Avian Reproductive Disorders

Sex determination in budgerigars using radiographic pelvimetry

BACKGROUND

The purpose of this study was to assess the pelvimetric values obtained from radiographic pelvis images of budgerigars in terms of sexual dimorphism. The objectives included determining linear osteometric and angle measurements of the pelvis, as well as calculating the length-to-width ratios among different pelvimetric measurements. Additionally, the study aimed to reveal the correlations between age and body weight with both the pelvimetric measurements and ratio measurements in these animals.

METHODS

In this study, measurements of linear distance, angle and length-to-width ratios were obtained from ventrodorsal images of the pelvis in a sample of 60 budgerigars, consisting of 30 males and 30 females. Subsequently, the statistical analysis of the obtained measurement values was performed.

RESULTS

When analysing the morphometric measurement values based on sex, it was observed that all linear measurements (L1, L2, L3, L4, L5, L6, L7, L8, L9, L10 and L11) were higher in males, whereas the angle measurements (A1, LA2 and RA2) were found to be significantly greater in females (p < 0.05). Additionally, both male and female budgerigars exhibited a greater pre-acetabular length of the ilium compared to the post-acetabular length. Moreover, there were mostly positive significant correlations between age and body weight with the pelvic measurement values in both sexes (p < 0.05).

CONCLUSIONS

The obtained biometric measurement values from pelvimetric X-ray images in budgerigars were analysed to assess sexual dimorphism. Furthermore, this study presents fundamental morphometric data that can be valuable for clinical, taxonomic, phylogenetic, ornithological, allometric and characterization studies of budgerigars.

Canaries' Microbiota: The Gut Bacterial Communities along One Female Reproductive Cycle

Investigations of bacterial communities are on the rise both in human and veterinary medicine. Their role in health maintenance and pathogenic mechanisms is in the limelight of infectious, metabolic, and cancer research. Among the most considered, gut bacterial communities take the cake. Their part in animals was assessed mainly to improve animal production, public health, and pet management. In this regard, canaries deserve attention, being a popular pet and source of economic income for bird-keepers, for whom breeding represents a pivotal point. Thus, the present work aimed to follow gut bacterial communities' evolution along on whole reproductive cycle of 12 healthy female canaries. Feces were collected during parental care, molting, and resting phase, and submitted for 16S rRNA sequencing. Data were analyzed and a substantial presence of Lactobacillus aviarius along all the phases, and a relevant shift of microbiota during molting and rest due to an abrupt decrease of the Vermiphilaceae family were detected. Although the meaning of such change is not clear, future research may highlight unforeseen scenarios. Moreover, Lactobacillus aviarius may be deemed for normal bacteria flora restoration in debilitated birds, perhaps improving their health and productivity.

Physiological factors influencing female fertility in birds

Fertility is fundamental to reproductive success, but not all copulation attempts result in a fertilized embryo. Fertilization failure is especially costly for females, but we still lack a clear understanding of the causes of variation in female fertility across taxa. Birds make a useful model system for fertility research, partly because their large eggs are easily studied outside of the female's body, but also because of the wealth of data available on the reproductive productivity of commercial birds. Here, we review the factors contributing to female infertility in birds, providing evidence that female fertility traits are understudied relative to male fertility traits, and that avian fertility research has been dominated by studies focused on Galliformes and captive (relative to wild) populations. We then discuss the key stages of the female reproductive cycle where fertility may be compromised, and make recommendations for future research. We particularly emphasize that studies must differentiate between infertility and embryo mortality as causes of hatching failure, and that non-breeding individuals should be monitored more routinely where possible. This review lays the groundwork for developing a clearer understanding of the causes of female infertility, with important consequences for multiple fields including reproductive science, conservation and commercial breeding.

Asymmetrical Cloacoplasty for the Treatment of Chronic Cloacal Prolapse in Psittaciformes: A Case Series

Chronic cloacal prolapse is a common condition in psittacine birds, particularly in cockatoos and African grey parrots (Psittacus erithacus). Techniques to permanently reduce the prolapse have been developed and include cloacal sutures, percutaneous cloacopexy, and open circumcostal or rib cloacopexy. Several complications, some of which are life-threatening, have been reported with these tissue reduction techniques. Cloacoplasty surgeries have also been advocated, but most often as an adjunct therapy. Recurrence of cloacal prolapse may occur in traditional symmetrical cloacoplasty techniques since straining pressure remains. In this case series, 5 psittacine birds (2 male and 2 female umbrella cockatoos [Cacatua alba] and 1 male African grey parrot) with chronic recurrent cloacal prolapses were treated with a novel asymmetrical cloacoplasty technique. A semicircular excision at the mucocutaneous junction from the right side with a 2-layer closure reduced the cloacal opening by 50%-75%. A tension-relieving suture was applied to aid in healing of the incision. All 5 cases had successful outcomes with no recurrent prolapses (6 months to 3 years of follow-up), except for 1 case, due to incisional dehiscence. This animal underwent a second surgical procedure that incorporated the tension-relieving suture and has not had a recurrent prolapse in over a year. This asymmetrical cloacoplasty technique provides a simple but effective method of cloacal prolapse treatment and prevention in cases of recurrent and chronic cloacal prolapses, and creates a midline physical barrier not present in symmetrical cloacoplasties. Long-term complications may include cloacolith formation or dystocia in females, and therefore reproductive management of female birds is required.

