May 2023 newsletter
Hello, Vetaheader! Our monthly newsletter is here.
First, we have a paper on the effectiveness of common disinfecting agents against isolates of Nannizziopsis guarroi. Nannizziopsis guarroi is a keratinophilic fungus, and an important cause of dermatomycosis in companion lizards. It was previously known as “yellow fungus disease”, but this terminology is outdated. This fungus has prolonged environmental persistence, can be cultured from environment for prolonged period, and its mode of transmission is unknown.
Therefore, this study tested the qualitative in vitro–disinfecting capability of eight commonly used disinfectants, at two different contact times (2 and 10 min) with three different aqueous fungal concentrations of four molecularly confirmed N. guarroi isolates. After contact with disinfectant or saline (control), the isolates were incubated, and photographic images were taken of plate growth on day 10. Images of each plate were scored using a semiquantitative scoring system. The only disinfectant that completely inhibited growth for all four isolates at both contact times and at all three isolate dilutions was the 10% dilution of commercial bleach (0.74% hypochlorite).
It is important to note that this study did not include activated hydrogen peroxide within the disinfectants tested, and did not test non-chemical disinfectants (UV light and desiccation). The take home message is to use 10% bleach for at least 2 minutes after cleaning biological material from surfaces to disinfect environment for N. guarroi.
Second, we have a study characterizing cells collected from nasolacrimal duct flush samples in healthy rabbits. This paper is co-authored by our dear Dr. Miranda Sadar!
Ophthalmologic diseases have an incidence rate of approximately 10% in pet rabbits, and dacryocystitis (inflammation of the nasolacrimal drainage system) is commonly seen in these cases. It can be accompanied by nasolacrimal obstruction, leading to caseous material accumulation in conjunctival sac, particularly in cases secondary to dental disease.
Nasolacrimal duct flushing is frequently performed on domestic rabbits. The procedure is technically straightforward, requires minimal equipment, and can be both diagnostically and therapeutically useful. Since cytological quantification of nasolacrimal duct flushes of healthy rabbits had not been reported previously, the researchers reviewed cytocentrifuged preparations of nasolacrimal duct flushes from 10 rabbits (n = 20 eyes).
Their results showed a low cell count (median 500 cells/μL; min <500 cells/μL, max 1500 cells/μL). Columnar cells were found in highest percentages, which is expected, as duct mucosa is lined with columnar stratified or pseudostratified epithelium. All samples had mixed population of bacteria, including cocci and rod-shaped bacteria. The take home message is: the typical cellularity in the nasolacrimal duct of healthy rabbits has heterophils in higher percentages and an absence of other polymorphonuclear cells.
Lastly, we have a study on the pharmacokinetics of cannabidiol (CBD) in Hispaniolan Amazon parrot (Amazona ventralis). Given its potential as a treatment option that may alleviate pain in companion animals and humans, a pilot study was performed, in which a single oral dose of CBD in hemp oil at 10 mg/kg and 20 mg/kg were considered too low for clinical use in this species. Therefore, a study was designed, in which 14 healthy adult parrots of both sexes and weighing were enrolled, and divided into two groups, for 60 mg/kg PO and 120 mg/kg PO.
The results showed that the serum half-life could not be determined in the 60 mg/kg treatment, but was 1.28 hours at 120 mg/kg. Adverse effects were not observed in any bird. Plasma concentrations extremely variable – this is likely related in interindividual differences in first pass metabolism and amount of food in crop at dosing, leading to a variable amount of crop retention.
The take home message is: given the highly variable results and short half-life of the drug in Hispaniolan Amazon parrots, even at high doses, suggests that this drug formulation was inconsistent in achieving targeted concentrations as reported in other animal species.
Hope these help you, and I will see you next month!
Sincerely,
Laila Proença
