Columbiformes

Question 1

What is the difference between a pigeon and a dove?

Answer 1

Pigeons are generally larger, doves smaller.

Both are columbiformes, terms can be interchangable.

Question 2

What is the scientific name of the domestic pigeon or rock dove?

Answer 2

Columba livia

Question 3

What is the scientific name of the Victoria crowned pigeon?

Answer 3

Goura victoria

Question 4

What is the scientific name of the Mourning Dove?

Answer 4

Zenaida macroura

Question 5

Describe columbiform anatomy.

What foot pattern do they have?

Any unique anatomic or physiologic traits?

Do they have a ceca or a gallbladder?

Answer 5

Anisodactyl feet

No cervical apterium

Uropygial gland is rudimentary or absent.

They have a prominent crop & produce crop milk

The ceca is rudimentary, gallbladder is absent in many species

There is a cervical vascular plexus for thermoregulation and mate signaling.

Question 6

Crop milk production in columbiformes is stimualted by what hormone?

Answer 6

Prolactin

Terio

Question 7

Describe the ideal husbandry of columbiforme species.

Answer 7

Housing (F8)

• Tropical fruit doves may have a lower basal metabolic rate compared to other birds and are more intolerant of temperature extremes
• Protected lofts are common
• Variety of natural perching
• Roost areas, water features

Question 8

What is the extinct group of columbiformes?

Answer 8

• Raphidae - dodos - extinct

Terio

Question 9

Describe the typical diet of columbiform birds.

Answer 9

Feeding (F8)

• Frugivorous and granivorous species
• Commercially available pellet combined with seeds, legumes, vegetables, fruits, insects
• For frugivorous doves a higher proportion of fruits and berries should be offered
• Species prone to iron overload should be rationed less iron and vitamin C and supplemented with dietary tannins

Question 10

Describe a typical preventative medicine protocol for columbiform birds.

Answer 10

Preventive medicine (F8)

• Screening for chalmydophila and trichomonas during acquisition
• Appropriate quarantine
• Routine fecals
• Although rarely used, commercial vaccines are available for poxvirus, PMV-1, and salmonella

Question 11

A variety of injectable anesthetics have been used in columbiformes.

Describe the effects of midazolam, alpha 2’s, and propofol on pigeons & doves.

Answer 11

· Midazolam

§ Pigeons: midazolam 5mg/kg IN - minimal cardiopulmonary effects but inadequate restraint. In combo with dexmedetomidine 0.08mg/kg IN it produced effect immobilization in 3 minutes, 20 to 30 minutes after administration. Atipamezole reversed the mild cardiopulmonary effects of the combo. Signs of excitation reported.

· Alpha-adrenergic agonist

§ In pigeons: xylazine 16mg/kg IM or detomidine 1.4mg/kg IM produced only minor to moderate sedation.

§ Pigeons and amazon parrots: medetomidine 0.08-0.2mg/kg IM produced inadequate sedation for handling as well as moderate bradypnea and bradycardia.

§ Similar to benzodiazepines: can be used IN - but immobilization appears poor. Xylazine 30mg/kg pigeons did not produce dorsal recumbency and

· Propofol

· IV for induction, IO reported in pigeons; not analgesic

· Evaluated in different species: pigeons, wild turkeys, chickens, waterfowl and amazon parrots.

· 14mg/kg IV smooth, rapid induction and good muscle relaxation – duration 2-7 minutes with marked respiratory depression.

Ketamine has also been used

West

Question 12

What is the predominant opioid receptor of the pigeon forebrain?

What is the predominant GABA receptor in the pigeon pallium?

Answer 12

Kappa (76%) - West

GABA A receptors (sedation, muscle relaxation, anxiety) - West

Question 13

Does buprenorphine provide analgesia in pigeons?

Answer 13

Yes,

o Buprenorphine

§ Pigeons: 0.25 and 0.5 mg/kg IM

§ increased electrical withdrawal threshold for 2 and 5 hours, respectively

West

Question 14

What doses of meloxicam provide adequate analgesia in Columbiformes?

