Coraciiformes/Bucerotiformes Flashcards
Southern ground hornbills at risk of Newcastle Dz - Conclusion of vaccine study?
Immunogenicity of Newcastle Disease Vaccine in Southern Ground-hornbill (Bucorvus leadbeateri).
Koeppel, K.N., Kemp, L.V., Maartens, L.H. and Thompson, P.N.
Journal of Avian Medicine and Surgery, 2020;34(3):229-236.
Background
• 2 southern ground hornbills raised in captivity and reintroduced died of Newcastle disease (PCR)
o Virulent strain of pigeon paramyxovirus (PPMV) - probably scavenged on dead doves
• Poultry vaccination: commonly live (for mucosal immunity) followed by inactivated (for antibodies)
Key Points
• Live (ocular) + killed (SC), live (ocular) + killed (IM), live (ocular) + live (IM), oral via chick embryo inoculated with live +/- killed (IM) booster - Titers by HI, positive dilution of 1/16
• No adverse effects
• Highest titers with live (ocular or oral) + live (IM) booster
• Higher titers maintained 13 mo out with IM booster vs SQ
• Titers declined after annual SQ boosters discontinued
• Titers in wild birds were all negative except 1 with low titers
• Oral vaccine alone did not provide adequate titers and required IM booster
• Vaccinate at 3-4 mo (fledgelings)
o Chicks should not be vaccination by injection until 3 weeks old to prevent maternaly antibody interference
• Consider timing boosters prior to breeding season (coincides with ND peaks in wild birds)
Conclusions
• Southern ground hornbills should be considered at risk of ND
• Vaccination of southern ground hornbills with live Ulster strain ND vaccine in eye drops followed by SQ Struvac vaccine provided protective antibody titers to AAvV1 with no adverse effects
o Required annual boosters, IM booster were superior to SQ
What is the scientific name of the northern and southern ground-hornbill?
Describe their unique anatomy?
- What is unique about their gait?
- What is their GI transit time like?
- What makes venipuncture difficult in these species?
Describe their life history:
- What is their breeding like?
- What is a concern when multiple eggs are laid?
Bucorvus abyssinicus (Northern ground-hornbill)
Bucorvus leadbeateri (Southern ground-hornbill; SGH)
SGH Unique Anatomy:
* Bucorvus spp also unique d/t dev of syncervical vertebra (fused atlas and axis vert) 🡪 may have dev to support forceful head motion of skull
* Carotid arteries run parallel to jub veins + pneumogastric nerve
* 14 neck vertebrae (instead of 15)
* Reduction in # nerves in brachial plexus
* Extra tendon running from pelvis to femur
* Limb structure 🡪 allows them to walk instead of hop unlike other hornbills (exception being small members of subgenus Tockus (w/in genus Tockus)
* Rapid GIT = 30 min; prominent muscularis of SI 🡪 predisposes to GIT stasis
* Extensive SC emphysema body/wings/legs 🡪 complicates blood collection
SGH Life Hx:
* Diurnal, long-lived, large, conspicuous, top-order avian predator
* Large spatial needs 🡪 low densities and small pop size per unit area
* Cooperative breeding and complex social structures
* Above results in slow rates of breeding + pop recruitment
* Obligate brood reduction (younger/weaker chick dies of parental neglect) 🡪 no reports of more than one chick successfully raised from clutch of 2/3 eggs even in captive scenario w/ adequate nutrition
* Other forms of brood reduction include cainism (one chick actively kills its siblings), oligate siblicide (one chick outcompetes the other)
* Chicks altricial at hatch 🡪 need sig care
Describe the infectious diseases of ground hornbills.
Bacterial:
- What are common causes of enteritis in these species?
- What is an important infectious disease in European collections?
Viral:
- What is the most significant viral disease of these wild birds?
- What viruses have caused mortality in NA and European birds?
Parasites:
- What hemoparasites have been documented?
- What nematode is common in managed SGH?
