Correction of a Hyperflexed Hallux in a Saker Falcon (Falco cherrug) by Hemisectioning the Deep Digital Flexor Tendon.

A 3-year-old male saker falcon (Falco cherrug) was presented with a history of hyperflexion of the first digit of the left pelvic limb with what appeared to be a hypercontracted distal end of the deep digital flexor tendon (m. flexor hallucis longus). Conservative treatment, bandaging, and splinting techniques failed to resolve the hypercontraction of the deep digital flexor tendon and improve digit function. Intraoperatively, the deep digital flexor tendon was found to have formed adhesions with the tendon sheath as well as the bone and soft tissue structures underneath it, impeding its ability to move freely within the tendon sheath. The adhesions were surgically resolved, and the tendon was lengthened by hemisectioning the deep digital flexor tendon at its distal end. Postsurgically, the digit was maintained in an extended position by bandaging. Mild physiotherapy was provided at 5-day intervals to retain function and prevent adhesions. Digit extensibility and function were restored to nearly normal levels after 4 weeks.

Linked-Read Sequencing of Eight Falcons Reveals a Unique Genomic Architecture in Flux.

Falcons are diverse birds of cultural and economic importance. They have undergone major lineage-specific chromosomal rearrangements, resulting in greatly-reduced chromosome counts relative to other birds. Here, we use 10X Genomics linked reads to provide new high-contiguity genomes for two gyrfalcons, a saker falcon, a lanner falcon, three subspecies of peregrine falcons, and the common kestrel. Assisted by a transcriptome sequenced from 22 gyrfalcon tissues, we annotate these genomes for a variety of genomic features, estimate historical demography, and then investigate genomic equilibrium in the context of falcon-specific chromosomal rearrangements. We find that falcon genomes are not in AT-GC equilibrium with a bias in substitutions towards higher AT content; this bias is predominantly but not exclusively driven by hypermutability of CpG sites. Small indels and large structural variants were also biased towards insertions rather than deletions. Patterns of disequilibrium were linked to chromosomal rearrangements: falcons have lost GC content in regions that have fused to larger chromosomes from microchromosomes and gained GC content in regions of macrochromosomes that have translocated to microchromosomes. Inserted bases have accumulated on regions ancestrally belonging to microchromosomes, consistent with insertion-biased gene conversion. We also find an excess of interspersed repeats on regions of microchromosomes that have fused to macrochromosomes. Our results reveal that falcon genomes are in a state of flux. They further suggest that many of the key differences between microchromosomes and macrochromosomes are driven by differences in chromosome size, and indicate a clear role for recombination and biased-gene-conversion in determining genomic equilibrium.

Laterality preferences at rest and predatory behaviour of the Gyrfalcon (Falco rusticolus): An alpha predator of the sky.

Brain lateralization is generally considered adaptive for an individual and it can be ascertained, for example, by measuring the preferential use of limbs. Avian models have been extensively used to investigate the evolution and the advantages of brain lateralization. Birds of prey are a good model to study motor laterality, however to date they have been studied almost exclusively in the context of predatory behaviour. In this study, we tested lateralization in Gyrfalcon (Falco rusticolus) across multiple contexts, and collected the following measures:(1) standing leg preference when sleeping, (2) wing preference to position the head while sleeping and (3) leg preference to grasp food. At the population level, we found left-leg lateralization while sleeping and no preference for placing the head under the left or the right wing. In the context of the predatory behaviour, we found a trend towards using the left leg to grasp food. Across the behaviours observed, we did not find evidence of lateralization at an individual level, as most of the subjects were ambidextrous. This study highlights the importance of the behavioural context when investigating side-bias and hemispheric laterality.

Management of Knuckling in an Ostrich (Struthio camelus) Using a Custom-Made Orthotic Shoe.