Answer 14

· Meloxicam

· Pigeons, 2 mg/kg PO q12 provided quantifiable analgesia following experimental femoral osteotomy, but 0.5 mg/kg was not effective

· Studies looking at adverse effects used in domestic pigeons (2 mg/kg IM) w/o adverse effects

West

Question 15

What are the clinical signs associated with pigeon adenovirus?

What lesions are observed on necropsy and histopathology?

Answer 15

• Pigeon adenovirus -
  
  • Classic adenovirus - pigeons <1y - diarrhea, vomiting, weight loss
  • Villous atrophy - BASOPHILIC INTRANUCLEAR INCLUSIONS in enterocytes; necrotizing hepatitis in pigeons of all ages
  • vomiting, watery yellow diarrhea, death in 1-2d

Terio

Question 16

What are the clinical signs of pigeon circovirus?

How is it transmitted?

Describe its pathogenicity?

What lesions are present on necropsy and histopathology?

Answer 16

Immunosuppression and secondary infections; feather loss or feather dystrophy are rare.

• Pigeon circovirus - nonenveloped ssDNA virus
  
  • pigeons worldwide <4m old - adults carriers - leads to immunosuppression secondary to bursal lymphocyte apoptosis
  • horizontal transmission is primary
  • up to 100% mortality
  • bursa of Fabricius large or small +/- exudate at bursa + splenomegaly + lymphoid depletion
  • INTRANUCLEAR and INTRACYTOPLASMIC BASOPHILIC botryoid inclusions

Fowler 8, Terio

Question 17

What are the clinical signs of pigeon herpesvirus 1 in columbiformes?

What age class is most commonly affected?

Are any other species affected? How is it transmitted?

What lesions are present on histopathology?

Answer 17

• Pigeon herpesvirus 1 -
  
  • lethargy, depression, lacrimation, nasal discharge, diarrhea, neuro, death - squabs may have maternal Ab protection and become carriers
  • usually young birds (squabs) -
  • also causes disease in raptors + owls (from eating pigeons)
  • spread via environment/food/water/crop milk
  • EOSINOPHILIC INTRANUCLEAR inclusions in hepatocytes/spleen/pancreas

Terio

Question 18

A wild powerful owl in Australia was found deceased with necrosis in the spleen, liver, pancreas, adrenal gland, intestinal mucosa with eosinophilic intranuclear inclusion bodies observed.

What is a top differnetial for these lesions?

What location for swabbing is best to detect this disease?

Answer 18

Columbid herpesvirus 1 (CoHV-1)

• Columbid herpesvirus 1
  
  • Widespread in North America, Europe, [and Australian] pigeons
  • This study found 70-100% prevalence in Australian flocks
  • Causes multisystemic disease and mortality
  • Infects raptors when they eat infected prey – don’t feed pigeons to raptors
  • Significant cause of mortality in periurban Canadian Great Horned Owls
• Powerful Owl
  
  • Necrosis in spleen, liver, pancreas, adrenal gland, intestinal mucosa
  • Eosinophilic intranuclear inclusion bodies in hepatocytes, pancreatic acinar cells, and adrenal cortical cells
• Oral swabs preferred over cloacal swabs for detection

Phalen, D. N., Alvarado, C., Grillo, V., Mason, P., Dobson, E., & Holz, P. (2017). Prevalence of Columbid herpesvirus infection in feral pigeons from New South Wales and Victoria, Australia, with spillover into a wild powerful owl (Ninox struena). Journal of wildlife diseases, 53(3), 543-551.

Question 19

What poxvirus affects columbiformes?

What lesions are present on gross and histopathology?

