Bustards (UAE)
Category Condition
Captive
adult
Traumatic injuries, musculoskeletal diseases including
capture myopathy and handling-related injuries, fatty liver
change and parasitic conditions including trichomoniasis.
Captive-
reared
juvenile
Musculoskeletal disorders, particularly nutritional bone
disease, mechanical gastro-intestinal tract conditions and
bacterial infections.
Imported
adult
Traumatic injuries, parasitic infections, opthalmological
conditions, aspergillosis, transportation associated deaths
and infectious viral diseases (PMV-1, avian pox).
Summary of major causes of morbidity of
imported and captive adult bustards
Clinical finding Imported
adult
Captive
adult
Soft tissue related traumatic injuries 26.3% 50.7%
Musculoskeletal findings 4.9% 22.9%
Parasitic findings 24.7% 15.5%
Viral findings 20.1% 0.4%
Fungal findings 0.7% 2.2%
Opthalmological findings 15.1% 5.4%
Miscellaneous disorders 8.2% 2.9%
Avian Dis 1996: 40; 121-129
Avian Dis 1996: 40; 296-305
Serological Survey of Adult Bustards
Serological surveys play an important
role in the investigation of wildlife
diseases because they can reveal
evidence of the presence of disease
when apparent infections and clinical
cases have not been detected.
Serological survey of bustards in UAE.
– Group 1 - birds in private collections in the UAE.
– Group 2 - birds imported from Pakistan into the
UAE.
– Group 3 - free-ranging birds that were trapped for
a satellite tracking project in 1994-1995.
Vet Rec 1996: 139; 238-239
Serological results following the testing of sera
from houbara bustards against avian viruses.
Virus Group 1 Group 2 Group 3
Avian influenza 0/17 0/26 0/6
PMV-1
PMV-1
9/17
51/141
17/26
36/60
1/6
PMV-2 0/17 5/26 0/6
PMV-3 0/17 0/26 0/6
Avian pox 0/17 8/26 1/6
Infectious bronchitis 0/17 0/26 0/6
Avian Pneumovirus 0/12 0/24 0/5
Serological Survey
Major Findings
– Grp 1 - 38% +ve to PMV-1
– Grp 2 - 62% +ve to PMV-1
– Grp 2 - 31% +ve to Avian pox
– Grp 2 - 19% +ve to PMV-2
Conclusions
– importation exposes HB to viral diseases.
– do not manage HB and poultry on same
premises.
– vaccination programmes against viral
diseases necessary for CBRPs.
Seasonal pre-breeding health
monitoring
Two months before the breeding season birds:
weighed.
clinically examined.
identified with a ring or PIT.
collection of biomedical samples
– routine health screening
– storage in biomedical reference collection
– specific research projects.
treated for ectoparasites and endoparasites.
Vaccinated
– Avian pox and Newcastle disease virus.
Range of samples collected during pre-
breeding health examination
Parasitology
– OP swab in saline for direct microscopic examination
– Fecal sample for flotation and direct microscopic
examination
Microbiology
– Cloacal swab - aerobic bacteriology
Blood samples collected in pediatric tubes
– EDTA -haematology and blood parasites
– Plasma -biochemistry, vitamin or trace element
analysis
– Serum -vaccine assessment, serological surveys or
banking
Chlamydia status
– choana/cloacal swabs for ELISA antigen
Virology
– choana/cloacal swabs for virus isolation
Prophylactic medications
Trichomoniasis control.
– All adult and juvenile bustards receive anti-protozoal
medication administered in the water three times a year, in
February, June and October.
Endoparasite control.
– All adult and juvenile bustards receive anthelmintic medication
administered in the food three times a year, in February, June
and October.
In-feed medication
– Addition of anthelmintic and antiprotozoal medication used in
1992. Beware resistance.
Pox Vaccination
Cross-protection study at NWCD, KSA used pox isolated
from HB and vaccinated/unvaccinated canaries (canary
pox virus vaccine).
Study demonstrated that vaccinated canaries survived
challenge with HB pox and canary pox virus.
Studies needed to confirm this using houbara but this
trial supports the recommendation that HB should be
vaccinated with CP vaccine.
Poulvac P Canary (Duphar, Holland) used at NARC
See Avian Dis 1996: 40; 762-769
Newcastle Disease Vaccination
Trials at NARC using previously vaccinated adult HB
given a booster of 1ml/kg s/c inactivated oil emulsion
PMV-1 vaccine (Newcavac Nobilis, Intervet).
Antibody levels monitored monthly for 12 months by ND
HI.
