Retrospective Evaluation of Horses Diagnosed with Neuroborreliosis on Postmortem Examination: 16 Cases (2004-2015)

BACKGROUND

Equine neuroborreliosis (NB), Lyme disease, is difficult to diagnose and has limited description in the literature.

OBJECTIVE

Provide a detailed description of clinical signs, diagnostic, and pathologic findings of horses with NB.

ANIMALS

Sixteen horses with histologically confirmed NB.

METHODS

Retrospective review of medical records at the University of Pennsylvania and via an ACVIM listserv query with inclusion criteria requiring possible exposure to Borrelia burgdorferi and histologic findings consistent with previous reports of NB without evidence of other disease.

RESULTS

Sixteen horses were identified, 12 of which had additional evidence of NB. Clinical signs were variable including muscle atrophy or weight loss (12), cranial nerve deficits (11), ataxia (10), changes in behavior (9), dysphagia (7), fasciculations (6), neck stiffness (6), episodic respiratory distress (5), uveitis (5), fever (2), joint effusion (2), and cardiac arrhythmias (1). Serologic analysis was positive for B. burgdorferi infection in 6/13 cases tested. CSF abnormalities were present in 8/13 cases tested, including xanthochromia (4/13), increased total protein (5/13; median: 91 mg/dL, range: 25-219 mg/dL), and a neutrophilic (6/13) or lymphocytic (2/13) pleocytosis (median: 25 nucleated cells/μL, range: 0-922 nucleated cells/μL). PCR on CSF for B. burgdorferi was negative in the 7 cases that were tested.

CONCLUSION AND CLINICAL IMPORTANCE

Diagnosis of equine NB is challenging due to variable clinical presentation and lack of sensitive and specific diagnostic tests. Negative serology and normal CSF analysis do not exclude the diagnosis of NB.

Fasting blood glucose and insulin sensitivity are unaffected by HAART duration in Cameroonians receiving first-line antiretroviral treatment

AIMS

This study assessed the relationship between highly active antiretroviral therapy (HAART) duration and cardiometabolic disorders in HIV-infected Cameroonians.

METHODS

HIV-infected Cameroonians aged 21 years or above were cross-sectionally recruited at the Yaoundé Central Hospital, a certified HIV care centre, and their anthropometry, body composition (impedancemetry), fasting blood glucose (FBG) and lipid levels, and insulin sensitivity (IS; short insulin tolerance test) were measured.

RESULTS

A total of 143 participants with various durations of HAART [treatment-naïve (n=28), 1-13 months (n=44), 14-33 months (n=35) and 34-86 months (n=36)] were recruited. They were mostly women (72%), and had a mean age of 39.5 (SD: 9.8) years. Half (52%) were using a stavudine-containing regimen. There was a significant trend towards a positive change in body mass index and waist-to-hip ratio with increasing duration of HAART (all P=0.02). Systolic (P=0.04) and diastolic (P=0.03) blood pressure, total cholesterol (P=0.01), prevalence of hypertension (P=0.04) and hypercholesterolaemia (P=0.007) were also significantly increased with HAART duration, whereas triglycerides, FBG and IS were unaffected. Clustering of metabolic disorders increased (P=0.02 for ≥1 component of the metabolic syndrome and P=0.09 for ≥2 components) with HAART duration.

CONCLUSION

HAART duration is associated with obesity, fat distribution, blood pressure and cholesterol levels in HIV-infected Cameroonians, but does not appear to significantly affect glucose metabolism.

Flow-mediated K(+) secretion in horses intoxicated with lolitrem B (perennial ryegrass staggers)

AIM

To investigate the effects of lolitrem B intoxication on renal K(+) secretion in response to increased tubular flow rates.

METHODS

Results are derived from a repeated measure pilot study of seven horses fed non-perennial ryegrass feed for a week prior to exposing them to perennial ryegrass seed and hay that contained an average of 2 ppm lolitrem B. At the end of the control and treatment period frusemide (1 mg/kg I/V) was administered and serial fractional excretion of K(+)(FEK(+)) and fractional excretion of Na(+)(FENa(+)) calculated. Baseline concentration of aldosterone in plasma, serum K(+)concentration and feed K(+) concentration were also compared.

RESULTS

Key findings included a reduced change in FEK(+) from 0 to 15 minutes in response to frusemide administration (p=0.022, Wilcoxon signed-rank test) and a reduced baseline concentration of aldosterone in plasma (p=0.022, Wilcoxon signed-rank test) during the treatment period compared with the control.

CONCLUSIONS

Results suggest that lolitrem B intoxication reduced flow-mediated K(+) secretion and interfered with aldosterone production or secretion. However, further investigation is required to validate these findings and to further elucidate the underlying pathophysiology.

CLINICAL RELEVANCE

Lolitrem B intoxication in horses may cause disruption to electrolyte handling in addition to neurological deficits.