Aortic root disease in four horses

Clinical findings in 4 horses with aortic root disease are described. Three of the horses had aneurysms of the right aortic sinus, and in 2 of the 3, the aneurysm ruptured, creating a fistula between the aorta and right ventricle. One of these horses had had a murmur since birth, and the aortic sinus aneurysm may have been a congenital anomaly. In a second horse, the aneurysm may have been an acquired condition that developed secondary to chronic aortic regurgitation. Another horse had a large subendocardial hematoma associated with dissection of blood from the aorta to the interventricular septum because of a tear in the aortic root near the right aortic sinus. Ventricular ectopy and signs of abdominal pain were the most common initial signs in these horses.     

Relationship between terrain use and performance of beef cows grazing foothill rangeland

A study was conducted on foothills rangeland to determine whether grazing patterns differed among cow breeds and to determine whether there was a relationship between individual grazing patterns and performance of beef cows. Hereford (HH), Tarentaise (TT), 3/4 Hereford x 1/4 Tarentaise (3H1T), 1/2 Hereford x 1/2 Tarentaise (HT), and 1/4 Hereford x 3/4 Tarentaise (1H3T) cows were observed during the summers of 1997 (n = 183) and 1998 (n = 159). Locations of individual cows were recorded two to three times per week during 1.5- to 2.5-h periods in the morning by observers on horseback. Statistical models included cow breed, age, and nursing status. Data from each year were analyzed separately. During 1997 and 1998, nonlactating cows were located at greater (P < 0.05) vertical distances from water than lactating cows. In 1998, nonlactating cows used steeper (P < 0.05) slopes than lactating cows. However, nonlactating cows did not travel as far horizontally from water (P < 0.05) as lactating cows in 1997. Younger cows (3 yr) traveled further (P < 0.05) from water both vertically and horizontally than older cows (5+ yr) in 1997, but not during 1998. Tarentaise and 1H3T cows were observed at greater (P < 0.05) vertical distances from water than HH cows during both years of the study. During 1998, TT and 1H3T cows used steeper (P < 0.05) slopes than HH cows. Using residual correlations, there were no consistent relationships between topographic aspects of individual grazing locations and cow weight, height, and body condition score. In 1997, cows with earlier calving dates and correspondingly heavier calf weaning weights used areas that had greater vertical distances to water; however, in 1998 there were no relationships (P > 0.05) of calving date and weaning weight with cow location. During both years, pregnant and nonpregnant cows used terrain similarly (P > 0.05), which suggests that cow reproductive performance was not related to terrain use. Grazing patterns in foothills rangeland varied among cow breeds. Performance of cows that used more rugged topography was similar to cows using gentler terrain.     

Characterisation of the kappa light chain of the brushtail possum (Trichosurus vulpecula)

Two full length cDNA sequences encoding the kappa light chain of the Australian marsupial, Trichosurus vulpecula, the brushtail possum, were isolated from a mesenteric lymph node cDNA library. The constant regions (Ckappa) of the two light chains were identical, but the variable (Vkappa) and joining (Jkappa) regions were different. At the amino acid level, possum Ckappa was most similar to Ckappa of an American marsupial, Monodelphis domestica (75%), with similarity to eutherian Ckappa ranging from 47 to 63%. The availability of molecular data will enable the development of immunological reagents for studying immune responses and disease in marsupials, thereby aiding conservation strategies and veterinary medicine.     

Effects of sodium nitroprusside after load reduction and/or atropine pre-treatment prior to dexmedetomidine administration on cardiovascular variables in dogs