Answer 19

• Avian poxvirus -
  
  • Avipoxviruses - fowlpox, pigeonpox, quailpox, turkeypox
  • morbidity 100%, mortality low
  • cutaneous form = tan proliferative nodules on unfeathered areas of head - wet/diphtheritic form = nodules in oropharynx, conjunctiva, upper respiratory tract -
  • EOSINOPHILIC INTRACYTOPLASMIC inclusions (Bollinger bodies) - transmissino via mosquitos, incubation 4-10d

Terio

Question 20

Is West Nile Virus a significant pathogen for columbiformes or galliformes?

Answer 20

NO - Terio

Question 21

Pigeons are common carriers of what two zoonotic diseases?

Answer 21

Salmonella and Chlamydia

Fowler 8

Question 22

What is the most common fungal disease of columbiformes?

What clinical signs?

How is this disease transmitted?

Answer 22

• Candidiasis = crop mycosis = thrush -
  
  • Candida albicans (yeast) - most common mycotic disease in pigeons
  • CS anorexia, diarrhea, depression, regurgitation, crop distention, morbidity/mortality - Turkish towel appearance = proliferative white plaques
  • concurrent circovirus infections in pigeons make them very susceptible
  • transmitted via crop milk, contaminated feed/water, environment

Terio

Question 23

What flagellated protozoal parasite causes oral lesions in pigeons?

How is it transmitted? Are any other species affected?

Are any species columbiform species particulary susceptible?

Answer 23

• Trichomoniasis
  
  • Trichomonas gallinae - flagellated protozoa
  • canker in pigeons, frounce in raptors - pigeons are primary carriers - can affect galliformes
  • may have mortality events in woodpigeon
  • free-ranging passerines may have outbreaks
  • transmission via water/feed infected by pigeons - young pigeons infected via crop milk -
  • CS stomatitis, esophagitis, ingluvitis

Terio

Question 24

Describe the reproductive strategy of columbiform birds.

Answer 24

Reproduction

• Monogamous pairs, at least seasonally
• Both sexes incubate the eggs and produce crop milk
• Crop milk is a holocrine secretion consisting of 50% dry-matter (DM) protein (sloughed epithelial cells), 45% DM fat (lipid droplets), and negligible carbohydrates (no lactose)
• It is also an important source of immunoglobulins

Fowler 8

Question 25

Do pigeons have a cervical apteryla?

Answer 25

Nope

Fowler 8

Question 26

In pigeons with experimental humeral fractures what fixation method provided teh best treatment - external skeletal fixator-intramedullary pin tie-in, locking plates, or non-locking plates?

Are there any advantages one over another?

Any important anatomy to avoid while performing one of these orthopedic procedures.

Answer 26

ESF-IM were stiffer/stronger than plates, are low-cost and highly versatile. Plate fixation an option in vitro, but further in vivo studies needed before recommendations can be made.

• External skeletal fixator-intramedullary pin (ESF-IM) most often recommended treatment for bird humeral fractures
• Internal fixation via plates common in mammals and could be advantageous given increased fracture compression, no risk of involuntary joint penetration, and no external component that to lead to self trauma
• ESF-IM significantly stiffer and stronger then either plate constructs; appropriate stiffness of a construct is principal component for bone healing
  
  • No significant difference in stiffness, strength, and strain energy between locking and nonlocking plate

· All applications dorsal, but caudal application → equivalent strength and increased stiffness compared to ESF-IM

o Take care with radial nn in both dorsal and caudal applications

o Morbidity secondary to caudal application unknown (tendon interference, fibrosis, joint ankylosis, etc)

o Ideal case for either dorsal or caudal plate fixation = closed mid-diaphyseal fracture that allows 6 cortical bone-screw contact points (minimum of at least 4) proximal and distal to the fracture line

· Bone of the avian wing has high torsion → torsion = greater limiting factor than bending when addressing avian wing fracture repair

JAMS 2019 33(1): 29-37 Ex Vivo Biomechanical Comparison of Titanium Locking Plate, Stainless Steel Nonlocking Plate, and Tie-in External Fixator Applied by a Dorsal Approach on Ostectomized Humeri of Pigeons (Columba livia)

Question 27

Tibiotarsal rotations are fairly common in young birds.

