A survey of equine parasite control practices in Tennessee

A weighted, random sample of 130 horse owners in Tennessee was selected from subscribers to an equine newsletter published by the Agricultural Extension Service. Data about the participants' farms, horses, parasite control practices, and sources of information regarding equine parasite control were obtained through a telephone survey. The response rate was 98%. The typical respondent kept 4 horses on 2 pastures totaling 15 acres, and did not rotate pastures as a parasite control measure. The majority (83%) of horse owners indicated that they administered anthelmintics according to a regular schedule; 9% delayed deworming until the onset of weight loss. Proportions of owners deworming the various classes of horses at least 1, 2, 3, or 4 times annually were as follows: foals (0 to 6 months) 100, 60, 15, and 0%, respectively; weanlings (6 to 12 months) 100, 91, 32, and 0%, respectively; yearlings (1 to 2 years) 100, 100, 86, and 51%, respectively; and adults (greater than 2 years) 100, 94, 56, and 24%, respectively. Median treatments of yearlings and adults were evenly spaced at 6-, 4-, or 3-month intervals when the owners dewormed 2, 3, or 4 times annually, respectively. Mean intervals between treatments of foals and weanlings were less regular. Of the horse owners who dewormed 2 or more times annually, most (53 to 80%) used the same product exclusively for all treatments. In all age classes of horses, ivermectin paste (46 to 63%) was the most common product used, followed by tube deworming (23 to 38%) and use of benzimidazoles (4 to 16%).(ABSTRACT TRUNCATED AT 250 WORDS)     

New types of virus infections of domestic animals in the German Democratic Republic. 3. Seroepizootiologic and experimental studies of herpesvirus infections in sheep--the etiology of pulmonary adenomatosis

Neutralisation tests for antibodies against ovine herpesvirus were applied to 848 sera which had been sampled from different sheep herds across the GDR. Between six and 20 percent of sheep in the herds tested exhibited neutralising antibodies, notwithstanding their pulmonary adenomatosis status. Incidence and titre distribution of antibodies against ovine herpesviruses in pulmonary adenomatosis herds were identical with those recorded from unsuspected herds. From among 21 sheep with pathomorphologically secured pulmonary adenomatosis, six animals exhibited antibody titres just as high as those recorded from responders of all herds examined. Lambs were obtained by hysterectomy and raised without mothers and were experimentally infected with Herpesvirus ovis. All of these animals responded to infection by clearly rising titres (between 1:2 and 1:32). Adenomatous pulmonary lesions were not recordable from any of them. One lamb, following experimental ovine herpesvirus infection, exhibition, exhibited subclinical interstitial pneumonia. Herpesvirus ovis has been widespread in sheep herds across the GDR. The authors' serological and experimental investigations do not support the assumption of an aetiological relationship between ovine herpesvirus infection and incidence of pulmonary adenomatosis.     

Use of a multivariable model to estimate the probability of discharge in hospitalized foals that are 7 days of age or less

OBJECTIVE: To create a mathematical model to assist in early prediction of the probability of discharge in hospitalized foals < or= 7 days old. STUDY DESIGN: Prospective study. ANIMALS: 1,073 foals. PROCEDURES: Medical records from 910 hospitalized foals < or = 7 days old for which outcome was recorded as died or discharged alive were reviewed. Thirty-four variables including historical information, physical examination findings, and laboratory results were examined for association with survival. Variables associated with being discharged alive were entered into a multivariable logistic regression model. Accuracy of the model was validated prospectively on data from 163 foals. RESULTS: Factors in the final model included age group, ability to stand, presence of a suckle reflex, WBC count, serum creatinine concentration, and anion gap. Sensitivity and specificity of the model to predict live discharge were 92% and 74%, respectively, in the retrospective population and 90% and 46%, respectively, in the prospective population. Accuracy of an equine clinician's initial prediction of the foal being discharged alive was 83%, and accuracy of the model's prediction was 81%. Combining the clinician's prediction of probability of live discharge with that of the model significantly increased (median increase, 12%) the accuracy of the prediction for foals that were discharged and nonsignificantly decreased (median decrease, 9%) the accuracy of the predication for nonsurvivors. CONCLUSIONS AND CLINICAL RELEVANCE: Combining the clinician's initial predication of the probability of a foal being discharged alive with that of the model appeared to provide a more precise early estimate of the probability of live discharge for hospitalized foals.     

Ultrastructural Characteristics of Non-matured and In Vitro Matured Oocytes Collected from Pre-pubertal and Adult Domestic Cat Ovaries

The present study describes the ultrastructural characteristics of cat oocytes before maturation and after 12- and 24-h in vitro maturation (IVM). Oocytes were recovered from pre-pubertal and adult queen ovaries after ovariohysterectomy and a proportion were stored in glutaraldehyde at 4°C until examination by transmission electronic microscopy (TEM). Those selected for maturation were cultured before TEM in DMEM for 12 and 24 h at 38°C in a humidified environment of 5% O₂, 5% CO₂ and 90% N₂. Specimens were divided into six groups: non-matured oocytes from pre-pubertal queens (PP0), non-matured oocytes from adult queens (A0), 12-h in vitro matured oocytes from pre-pubertal queens (PP12), 12-h in vitro matured oocytes from adult queens (A12), 24-h in vitro matured oocytes from pre-pubertal queens (PP24) and 24-h in vitro matured oocytes from adult queens (A24). Across the treatment groups, it was possible to observe differences in the thickness of the perivitelline space, the penetration of cumulus cell projections forming a junctional complex, distribution and density of small vesicles, lipid droplets, microvilli, mitochondria and cortical granules and variable degrees of development of Golgi complexes. These findings demonstrated that ultrastructural analysis of oocytes matured in vitro is a valuable tool to evaluate oocyte cytoplasmic maturation and that this IVM protocol was efficient in inducing gradual morphological changes necessary for cytoplasmic maturation of pre-pubertal and adult cat oocytes.     