Assessment of a vessel and tissue-sealing device for ovariectomy in chickens to evaluate the potential application of the procedure to other avian species

OBJECTIVE

To assess the feasibility of a novel technique involving a vessel and tissue-sealing device (VTSD) for ovariectomy in chickens to evaluate the potential application of the procedure to other avian species.

ANIMALS

20 domestic laying hens (Gallus domesticus), of which 10 were immature (< 4 months old) and 10 were adults (> 18 months old).

PROCEDURES

Ovariectomy was performed with a VTSD through a left lateral celiotomy. Birds were allowed to recover for 14 days after the procedure and then were euthanized for necropsy. A board-certified veterinary pathologist performed complete necropsies, with particular attention to identifying any remaining ovarian tissue.

RESULTS

All birds survived the procedure. For the mature and juvenile birds, the mean ± SD durations of anesthesia (interval from intubation to extubation) were 67.2 ± 7.6 minutes and 50.5 ± 5.1 minutes, respectively, and mean durations of surgery were 45.3 ± 8.5 minutes and 31.6 ± 5.1 minutes, respectively. Three birds had severe hemorrhage during ovariectomy. At necropsy, ovarian tissue was present grossly in 2 mature birds and histologically in 6 additional birds (2 mature and 4 juvenile birds), indicating incomplete excision in 8 (40%) birds.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated that the evaluated VTSD can be used to successfully perform ovariectomies in both juvenile and mature chickens, although the procedure was associated with major hemorrhage and incomplete excision of ovarian tissue in some cases. Use of this VTSD for ovariectomy in birds of other species, particularly birds with reproductive tract disease, should be investigated.

Development and evaluation of a technique for spinal anaesthesia in broiler chickens

AIMS

To develop a technique for the injection of local anaesthetic into the spinal canal of broiler chickens by first determining the ideal location for needle placement based on anatomy and histology, and then using the developed technique to assess the onset and duration of action of three doses of lidocaine.

METHODS

Two-month-old Ross broiler chickens (n = 30) were used in this study. Computed tomography imaging followed by anatomical examination of fresh cadavers (n = 6) were used to identify a suitable intervertebral space for injection of local anaesthetic, and landmarks to locate this space. Histological evaluation of the microanatomy of the caudal vertebral column in another six birds was used to examine the position of the spinal cord within the canal. Spinal anaesthesia was attempted using injection of lidocaine at 0.5 mg/kg (n = 6), 1 mg/kg (n = 6), and 2 mg/kg (n = 6) via the selected intervertebral space. Analgesia was tested by pinching the skin of the pericloacal area with thumb forceps to determine the onset and duration of analgesia. Respiratory rate, and cloacal temperature were measured at 0 minutes and every 10 minutes after injection until sensation returned.

RESULTS

The space between synsacrum and first free coccygeal vertebra (synsacrococcygeal space) was selected as the most suitable site for spinal injection. In this region, the dura mater adhered to the internal wall of the spinal canal, and the subarachnoid space was large indicating that injection would be into the subarachnoid rather than the epidural space. The interval to onset of analgesia was similar for all doses of lidocaine (1.5 (SD 0.7), 2 (SD 1) and 1.3 (SD 0.5) minutes for 0.5, 1 and 2 mg/kg, respectively; p = 0.604). Duration of analgesia was longer following injection with 2 than 0.5 or 1 mg/kg lidocaine (21.3 (SD 2.5) vs. 4.5 (SD 3.5) vs. 11.3 (SD 2) minutes, respectively; p = 0.002). Mean cloacal temperature decreased between 0 and 20 minutes after injection with all doses of lidocaine (p = 0.021).

CONCLUSIONS AND CLINICAL RELEVANCE

Spinal anaesthesia in chickens is feasible and is a practical, inexpensive and simple technique for regional anaesthesia of the pericloacal area.