What species are commonly represented?

Are there any contributing factors?

Describe the procedure for correcting this deformity.

What are the advantages of this procedure?

Are there any factors predicting the success of the procedure?

Answer 27

• Pelvic limb deformities common in captive-reared chicks – rotational deformities of long bones.
  
  • Tibiotarsal rotations during fast-growth period in chickens and turkeys (2-10 wks), ostriches at 2-3 weeks.
  • Leg may deviate up to 180 deg from dorsoplantar axis in days.
  • Usually asymmetrical, may cause secondary deformities in sternum.
• Factors that cause tibiotarsal deformities
  
  • genetics, rapid growth rate, poor diet, inappropriate cage design, environmental/seasonal factors, disorders in bone mineralization, excessive or insufficient ratios of calcium, phosphorus, vitamin E, selenium, zinc, methionine, choline, or manganese.
  • Cartilaginous growth plate may be easily damaged and result in tibiotarsal rotation.
  • Birds lack a calcified epiphysis until the end of the growth period (unlike mammals).
• Earliest time to weight bearing 12 days, earliest formation of callus at 22 days, earliest implant removal 38 days. Complete functional recovery achieved on average of 46 days.
  
  • Rotation treatment is possible by creating a closed fracture and fixing the fracture after derotation. The technique was successful in all birds in the study.
  • Avian orthopedic surgical procedures and differences vs mammals – avian bones less soft tissue coverage, thinner cortices, more fragile.
  • Tie-in fixator method advantages – ease of application, use of a smaller diameter IM pin than otherwise could be used, less damage to IM blood supply, increase in resistance to bending and rotational forces vs either an ESF or IM pin alone.
    
    • Normal alignment of long bones achieved.
    • Leg is protected vs longitudinal rotation.
    • Pin removal by the bird is prevented.
    • Strong stabilization is produced.
    • Biplanar ex fix is preferred because of better rigidity in these cases.
      
      • Smooth, nonthreaded pins were used.
      • With positive profile threaded pins, a uniplanar configuration would be sufficient.
• Best for birds less than 1 kg

Kaya, D. A., & Özsoy, S. (2017). Repair of tibiotarsal rotation in 7 chukar partridges (Alectoris chukar) and 12 domestic pigeons (Columba livia domestica) with type-2 external skeletal fixator intramedullary pin tie-in. Journal of avian medicine and surgery, 31(3), 206-213.

Question 28

What is the scientific name of the pink pigeon?

What are the most common causes of mortality in neonates, juveniles, and adults respectively?

What is the highest cause of mortality in wild pink pigeons?

Answer 28

Nesoenas mayeri

Neonates:

o Most common COD: non-infectious disease due to parental neglect and failure to thrive

§ Reduced over the 40 year period: may suggest improvement in management, parental selection, and monitoring of the neonate

§ Inbreeding in wild population resulted in poorly feeding chicks w/ poor squab survival upon fledging = inbreeding may be a factor in captive population

o Second most common COD: trauma, mostly intraspecific, mostly caused by foster parents

o Domestic pigeons trialed as foster parents in two collections but noted to be less suitable than Barbary doves

o Infectious diseases: E. coli omphalitis and septicemia

• Juveniles:

o Most common COD: non-infectious disease due to nutritional secondary hyperparathyroidism > musculoskeletal disease. All cases reared by foster parents

§ May be due to dietary Ca deficiency or vit D deficiency

o Second most common COD: impact trauma

o Infectious diseases: Candida albicans (esophageal and respiratory); Citrobacter septicemia

• Adults:

o Most common COD: impact trauma (flying into aviary walls or ceilings), interspecific trauma

§ Sig more males died from interspecific aggression and sig more females died from intraspecific aggression

o Second most common COD: infectious disease due to Yersinia pseudotuberculosis (seasonal, in winter months) or Mycobacterium avium

o Other non-infectious COD: cardiac disease, renal disease, reproductive disease

• Only 1 death due to trichomoniasis, which is the highest cause of mortality in wild population

o May be due to resistance in this population or that strains in Europe are lower virulence than in Mauritius

RETROSPECTIVE REVIEW OF MORTALITY IN CAPTIVE PINK PIGEONS (NESOENAS MAYERI) HOUSED IN EUROPEAN COLLECTIONS: 1977–2018_Shopland et al_JZWM 51(1): 2020

Question 29

What diseases put the wild Pink Pigeon at risk of extinction in the wild?

