Gruiformes Flashcards
Cranes family
Gruidae
Unique anatomy cranes
Many spp have bright-red thick skin over head and neck, perforate nares.
Long, convoluted trachea within keel - adaptation for producing loud calls (tracheal characteristic shared with swans Cygninae); African crowned cranes do not have this adaptation.
Three viral diseases identified as potential problems in captive cranes maintained in North America
EEE - Eastern Equine Encephalitis
WNV - West Nile Virus
Gruid Herpesvirus 1 - Inclusion Body Dz of Cranes
Causative agent of inclusion body disease of cranes
Gruid herpevirus 1
Mosquito vector for Eastern Equine Encephalitis virus
Tropism in whooping cranes vs mississippi sandhill cranes?
EEE – Arbovirus (alphavirus, togaviridae).
• Transmitted by vector mosquito – Culisetta melanura.
o Infection in variety of indigenous birds in the eastern US.
o Some die without signs, other show lethargy, ataxia, paresis.
o May invade the CNS and cause depression, uncoordination, paralysis, abnormal head and neck posture.
o Whooping cranes exhibit mainly the viscerotropic form with minimal neural involvement (coelomic gross lesions).
o Mississippi sandhill cranes have been diagnosed with the neurotropic form.
Viral dz causing significant mortality in MI and FL sandhill crane chicks, adults appear resistant. Transmitted by Culex spp.
WNV – Arbovirus (Flaviviridae).
• Transmitted by Culex spp.
• Significant mortality in Mississippi and FL sandhill crane chicks.
• Adults appear relatively resistant to the virus.
• CS – Lethargy, weakness, ataxia, weight loss, inappetence.
• Mortalities rate, even without implementation of routine WNV vaccine in captivity.
• WNV mortalities also in Aramidae and Rallidae.
Why is housing cranes in an exhibit with or near chickens or turkeys of concern?
IBD – Avibirnavirus, birnaviridae.
• Acute onset, targets lymphoid tissue of the bursa and results in immunosuppression.
• Highly contagious among young chickens.
• Endemic in FL.
• Housing cranes in an exhibit with or near chickens or turkeys should be avoided to reduce exposure to IBD.
Common coccidian parasites of captive cranes, causes mortality/diarrhea.
Eimeria gruis
Eimeria reichenowi
Especially pathogenic - Infection may become systemic and widespread extraintestinal dissemination aka disseminated visceral coccidiosis occurs.
o Lesions – Granulomatous pneumonia and tracheitis, hepatitis, myocarditis, hepatitis, splenitis, enteritis.
o Eimeria in the substrate in captivity can increase substantially because of the direct LC.
Appropriate measures including parasite surveillance, pen rotation, separation of cranes by age class recommendended.
Anticoccidial monensin has been effective as prophylaxis.
• Can mill into feed and give continuously or for a few months before and after the chick rearing season.
What has been known to reduce the incidence of leg deformities in captive crane chicks?
o Exercise is known to reduce the incidence of leg deformities in captive crane chicks.
Captive cranes can be walked, placed in a pool several times a day.
Encourage exercise by placing food and water on opposite ends of enclosures.
Control feedings to keep weight gain equal to or less than 10% body weight per day.
o Natural incubation, hatching, and rearing (parent or foster) of chicks also reduces the occurrence of leg and toe abnormalities. Diets with low methionine or sulfur-containing AA appear to be effective in reducing chick growth rates.
What toxicosis has been associated with contaminated peanuts in sandhill cranes in TX and NM?
Fusarium
- Inability to hold the head straight while flying or standing.
- Multiple muscle hemorrhages, submandibular edema.
- Tilling peanut fields in the fall reduced this cause of crane mortality.
What lesion has been associated with hyperparathyroidism in whooping cranes?
Parkinson, L., & Hartup, B. K. (2019). Manifestations of hyperparathyroidism in juvenile whooping cranes (grus americana). Journal of Zoo and Wildlife Medicine, 50(3), 731-734.
Mild hyperparathyroidism in precocial whooping cranes may result when dietary constraints and/or outdoor access is compromised and manifest as rib fractures in the absence of traumatic injury.
