Charadriiformes Flashcards
Differences between applanation tonometry and rebound tonometry?
Ways to measure tear production in birds?
Ways to measure corneal thickness in birds?
In which sex was cornea thicker?
Ways to determine corneal sensitivity?
What was observed in corneal sensitivity with age?
Westmoreland, L. S., Hadfield, C. A., Clayton, L. A., Atkins, R. M., Hyman, J. A., & Rossi, B. H. (2020). Ocular Examinations and Investigation of Intraocular Pressure, Tear Production, Central Corneal Thickness, and Corneal Touch Threshold in a Captive Flock of Atlantic Puffins (Fratercula arctica). Journal of Avian Medicine and Surgery, 34(2), 123-131.
Key Points:
- Applanation tonometry requires 3-4 mm corneal diameter and application of topical anesthetic.
- Rebound tonometry can be used with smaller corneal diameters and without topical anesthetics, used in this study.
- IOP can vary by age, head and body position, and species.
- Tear production freq assessed by STT or phenol red thread test.
o STT measures residual, basal, and reflexive tearing.
o Phenol red thread test measures residual and basal tearing.
▪ Faster than STT, affordable, used for animals with small palpebral fissures.
▪ Avian tear production has been assoc with age and species.
● One study in Humboldt penguins found that birds housed in SW had lower tear production vs FW.
- Corneal thickness can be measured by US pachymetry, confocal microscopy, optical coherence tomography.
- Corneal sensitivity determined with esthesiometer, which measures ocular tactile sensitivity.
- Results:
o No corneal abnormalities. Some cataracts.
▪ Cataracts in these birds etiology unknown but can be assoc with trauma, inflammation, infection, nutritional deficiencies, toxins, excessive UV light, genetics, and age.
o NSD between OS and OD IOP, corneal thickness, or corneal sensitivity.
o Significant difference between OD and OS tear production with OD >.
▪ Study in vultures showed significantly higher tear production OS vs OD.
o NSD between sex and IOP, tear production, and corneal sensitivity.
o Significant difference between sex and corneal thickness, with males > females.
▪ Male puffins generally larger, but no significant correlation between weight and corneal thickness.
o No associations between age and IOP, tear production, or corneal thickness.
▪ Other avian studies have found correlations between IOP and age.
● Af penguins – increasing age, decreasing IOP.
● Some raptors lower IOP in juveniles vs adults.
▪ Corneal thickness in puffins similar to chickens and less than Af penguins.
▪ Male puffins significantly thicker corneas vs females, similar findings in striped owls.
o Moderate correlation between age and corneal sensitivity, with older birds showing decreased corneal sensitivity.
▪ Puffins appear to have less sensitive corneas vs birds of prey, more sensitive vs Amazon parrots.
o Tear production in these puffins was lower vs a study with Amazons.
Takeaways: Tear production OD > OS. Male corneal thickness > females. Trend showed older birds had decreased corneal sensitivity. Paper compares and contrasts with many other avian spp.
Leading cause of pathology in all groups except neonates for Tufted Puffins in a zoo?
Seasonality associated with mortalities?
Second most common cause of death? Seasonality?
Major cause of death in neonates and nestlings? Which bacteria?
Heinz, J., Anderson, K., & Wolf, K. (2022). RETROSPECTIVE MORTALITY REVIEW OF TUFTED PUFFINS (FRATERCULA CIRRHATA) AT A SINGLE INSTITUTION (1982–2017). Journal of Zoo and Wildlife Medicine, 53(1), 11-18.
- Most mortality in wild puffins and other alcids related to environmental or human activities.
o Neonatal mortality linked to scarcity of food resources and predation by gulls. - In captive populations – Asper, Plasmodium common.
- Point Defiance Zoo and Aquarium in Pac NW, year-round outdoor management of puffin flock.
o Neonates 7d or less, nestlings 8-60 d, juveniles 2-12 mon, adults 1 yr+. - High rate of neonatal death, 30% all mortalities.
- Mortality highest in the first year of life.
- No conclusions drawn on the basis of sex (most unrecorded, young birds).
- Most deaths between July and October. Also high percentage of neonatal and nestling deaths in July and August.
- Aspergillosis leading cause of pathology, all age groups except neonates.
o Asper most prevalent in adults, most common in individuals that died in July through Oct.
o Not correlated with the density of the population on exhibit.
o Timeline of July to October correlates with the breeding, nesting, and parental provision of the puffins at this institution. - Hemoparasitism second most common in all individuals, only found in adults.
o All cases of malaria occurred between July and Sept, with majority in August.
o Almost all cases reported as acute death without clinical signs, good BCS. - Predation occurred in almost all age classes. Most cases during single mink predation event.
- Asphyxiation caused by nematodiasis in three individuals < 3 mos age.
o Tracheal hyperplasia, nematode obstruction or inflammatory pneumonia.
o All speculated to be Syngamus or Cythostoma spp on histopathology.
o Eggs shed from feces into soil, develop into larvae within earthworm and other invert hosts and are ingested by birds. - Avian pox in three individuals. First study documenting probable toxoplasmosis (t. gondii infection).
- Omphalitis or yolk sac dz and sepsis major cause of death in neonates and nestlings.
o Bacteria most commonly E. Coli.
o Few with retained yolk sacs, significant cause of mortality in waterfowl and penguins and is fatal without surgical correction.