What is young pigeon disease syndrome caused by?

What disease risks do captive populations pose to wild ones with reintroductions?

Answer 29

• Columbiformes diseases
  
  • Trichomonas – high squab mortality in PP and threat to species recovery
  • Leukocytozoon – seen in free ranging PP population – 18.3-30% prevalence
  • Pox – 10% in wild suffer from it
  • Young pigeon disease syndrome – circovirus, adenovirus, herpesvirus cause immunosuppression, mortalitiy is 20% and circovirus appears to be the leading cause
  • Paramyxoviruses (APMV-1 and Pigeon PMV-1) – high morbidity but varying mortality
  • Salmonella in feces
  • Chlamydia, mycobacterium, and Yersinia
• All birds negative for pigeon circovirus, pigeon herpesvirus, PPMV-1, APMV-1, Chlamydia, Mycobacterium, Salmonella, Leucocytozoon, Plasmodium, & Hemoproteus
• 26.2% (7 males, 4 females) tested positive for at least one of the following: T. gallinae (5), coccidial oocysts (3), strongyle ova (3), and Yersinia spp. (Yersinia kristensenii [2] and Yersinia aleksiciae [1])

Journal of Zoo and Wildlife Medicine51(4): 970–980, 2020

HEALTH SCREENING OF THE EUROPEAN ENDANGERED SPECIES PROGRAM CAPTIVE POPULATION OF THE PINK PIGEON (NESOENAS MAYERI)

Sara Shopland, BVSc, BSc (Hons), Cert AVP (ZM) MRCVS, Alberto Rodriguez Barbon, LdoVet, CertZooMed, Dipl ECZM (Avian nonpracticing) MRCVS, David S. Richardson, BSc (Hons), PhD, BVMS,Michelle Barrows, BVMS, BSc, RCVS Dipl ZooMed (Avian), Dipl ECZM MRCVS

Question 30

What role do mycoplasma and herpesvirus play in disase of racing pigeons?

Answer 30

• A total of 39.8% of tested pigeons (54.5% of tested lofts) were positive for Mycoplasma species, and 30.6% of tested pigeons (48.6% of tested lofts) were positive for PHV-1.
• In 15.8% of the tested pigeons (26.8% of tested pigeon lofts), coinfection by Mycoplasma species and PHV-1 was identified
• Mycoplasma in pigeons
  
  • M. colubinum, columborale, columbbinasale
  • Isolated from RT & eyes
  • CS – dyspnea, abnormal respiratory sounds, sneezing, conjunctivitis, and rhinitis (arthritis too)
  • Evidence for primary pathogenesis is lacking
• Herpesvirus in pigeons
  
  • 50% of racing pigeons are persistently infected with PHV-1
  • Risk factors – inadequate hygiene, overcrowding, transportation, high intensity training

Hellebuyck, T., Göbel, S., Pasmans, F., Adriaensen, C., & Martel, A. (2017). Co-occurrence of Mycoplasma Species and Pigeon Herpesvirus-1 Infectionin Racing Pigeons (Columba livia). Journal of avian medicine and surgery, 31(4), 351-355.

Take Home: Both pathogens are common, but a synergistic effect was not able to be demonstrated

Question 31

What fungal pathogen is frequently isolated from pigeon droppings?

