No abstract

A 2.5‐year‐old Barzona bull presented for right‐sided head tilt and decreased libido of three‐week duration. Video otoscopy of the external ear canal revealed severe erythema, stenosis, purulent debris, necrosis and numerous live Raillietia auris mites. Decontamination via saline lavages, injectable ceftiofur and dexamethasone treatments failed. Topical 10% permethrin solution in mineral oil proved efficacious at killing R. auris mites, and injectable tulathromycin and dexamethasone were administered until resolution of the bacterial otitis; however, the head tilt persisted, and the bull was slaughtered. Systemic administration of ceftiofur was not effective as a sole treatment, and topical antimicrobial treatments were significantly limited per Food Animal Residue Avoidance Databank regulations. Video otoscopy was a useful tool in the rapid diagnosis and management of the otitis. This case highlights the long‐lasting impact of otitis secondary to R. auris mite infestation and the importance of ectoparasite control and rapid treatment of otitis in bovids.

Hair cycle arrest is a relatively common condition of double‐coated breeds with a complex and poorly defined pathogenesis. Several therapeutic options have been described; however, the clinical response is often variable, and some treatment options can be invasive and may invoke adverse effects. Herein is described the first case of hair cycle arrest in a Pembroke Welsh corgi, which was successfully treated with photobiomodulation therapy. Photobiomodulation therapy (previously known as low‐level laser therapy) proved to be a well‐tolerated treatment, with no adverse effects appreciated. Videodermoscopy, a non‐invasive technique, was utilised to objectively measure response to treatment and was a readily repeatable tool for in‐hospital use. This case highlights a previously unrecognised breed to consider for the diagnosis of hair cycle arrest, as well a new indication for photobiomodulation therapy as a treatment option and videodermoscopy diagnostic analysis software as an aid in case management for practitioners moving forward.

BackgroundAdditional efficacious immunomodulatory treatment is needed for the management of immune‐mediated disease in horses. Mycophenolate mofetil (MMF) is an immunosuppressive drug that warrants assessment as a viable therapeutic agent for horses.Hypothesis/ObjectivesTo evaluate the pharmacokinetics (PK) of multiple‐day oral dosing of MMF in healthy horses and to determine the tolerability of this dosing regimen.AnimalsSix healthy Standardbred mares.MethodsHorses received MMF 10 mg/kg PO q12h for 7 days in the fed state. Serial sampling was performed over 12 hours on Days 1 and 7 with trough samples collected every 24 hours, immediately before morning drug administration. Noncompartmental PK analyses were performed to determine primary PK parameters, followed by calculation of geometric means and coefficients of variation. A CBC, serum biochemical profile, physical examination, and fecal scoring were used to assess dose tolerability.ResultsSeven days of treatment resulted in a mycophenolic acid (MPA) area under the curve (AUC0‐12) of 12 594 h × ng/mL (8567‐19 488 h × ng/mL) and terminal half‐life (T1/2) of 11.3 hours (7.5‐15.9 hours), yielding minor metabolite accumulation in all horses treated. Salmonellosis was detected in the feces of 2 horses by Day 7, and all horses developed myelosuppression, hyperbilirubinemia, hyporexia, decreased gastrointestinal motility, and decreased fecal output by the seventh day of treatment.Conclusion and Clinical ImportanceAdministration of MMF at 10 mg/kg PO q12h resulted in hematologic and clinical toxicity within 1 week of treatment. A decreased MMF dose, frequency, or both is needed to avoid colic. Drug monitoring should include frequent hemograms, serum biochemical profiles, and strict biosecurity protocols.