Veterinary Research Highlight

A paper published in The Equine Veterinary Journal submitted by Madison Dedman, Lincoln Memorial University

Using mycobacterium cell wall fraction to decrease equine chorionic gonadotropin after abortion

Carleigh E. Fedorka, Maria R. Schnobrich, Natacha D. Muderspach, Kirsten E. Scoggin, Madison T. Dedman, Kelly E. Weigle, Mary G. May, Heidi Twist, Cara R. Linse, Robert H. Douglas, Mats H. T. Troedsson

Abstract

Background: Equine embryonic loss following the development of endometrial cups delays return to cyclicity due to the production of equine chorionic gonadotropin (eCG). Natural degradation of endometrial cups coincides with an influx of immune cells at 100–120 days of gestation, but therapeutic stimulation of reduced eCG production

has been relatively unsuccessful. Recently, we observed an increase in pro-inflammatory cytokine production following the use of the immunostimulant mycobacterium cell wall fraction (MCWF).

Objectives: To evaluate the efficacy of hysteroscopic-guided injection of MCWF on the accelerated decline of eCG secretion.

Study design: In vivo experiment.

Methods: Mares were pharmacologically aborted at 40–45 days of gestation, and then divided into groups: MCWF-treated (6 mg MCWF suspended in 20 mL LRS; n = 10) and Control (20 mL LRS; n = 6). Five days after abortion, hysteroscopic-guided injection of endometrial cups was performed, with 1 mL of volume placed into each visible endometrial cup. This was repeated 7 days later. Trans-rectal ultrasonography was performed to monitor ovarian activity, and serum was obtained to assess eCG and cytokine concentrations.

Results: Concentrations of eCG decreased in the MCWF-treated group (p < 0.01) with a significant suppression noted as early as 14 days after onset of treatment and remained suppressed for the duration of the study. This coincided with an increase in peripheral IFN-γ (p < 0.01) and IL-1β (p < 0.01) concentrations. Eight out of ten MCWF-treated mares (80%) developed pre-ovulatory follicles, in comparison to 2/6 controls (33%). A pre-ovulatory follicle was noted 23 ± 4 days after onset of treatment.

Main limitations: No pregnancy data was obtained following treatment.

Conclusions: This is the first report of a treatment for the accelerated reduction of eCG following abortion. Stimulation of this process allowed mares to develop a pre-ovulatory follicle within a month of MCWF treatment onset, granting repeat attempts at breeding within the confines of a single breeding season.

Photography

Submitted by Yuhui Yang, Royal (Dick) School of Veterinary Studies 

Cutest Pet

"Dennis" Submitted by Megan Dennis, University of Georgia

Foot in Mouth Disease

Submitted by Hannah King North, Carolina State University

Veterinary Research Highlight

A paper published in The Journal of Exotic Pet Medicine submitted by Varun Seth, University of Illinois

Benzalkonium chloride and polyhexanide disinfectant (F10 SC) requires off- label use for environmental disinfection to be effective against Nannizziopsis guarroi

Varun Setha, Laura Adamovicz, Krista A Keller

Background: Nannizziopsis guarroi causes contagious dermatomycosis in lizards. Treatment failures are commonly encountered and may be related to the prolonged environmental persistence of this microbe. F10 SC, containing benzalkonium chloride and polyhexanide, is a commercially available disinfectant often used in management of reptile infections particularly by hobbyists and breeders.

Methods: Three molecularly confirmed isolates of N. guarroi were aseptically collected into aqueous suspensions and diluted to 2 fungal concentrations. Each concentration of each isolate was exposed to 3 dilutions of F10 SC (1:20, 1:100, 1:500) for a 10-minute contact time based upon product label recommendations. Culture growth on standard potato-dextrose agar after 10 days of incubation was assessed for characteristic colony growth and cytology evaluation for fungal elements. The experimental design included control conditions as well as biological and technical replication.

Results: All control conditions grew characteristic fungal colonies with fungal elements visualized cytologically. Both concentrations of all 3 isolates exhibited no growth after contact with the highest concentration of the disinfectant (1:20) however fungal growth was evident after contact with the lowest concentration of disinfectant (1:500).

Conclusions and clinical relevance: Environments exposed and/or contaminated with N. guarroi can be effectively disinfected using F10 SC for a contact time of 10 minutes. Exposure to living tissue has not been evaluated and cannot be recommended at this time. Further work evaluating F10 SC disinfection against clinically relevant microbes should be pursued.