Answer 31

· Cryptococcosis

o systemic mycosis

o acquired by inhalation of environmental basidiospores or desiccated yeast cells produced by basidiomycetous yeasts Cryptococcus neoformans and Cryptococcus gatii

o C neoformans found in bird droppings

§ estimated 50% of birds are reservoirs and carriers of fungi that are potentially pathogenic

§ pigeon droppings - main environmental source of C neoformans

· Study - C neoformans and other opportunistic fungi isolated and evaluated from pigeon excreta in Mashhad in NE Iran

· C neoformans isolated in 77.5% of 120 samples of pigeon droppings collected from different sites in Mashhad, Iran

· opportunistic yeast and mold fungi also isolated - Candida species and allergenic fungi such as Aspergillus, Penicillium, and Alternaria species

· All pigeon dropping samples collected were desiccated - C neoformans does not grow on fresh feces because of bacterial competition

Ghaderi, Z., Eidi, S., & Razmyar, J. (2019). High Prevalence of Cryptococcus neoformans and Isolation of Other Opportunistic Fungi From Pigeon (Columba livia) Droppings in Northeast Iran. Journal of Avian Medicine and Surgery, 33(4), 335-339.

Question 32

Describe the procedure for gastroscopy and biopsy of the proventriculus & ventriculus in pigeons.

What complications were observed?

Answer 32

• Oral approach
• Preparation of the upper GI tract was achieved by flushing with warm sterile saline solution prior to gastroscopy
• Only small amount of saline needed to distend the GI lumen for visualization
  
  • Conservative saline use reduce aspiration risk from fluid back up into oropharynx
• Proventriculus mucosa easily visualized
• Mucosal biopsies easily and safely collected by distending the proventriculus and collecting specimen with biopsy forceps nearly parallel to the long axis of the proventriculus (to avoid perforation)
• Visibility of cranial ventriculus excellent but scope length prohibited good visualization of the middle and caudal ventriculus
• Two layer biopsy technique for ventriculus – koilin first then mucosa
  
  • Koilin layer easy to sample with biopsy jaws perpendicular to wall
  • Mucosa difficult to grasp
• Complications:
  
  • 1 pigeon had perforated proventriculus
  • 1 pigeon aspirated saline and arrested
  • Some pigeons had possible melena 1-2 days post procedure
• Crop, short esophagus, and patient positioning (reverse Trendelenburg) make air insufflation less useful for GI distention for gastroscopy
  
  • Saline better than air for lumen distention – better visualization, can wash out debris
• Positioning in dorsal recumbency – crop expands with excess fluid, monitor crop size during infusion
• Ingluviotomy may be recommended in birds >400g or with longer necks
  
  • Better visualize caudal compartments of upper GI
  • Reduce aspiration risk
  • More invasive
• For proventricular biopsy, recommend keeping biopsy forcep jaws parallel to wall
  
  • Proventricular wall thinner than mammals so perforates easier
• The proventriculus appeared to yield specimens of higher diagnostic quality than the ventriculus
• Minimal hemorrhage at biopsy sites but evidence of melena following procedure, PCV remained stable
• Overall, gastroscopy and biopsy using these techniques was considered safe

Question 33

What options are avialable for removal of a ventricular foreign body in birds?

Is one preferable over another/

Answer 33

• options for GI FB removal in birds
  
  • medical – magnet on probe, endoscopy
  • surgical
• Proventriculotomy is typically recommended over ventriculotomy in birds
  
  • high risk of postop wound dehiscence given the highly muscular walls of the ventriculus
  • usually not possible to close the incision with an inverting pattern – contents may leak
  • ventriculus more highly vascularized than proventriculus – higher risk of hemorrhage
• Techniques used to decrease complication rate of ventriculotomy
  
  • application of a collagen patch over the surgical site
  • application of a coelomic fat patch
  • both patches associated with an increase in serosal inflammation and did not improve healing

Perforating foreign body in the ventriculus of a pet pigeon (Columba livia domestica)

Delphine Laniesse DVM, DVSc; Hugues Beaufrère DVM, PhD; Shawn Mackenzie DVM, DVSc; Ameet Singh DVM, DVSc; Ayman Samman DVM, PhD; Leonardo Susta DVM, PhD

J Am Vet Med Assoc 2018;253:1610–1616

Question 34

Describe the measurement of intraocular pressure in pigeons.