The purpose of this study was to determine the cardiovascular effects of sodium nitroprusside (SNP)‐induced after load reduction in dogs administered dexmedetomidine (DEX). Using a randomized crossover design and allowing at least 2 weeks between treatments 12 adult hound dogs of either sex weighing 22 ± 1.7 SD kg were anesthetized by face mask administration of 2.9% ET sevoflurane to facilitate instrumentation prior to administration of treatment drugs. Dogs were intubated and instrumented to enable measurement of heart rate (HR), systolic (SAP), mean (MAP) and diastolic (DAP) arterial pressures, mean pulmonary arterial pressure (PAP), pulmonary capillary wedge pressure (PCWP), central venous pressure (CVP), pulmonary arterial temperature (TEMP), and cardiac output (CO). Systemic (SVR) and pulmonary vascular resistances were calculated. Following completion of instrumentation dogs were allowed to recover for 40 minutes. After collection of baseline data, dogs were administered one of four treatments at T–10 minutes prior to injection of DEX (500? g M^–2 IM): 1) saline (SAL); 2) atropine (ATR, 0.02 [n = 6] or 0.04 [n = 6] mg kg^–1 IM); 3) SAL + SNP (infused at 1–10 ?g kg^–1 minute^–1, IV as needed to maintain MAP between 90–110 mm Hg; or 4) ATR + SNP. Cardiovascular data were collected at T‐20 minutes prior to administration of DEX, T‐5 and at 5, 10, 20, 30, 40, and 60 minutes following DEX. Data were analyzed using anova for repeated measures with post hoc differences between means identified using Bonferroni's method (p < 0.05). Differences in ATR dose were not found to be significant and thus results for ATR dose groups were pooled. Administration of SAL (dexmedetomidine alone) was associated with decreases in HR and CO and increases in SAP, MAP, DAP, CVP, and SVR. Administration of ATR was associated with an increase in HR and CO compared with SAL. Administration of SNP was associated with an increase in HR and CO and a decrease in SVR, MAP and CVP compared with SAL. Administration of SNP + ATR was associated with effects similar to that of SNP or ATR alone and resulted in an additive increase in CO. We conclude that SNP‐induced afterload reduction with or without atropine is effective in mitigating DEX‐induced impairment of cardiovascular function.     

Occurrence of Piscirickettsiosis-like syndrome in tilapia in the continental United States.

From 2001 to 2003, tilapia (Oreochromis sp.) farms in Florida, California, and South Carolina experienced epizootics of a systemic disease causing mortality. The fish exhibited lethargy, occasional exophthalmia, and skin petechia. The gills were often necrotic, with a patchy white and red appearance. Grossly, the spleen and kidneys were granular with whitish irregular nodules throughout. Granulomatous infiltrates were observed in kidney, spleen, testes, and ovary tissues, but not in the liver. The granulomas contained pleomorphic coccoid bacteria, measuring 0.57 +/- 0.1 x 0.8 +/- 0.2 microm, that were Giemsa-positive, acid-fast-negative, and Gram-negative. The bacteria had a double cell wall, variable electron-dense and -lucent areas, and were present in the cytoplasm and within phagolysosomes. The syndrome was associated with cold stress and poor water conditions. These findings are consistent with an infectious process caused by a Piscirickettsia-like bacterium described previously in tilapia in Taiwan and Hawaii. This report involves the first identified cases of a piscirickettsiosis-like syndrome affecting tilapia in the continental United States.     

Clostridium septicum myositis in a western lowland gorilla (Gorilla gorilla gorilla).

A 10-yr-old male gorilla (Gorilla gorilla gorilla) with a history of conspecific bite wounds was evaluated for acute onset of depression, anorexia, and right hemiparesis. The animal was immobilized for diagnostic examination and treatment for suspected toxic shock from a necrotizing, emphysematous wound infection, but was euthanized due to complications during recovery. Gross and histopathologic examination revealed acute necrotizing myositis, fasciitis, cellulitis, and emphysema in the affected wound area, with large numbers of large Gram-positive rods among necrotic muscle fibers. Severe pulmonary edema with airways containing fibrin, acute hemorrhage in multiple body sites, thrombosis in blood vessels in the skeletal muscle, liver, and lung, and lymph node hyperplasia with lymphoid necrosis and hemorrhage. Immunohistochemical fluorescent antibody staining of muscle from the wound site was positive for     

A Japanese powdery mildew isolate with exceptionally large infection efficiency on Mlo-resistant barley

