The avian respiratory system and its noninfectious disorders: A review

The avian respiratory system is well adapted to the manifold physiological requirements. The lungs are relatively small, though extremely functional. The main bronchus runs through the lungs to open in the air sacs. The ventrobronchi branches cranially from the main bronchus. More caudally, the dorsobronchi branches from the main bronchus. Then, the dorso-bronchi split to form the para-bronchi. The air sac walls in the pigeon (Columba livia) appear to consist of two perpendicularly arranged thin layers of connective tissue, covered with flat epithelium. Trauma, vitamin A deficiency and, hormonal unbalances are known to cause lesions in the respiratory system. On rare occasions, pathology of the trachea can be found. Aspirated particles of seeds or peanuts may lead to accumulations of fat in the main bronchus. More chronic irritation may lead the production of "Bronchiolar Associated Lymphoid Tissue". A variety of pathologies resulting in respiratory dysfunctions are described.     

The association between bloodwork,signalment, and urolithiasis in guinea pigs (Cavia porcellus)

Urolithiasis represents a common, potentially life-threatening condition in pet guinea pigs (Cavia porcellus). The purpose of this study is to determine the potential association between signalment, packed cell volume, total solids, selected biochemical parameters, and imaging evidence of urolithiasis in client-owned guinea pigs presented to two veterinary teaching hospitals. Medical record databases from two veterinary teaching hospitals were searched for cases of client-owned guinea pigs that had both a plasma biochemistry panel and an imaging study performed during one medical event. Other parameters including age, sex, weight, packed cell volume, and total solids were also recorded.Of the 81 guinea pigs that met the inclusion criteria, 32 animals (40%) had evidence of urolithiasis present on at least one of their imaging modalities. The odds for the imaging presence of urolithiasis increased with a decreasing packed cell volume, an increasing plasma creatinine concentration, and with a decreasing plasma phosphorus concentration.While these variables were statistically significant and associated with imaging presence of urolithiasis, they had low predictive value to discriminate between guinea pigs with and without imaging evidence of urolithiasis.Given the relatively high prevalence of urolithiasis in guinea pigs in this study, imaging is strongly recommended for every animal with suspected affliction.     

SPONTANEOUS PANCREATIC ISLET CELL ADENOMA WITH PERIPHERAL NEUROPATHY IN A PET RAT (RATTUS NORVEGICUS)

A pancreatic islet cell adenoma was suspected in a 2.5-year-old pet rat that was presented for lethargy and progressive paraparesis. Hypoglycemia was confirmed using a handheld glucometer. Mild improvement was noted after initial corticosteroid treatment. No evidence of a pituitary mass was identified on magnetic resonance imaging. Although a slight treatment response was observed following drug administration the patient's clinical condition deteriorated to the point that the owners elected to have the rat euthanized. Histopathologically, an islet cell adenoma was identified within the pancreas, along with peripheral neuropathy and muscle atrophy, which were consistent with clinical findings. Immunohistochemical staining of neoplastic cells was positive for insulin. Pancreatic islet cell adenomas are not commonly reported, and their clinical prevalence in pet rats is undetermined. The current report describes a case of pancreatic islet cell adenoma in a rat with concurrent peripheral neuropathy secondary to hypoglycemia.     

Monitoring Northern Bobwhite (Colinus virginianus) Populations in the Rolling Plains of Texas: Parasitic Infection Implications

The Northern bobwhite quail (Colinus virginianus) is an important gamebird among hunters that has been experiencing a nationwide decline for > 50 yr. In West Texas, one of the last regions to experience this downward trend, research on bobwhite populations has focused on habitat variables and, increasingly, on parasitic infection. In bobwhite, two of the most common parasites are the caecal worm (Aulonocephalus pennula) and eyeworm (Oxyspirura petrowi). To better document the state of bobwhite populations in the Rolling Plains Ecoregion, trapping, summer rooster counts, fall covey counts, and parasitic infection assessments were conducted in three counties during 2018. These efforts were compared with previous years for a longitudinal perspective. In 2018, bobwhite populations experienced a widespread decline, although some counties surveyed fared slightly better than others. More effort was required to trap fewer total bobwhite, and fewer roosters and coveys were counted than in previous years. In addition, in 2018, parasitic infection levels of caecal and eyeworms were higher than or similar to levels in previous years. Additional research is necessary to understand which factors influence bobwhite populations in allopatric locations and over time.     

Simulation modelling of potato virus Y spread in relation to initial inoculum and vector activity

Potato virus Y(PVY) is a non-persistent virus that is transmitted by many aphid species and causes significant damage to potato production. We constructed a spatially-explicit model simulating PVY spread in a potato field and used it to investigate possible effects of transmission efficiency, initial inoculum levels, vector behavior, vector abundance, and timing of peak vector activity on PVY incidence at the end of a simulated growing season. Lower PVY incidence in planted seed resulted in lower virus infection at the end of the season. However, when populations of efficient PVY vectors were high, significant PVY spread occurred even when initial virus inoculum was low. Non-colonizing aphids were more important for PVY spread compared to colonizing aphids, particularly at high densities. An early-season peak in the numbers of noncolonizing aphids resulted in the highest number of infected plants in the end of the season, while mid-and late-season peaks caused relatively little virus spread. Our results highlight the importance of integrating different techniques to prevent the number of PVY-infected plants from exceeding economically acceptable levels instead of trying to control aphids within potato fields. Such management plans should be implemented very early in a growing season.     

Impact of the COVID-19 pandemic on agricultural exports

The COVID-19 outbreak has shocked the world's economies in the year of 2020. As this pandemic spreads around the globe, many experts feared that the global food supplies might start running short, especially if supply chains were disrupted. COVID-19 also added to the uncertainty of the business operation. Therefore, it is critical to understand how COVID-19 pandemic affected global food supply and market. In this study, we investigate the impact of COVID-19 on agricultural export companies in China using a unique firm-level survey data. We found that although on average agricultural businesses experienced declines in the exports, exports of some agricultural products especially grain and oil held strong and even increased, implying the essential demand for staple food during the pandemic. Not surprisingly, exports of medicinal herb also increased significantly during the pandemic. However, exports of goods such as edible fungus and horticultural products sharply decreased. Our results also showed that in general, impact of COVID-19 on smaller firms was more severe than that on larger firms. The results of this study can provide useful guidance and implications for agricultural businesses and policy makers on their COVID-19 mitigation efforts to navigate this global pandemic.