Answer 34

: TonoVet IOP measured in ‘d’ mode was 10.6 +/- 1.9 mm Hg

• Converting this into the regression formula the reference IOP of pigeons was actually 19.5 +/- 4.4 mm Hg

Lim, J., Kang, S., Park, S., Park, E., Nam, T., Jeong, S., & Seo, K. (2019). Intraocular Pressure Measurement by Rebound Tonometry (TonoVet) in Normal Pigeons (Columba livia). Journal of avian medicine and surgery, 33(1), 46-52.

Question 35

Following insult with acetominophen, administration of silymarin (35 mg/kg PO q12h) had what effectin domestic pigeons?

Answer 35

Signs of acute toxicity were observed in groups A and B (vomiting, weakness, dec appetite)

· Group B birds appeared to recover after being treated with silymarin

· 86% of group A died between 48-86 hors post AA, none in group B died

· Group B pigeons decreased the serum levels of AST, ALT, urea, and uric acid compared with Group A

· Silymarin also prevented decreases in serum alkaline phosphatase, total protein, albumin, and cholesterol seen in Group A.

· Histopath of group A showed severe and diffuse vacuolation of the hepatocytes, hepatocellular necrosis and mononuclear inflammatory infiltration

· In group B hepatocellular vacuolation and necrosis were absent

· No lesions in group C

· Takeaway: Silymarin was protective against both hepatic and possibly renal toxicity from acetaminophen in pigeons, may also be useful for liver disease in general

The Effects of Silymarin on Acetaminophen-Induced Acute Hepatic and Renal Toxicities in Domestic Pigeons (Columba livia)

Journal of Avian Medicine and Surgery 34(4):348–357, 2020

Question 36

What is trazodone?

What effects were seen in pigeons administered a dose of 30 mg/kg?

How long did the drug appear to maintain at therapeutic levels?

Answer 36

• Trazodone = antidepressant used in human medicine
  
  • serotonin antagonist and reuptake inhibitor
  • antagonist activity on the 5-hydroxytryptamine 2A receptor subtype and provides fairly weak inhibition of the serotonin transporter 5-HT; also blocks α1 and α2, adrenoreceptors and histamine H1 and 5-HT2C receptors
  • Low incidence of adverse effects for humans- anxiety, insomnia, sexual dysfunction
  • Pharmacokinetics have been evaluated in horses and dogs
    
    • used to decrease anxiety and stress during the perioperative period, treat thunderstorm and noise phobias, manage anxiety disorders
  • 2 studies on birds- trazodone did not appear to have any antidepressant or anxiolytic effects in young domestic fowl or pigeons
• 30 mg/kg dose gave drug concentrations that were considered therapeutic for dogs/horses within 1 hour of drug administration PO
• Unexpected fast absorption of the drug
• Trazodone was not associated with any sedation or adverse effects in these pigeons
  
  • The authors are unsure if the dose was just not high enough to induce sedation or the mechanism of action of trazodone OR if the trazodone offset the stress/increase in activity of the handling needed to give the trazodone

Desmarchelier, M. R., Beaudry, F., Ferrell, S. T., & Frank, D. (2019). Determination of the pharmacokinetics of a single oral dose of trazodone and its effect on the activity level of domestic pigeons (Columba livia). American Journal of Veterinary Research, 80(1), 102-109.

Question 37

What diagnostics are available for measuring renal funciton in pigeons?

Specifically renal tubular excretion and glomerular funciton?

Answer 37

Takeaway: DTPA (99mTc99-DTPA -diethylenepentaacetic acid, DTPA) clearance can be used to evaluate glomerular function in pigeons. MAG (99mTc-MAG3 - mercaptoacetyl triglycine, MAG3) similar for examining renal tubular excretion.