Mean titre (n=6) log2 7 for 6 months and > log2 4.5 for
the remaining 6 months.
Work in chickens has shown that field challenge with
PMV-1 will not kill chickens with antibody titres > log2 5.
Annual vaccination of previously vaccinated adults
should provide protection against PMV-1.
Mean PMV-1 HI inhibition titer in adult
bustards given inactivated vaccine
0
2
4
6
8
0 4 8 12
16
20
24
28
32
44
48
52
56
Time after vaccination (weeks)
HI ti
tre
2^y
See J. Zoo & Wildl Med 1998: 29; 441-450
Other vaccinations
Avian influenza
– H9N2 (Gallimune 208 ND
+ Flu H9)
– H5N2 (Nobilis Influenza
H5, Intervet)
Reovirus
– Heuglin’s bustards
(Dubai, P McKinney) –
Nobilis Reo (Intervet)
Pre-catch medications for adult bustards
Water soluble multivitamin products routinely
administered to the water of aviaries (and/or food) of
bustards for periods of up to one week before a known
catch or translocation is planned.
Done to reduce the incidence of capture-related causes
of morbidity and mortality such as paresia or stress-
related deaths.
Important for the more nervous birds in the collection
that are not used to being handled.
Bustard Pediatric Diseases
Chick health can limit success of CBRPs
Conditions of chicks different to adult diseases
Understanding of ‘disease profile’ necessary for the
creation of health recommendations for captive bred
birds
Review of pediatric diseases at NARC (1993-1995)
during first 180 days of life
Survey of 137 chicks
Species - HB, RCB, KB
J. Av Med & Surg 1997: 11: 166-174
Mortality of bustard chicks over first 180
days after hatching
27
11
76
12
0
5
10
15
20
25
30
<30 31-60 61-90 91-120 121-150 151-180
Age (days)
Mo
rtality
Morbidity of bustard chicks during first 180
days after hatching
118
3240
2024 27
0
20
40
60
80
100
120
140
<30 31-60 61-90 91-120 121-150 151-180
Age (days)
Mo
rbid
ity
Bustard Pediatric Survey
Results
45% morbidity occurred during 1st 30 days.
52% mortality occurred during 1st 30 days.
Major juvenile health problems
Bacterial diseases.
Mechanical abnormalities of GIT.
Musculoskeletal problems.
Parasitic problems.
Mechanical abnormalities of GIT
Important cause of death (16%) and morbidity
(4%) over the 180 day period.
RCB susceptible to gizzard impactions cf other
species .
Foreign body impactions of proventriculus or
ventriculus.
– Septicemia sequela to impaction.
– Surgical removal often possible.
‘Overload ventriculus’ reported in other bustards,
recommended to feed some small grit until chicks
learn to pick grit themselves.
– Impaction with grit reported in HB at NWRC, KSA.
Care with environmental contamination.
‘Hardware’ disease in bustards
Clinical signs
– decreased appetite, depression, palpable abscesses,
intermittent feces with partially digested ingesta, weight loss
Diagnosis
– radiography - confirmation of foreign body in ventriculus
– haematology heterophilia in acute cases, monocytosis in
chronic cases
Surgical treatment
– ventriculotomy via saccus caudalis following lateral or midline
celiotomy
– supportive medical treatment (fluids, antibiotics, diet)
Above (right). Juvenile RCB, lateral projection. Massive enlargement of the ventriculus (black
arrows) and enlarged renal shadow (white arrows). This bird was under treatment of gastric
stasis and died shortly after hospitalisation. The cause of death was peritonitis and
generalised bacteraemia secondary to impaction of the ventriculus.
Anatomical features
Ventriculotomy described in cranes
– BUT as a muscular organ the poor holding strength of sutured
muscle combined with the rhythmic ventricular contractions make
dehiscence of the suture line a possible complication
BUT - in bustards the tenuis craniodorsalis and tenuis
caudoventralis muscles are comparatively thin and are
present in the saccus cranialis and saccus caudalis which
make up the tapering ends of the ventriculus
Surgical access to ventriculus in bustards possible
through the saccus caudalis
Left lateral celiotomy
Skin incision posterior and parallel to the last rib
Separate abdominal muscles, expose and cut
peritoneum to enter abdominal cavity
Exteriorize ventriculus with stay sutures
Incision through the saccus caudalis at the caudal end
of the ventriculus
Remove FB
2 layer closure of ventriculus with polyglactin 910
– 1) the mucosa and submucosa closed with continuous sutures
– 2) muscle wall closed with Cushing’s sutures
Ventral laparotomy
saccus caudalis
in bustards is
accessible by a
ventral
laparotomy
Ventral midline approach to the abdominal cavity
of a kori PM demonstrating the accessibility of the
saccus caudalis of the caudal ventriculus by this
approach.
