Ratites Flashcards
What birds are in the Order Struthioniformes?
Ratites
Unique features of ratites
Flat keel, features lack barbules, no uropygial gland, illia form shield over the synsacrum
Unique feature of the Emu trachea
Tracheal sac - Series of incomplete cartilage rings on anterior aspect covered by thin membrane for drumming noises during breeding season
Anatomical feature in emus, rheas, cassowaries that ostriches lack
Gallbladder
What spp has two functional ovaries that ovulate alternately
Kiwi; Also they make GIANT eggs - This is normal
Anatomical differences between Tinamous and Ratites
Tinamous are flighted, have well-developed pectorals, highly pneumatized skeleton, elaborate ceca
Unique anatomic features of the skeleton
No patellas; Emus, cassowaries, rheas tridactyl; Cassowaries sharp claw inner toe
Number of toes - Ostrich, cassowaries, emus, rheas
Ostrich didactyl with nail on medial toe only; Others tridactyl with nail on all toes
Unique feather anatomy of ratites
Barbules do not interlock (fluffy); No down feathers; Continuously molt
Unique metabolic differences between Kiwi and others
Kiwis have a lower basal average temp
Compare and contrast GI anatomy for ostrich, rea, cassowaries, emus
Ostrich and rheas have small glandular patch in PV with thick-walled ventriculus; Ostrich has voluminous colon and small ceca; PV in emus and cassowaries large and diffusely glandular with small ventrilucus that lacks a koilin layer; Rhea has enormous paired ceca; Strong rectal-coprodeal sphincter results in separate defecation and urination
Describe what position eggs needs to be in for ostrich incubation
Vertical positioning during incubation is beneficial, turning of eggs is crucial
Compare and contrast rhea and kiwi reproduction
Rheas polygamous with 1 male competing for several females, communal nests, parental care exclusively by males; Kiwis pair for life, largest egg-to-body ratio (20% female BW).
Compare and contrast ostrich and cassowary environmental ideals
Ostriches prefer semi-arid and are adapted to hot and dry environments; Cassowaries prefer rain forests. All may swim; Ostrich males territorial during breeding season, harem groups recommended.
Compare and contrast diets for ostrich, emus, cassowaries, kiwi
Ostrich and rhea exclusively vegetarian; Emus eat a lot of insects; Cassowaries largely frugivores; Kiwis inverts in wild but meat and fruit/carbs in captivity
What anatomic feature of cassowaries make manual restraint dangerous
Daggerlike claw on limbs
Describe preventive measures/considerations for preventing capture myopathy in ratites
Vit E/Se, fluid therapy and NSAIDS; fast 12-24h before and restrain water for 4 hrs; Ideal dart perpendicular to proximal thigh; Underdosing may result in overexertion during excitatory phase. Excessive running during excitatory phase, refractory to sedative effect of opioids; Apnea common during anesthesia; Lateral recumbency for prolonged periods = peroneal nerve paralysis/padding essential
IM injection sites in Ratites
Epaxials, proximal leg muscles; Lack pectoral musculature
Spirochete assoc with necrotizing typhlitis in young rhea
Serpulina hyodysenteriae
Etiologic agents for GI infections common in chicks
E. coli, Salmonella, S. hyodysenteriae, avian influenza, coronavirus, rotavirus, Histomonas meleagridis, cryptosporidia, Macrorhabdus ornithogaster
Why are kiwi thought to be more susceptible to fungal infections?
Lower body temp vs other bird spp
Tropism of EEE virus for emus and rheas
Unique visceral tropism results in GI symptoms; DIFFERENT than other birds (neuro dz)
Nematodes found in deep proventricular glands and under koilin layer in ostriches
Trichostrongylid nematodes (Libyostrongylus)
Rheas - Nematode between the koilin layer and ventricular mucosa
Sicarius uncinipenis
Fatal cerebral nematodiasis Chandlerella quiscalis in ratites - what is its reservoir and transmission
Songbirds reservoir, transmitted by Culicoides mosquitoes
Identify 5 drug/food toxicities in ratites
Lindaine-containing antiparasitics, lincomycin, streptomycin, colistin abx,
Se oversupplementation in chicks;
parsley - photosensitivity;
avocado - epicardial edema and myocardial degeneration;\
oak leaves in cassowary - enteritis and nephritis
Causes of developmental angular limb deformities in ratites.
Imbalances in vit D3, Ca, P, Mn, Zn, Cu, Se, riboflavin deficiency, protein excess.
Cause of rickets in ratite chicks (folding fractures, ALD, pliable long bones)
Hypophosphatemia
Viral disease that causes cutaneous nodules in kiwis
Avian pox; eosinophilic intracytoplasmic inclusions
Avian influenza virus clinical signs in ostriches and emus
OIE reportable; Ostriches - anorexia, depression, poor growth, biliverdinuria; Emus - Respiratory signs.
Name 2 OIE reportable diseases affecting ratites
Avian influenza; Newcastle
Viral disease with high mortality in emus, causes hemorrhages throughout small intestines.
How does this disease differ in cassowaries?
Eastern equine encephalitis; NEURO dz in cassowaries (NOT GI LIKE EMUS)
Protozoal disease that causes significant disease in kiwi
Intestinal and extraintestinal coccidia - E. kiwi (intestinal); E. parairii (colorectal polyps); E. mantelli (feces); E. apteryxii (renal)
Ostrich louse
Struthiolipeurus struthionis
Which digit is the largest digit of the ostrich foot?
Is there a connection between the metatarsophalangial joint cavities of the 2 digits?
Are there communications between metatarsophalangeal joints 3 and 4?