• DTPA cleared similar to inulin, supports use for avian qualitative or semiquantitative glomerular function studies. MAG similar potential for examining renal tubular excretion.
• Creatinine does not seem to be useful, further studies needed in birds.

Other Info

• Uric acid is excreted by active tubular secretion and does not provide reliable information about glomerular function
• Conversion of creatine to creatinine inefficient in avian species -> creatinine poor marker of glomerular function in birds. Creatine is the dominant circulating metabolite.
• Birds are uricotelic, only produce limited amts of urea, reduces utility for renal function.
  
  • Not sensitive measure of renal filtration.
• Creatinine also not produced in large amounts, less sensitive for renal dysfunction. UA excreted by active tubular secretion, not reliable for glomerular function.

Wimsatt, J., Pearce, R., Steyn, P. F., Vap, L., & Glover, D. K. (2020). Comparative renal disposition of creatine, and technetium diagnostic contrast agents in the pigeon (columba livia). Journal of Zoo and Wildlife Medicine, 50(4), 891-896.

Question 38

A recent study investigated the effects of various anticoagulants on the biochemistry values of domestic pigeons.

What anticoagulant was deemed most appropriate for pigeon biochemistry samples?

Answer 38

JAMS 2022 36(2):173-177
Effects of Various Anticoagulants on Biochemistry Analytes From Domestic Pigeons (Columba livia domestica)
Heidarpour M, Razmyar J, Mohri M, Ghari M

Key Points:
- Prospective anticoagulant comparison study (n = 8 adult domestic pigeons)
– Blood samples collected from right basilic vein
- Majority of biochemical tests in birds are conducted using plasma (vs. serum in mammals)
- Significant decreases for many biochemical parameters in the sodium citrate & EDTA plasma
– Not resolved by applying a correction factor for the dilution
– Alterations of biochemical analytes in EDTA plasma have been described in humans, cattle, dogs, horses, cats, and sheep
- Lithium heparin plasma samples and serum samples demonstrated similar results
– Except for significant decreases in ALP, albumin, triglyceride, calcium, and cholesterol
– Statistically significant reductions for triglyceride, calcium, cholesterol, and ALP may not be clinically significant because all values were within reference intervals
– However, the reduction of albumin may affect clinical decisions

TLDR: Lithium heparin = most appropriate anticoagulant for domestic pigeon biochemistry panels

Question 39

A recent study evaluated voriconazole administered intramuscularly in pigeons.

What is the mechanism of voriconazole?
- What are some reported adverse effects of teh drug?

What dose was given in this study?
- Were any adverse side effects or lesions seen?

Answer 39

Journal of Avian Medicine and Surgery, 36(3), 262 271.
Safety of an Intravenous Formulation of Voriconazole as an Intramuscular Injection in Pigeons (Columba livia f. domestica).
de Castro, I. F. C., Schmidt, V., Silvanose, C. D., Binoy, A., & Azmanis, P. N.

Key Points:
- Asper is a ubiquitous fungi, one of the main causes of death in hunting falcons in the Middle East.
– Azoles are used for treatment
– Voriconazole is a triazole (lanosterol 14a- demethylase inhibitor) with efficacy against many types of fungi including Aspergillus spp.
– Given PO, IV or nebulized
– IM in a recent falcon study showed that IM had a higher bioavailabuility than PO, no adverse effects
– Reports of vori-induced myositis, myopathy, and multifocal periostitis in humans after PO admin
– Adverse effects reported in birds include liver fxn alterations, GI signs, and neuro signs
- Injectable voriconazole given IM appears to be a safe short-term option in pigeons.
- IV voriconazole given IM at 12.5mg/kg BID x7d produced mild macroscopic and histo lesions in the pectoral muscles but no changes in CBC/chem values (not even CK- remained within RI!) AST, ALT and LDH all remained within RI
- No long term pathology (no lesions seen after 14 days)