Demographic and clinical characteristics of geriatric horses: 467 cases (1989-1999)

OBJECTIVE: To describe the demographic and clinical characteristics of a population of geriatric horses. DESIGN: Retrospective study. ANIMALS: 467 horses that were > or = 20 years of age. PROCEDURE: Medical records of 539 geriatric horses that were evaluated at a university large animal hospital between 1989 and 1999 were reviewed. Data collected included signalment, reason for evaluation, specific diagnoses, surgical procedures, inpatient or outpatient care, duration of hospitalization, and outcome. RESULTS: 467 horses met the criteria for inclusion in the study. Horses that were > or = 20 years of age comprised 2.2 and 12.5% of horses evaluated during 1989 and 1999, respectively. Pony breeds were significantly overrepresented in the > or = 30-years-of-age group. Gastrointestinal tract, musculoskeletal, and respiratory tract problems were most frequently reported. Colic was the most common clinical sign, followed by lameness. Diagnoses made most frequently included pituitary dysfunction, strangulating lipoma of the small intestine, laminitis, heaves, large colon impaction, and gastric ulcers. Pituitary dysfunction was significantly more prevalent in horses that were > 30 years of age. Laminitis was significantly associated with the presence of pituitary dysfunction. CONCLUSIONS AND CLINICAL RELEVANCE: It was difficult to assess association of age with illnesses identified in these horses. Demographic data and information regarding common diseases of horses that are > or = 20 years of age are limited but will become increasingly important as this geriatric population increases.     

Assessment of clinical characteristics,management practices,and activities of geriatric horses

OBJECTIVE: To describe the demographic and clinical characteristics, management practices, and owner perception of a population of geriatric horses, and to compare these data with findings in a group of younger horses. DESIGN: Original study. ANIMALS: 218 horses. PROCEDURE: Data were collected via a survey tool from owners of 165 horses that were > or = 20 years of age and 53 horses that were < 20 years of age. RESULTS: Compared with young horses, the geriatric group included a significantly greater number of ponies; geriatric horses were also more likely to have a history of colic, dental disease, tumors, lameness, and pituitary disease, but not laminitis, diarrhea, allergies, respiratory tract disease, thyroid disease, or fractures. Horses that had participated in Western equestrian disciplines were more likely to have a history of lameness. Among old horses, those with pituitary dysfunction were more likely to have a history of laminitis than those without pituitary dysfunction. Geriatric horses were more likely to have long hair and shedding abnormalities than were younger horses. Owners perceived their horses as old at approximately 22 years of age. In horses older than 16.5 years of age, age was a negative factor in the purchase of horses. CONCLUSIONS AND CLINICAL RELEVANCE: Geriatric and young horses share some similar health problems, but old horses have distinct health problems and veterinary medical requirements. The management and athletic history of horses may influence health as they age.     

Comparison of the intravenous chicken challenge method with the embryo lethality assay for studies in avian colibacillosis

In previous studies, the embryo lethality assay (ELA) was able to discriminate between virulent and avirulent avian Escherichia coli isolates and to predict percent mortality of the embryos resulting from an isolate based on three traits. The abilities to resist host complement, presence of Colicin V activity, and presence of the increased serum survival gene cluster (iss), were used together in a logistic regression analysis to predict the percentage of embryo deaths resulting from each of 20 avian E. coli isolates used in the ELA. In the present study, the same 20 isolates are used in an intravenous chicken challenge model in an effort to determine whether the ELA could be used to replace chicken challenge studies. Correlations between the mortality and a combination of mortality and morbidity (the survivors at trial termination with lesions suggestive of colibacillosis) and the previous ELA results and with selected isolate traits were performed. Additionally, resulting body weights in surviving chickens were compared between groups. The highest positive correlations were observed between the ELA and the combined mortality/morbidity of the intravenous challenge (r = 0.861, P < 0.0001 for the first ELA challenge, and r = 0.830, P < 0.0001 for the second ELA challenge). The IV challenge combined mortality/morbidity results had the highest correlation coefficients with the presence of iss (r = 0.864, P < 0.0001) and the expression of ColV (r = 0.878, P < 0.0001). The presence of tsh was slightly correlated with mortality (r = 0.465, P = .0389) but demonstrated a higher correlation with the combined mortality and morbidity of the IV challenge (r = 0.558, P = 0.0106). Even though the ELA results in a higher number of nonspecific deaths, the two challenge methods exhibit similar results and a high correlation with each other. Interestingly, some of the isolates showed differences in their ability to cause mortality between the ELA and the IV challenge model. Furthermore, some isolates reflected significant differences in body weights of surviving birds at IV trial termination.     

Roles of stolbur phytoplasma and <Emphasis Type="Italic">Reptalus panzeri</Emphasis> (Cixiinae,Auchenorrhyncha) in the epidemiology of Maize redness in Serbia

Maize redness (MR), a disease causing midrib, leaf and stalk reddening and abnormal ear development in maize, has been reported from Serbia, Romania and Bulgaria for 50 years. Recent epiphytotics reduced yields by 40%–90% in southern Banat, Serbia. MR was recently associated with the presence of the stolbur phytoplasma, although the epidemiology of the disease remained unknown. Diseased fields in southern Banat were surveyed for potential vectors of the phytoplasma during 2005 and 2006, and high populations of Reptalus panzeri were found. In affected fields, 20% of the R. panzeri individuals and 85% of symptomatic maize plants carried the stolbur phytoplasma. When stolbur phytoplasma-infected R. panzeri were introduced into insect-free mesh cages containing healthy maize plants, midrib and leaf reddening developed on 48% of plants and stolbur phytoplasma was detected in 90% of the symptomatic plants. No symptoms or phytoplasma-positive plants were found in cages without insects. These data indicate that MR symptoms are associated with the stolbur phytoplasma. Reptalus panzeri is both abundant in affected fields and can transmit the stolbur phytoplasma, indicating the insect is likely to be a major vector of MR.