nwra symposium march 5-9 2019 st. louis, mo · 2019-02-24 · #19007 – admitted 2015-08-11 keel...

Carolina Raptor Center

NWRA Symposium

March 5-9 2019

St. Louis, MO

Neurologic signs • Ataxia/paresis

• Lethargy

• Tremors/seizures

• Disorientation

• Torticollis

Systemic signs • Lethargy

• Emaciation

• Feather issues?



Trauma

Toxin

Infectious

Must consider the

cost/benefit/speed of

each diagnostic test

Do inexpensive/fast tests

first ( exam, lead, CBC,

rad)

Follow up with more

expensive/slower tests

(PCR, toxicology,

histopathology)

Vehicular trauma/window strikes

Physical exam • Usually not more obvious problems

like fractures.

• Look for blood in eyes, ears, mouth

• Bruises and wounds can be hidden underneath the feathers

• Fundic exam – anterior chamber is usually normal even with severe head trauma. Especially important with referrals

from home rehabbers.


Raptor Ophthalmology Powerpoint - Mark Mitchell,

Univ of Illinois CVM

Necropsy • Intracranial hemorrhage • Hemorrhagic lungs • Free blood in coelomic

cavity


Did the trauma happen

secondary to another cause?

19873 - RSHA

Sometimes not visible

thru the skin.

Lead • Affects many tissue but particularly the brain • From metal fragments ingested in carcasses

More likely during deer hunting season

Absorbed vis GI tract

• Acute vs chronic form • Scavengers such as eagles and vultures. But what

about osprey swallowing (lead sinkers)? Mercury bio-accumulation in fish (flat-head

catfish) so osprey and bald eagles are at risk.


Blood lead level – ante mortem • In house LeadCare unit • Results in 3 minutes • > 20 ug/dl for most species

Mercury requires outside lab.

Radiographs are often negative (TRC 10%??)



BAEA 16152 2012-06-08

Lead toxicity not typically from gunshot fragments embedded in tissue

In 1992 in the US, 500,000 tons of 600

different types of chemicals were used!


Pesticide intoxication • Species that hunt grubs/insects in yards like red-

shouldered hawks or juvenile red-tailed hawks.

• Multiple cases from same street/block

• Many bio-accumulate in environment and can be

absorbed via inhalation of dust.


Pesticide Screen on liver, stomach contents, brain – post mortem • Avitrol (4-aminopyridine) – Affects K+ channels

and induces seizures/convulsions • Organophosphates (Malathion, Parathion,

Dichlorvos) are irreversible acetylcholinesterase (ACHE) inhibitors Whole blood acetylcholinesterase levels

• Carbamates reversibly inhibit ACHE • Metaldehyde is used in snail bait. • Organochlorine pesticides are DDT-like. Work on

Na+ channels in PNS (Aldrin/Dieldrin, Chlordane for termite control, Heptachlor)


Flavivirus transmitted by mosquitoes

First seen in Western Hemisphere in 1999

Most avian species affected but can also be non-clinical carriers • Corvids, great-horned owls, Cooper’s

hawks • Several recent cases in Buteo spp. • Humans also affected


2006

Birds can become viremic and serve as a reservoir host

Non-avian species do not typically develop viremia and are thus “dead-end” hosts.


www.ci.greenfield.ca.us/Public_Health_Info.htm

Neurologic signs • Ataxia • Lethargy • Tremors/seizures

• Disorientation • Torticollis

Vision loss from retinal damage

Abnormal feather growth with “pinched off” shaft

Sudden death – birds “falling from the sky”


Species – corvid, GHOW, COHA Clinical signs – neuro +/- feather anomalies Seasonality – when mosquitoes are present. PCR

• Blood vs choanal/chloacal swab –more likely to get positive test result with blood?

Serology – a single sample is not useful. Need to observe trends

Feather shafts • PCR – low detection rates?

Histopathology of brain tissue – post mortem • Immunohistochemical stains

Note: PCR/serology can be NEG depending on timing and phase of the infection. May

be viremic early and shedding later. Note: a POS result does not necessarily imply disease.



http://www.annals.org/cgi/content /full/140/7/545

PCR may be negative

What about shedding detectable via swab?

Not practical

Paramyxovirus PMV-1/Newcastle’s disease • Primarily a poultry disease but raptors infected after

consuming affected birds

• Few published case reports (mostly pigeons and poultry)

• Most reports from falcons in the Middle East

Avian Influenza (LPAI vs HPAI)

• Almost any clinical signs including lethargy and neurologic signs

• Mostly poultry but many species can been infected.

• Several raptor species affected in 2015 outbreak


Avian vacuolar myelinopathy (AVM) • Affects mostly water birds (Coots) or those

that feed on water birds (Bald eagles) • Mostly in southeastern states • Causative agent is a cyanobacteria that grows

on aquatic plants (Hydrilla spp.) which are ingested by waterfowl. Bald eagles and American coots.


http://www.nwhc.usgs.gov/publications/fact_sheets/pdfs/avm091002.pdf

PCR • Avian & Exotic Lab

• Veterinary Molecular Diagnostics Serology – HI, ELISA For AI, check with USDA/APHIS

• www.usda.gov/documents/usda-avian-influenza-diagnostics-testing-factsheet.pdf

• Rapid screening test

• Confirmatory tests (VI, etc).

• Many different subtypes with variable pathogenicity (LPAI vs HPAI) What is LP in one species may be HP in another.