A 4-year-old female ostrich (Struthio camelus) developed knuckling on its left foot after a traumatic event. Conservative treatment, rest, and traditional splinting methods failed to resolve the gait abnormality or improve mobility. A dynamic multicomponent orthotic shoe was then custom designed and fabricated with an ultra-high-molecular weight, low-pressure polyethylene polymer (St 1000 DIN16972 TG2) to correct the foot malposition. The affected foot and leg were wrapped with soft padding and the orthosis was attached and secured by nylon belts (Nylon PA [polyamide] 6, a semicrystalline polyamide polymer) with self-locking modified wrench straps. The orthosis immediately prevented knuckling and improved ambulation. After 2 weeks, this shoe was replaced with a modified orthotic shoe of lighter weight to improve kinetics and ease of use by the bird. The modified orthosis dramatically improved ambulation and was left attached to the affected leg for 7 more weeks. Thereafter, the bird was able to ambulate comfortably without the aid of the shoe, even though permanent anatomical changes to the affected leg seemed to restrict its speed of locomotion. The ostrich had another unfortunate traumatic event 10 weeks later, the result of which was knuckling on the contralateral (right) foot. After routine medical and supportive care, the orthosis was then applied to the right foot for a period of 9 weeks. During this period the bird was able to ambulate well, despite having to support the bulk of its weight on the previously affected left limb. At the end of 9 weeks, the orthosis was removed, and the bird was able to ambulate without aid, although the bird's speed of locomotion was considerably reduced. After recovery of its leg problems, the ostrich was confined to a relatively small paddock for the rest of its life.

Prevalence of Caryospora (Apicomplexa: Eimeriidae) Oocysts in the Environment of a Gyrfalcon (Falco rusticolus) Breeding Center in the United Arab Emirates.

A total of 356 gyrfalcon (Falco rusticolus) fecal, fomite, and environmental samples were collected from a breeding center located in the United Arab Emirates to assess the prevalence of Caryospora species oocysts in the environment. These included 136 samples (38%) from fomites and fecal samples from chicks at 0 to 10 days old, 29 samples (8%) at 15 days old, 23 samples (6%) at 60 days old, 7 samples (2%) at 67 days old, and 24 samples (7%) at 70 days old. In addition, 105 samples (29%) were collected from the environment of 13 breeding chambers, and 32 samples (9%) from the environment of 17 juvenile falcons. The prevalence of Caryospora species oocysts in fomites and fecal samples from the chicks had negative results from 10 to 60 days old. However, at 67 and 70 days old, the prevalence increased to 71.42% (5 of 7) and 95.83% (23 of 24), respectively. The prevalence of Caryospora species in the environment of 13 pairs of falcons housed in 13 breeding chambers was 0.15 oocyst/m2 in the sand, whereas, in the environment of 17 juvenile falcons housed in the free-flying aviary, the prevalence was 0.00086 oocyst/m2 in the sand and 0.15 oocyst/L in contaminated water. These results indicate that oocysts of Caryospora species may be found in the environment and in areas of poor and substandard hygiene. Caryospora species is an important protozoon parasite affecting captive falcons maintained in breeding centers and those used for falconry in the Middle East.

Inclusion Body Herpesvirus Hepatitis in Captive Falcons in the Middle East: A Review of Clinical and Pathologic Findings.

Inclusion body hepatitis in falcons is caused by a herpesvirus designated Falconid HV-1. This herpesvirus and other herpesviruses affecting birds of prey have not been assigned to a genus and include inclusion body herpesvirus hepatitis in eagles (Accipitrid HV-1) and inclusion body herpesvirus hepatitis in owls (Strigid HV-1). Herpesvirus infections have been diagnosed in both captive and free-living raptors across Europe, North America, and Asia in different species of the family Falconidae. Herpesviruses affecting owls and falcons have been found to be antigenically similar to pigeon herpesvirus (Columbid HV-1) and distinct from other avian herpesviruses. When the herpesvirus isolates from owls, falcons, and pigeons were compared by sequencing a fragment of the herpes viral DNA polymerase gene from those birds naturally infected with the virus, the sequences from these 3 sources were found to be nearly identical. The authors of this study concluded that the Falconid HV-1, Strigid HV-1, and Columbid HV-1 were the same virus. Furthermore, the authors also proposed that the virus therefore be referred to as Columbid HV-1 (CoHV-1), because pigeons may be responsible for the transmission of the virus to birds of prey. Pigeons are often carriers of the virus without showing any clinical signs. It has long been suspected that raptors may contract the infection by the ingestion of infected pigeons. Some studies have suggested that falcons may not contract the infection through the oral route by ingesting carrier pigeons, but through the ocular or nasal route. Inclusion body herpesvirus hepatitis is a frequently diagnosed disease in the captive falcon population used for falconry, racing, and breeding in the Middle East, and it seems to be associated with the extensive use of pigeons for training and as a food item. This paper reviews the clinical and pathological findings in falcons affected by inclusion body herpesvirus hepatitis in the Middle East.

