Clinical, pathologic, and epidemiologic features of nocardioform placentitis in the mare.

Placentitis is the leading cause of infectious abortion in the horse and contributes to roughly 19% of all abortions in the United States. A type of placental infection, nocardioform placentitis (NP) is associated with gram-positive branching actinomycetes localized within the ventral body of the feto-maternal interface to create a lymphoplasmacytic mucoid lesion. While the etiology of this disease is poorly described, this placental infection continues to cause episodic abortions in addition to weak and/or growth retarded neonates. The goal of the present study was to perform a comprehensive analysis of pregnancies associated with a nocardioform-affected placenta and make inferences into the epidemiology of this elusive disease. To do so, 264 mares were enrolled in the study, with 145 as having suspected disease (n = 145; NP) either based on pregnancy-related complications or postpartum placental evaluation, while an additional 119 were enrolled as healthy pregnancies (n = 119; CON). Following diagnosis as either NP or CON based on gross and histopathology at the University of Kentucky Veterinary Diagnostic Laboratory, information was gathered on the mares and neonates for comparisons between diseased and healthy pregnancies. Clinically, a significant portion of diseased mares had clinical indications of NP, including premature mammary gland development, thickening of the placenta noted on transrectal ultrasonography, and separation between the chorioallantois and endometrium noted on abdominal ultrasonography, while vulvar discharge was not commonly noted. Additionally, NP was correlated with increased mare age, decreased gestational length, and decreased neonatal weight, although neonatal IgG and WBC were comparable to CON. Incidence of NP was not correlated with last breeding date, pre- and post-breeding therapeutics, parity, prophylactic medications, or housing. Additionally, NP did not affect postpartum fertility. While NP was associated with a poor neonatal outcome (abortion and/or growth retarded neonate), this did not appear to be influenced by the bacteria isolated (Amycolatopsis spp. vs. Crossiella equi), and mares diagnosed with NP do not appear to be infectious to other pregnant mares nor have repetitive years of the disease. Interestingly, lesion size was positively correlated with last breeding date, as mares bred later in the breeding season correlating with a larger placental lesion. In conclusion, while the etiology of NP continues to elude researchers, the epidemiology of this disease has gained clarity, providing inferences into the management of suspect mares.

Evaluation of updated sepsis scoring systems and systemic inflammatory response syndrome criteria and their association with sepsis in equine neonates.

BACKGROUND: The original equine sepsis score provided a method of identifying foals with sepsis. New variables associated with sepsis have been evaluated, but the sepsis score has not been updated. OBJECTIVES: To evaluate the sensitivity and specificity of 2 updated sepsis scores and the systemic inflammatory response syndrome (SIRS) criteria in regard to detecting sepsis in foals. ANIMALS: Two-hundred and seventy-three ill foals and 25 healthy control foals. METHODS: Historical, physical examination, and clinicopathologic findings were used to calculate the original sepsis score and 2 updated sepsis scores. SIRS criteria were also evaluated. Sepsis scores and positive SIRS scores were statistically compared to foals with sepsis. RESULTS: One-hundred and twenty-six foals were septic and 147 sick-nonseptic. The original and updated sepsis scores were significantly higher in septic foals as compared to sick-nonseptic and healthy foals. The sensitivity and specificity of the updated sepsis scores to predict sepsis were not significantly better than those of the original sepsis score. One-hundred and twenty-seven of 273 (46.5%) foals met the original SIRS criteria and 88/273 (32%) foals met the equine neonatal SIRS criteria. The original SIRS criteria had similar sensitivity and specificity for predicting sepsis as did the 3 sepsis scores in our study. CONCLUSIONS AND CLINICAL IMPORTANCE: The updated sepsis scores did not provide improved ability in predicting sepsis. Fulfilling the original SIRS criteria provided similar sensitivity and specificity in predicting sepsis as the modified sepsis score and might serve as a diagnostic aid in identifying foals at risk for sepsis.

Use of Renal Replacement Therapy in a Neonatal Foal with Postresuscitation Acute Renal Failure.

A newborn foal was presented because it was unresponsive and in cardiopulmonary arrest. Aggressive cardiopulmonary cerebral resuscitation was administered to the foal, which revived the foal; however, acute renal failure developed. Fluid retention and azotemia occurred although the foal was alert and able to suckle. A 6-hour renal replacement therapy session using hemodiafiltration and a continuous renal replacement therapy machine was administered to the foal at 3 days of age which lowered the foal's azotemia and facilitated removal of some of the excess body fluid. Despite therapy, the foal developed pulmonary edema and was euthanized. Although the foal in this case did not survive, this report highlights the possibility of developing postresuscitation complications such as acute renal failure and describes the use of renal replacement therapy using hemodiafiltration as a viable option in neonatal foals with acute kidney injury.

Pharmacokinetics and preliminary safety evaluation of azithromycin in adult horses.

Azithromycin is widely used in foals but has not been studied in adult horses. The goals of this study were to determine the pharmacokinetic profile and to make a preliminary assessment of the safety of azithromycin in adult horses. Azithromycin was administered intravenously (5 mg/kg) and intragastrically (10 mg/kg) to six healthy mares in a crossover design. Serial plasma samples, blood neutrophils, and pulmonary macrophages were collected for the measurement of azithromycin concentrations. Azithromycin was also administered orally (10 mg/kg) once a day for 5 days to five healthy mares for preliminary evaluation of safety in adult horses. The bioavailability of azithromycin following intragastric administration was 45 ± 12%. Concentrations within peripheral neutrophils and bronchoalveolar macrophages were several fold higher than that of plasma. Mild decreases in appetite (n = 3) and alterations in fecal consistency (n = 3) were noted following repeated oral administration. The pharmacokinetic profiles of azithromycin in adult horses, especially the slow elimination rate and intraneutrophil and intrapulmonary macrophage accumulation, demonstrate that it is conducive to use in this age group. Because of the gastrointestinal alterations noted, further studies are warranted before azithromycin can be recommended for use in adult horses.

Actinomyces species as a cause of abscesses in nine horses.

The characteristics, history, clinical signs, treatment and outcome of nine horses with abscesses caused by Actinomyces species were reviewed. dna sequencing was used to determine the species of one of the isolates. The horses were one to 11 years of age, and the abscesses were most commonly located in the submandibular and retropharyngeal regions. The bacterium was usually cultured as the sole isolate and the horses were most often affected in the autumn. Most of the abscesses were treated with antimicrobials and drainage, but some of them recurred. The horses with submandibular abscesses had residual scar tissue that in some cases did not resolve.