• Need to have an emergency response plan ready to go.


Adult red-shouldered hawk (Buteo lineatus) #19805 – Admitted 2016-07-03 Recent history of vehicular trauma Lethargic. Tremors -> seizures Midazolam worked well to calm bird and

stop seizures Exam – deep wound at base of skull behind

right ear. Euthanized Cost: $0

Adult bald eagle (Haliaeetus

leucocephalus)

#18525 – Admitted 2015-01-13

Keel score 3/5

Moderate to severe flaccid paralysis of

both legs

Radiograph negative for metallic FBs.

Lead level checked using LeadCare unit.

Cost: $10

May need to dilute samples to get reading.

Initial level was > 180 ug/dl!

Chelation with CaEDTA and DMSA worked well.

Be on the lookout for rebound.

Hatch-year red-shouldered hawk (Buteo lineatus) #19007 – Admitted 2015-08-11 Keel score 2/5 Severe neuro signs (ataxia, tremors) No signs of severe/acute trauma (i.e. - blood in

mouth, eyes) Treatment

• Supportive care with fluids, meloxicam (1 mg/kg) and midazolam

• Suspected toxin due to habit of insect hunting in yards

Condition deteriorated and bird was euthanized within 24 hours

Necropsy: • WNL – rarely anything visible on gross necropsy

• Brain WNL – usually WNL with WNV

Toxin highly suspected so stomach contents and liver submitted for toxicology. • Toxicology negative

Brain submitted for histopathology and IHC

Total cost: $220

Perivascular lymphoplasmacytic encephalitis. Suspected WNV or EEE.

IHC POS for WNV

Hatch-year red-tailed hawk (Buteo jamaicensis) #19779 – Admitted 2016-06-26 Keel score 1/5 Subtle neuro signs developed over 3 weeks. Dropped all tail feathers with 8 days Began meloxicam at 1 mg/kg while waiting for

bloodwork CBC – 39,000 with 4700 monocytes (Asper?). TS = 5.2

g/dl Has been on antifungals since admission WNV PCR POS Began dropping all main flight feathers. Otherwise doing well, gaining weight and molting. Cost: $50

Hatch-year red-shouldered hawk (Buteo lineatus)

#19460 – Admitted 2016-03-23 Extremely neurologic with violent

vocalizations during transport. Dead on arrival.

Severe extensor rigidity within minutes of death.

Exam did not reveal any signs of trauma. Gross necropsy and histopathology WNL

Toxicology (liver and stomach contents): • DDE 0.7 ppm Metabolite of DDT.

Consistent with chronic background exposure.

Banned in 1972

• Heptachlor 4.1 ppm Metabolite of Chlordane.

Outlawed in 1988. Was used for treating termites.

Bio-accumulates in fatty tissue.

“One of the most potent carcinogens ever tested in animal models”

5 ppm in brain considered lethal in birds

Cost: $180


Trauma

?

YES

NO

Lead?

NO

YES

Supportive

Care

(mannitol)

Begin

chelation

Begin

meloxicam

(1 mg/kg

BID)

WNV

PMV-1, AI

PCR

POS NEG

Supportive

care

Euthanasia

Improvement

?

NO

Histopatholog

y

Toxicology

Response to

Atropine?

YES

NO

Histopathology - NC State Vet Diagnostic Lab (NCVDL) • $40 + 45 for IHC

PCR/serology • Avian and Exotic Lab - $35

Lead • In-house with Lead Care unit - $9

Toxicology • Penn Animal Diagnostic Lab System (PADLS) – New

Bolton Center – Pesticide screen - $75

• Mercury $28

• Lead $22 Don’t forget shipping fees


Cost for complete workup: $204

13 RSHA in last 12 months

All presented with neuro signs/seizures/tremors

All dead with 24 hours

Cause of death • WNV – 1

• Not worked up – 3

• Pesticide – 6

• Pending – 2

• Other - 1



19460 3/23/2016 RSHA Chlordane - 4.1 ppm in liver (5 ppm lethal in brain)

19577 5/8/2016 RSHA Chlordane - 0.88 ppm in liver, 4.3 ppm in stomach

DDE - 0.6 ppm in stomach (chronic exposure)

PCB - 1.8 ppm in stomach, ND in liver

19581 5/9/2016 RSHA Chlordane - 0.6 ppm in liver, 3.7 ppm in stomach

DDE - 0.8 ppm in stomach (chronic exposure)

PCB - 2.3 ppm in stomach, ND in liver

19753 6/20/2016 RSHA Dieldrin - 59.2 ppm in brain ( 4 ppm lethal in brain)

Heptachlor/oxychlordane - 6.2 ppm in brain

DDE - 1.7 ppm in brain PCB - 9.5 ppm in brain

19677 5/29/2016 RSHA Dieldrin - 705 ppm in liver Heptachlor/oxychlordane - 17.1 ppm in liver

Alpha chlordane - 13.3 ppm in liver

19676 5/29/2016 RSHA Dieldrin - 101 ppm in liver Heptachlor/oxychlordane - 6.3 ppm in liver

Alpha chlordane - 3.3 ppm in liver

Toxicology on

brain is best.

No chance for

recovery.

COLLABORATION?

Dave Scott


704-875-6521 x105

dscott@carolinaraptorce

nter.org


nwra symposium march 5-9 2019 st. louis, mo · 2019-02-24 · #19007 – admitted 2015-08-11 keel...

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