Bacterial Diseases
Bacterial diseases - important cause of death over 1st 30
days (62%) and in total over 180 days (40%).
Factors predisposing chicks to infection
– stress, poor nutrition, environmental contamination, immaturity of
the immune system.
Conditions
– septicemia, sinusitis, meningitis, YSI, rhinitis, stomaitis,
conjunctivitis.
82% bacterial isolates G-ve.
– Pseudomonas aerugenosa, E.coli, Salmonella spp., Yersinia
pseudotuberculosis.
– Staphylococcus spp most common G+ve.
Chicks are coprophagic - isolate sick birds.
Depressed white-bellied bustard
chick with Escherichia coli
septicaemia and enteritis, notice the
closed eyes and ‘sleepy’ appearance Houbara bustard chick with
omphalitis caused by E. coli
Buff-crested bustard chick showing enteritis and CNS
signs including ataxia, loss of balance and
incoordination. Salmonella sp. was isolated from
clinical samples and the bird responded to antibiotic
therapy
Musculoskeletal Disorders
Bustards are long-legged birds and MS abnormalities
are and important factor in their health and
development.
Musculoskeletal conditions - important cause of
morbidity over 1st 30 days (50%) and over 180 days
(49%).
In bustards 46% of MS findings occurred during 1st 30
days. In HB most findings during 31-60 days.
See J. Av Med & Surg 1998: 12: 82-90
Bustard Pediatric Diseases
Angel Wing
Lateral rotation of the distal wing
Most common MS finding - 18%
chicks at 5-19 days
More common in WB (83%) & KB
(26%) cf RCB (10%) & HB (6%)
Causes - weight of blood-filled
primary feathers causing wing tips to
twist outwards, incubation
interruption, XS heat during growing
period, high protein, genetics, Mn
deficiency
Correct by taping wing in normal
position for 3-5 days
Kori bustard with wings taped to
correct angel wing
Bustard Pediatric Diseases
Rolled Toe
Medial rotation of the
phalanges.
Common MS finding (12.6%
chicks).
Causes - riboflavin deficiency,
embryo malposition, genetics,
incubation problems,
unsuitable substrates,
inherited in chickens.
Correct early by prompt
taping or splinting.
Curly toe in a kori bustard chick
Bustard Pediatric Diseases
Spraddle/Splayed leg
More common in RCB (23%), but occasionally seen in
HB.
Occurs from 0-48 hours after hatching until 8 days.
Causes - incubation, floor of hatching box, prolonged
hatching, high incubation, poor egg quality, lack of
exercise, high protein diet.
Correct by hobbling chicks with 3M Vetwrap at level of
mid-metatarsus and keep in small padded container.
Provide newly hatched chicks with rough surface.
White-bellied bustard with
hobbles to correct splayed legs
White-bellied bustard with
splayed legs
Bustard Pediatric Diseases
Angular and rotational limb deformities
ALD and RLD can occur until 120 days post hatching.
Common in chicks (19% total findings), highest
incidence in KB.
Varus deformity common.
Most abnormalities in distal tibiotarsus and proximal
tarsometatarsus where most longitudinal growth
occurs, but deviation of radius and ulna seen in KB.
Causes - multifactorial, genetics, incubation, decreased
exercise, high fat/protein diet, poor substrates, rapid
growth rate, nutritional imbalances.
Marked distortion of the right
leg of a kori bustard due to a
rotation of the tibiotarsus
Bilateral distortion of legs of a WB
bustard due to bilateral rotation of
the tibiotarsus bones
Houbara bustard chick with
shortened metatarsi
Houbara bustard chick with fused
tarsometatarsal trochlea of digits
I and II
Legs of a 50-day-old houbara bustard with a) soft
tissue swelling above the intertarsal joint, b) short
tarsometatarsus, c) varus deformity of the distal
tarsometatarsus, and d) fused tarsometatarsal
trochlea of digits I and II. The ossification of the
proximal tarsometatarsus is in progress (arrow).
Bustard Pediatric Diseases
Fractures
Common (25% of MS findings).
Timing differs between species; RCB - 61-120 days;
HB 31-120 days; KB 31-180 days.
Ulna and radius most common site.
53% found incidentally during routine radiography
which could indicate that nutrition is imbalanced.
Pinioned wings more prone to fracture d/t lack of
protection by primary feathers.