Radiographic Anatomy of the Metatarsophalangeal Joint and Digits of the Ostrich (Struthio camelus)
Tehrani PR, Gilanpour H, Veshkini A.
J Avian Med Surg. 2017 Sep;31(3):198-205.
- D3 – 4 phalanges with 3 interphalangeal joints.
- First IP joint between P1, P2.
- Saddle-shaped, sagittal groove and ridge system helps limit medial and lateral movement.
- Second IP joint between P3, P2.
- Third IP joint between P4, P3.
- D4 (smaller, outer toe) – 5 phalanges, 4 IP joints.
- Arthrography of MTP joint:
- Dorsal, plantar pouches.
- Pouches around flexor tendons.
- No connection between MTP joint cavities of the 2 digits.
What was the most common issue affecting ratite neonates < 1wk in a French zoo? What type of rearing was this associated with?
What were the most common issues for chicks - ostriches, rheas, emus?
What were the most common issues for juveniles - Ostrich, rhea, emu?
Adults?
What conditions had an increased incidence with male sex?
RETROSPECTIVE STUDY OF MORTALITY IN CAPTIVE STRUTHIONIFORMES IN A FRENCH ZOO (1974–2015)
Benjamin Lamglait, D.M.V., M.Sc., Dipl. E.C.Z.M. (Z.H.M.)
Journal of Zoo and Wildlife Medicine 49(4): 967–976, 2018
SURVIVAL RATES: Emus 59% > rheas 31%> ostriches 29%
AGE: chicks 38% > neonate & juvenile 22% > adult 10% > subadult 8%
Emu chick death and adult death LESS prevalent. Common rhea juvenile death MORE prevalent
NEONATE (<1WK)
MOST COMMON = Yolk sac infection 97% - E. coli the most common bacterium identified (57% of tested)
2nd = musculoskeletal (emus and rheas = trauma or stress myopathy; ostriches = trauma, crushed by parents)
CHICKS (1WK – 1 MO)
Ostriches: DIGESTIVE (impaction > enteritis > FB and gastric perf > rectal prolapse) > sepsis
Rheas: DIGESTIVE (most bacterial enteritis, E. coli and Salmonella most common)
Salmonella serovars typhimurium and enteritidis suggestive of environmental contamination
Emus: musculoskeletal (most perosis, leg deformitiy 🡪 euth) > sepsis
JUVENILES (1-<6MO)
Ostriches: DIGESTIVE (gastric impaction > enteritis > FB and gastric perf > rectal prolapse) and musculoskeletal (mostly perosis)
Rheas: DIGESTIVE (Salmonella fibrinonecrotic enteritis)
Emus: musculoskeletal (mostly perosis)
Subadults (6MO – 3YR)
Ostriches and emus: trauma from conspecifics
Rheas: musculoskeletal (stress myopathy during introduction of new individual to enclosure)
Adults (>3YR)
Ostriches: trauma (mostly evisceration) > genitourinary deaths (mostly fatal peritonitis d/t salpingitis)
Emus: ocular issues (palpebral > conjunctival) *mostly males that were nesting
Rheas: Digestive and sepsis
SEX: males more likely to be affected by trauma (ostriches) and ocular disorders (emus) when adult age
REARING: 1/3 parent reared, 2/3 hand-reared
More yolk sac infection when hand reared
Conclusions: Majority of deaths in neonatal, chick, and juvenile age groups was digestive origin, yolk sac infection (especially hand reared chicks), and trauma.
A recent paper described a new technique for candling thick shelled eggs, like those of the emu and rhea.
What is this technique?
How did it affect the development of normal incubation?
ZB 2023 42(2) 296-307
A new candling procedure for thick and opaque eggs and its application to avian conservation
Key Points:
- Overall, these results indicate that the fenestration process has little effect on the normal incubation and hatching process.
- The results show this study was successful in achieving its aims of developing and testing a method to safely apply egg candling methods to thick and opaque eggs via candling, with embryonic development observed for viable eggs
- We have also demonstrated that this technique facilitates the application of existing blood draw methods, which was proven by the successful extraction of DNA from drawn blood samples from emu eggs
- The procedure developed allows sex determination and therefore the incubation to be discontinued for an undesired sex within an ethical timeframe
A recent paper described cervical esophagectomy and anastomosis in an ostrich.
What is the scientific name of the ostrich?
Why was an R&A needed?
How was this bird anesthetized for the procedure?
What are some common complications with esophageal surgeries?
JAMS 2023 36(4):421-425
Subtotal Cervical Esophagectomy and Anastomosis in an Ostrich (Struthio camelus domesticus)
Zafalon-Silva B, Costa PM, Schmidt VRQ, C Beck CA, Alievi MM
Key Points:
- Provided supportive care 48 hours pre-op to better stabilize the ostrich
– Supportive care included analgesia and antibiotic coverage
– An esophagostomy tube was placed distal to the fistula during hospitalization
– Maintained post-op for 15 days too
- Sedation: 4 mg/kg midazolam IM
– Induced with midazolam 0.1 mg/kg IV + ketamine10 mg/kg IV
– Maintained with 1.5-2.5% isoflurane during surgery
- Performed partial esophagectomy then resection with end-to-end anastomosis
– Complications in esophageal surgeries:
– Delay in closure, dehiscence, fistulae, and strictures
– A double-layer suture closure was used to achieve end-to-end anastomosis
- The fistula was likely caused by the accidental ingestion of a foreign body
– Ostriches in captivity are not selective in their feed intake
TLDR: Successful outcome for the treatment of a fistulated esophageal stricture in a captive ostrich