Prevalence of Caryospora Species (Apicomplexa: Eimeriidae) in Falcons in the United Arab Emirates.

A total of 3975 fecal samples, originated from the same number of individual birds, from 7 dedicated falcon hospitals, were examined to determine the prevalence of Caryospora species in the falcon population used in the sport of falconry in the United Arab Emirates (UAE). From that total, 297 (7.5%) were positive for the presence of Caryospora species. The falcons were all captive bred within the UAE and abroad, mainly from Germany, Spain, the United States, and Canada. Positive samples for the presence of Caryospora species were sporulated, and the taxonomy was established based on morphologic characteristics. The results showed the prevalence of the following Caryospora species: C kutzeri 41.4%, C neofalconis 25.6%, C megafalconis 18.2%, C falconis 10.4%, C cherrughi 3.7%, and C boeri 0.7%. The prevalence of Caryospora species among the various falcon species in this study was: gyr × peregrine hybrid falcons ( Falco rusticolus × Falco peregrinus), 27.3%; gyr falcons ( Falco rusticolus), 25.6%; peregrine falcons ( Falco peregrinus), 20.5%; saker falcons ( Falco cherrug), 16.5%; gyr × saker hybrid falcons ( Falco rusticolus × Falco cherrug), 8.1%; Eurasian kestrels ( Falco tinnunculus), 1%; red-napped shaheen ( Falco pelegrinoides babylonicus), 0.7%; and American kestrels ( Falco sparverius), 0.3%.

VITAMIN B6 (PYRIDOXINE HYDROCHLORIDE) TOXICOSIS IN FALCONS.

This manuscript reports three independent accidental cases of vitamin (Vit) B6 toxicosis in gyrfalcons (Falco rusticolus) and peregrine falcons (Falco peregrinus) and a toxicology study that was conducted to characterize the clinical responses of gyrfalcons and gyrfalcon × peregrine falcons to a range of single intramuscular (IM) and oral (PO) doses of Vit B6. Both lethal and nonlethal doses were determined. Twelve female gyrfalcons died following IM injection of 1 ml of a vitamin B preparation. Within 30 min of injection, the birds passed pistachio green-colored urates and progressed to vomiting, anorexia, cessation of normal activity, ptosis, collapse, and death, occurring 24-36 hr post injections. Three individuals vomited frothy, partially digested blood and had clonic spasms and convulsions. Postmortem and histopathology revealed multifocal severe hepatic necrosis, splenic lymphoid tissue depletion and hemorrhages with arterial necrosis, and acute renal tubular necrosis. Following administration of a different, oral, mineral-vitamin supplement, a total of 21 peregrine falcons in two separate European facilities died suddenly. Histology of the liver showed diffuse congestion and multifocal coagulative necrosis with mild infiltration of heterophils. The particular nutritional supplement, used by both breeders, was analyzed and found to contain 5-9.7% Vit B6. Other randomly selected lots of the product contained 0.007-0.27% Vit B6. According to the product label, Vit B6 should have been present at 0.004%. To confirm the hypothesis that Vit B6 was responsible for the deaths of the falcons in Abu Dhabi, Vit B6 (British Pharmacopoeia [BP] grade) in powder form was diluted in water for injection and administered IM to four groups of falcons. Groups of four gyrfalcon × peregrine hybrid falcons or gyrfalcons (or both) were given a single IM dose of 5, 10, 15, or 20 mg/kg of Vit B6 or received an oral dose of 25, 50, or 75 mg of Vit B6. Only birds in the lowest-dose groups survived. The maximum nonlethal single doses of Vit B6 in falcons were 5 mg/kg i.m. and 25 mg/kg p.o.

Newcastle disease in captive falcons in the Middle East: a review of clinical and pathologic findings.