• Dietary management difference identified- in 2017, juvenile cranes were fed a different diet for the first two weeks (Chick Starter/Grower Poultry Feed), then transitioned to a Crane Starter Diet- possible improper concentration of vitamin D3 in this feed, Ca: P ratio in the diet was 18% lower than the mean from previous diets fed
• Higher Ca:P ratios have been recommended for fast-growing avian species, but an ideal ratio has not been determined
• Hatching was earlier in 2017 than 2010 and coincided with rainy/cold weather- overall exposed to lower UVB radiation in their first 30 days (could have compounded the lower Ca:P ratio)
• Support for the theory that the fractured ribs are secondary to husbandry discrepancies leading to hypovitaminosis D and nutritional secondary hyperparathyroidism (metabolic bone disease)
Highest causes of mortality following reintroduction of whooping cranes in the eastern US?
Yaw, T. J., Miller, K. J., Lankton, J. S., & Hartup, B. K. (2020). Postmortem Evaluation of Reintroduced Migratory Whooping Cranes (Grus americana) in Eastern North America. Journal of wildlife diseases, 56(3), 673-678.
- Largest proportion of causes of death was predation. Also power line and HBC, gunshot.
- 6 deaths attributed to bacterial or fungal infections.
- PCRs for WNV negative, serology complicated by prior vaccination of released cranes.
- Two samples tested for lead were high, both cranes died from power line collisions.
- Brain cholinesterase measurements not indicative of exposure or intoxication.
Takeaway: Predation most common cause of mortality as well as other trauma in reintroduced whooping cranes.
Unique anatomy of the trachea (general birds)
Treatment options for tracheal strictures in birds
Yaw, T. J., Doss, G. A., Colopy, S. A., Kincaid, A. L., & Hartup, B. K. (2020). Emergency tracheotomy and subsequent tracheal resection and anastomosis in a blue crane (Anthropoides paradiseus). Journal of the American Veterinary Medical Association, 256(11), 1262-1267.
- Avian tracheal anatomy
- Closely spaced complete tracheal rings
- Luminal diameter tapers caudally in certain species such as cranes
- Recurrent laryngeal nerves do not innervate larynx, innervates portions of esophagus and crop as well as tracheal and syringeal muscles
- Cranes - elongated cervical trachea, extensive coiling of trachea within sternum
- Treatment options
- Balloon catheter dilation - typically provide only temporary improvement, may cause iatrogenic damage to tracheal rings
- Endoscopic laser ablation - typically provide only temporary improvement
- Stent placement – used with caution in birds because of complications associated with more rigid tracheal anatomy, considered when refractory to medical treatment or tracheal lesions too large for TRA
- Tracheal resection and anastomosis (TRA)
- Most common complications
- Formation of new stricture at surgical site – most common
- Place tension-relieving sutures
- Use minimally reactive suture material
- Trauma to recurrent laryngeal nerves 🡪 vocal changes, does not cause laryngeal paralysis
Pharmacokinetics of piroxicam in cranes - type of kinetics and any adverse effects?
Keiper, N. L., Cox, S. K., Doss, G. A., Elsmo, B., Franzen-Klein, D., & Hartup, B. K. (2017). Pharmacokinetics of piroxicam in cranes (family Gruidae). Journal of Zoo and Wildlife Medicine, 48(3), 886-890.
What are some threats to the wild crane population?
Pollock, C. (2018). Conservation Medicine: Cranes of the World. Journal of avian medicine and surgery, 32(2), 138-143.
Cranes face many challenges in captivity and in the wild. Direct threats include collisions with overhead power lines; poisoning from agricultural, municipal, and industrial runoff; infectious diseases; hunting; disturbances of nesting sites; illegal trade; as well as theft of eggs and chicks. One of the major goals of the ICF is to better understand these challenges.6–8 The conservation medicine program is embedded in a variety of Foundation efforts that can benefit from the veterinary perspective and/or applied skills.8
The captive flock at ICF is maintained as a “species bank.” Many scientific contributions and “firsts” have been achieved with this flock, including the first captive breeding of critically endangered Siberian cranes (Grus leucogeranus). The Foundation has developed state-of-the-art techniques for husbandry and health care, artificial insemination, egg incubation and chick rearing, health care, and genetic management.6,11 Active reintroduction projects strive to place as many cranes in the wild as possible and veterinarians have had a vital role in this effort.12
• Fecal steroid hormones more unpredictable in parent raised birds than costume raised birds
• Aspergillosis is a common problem in raising cranes in managed settings
• Whooping cranes less hardy than sandhill cranes