A Japanese field isolate (Race I) of Erysiphe graminis f.sp, hordei was tested on 17 barley lines carrying the mlo powdery mildew resistance gene. Race I produced many successful infections with infection type larger than or equal to 2 on six lines (M66, MC20, SRI, SR7, A tem and Totem), On the remaining 11 lines it reacted with infection type 0. Colony numbers on the Mlo-lines were between 26% and 12 9% of the numbers on a susceptible cultivar Manchuria, These numbers were larger than, or similar to those produced by isolate HL3/5, which has the highest recorded infection efficiency on Mlo-resistant cultivars. The interaction between isolates and lines was highly significant. The isolate GE3, from which HL3/5 was derived by selection, gave rise to occasional colonies corresponding to less than 03° o of the number produced on cv. Manchuria.     

Comparison of mobile and stationary spore-sampling techniques for estimating virulence frequencies in aerial barley powdery mildew populations

Gene frequencies in samples of aerial populations of barley powdery mildew ( Erysiphe graminis f.sp. hordei ), which were collected in adjacent barley areas and in successive periods of time, were compared using mobile and stationary sampling techniques. Stationary samples were collected from trap plants in three periods within 1 week at a distance of more than 1000 m from the nearest barley field. At four dates within the same 8-day period, other samples were collected by a mobile spore trap along four sampling routes of a total distance of 130 km around the stationary stand of exposure. The samples were characterized by virulence genotypes defined according to infection types on 12 near-isogenic barley lines, and frequencies of single virulence genes were subsequently calculated. The three samples collected at the stationary site differed significantly with respect to allele frequencies at three loci. The main wind direction was different in the three sampling periods, implying different powdery mildew sources. For the mobile exposure, the differences between routes were not significant for any locus. However, the routes differed most for the loci under direct selection by host resistances genes, indicating a different distribution of source varieties along routes. There was no difference between allele frequencies at different dates, indicating that the proportions of spores from different source varieties were similar at these dates. In conclusion, samples collected by the stationary technique will mainly reflect the source varieties present in the local area, whereas samples collected by the mobile spore trap will mainly reflect sources close to the sampling route. Therefore, sampling sites as well as sampling routes should be defined such that source varieties are representative for the overall varietal distribution in the survey region considered.     

Usefulness of aerobic microbial culture and cytologic evaluation of corneal specimens in the diagnosis of infectious ulcerative keratitis in animals

OBJECTIVE: To determine the diagnostic value of aerobic microbial culture and cytologic evaluation of corneal specimens in the diagnosis of infectious ulcerative keratitis (IUK). DESIGN: Prospective study. ANIMALS: 48 animals (26 dogs, 13 horses, 7 cats, 1 bird, and 1 llama) with corneal ulcers. PROCEDURE: Scrapings from corneal ulcers were examined cytologically. Corneal swab specimens were submitted for microbial culture. Animals were grouped according to whether they had been receiving antimicrobials at the time of admission. RESULTS: Of the 38 animals receiving antimicrobials, 19 had positive results for IUK on cytologic evaluation, 20 on microbial culture, and 26 on cytologic evaluation, microbial culture, or both. Of the 10 animals not receiving antimicrobials at the time of admission, 7 had positive results for IUK on cytologic evaluation, and 9 had positive results on microbial culture. In this group of 10 animals, additional animals with IUK were not identified on the basis of cytologic evaluation alone. When all 48 animals were considered irrespective of antimicrobial treatment, 26 and 29 had positive results for IUK on cytologic evaluation and microbial culture, respectively, whereas IUK was confirmed in 35 animals on the basis of cytologic evaluation, microbial culture results, or both. CONCLUSIONS AND CLINICAL RELEVANCE: Microbial culture and cytologic evaluation of corneal specimens maximizes identification of IUK, especially in animals receiving antimicrobial treatment. Because of serious consequences of untreated IUK, we recommend that both diagnostic tests be used to tailor treatment and reduce risk of vision impairment in animals.