Ca and Vit D3 deficiencies implicated in folding
fractures in juvenile HB at KSA.
Dropped wing in a white-bellied
bustard with a fractured ulna.
Metabolic bone disease
White-bellied bustard. Multiple
fractures of both humeri and ulna.
Metabolic bone disease
Bustard Pediatric Diseases
Conclusions
Aggressive care of bustard chicks during first 30 days
after hatching is important.
Implementing the recommendations described reduced
chick mortality from 71% to 25% between 1993-95 at
NARC.
Pediatric dietary management and monitoring of chick
growth rate is essential to minimise MS problems.
Consider environmental monitoring of incubation and
rearing facilities.
Health Recommendations for Juvenile
Bustards
The following procedures are carried out to maximise the
health of captive-bred, hand-reared bustard chicks;
Application of 1% iodine solution to the umbilici of
chicks promptly after hatching.
Administration of antibiotics and s.c. or p.o. electrolytes
for 24-48 hours to chicks that have had a delayed or
assisted hatch.
Supplementation of the rearing diet with a vitamin D3
and calcium (Neutrobal, Vetark, UK) from 2-90 days.
This product is lightly dusted onto the live food items.
Health Recommendations for Juvenile
Bustards
Supplement rearing diet with calcium between days 30-
60 at a dose rate of 300 mg elemental calcium per chick
twice a week.
Supplement rearing diet with probiotics from 0-14 days,
one week before and after translocations between
aviaries, and if birds are given antibiotics.
Ensure rearing environment is not contaminated by
material that could become ingested and cause foreign
body obstruction or perforation of GIT.
Health Recommendations for Juvenile
Bustards
Administer appropriate antibiotics to treat bacterial
conditions
– Gram-negative bacteria most frequent isolates from clinical and
post-mortem cases.
Vaccinate chicks against avian pox and Newcastle
disease using commercial poultry or pigeon vaccines.
– Chicks as young as 14 days can be vaccinated, but fewer side-
effects were seen when chicks >30 days are vaccinated.
Administer anti-protozoal medication to chicks that are
been translocated to naturalistic aviaries.
Vaccination protocols for juvenile bustards
Captive-bred bustard chicks are vaccinated against;
Newcastle disease.
– Vomiting and diarrhoea have been observed in chicks two
weeks of age following intra-ocular live Newcastle disease
vaccine.
– Chicks given live Hitchner B1 Newcastle disease vaccine at one
month of age and side-effects have rarely been seen.
Avian pox.
– Chicks as young as two weeks of age have been vaccinated
with half a dose of commercial poultry pox or canary pox
vaccine via the wing web route and no side-effects have been
observed.
Mean HI titres of bustards given live IO B1 ND vaccine (wk 0),
live IO La Sota ND vaccine (wk 4) and inactivated vaccine (wk
12) at 1.0 ml/kg
-1
1
3
5
7
9
0 4 8 12 13 14 15 16 20 26 30 34 38
Time after vaccination (weeks)
HI ti
tre
2^y
See J. Zoo & Wildl Med 1998: 29; 441-450
Mean ND HI titres of bustards given IO B1 ND vaccine (wk
0), three IO La Sota vaccines (wks 4, 10, 16) and
inactivated vaccine (wk 24) at 1.0 ml/kg SC
0
1
2
3
4
5
6
7
8
0 1 2 3 4 5 6 7 8 9 10 12 14 16 18 20 24 28 32 36 40 44 48 52
Time after first vaccination (weeks)
HI T
itre
2^y
See J. Zoo & Wildl Med 1998: 29; 441-450
Vaccination protocols for juvenile bustards
Juvenile bustards should receive a second dose of
inactivated PMV-1 vaccine 4-6 months after their first
dose of inactivated vaccine.
Objective of a (PMV-1) vaccination programme is to
minimise the susceptible period between waning
passive immunity and the establishment of active
immunity.
Vaccination of poultry derived from immune flocks is
hindered by maternally derived immunity (MDI).
PMV-1 HI antibody levels (log2 ) in KB dams and in
yolk, albumen or a yolk-albumen mixture (mix)
derived from infertile eggs.
PMV-1 HI Titer (log2 )
Dam ID (Egg
ID)
Dam pre-
breeding
season
Dam
post-
breeding
season
Yolk
Albumen
Mix
429 (96/18) 1 0 0 0 Nd
623 (96/26) 4 8 nd a nd 5
623 (97/01) 4 8 5 3 Nd
632 (96/09) 4 8 Nd nd 4
618 (97/02) 5 8 8 5 Nd
See J. Wildl Dis 1998: 29; 441-450
PMV-1 HI antibody levels (log2 ) in KB dams before
and after the breeding season and in their chicks.