Newcastle disease is an important viral disease of falcons in the Middle East. Two different clinical presentations producing distinct clinical symptoms and pathologic lesions have been identified in affected falcons, denoted as neurotropic velogenic and viscerotropic velogenic forms. Humoral response after vaccination with commercially available oil-emulsion inactivated poultry vaccines has been observed for up to 9 months in vaccinated falcons. Public awareness programs at falcon medical facilities in the region are needed to promote annual vaccinations to prevent Newcastle disease in falcons.

Vasectomy in birds: a review.

Vasectomy is done to produce infertility by surgically removing a portion of the ductus deferens from both testicles. In birds, vasectomy can be done internally or externally. Internal vasectomy is performed by severing and removing a section of the ductus deferens through bilateral celiotomy or by endoscopic-guided techniques. Vasectomy can be done externally using standard surgical procedures in those species possessing seminal glomera. In this review, the surgical techniques used to perform vasectomy in birds and the implications and applications of each technique are discussed.

Hematologic and plasma biochemical reference values in Indian peafowl (Pavo cristatus).

Blood samples were collected from captive, adult, clinically normal Indian peafowl (Pavo cristatus) for hematologic and plasma biochemical analyses. Hematologic parameters investigated were total red blood cell count, hemoglobin, packed cell volume, fibrinogen, mean cell volume, mean cell hemoglobin, mean cell hemoglobin concentration, total white blood cell count, differential white blood cell count, and thrombocyte count. Plasma biochemical parameters investigated were alanine aminotransferase, alkaline phosphatase, amylase, aspartate aminotransferase, bile acids, total bilirubin, blood urea nitrogen, calcium, cholesterol, creatinine, creatine kinase, gamma glutamyltransferase, lactate dehydrogenase, glucose, iron, phosphorus, and uric acid, as well as plasma protein electrophoresis. Results were compared with values from studies done in houbara bustards (Chlamydotis undulata), kori bustards (Ardeotis kori), stone curlews (Burhinus oedicnemus), and taxonomically related species, including ring-necked pheasants (Phasianus colchicus), red-legged partridges (Alectoris rufa), Kashmir native fowl (Kashmirfavorella), and Bangladesh native, Fayoumi, and Assil fowl (Gallus domesticus).

Health assessment of a spiny-tailed lizard (Uromastyx spp.) population in Abu Dhabi, United Arab Emirates.

A study was conducted to determine the health status of the free-living spiny-tailed lizard (Uromastyx spp.) population at Wrsan, Al Ajban, Abu Dhabi, United Arab Emirates. A total of 90 spiny-tailed lizards, 61 males and 29 females, were examined from June to August 2006. Mean body weights were 1,564.4 g and 809.4 g for males and females, respectively. Mean body lengths were 62.1 cm and 49.4 cm for males and females, respectively. Fourteen lizards were found with abnormalities including abscesses, bite wounds, and deformed or missing tail ends, digits, or claws. Radiographic examination revealed osteomyelitis, arthritis, and healed fractures. Reference hematology and chemistry values were obtained from the 76 clinically normal lizards. Hemoparasitemia included possible new species of Karyolysus and Hepatozoon. The most common oropharyngeal organisms isolated were Escherichia coli, Providencia spp., and nonhemolytic Staphylococcus; and the most common cloacal organisms were E. coli, Proteus spp., Providencia spp., and nonhemolytic Staphylococcus. Ascarids were the only endoparasites found. This is the first biomedical data published for the spiny-tailed lizard.

Age-related hematologic changes in captive-reared houbara, white-bellied, and rufous-crested bustards.

Blood samples were obtained at monthly intervals between April 1994 and March 1996 from captive-bred houbara (Chlamydotis undulata macqueenii), rufous-crested (Eupodotis ruficrista gindiana), and white-bellied (Eupodotis senegalensis) bustards from 4-24 wk of age. Hematology investigations were conducted to determine age-related changes and to establish reference values for growing chicks of these species. There were significant age-related changes in hematocrit, hemoglobin, and red cell count in young birds compared with those of adults. White cell counts (lymphocytes and monocytes) were higher in juvenile birds, compared with adult values.