An Early Cretaceous enantiornithine (Aves) preserving an unlaid egg and probable medullary bone

Understanding non-crown dinosaur reproduction is hindered by a paucity of directly associated adults with reproductive traces. Here we describe a new enantiornithine, Avimaia schweitzerae gen. et sp. nov., from the Lower Cretaceous Xiagou Formation with an unlaid egg two-dimensionally preserved within the abdominothoracic cavity. Ground-sections reveal abnormal eggshell proportions, and multiple eggshell layers best interpreted as a multi-layered egg resulting from prolonged oviductal retention. Fragments of the shell membrane and cuticle are both preserved. SEM reveals that the cuticle consists of nanostructures resembling those found in neornithine eggs adapted for infection-prone environments, which are hypothesized to represent the ancestral avian condition. The femur preserves small amounts of probable medullary bone, a tissue found today only in reproductively active female birds. To our knowledge, no other occurrence of Mesozoic medullary bone is associated with indications of reproductive activity, such as a preserved egg, making our identification unique, and strongly supported.

The fossil record of the reproductive traits of early birds is limited. Here, Bailleul and colleagues describe the Cretaceous enantiornithine bird Avimaia schweitzerae, which preserves an unlaid egg in the abdominal cavity and putative medullary bone.

Evaluation of the effects of a 4.7-mg deslorelin acetate implant on egg laying in cockatiels (Nymphicus hollandicus)

OBJECTIVE To evaluate effects of administration of a 4.7-mg deslorelin acetate implant on egg laying in healthy cockatiels (Nymphicus hollandicus). ANIMALS 52 cockatiels. PROCEDURES 26 breeding pairs (a female and its respective male in each pair) were selected on the basis of their history of egg laying. Female birds were sedated and received a 4.7-mg deslorelin acetate implant (n = 13) or placebo implant (13) in the subcutaneous tissues between the scapulae. Male and female birds of each breeding pair were placed in separate but adjacent cages. Birds were exposed to 16 hours of light and 8 hours of darkness. A nest box was placed in cages of female birds to stimulate reproductive activity. Egg production and quality were monitored daily for 365 days. RESULTS Deslorelin acetate implants significantly suppressed egg laying in cockatiels, compared with effects for the placebo implants. Eleven of 13 placeboimplanted birds laid eggs between 12 and 42 days after implantation. None of the deslorelin-implanted birds laid eggs within 180 days after implantation, and only 5 of 13 deslorelin-implanted birds laid an egg during the study period (first egg laid between 192 and 230 days after implantation). No differences in egg quality or number of eggs per clutch were observed between the 2 groups. CONCLUSIONS AND CLINICAL RELEVANCE Insertion of a 4.7-mg deslorelin acetate implant suppressed egg laying in healthy cockatiels for at least 180 days. Studies are necessary to evaluate effects of a deslorelin acetate implant in other avian species or in association with reproductive disorders.

Ovarian radiographic and direct measurements of Japanese Quail ( Coturnix coturnix japonica ) submitted to light restriction

ABSTRACT Often, in pet birds, any stimulus to lay eggs is unwanted in order to reduce reproductive diseases and disorders. The objectives of this study were: to determine the time necessary to promote ovary involution after an eight hour photoperiod using laying Japanese quails (Coturnix coturnix japonica); to connect the ovarian radiographic measurements with egg production; and to compare these measurements with direct ovary data obtained at necropsy. Birds were separated into three groups: 12h/24d (control group - 12h photoperiod for 24 days), 8h/24d and 8h/36d (8h photoperiod for 24 and 36 days). After euthanasia, all cadavers were x-rayed to measure ovary length and height. Birds were necropsied to measure ovarian length and weight. Results: radiographic ovary length demonstrated strong and positive correlation (r=0.96) with direct ovary length of all three groups; laying quails showed higher ovary height (p=0.025) and length (p=0.009) than non-laying quails; eight hours of artificial light per day promotes ovary length (p=0.025) and weight (p=0.009) reduction. Conclusions: radiography can estimate the ovary measure and indicate posture; an eight hour photoperiod of 24 days is not enough to promote ovarian regression, while the use of reduced photoperiod for 36 days promotes significant ovary involution.

Reproductive Disorders in Parrots

Disease affecting the reproductive tract of the companion parrot is often impacted by physiologic and environmental stimuli. In conjunction with appropriate medical management, some birds diagnosed with reproductive disorders may be successfully treated. Once the bird is diagnosed with a disease condition affecting the reproductive tract, therapeutic measures are focused on stabilizing and supporting the patient, and surgical intervention is required only in the most severe cases. Hormonal therapy with synthetic, long-acting GnRH agonists should be considered for chronic reproductive disease conditions in which decreasing ovarian activity can help alleviate certain disease processes.

Systemic Clinical and Metabolic Diseases

Like other animals pet and companion birds are also prone to systemic illness. This is presented in the form of certain clinical signs and symptoms which is known as “ sick-bird syndrome.”