PMV-1 HI Titer (log2 )
Dam
ID
Dam pre-
breeding
season
Dam
post-
breeding
season
Chick 1 Chick 2 Chick 3
429 1 0 0 nda nd
628 3 8 7 5 8
623 4 8 5 5 nd
632 4 8 4 5 8
637 5 8 8 nd nd
638 5 8 8 nd nd
See J. Wildl Dis 1998: 29; 441-450
Maternally derived immunity in bustards
In a study of previously vaccinated KBs at NARC it was
shown that maternal antibodies are transferred from
dams to their chicks.
PMV-1 antibodies are transferred to eggs and chicks
from KB hens previously given inactivated vaccine.
Chicks hatched from dams with high antibody titers had
high MDI levels.
Mean antibody levels in chicks was log2 6.3 on day 14
and log2 2.9 at day 42.
Antibody half-life in 14-21 day chicks was 5.5-6.3 days,
which is similar to chickens.
Decline of maternally derived PMV-1 HI
antibodies in kori bustard chicks.
0
1
2
3
4
5
6
7
8
0 7 14 21 28 35 42 49 56 63 70Age (days)
HI ti
tre
2^y
See J. Wildl Dis 1998: 29; 441-450
Maternally derived immunity in bustards
Antibody half-life in 28-42 day chicks was 12.3 days
– slower cf chickens (but similar to parrots).
Species differences in decline of MDI and hence in
timing vaccination regimens.
MDI levels of >log2 4 protects poultry chicks against
PMV-1 challenge.
Our data suggests that unvaccinated bustard chicks
could be protected against PMV-1 challenge for up to 4
wks.
High risk of PMV-1 infection - vaccinate at 3-4 wks
Low risk of PMV-1 infection - vaccinate at 6-8 wks
See J. Wildl Dis 1998: 29; 441-450
Other Measures
Other non-medical measures can be considered to
improve health of captive bustards.
Adult and juvenile bustards are “trauma susceptible”.
Minimise trauma by;
– 1. Modifying behaviour by taming nervous individuals or
housing such birds in naturalistic pens with cover.
– 2. Enclosure design using padding or shade-cloth to reduce
potential danger zones.
– 3. Pinioning and feather cutting.
– 4. Consider genetics (migratory behaviour in captive setting).
– 5. Chemical modification of behaviour (future).
Environmental monitoring
Environmental monitoring provides feedback on
efficacy of disinfection and hygiene protocols
Sources
– food samples
– food preparation areas
– artificial incubation,natural/surrogate incubation facilities
– hatching and rearing facilities
– water sources
Sampling
– aerobic bacteriology and fungal culture from settle plates and
direct swabs from environment
– aflotoxins in food samples
Quarantine
Essential to minimise
risk of infectious
disease being
introduced into CBRPs.
Quarantine should
facilitate screening of
birds entering or
leaving CBRPs.
Quarantine
Quarantine considerations
1. Locate safe distance from CBRP center and
neighbouring agricultural areas.
2. Protect from predators.
3. Multiple wards to enable multiple groups of
birds to be separately accommodated.
4. Central unit for clinical activities.
5. Buffer zone between wards and clinical area.
Quarantine
6. Facilities for personnel hygiene.
7. Facilities to disinfect car tyres/rubber boots.
8. Maintain required temperature and
humidity.
9. Observation of birds without causing
disturbance.
10. Ability to separate birds from a group to
allow catching (sliding doors between pens).
11. Incineration capability.
Int Zoo Yb 1997: 35; 256-261
Quarantine protocols
Incoming birds quarantined for 45 days
Health screened for:
1. Virus isolation (cloacal/choanal).
2. Serology (PMV-1, Chlamydia).
3. Chlamydia ELISA antigen (choana).
4. Parasitology (OP swab, fecal).
5. Haematology.
6. Microbiology (cloacal).
Optional - endoscopy, blood chemistry.
End Piece
Health and disease are dynamic processes.
New diseases emerge
– e.g. Chlamydia, Reovirus, Adenovirus, Avian Influenza
Old diseases decline due to improvements in husbandry
– e.g. Trichomoniasis important in naturalistic aviaries, but rarely
seen in environmental-control units
Health monitoring should be on-going.
Preventive medicine programmes need to be flexible.
Good science is needed to investigate health problems
and to find optimal solutions.
Thanks to colleagues at :
– NARC
– DFH
– IWC
– ZSL
– GBT
– HFI
– Who have shared information
with me over the years
Thanks