INFECTIOUS DISEASES of GH
Bacterial:
* Enteritis:
– Clostridium perfringens: neonate and adult SGH
– Salmonella enterica serovar Enteritidis: chicks
– E. coli: chicks
* Aeromonas hydrophila: fatal septicemia under stressful conditions
* Yersinia pseudotuberculosis: common cause of mort of SGH in Europe (esp in winter); not reported in SGH in South Af
* Clostridium botulinum Type C toxin: presumed suscept (from contam meat/carcasses)
Viral:
* Newcastle disease virus (avian Avulavirus 1): sudden death in hand-reared SGH (show no resistance to virus); oubreaks in poultry/wild birds occur in areas with SGH pop overlap
* NDV vx recommended for SGH: live oral vaccine (Ulster strain), followed by killed vx (Avivac ND Struvac Plus) 1mL IM 🡪 immunity short, ANNUAL Vx recommended
* West Nile virus: Ab + mortality in infected NGH in US
* Usutu virus: Ab detected from NGH in European zoos
* ARP Note: Usutu – flavivirus (similar to WNV) from Japanese encephalitis complex, mosquito-borne, ZOONOTIC
Parasitic:
* Capillaria spp: asymptomatic in captive SGH when documents; assoc with mortality in other hornbill spp and can be diff to tx d/t resistance to antihelminthics
* Hemoparasites – rare; Leucocytozoan – obs in blood smear from wild chick; Plasmodium/Haemoproteus id from liver
Describe the noninfectious diseases of ground hornbills.
What is the most common GI complication of this species?
What are two additional causes of morbidity & mortality?
What nutritional diseases are common in this species?
NON-INFECTIOUS DISEASES of Ground Hornbills
Foreign Bodies:
* Captive SGH (juveniles most common) – consume hardware and other FB; assoc fatal ventricular perforation reported
* Metal FB can be dx on xray and removed via scope or coeliotomy
Trauma:
* Intraspecific – common cause of morbid/mort in captive + wild SGH
* Captivity: inter + intraspec. aggression common
Electrocution:
* Roosting on transformer boxes
* Clin signs: death, trauma (cutaneous burns, cutaneous/visceral petechiae, fracture)
* Fractures – common sequelae d/t traumatic injury 🡪 micro fx lines (medullary bone of leg/wing most freq)
* Bloodwork: inc CK, inc LDH 🡪 indicate electrocution, but also consistent w/ severe musc trauma
Nutritional:
* Obesity: assoc w/ high fat diet 🡪 2e hepatic lipidosis + atherosclerosis
* Bloodwork: lipemic, inc liver enzymes (GGT, bile acids)
* Xrays: hepatomeg
* Degen changes + mineralized plaques in aorta, vessels of brachiocephalic trunk
* GI stasis: common in sick birds; tx w/ prokinetic agents for improved recovery time
* Vit B, Mg deficiency: rotation, curling of toes in hand-reared SGH
* PSGAG: fatal hemorrhage at injection site at dose 10 mg/kg (repeated tx) – use w/ caution if using for OA tx
* Stress lines (1e feathers, tail feathers): assoc w/ period of stress d/t dx +/- incorrect/under nutrition
* Note: once dev – stressful period already passed but long-term physio effects may continue
* Feather growth rate – 4-5mm daily in rock pigeons (assumed same in hornbills) 🡪 can use this to determine when stressful period occurred
Describe the complications associated with incubation and hand-rearing ground hornbills.
How long are they considered neonates?
What is the typical neonatal respiratory rate?
- Changes to this may indicate what diseases?
What is a common GI disease in these baby birds?
- How is it treated?
Describe the reproductive management of this species.
- HOw are males determined to be ready to breed?
- Describe your approach for a vasectomy in this species.
DISEASES ASSOC W/ INCUBATION & HAND-REARING IN SGH
* SGH: neonates until 20d post hatch
* Healthy neonatal chick resting: < 20 breaths/min
– Note: transient inc RR post feeding 🡪 should resolve w/in 30 min
– RR 24-32 breath/min assoc w/ colic
– Aspiration pneumonia – common in weak/compromised chicks
* Ventriculitis + impaction w/ 2e fatal septicemia: common in hand-reared SGH
– Note: chicks below 55g at hatch = predisposed to impaction
– Tx: lactulose – use to tx mild impaction (0.5 ml/kg BID-TID)
* Gout: assoc w/ insuffic fluids or removed sev days post hatch + dehyd
* Bacterial infections: common in stresse/immunocomp neonates
– Early indicator of infect = change in bacterial flora of feces; Gram stain of fresh feces 🡪 change in flora (unique to each chick)
* Nutritional 2e hyperparathyroidism + MBD: SGH fed diets low in Vit D + Ca or inverted Ca:Phos ratio
REPRO
* Testes inc in size prior to breeding 🡪 endoscopic eval prior to breeding allows for eval of readiness to breed
* Vasectomy – can be performed via right + left coelomic approach
* Vas deferens – runs along dorsomed aspect of testis (close prox to iliac artery)
* Electrocautery or vasc clamps an be used to remove min 5mm piece close to emergence from epididymis (similar technique to other spp, except testis more caudal)