Retrospective evaluation of sex hormones and steroid hormone intermediates in dogs with alopecia

The purpose of this study was to determine if there are specific steroid hormone aberrations associated with suspect endocrine alopecias in dogs in whom hypothyroidism and hyperadrenocorticism have been excluded. Steroid hormone panels submitted to the UTCVM endocrinology laboratory over a 7.5-year period (783 samples) from dogs with alopecia were reviewed. During this period, 276 dogs met the criteria for inclusion and were comprised of 54 different breeds. Approximately 73% of dogs had at least one baseline or post-ACTH stimulation steroid hormone intermediate greater than the normal range. The most frequent hormone elevation noted was for progesterone (57.6% of samples). When compared with normal dogs, oestradiol was significantly greater in Keeshond dogs and progesterone was significantly greater in Pomeranian and Siberian Husky dogs. Not all individual dogs had hormone abnormalities. Chow Chow, Samoyed and Malamute dogs had the greatest percentage of normal steroid hormone intermediates of the dogs in this study. Baseline cortisol concentrations were significantly correlated with progesterone, 17-hydroxyprogesterone (17-OHP) and androstenedione. Results of this study suggest that the pathomechanism of the alopecia, at least for some breeds, may not relate to steroid hormone intermediates and emphasizes the need for breed specific normals.     

Association of breed with the diagnosis of congenital portosystemic shunts in dogs: 2,400 cases (1980-2002)

OBJECTIVE: To determine the annual and overall proportion of diagnoses of congenital portosystemic shunts (CPSS) in dogs and identify breeds at increased risk for CPSS. DESIGN: Retrospective study. ANIMALS: 2,400 dogs with CPSS from veterinary teaching hospitals that reported to the Veterinary Medical Database (VMDB) from January 1, 1980 to February 28, 2002. PROCEDURE: The proportion of diagnoses of CPSS was calculated for all dogs and each breed recorded in the VMDB annually and for the 22.2-year period. Odds ratios and adjusted confidence intervals were calculated for breeds with at least 100 accessions by comparing odds of each breed with a diagnosis of CPSS with that of mixed-breed dogs. RESULTS: Congenital portosystemic shunts were reported in 0.18% of all dogs and 0.05% of mixed-breed dogs. The proportion of diagnoses of CPSS increased from 5 in 10,000 dogs in 1980 to 5 in 1,000 dogs in 2001. Yorkshire Terriers had the greatest total number of diagnoses of CPSS. Thirty-three breeds were significantly more likely to have a diagnosis of CPSS, compared with mixed-breed dogs. The greatest proportions of diagnoses were found in Havanese (3.2%), Yorkshire Terriers (2.9%), Maltese (1.6%), Dandie Dinmont Terriers (1.6%), and Pugs (1.3%). CONCLUSIONS AND CLINICAL RELEVANCE: Certain breeds appear to be at increased risk for CPSS, compared with mixed-breed dogs. The increased odds ratios among specific breeds support the hypothesis of a genetic predisposition for CPSS. Clients and veterinarians should consider appropriate diagnostic tests for dogs with clinical signs and those used for breeding from breeds with increased risk of CPSS.     

A comparison of the mechanical strength of two stapled anastomosis techniques for equine small intestine

OBJECTIVE: To compare bursting strength, time of construction, and cost of a closed one-stage, stapled functional end-to-end jejunojejunostomy (FEE) with a stapled side-to-side jejunojejunostomy (STS). STUDY DESIGN: Experimental, randomized block design. ANIMALS: Seven adult horses without gastrointestinal disease. METHODS: The jejunum was isolated, and three FEE, three STS, and three control segments were created in each horse using a randomized block design. Anastomosis time was recorded. The intraluminal pressure at failure and mode of failure were recorded. Length at failure was measured on digitized images. Bursting pressure (BP), bursting wall tension (BWT), anastomosis time, and cost were compared. RESULTS: Control jejunal segments were stronger (P < or = .0001) in bursting strength and bursting wall tension (P < or = .0001) than either anastomosis type; no difference was found between anastomosis types for either variable. Functional end-to-end jejunojejunostomy was significantly quicker and less costly than STS (P < or = .0001). CONCLUSIONS: Mechanically there were no significant differences between the FEE and STS techniques. The FEE technique maintained the physiologic direction of peristalsis of the segments, required less tissue manipulation, and was faster and more economical to create. CLINICAL RELEVANCE: The FEE is a clinically viable technique.