Three suborders of Charadriiformes?
o Three suborders:
Alcae – Auks.
Charadrii – Avocets, ibisbills, jacanas, oystercatchers, plovers, sandpipers, snipes, stilts, thick-knees, others.
• Live, breed, forage along water’s edge.
• Birds of the open, except woodcock, which inhabit edges of wet wooded areas, and solitary and spotted sandpipers may be found at heavily forested ponds and lakes in mountains or at sea level.
Lari – Gulls, terns, skimmers, skuas.
Alcae, Lari more aquatic.
Migrate long distances.
Most are gregarious, mixed flocks common.
Clinical signs of hyponatremia in alcids?
- MMWS – Marine spp such as alcids housed full-time on FW require salt supplementation.
o Hyponatremic behavior – inappetence, lethargy, obtundation that worsens the longer the bird remains in FW.
o Oversupplementation may lead to hypernatremia, dehydration, and seizures.
Don’t need to supplement if dry housed or housed in salt water.
Ways to prevent injuries when housing wild alcids in human care?
o Application of preventive carpal and metacarpal wraps aka bumper pads advisable for agitated birds.
o Protective foot wraps when out of water helps reduce development of foot lesions in alcids. For boots, do not apply vetrap proximal to the hock as this causes foot edema.
o Keel cushions to reduce development of keel lesions, but porr application or inappropriate design may cause harm.
o Net-bottoms, soft-sided caging prevents injuries.
o Housing on towels often leads to loss of waterproofing due to plumage contamination and damage by droppings, fleece better but still problematic.
o Clear plastic solid-walled pet containers are adequate for short-term care of shorebirds but cover clear walls to give privacy while allowing light in at the top.
o Debilitated individuals often hypothermic, cloacal temps can be helpful. Supplemental heat should be provided if < 103F.
Supplemental heat via hot pads on walls or under containers.
Incubators may result in severe hyperthermia.
• Not advisable for overnight without monitoring except in young chicks.
Primary venous access in aquatic birds?
- MMWS – Medial metatarsal vein is the primary venous access in aquatic birds.
o Avoid basilica and jugular in most spp, hemorrhage can adversely affect waterproofing following hematoma.
A recent study investigated the presence of phthalate esthers in the uropygial glands of seabirds along the coast of brazil.
What are phthalates?
Which phthalate was associated with the presence of plastic items in the upper GI tract of seabirds?
JZWM 2023 53(4):733-743
PHTHALATE ESTERS (PLASTICIZERS) IN THE UROPYGIAL GLAND AND THEIR RELATIONSHIP TO PLASTICS INGESTION IN SEABIRDS ALONG THE COAST OF ESPÍRITO SANTO, EASTERN BRAZIL
Vanstreels RET, Piccinin INL, Maraschin M, et al
Key Points:
- Estimated that 90% of all seabirds will ingest plastics at some point
– In addition to the direct effects that ingested plastics (e.g., obstruction & perforation), they can also release chemicals leading to systemic and chronic toxic effects
– Phthalates = group of chemicals widely used as plasticizers (additives to increase the flexibility, workability, and longevity of plastic products)
– Diethylhexyl phthalate (DEHP) is the most widely employed plasticizer in PVC
– Dibuthyl phthalate (DBP) and dimethyl phthalate (DMP) are widely used
– Once absorbed, phthalates are metabolized via hydrolysis and not biomagnified
– Their detection is a reliable indication of direct exposure to plastics
- Suggested the concentration of these lipophilic compounds in the uropygial or preen gland oil of seabirds could serve as a proxy to the presence of plastics in their GI tract
TLDR: DMP but NOT DBP and DEHP concentration in the uropygial gland was positively associated with the presence, number, and mass of plastic items in the upper digestive tract of tropical seabirds
A recent study investigated blood lactate as a prognostic indicator for birds with brevetoxicosis.
What is teh etiologic agent that produces brevetoxins?
How are animals exposed?
What are the typical clinical signs in affected birds?
Was lactate a useful prognostic indicator?
Troiano AT, Peel M, Cameron AI, Bast R, Flewelling L, Abbott J, Barron H.
INVESTIGATING BLOOD LACTATE CONCENTRATION AS A PROGNOSTIC INDICATOR FOR BIRDS PRESENTING WITH BREVETOXICOSIS: 2020-2021.
JZWM 2023 54(1): 23-31
Key Points
- Harmful algal blooms (HABs) are increasing in frequency. SW FL experiences annual HAB events or red tides, caused by Karenia brevis - produces potent neurotoxins called brevetoxins (PbTxs).
– Exposure in animals occurs via direct contact with water, ingestion or inhalation.
– Affect excitatory tissues in the nervous system as the toxins readily cross membranes
- Birds: ataxia, head tremors, muscle fasciculations, paresis, mentation changes, bradycardia, GI ileus, coma, and death.
- Lactate is a product of anaerobic glycolytic metabolism. No literature on lactate as a prognostic indicator for disease in birds.
- On average, blood lactate concentrations on admission were higher in birds that died or were euthanized as compared to those that were released, but the differences were not statistically significant
Take home message
- This study did not find blood lactate concentration to be a useful prognostic indicator in aquatic birds presenting with brevetoxicosis, nor did it appear to be useful as a serial biomarker to monitor trends to help guide therapy.
