EFFECTS OF A DIGITAL FILTER ON DETECTABILITY OF A PHANTOM LESION IN A SCINTIGRAM OF THE EQUINE TARSUS

The aim of this study was to examine the effects of a digital filter on the detectability of a phantom lesion in a scintigram of the equine tarsus. Lateral images containing 50, 100, 150, 500, or 1000 kcounts were acquired. A created phantom lesion of 0 (normal), 10, 15, 20, or 30% increased intensity relative to local background was placed in the centrodistal tarsal joint area in the images of different count levels. Duplicate images were filtered with a Metz filter. The complete set of filtered and unfiltered images totaling 180 images was projected as slides to a group of 9 observers. The sensitivity in 50 and 100 kcount images was improved by applying the filter. Digital filtering increased the false positive fraction at all count levels but this effect was most pronounced in 500 and 1000 kcount images. Based on receiver operating characteristic analysis, filtering of a 50 kcount image improved image quality to that of a 150 kcount image.     

OSTEOGENIC SARCOMA OF THE NASAL CAVITY IN A CAT: POSTOPERATIVE CONTROL WITH HIGH DOSE-PER-FRACTION RADIATION THERAPY AND METRONIDAZOLE

An 11-year-old Siamese cat with an osteogenic sarcoma of the nasal cavity was treated by partial surgical excision followed by a course of high dose-per-fraction radiation therapy in conjuction with metronidazole, a hypoxic cell sensitizer. Four thousand two hundred rads were delivered to the tumor in 7 weekly fractions. Each treatment was preceded by 6 gm/m² oral metronidazole given 3 hours before irradiation. There were no untoward side effects and the cat was in remission 2 years after treatment.     

The Effect of Two Antibiotic Mixtures on Haemophilus somnus, Campylobacter fetus ssp. venerealis, Mycoplasma bovis, and Ureaplasma diversum in Frozen Bovine Semen

A two-step semen-extending protocol was compared to a one-step protocol in its efficiency in inhibiting growth of Haemophilus somnus, Campylobacter fetus ssp. venerealis, Mycoplasma bovis , and Ureaplasma diversum in experimentally infected semen. In both protocols, the effect of an antibiotic mixture of 500 μg gentamycin, 100 μg tylosin, 300 μg lincomycin, and 600 μg spectinomycin (GTLS) was compared to a mixture of 500 IU penicillin, 500 IU streptomycin, 150 μg lincomycin, and 300 μg spectinomycin (PSLS). The one-step extending method was as effective as the two-step extending method. Both antibiotic mixtures were equally effective in controlling C. fetus . For H. somnus and U. diversum , the PSLS mixture was more effective than the GTLS mixture. It was striking that both antibiotic mixtures had no effect in decreasing the numbers of M. bovis .     

Uptake of pesticides from water and soil by earthworms

The uptake of pesticides by earthworms from aqueous solutions was examined and shown to be a reversible physical process. Measurements of distributions of pesticides between aqueous solutions and worm solids showed that adsorption coefficients were related to octanol-water distribution coefficients, as are soil-water distributions. From these relationships it was calculated that concentration factors of stable chemicals in earthworms from soil should be similar, except for polar substances which penetrate poorly, and be determined mainly by the soil organic matter content. Examination of uptake from soils indicated that the calculated concentration factors are unlikely to be achieved because of slow diffusion of chemicals in soils and because of metabolism in the soil or the worm.     

Congestive heart failure in two pet rabbits

This case report describes congestive heart failure with pleural effusion in two middle-aged, pet house rabbits. Both had a history of acute onset dyspnoea, weakness and weight loss. Bi-atrial enlargement was seen on echocardiography in both rabbits. One rabbit had atrial fibrillation and ventricular premature complexes identified on electrocardiography. There was a radiographically evident pleural effusion in both rabbits and thoracocentesis was undertaken in one rabbit. These findings were confirmed on post-mortem examination. The aetiology for the underlying heart disease was not found, but the potential types of cardiomyopathies are discussed.     

Prevalence of elevated alanine transaminase activity in dogs treated with CCNU (Lomustine)*

The purpose of this study was to evaluate prevalence of serum alanine transaminase (ALT) elevation in dogs receiving lomustine (CCNU) and to analyse the pattern of occurrence and potential risk factors. Serum ALT activity in 109 dogs during single‐agent CCNU chemotherapy was retrospectively analysed. The median initial dose, dose‐intensity and cumulative dose of CCNU were 64 mg m^?2, 21 mg m^?2 week^?1 and 171 mg m^?2, respectively. The overall prevalence of major ALT elevation [> 5‐fold upper reference limit (URL)] was 29% (32/109) and developed most commonly after one to three doses of CCNU. These ALT elevations occurred without preceding mild ALT elevation in 53% (17/32) of the cases. Three dogs (2.8%) developed clinical hepatopathy. For severe ALT elevation (>10‐fold URL), age ≤5‐year‐old was associated with higher risk. The findings of this study showed that elevation of ALT is common during CCNU chemotherapy in dogs and severe elevation can develop on a sudden onset.     

Reader performance in radiographic diagnosis of signs of mitral regurgitation in cavalier King Charles spaniels

O bjectives : To measure accuracy and variability of diagnosis by radiography of heart enlargement (HE) and heart failure (HF) in mitral regurgitation (MR).
M ethods : Sixteen readers representing four levels of experience evaluated 50 sets of radiographs with varying severity of MR for presence or absence of HE, left atrial enlargement (LAE) and HF. The performance of the readers was compared with a reference standard, using area under the curve (AUC) of receiver operating characteristic (ROC) curves. The interreader agreement value kappa (K) was calculated. A subset of difficult cases of HF was analysed before and after removing an outlying reader from each group.
R esults : AUC for HE was 0·89, for LAE it was 0·93 and for HF it was 0·92. Experience increased certainty of diagnosis but not accuracy. K ranges were HE, 0·53 to 0·67; LAE, 0·61 to 0·69 and HF, 0·49 to 0·58. When only difficult cases of HF were read, accuracy decreased and experienced readers performed better than inexperienced. When outlying readers were excluded, the differences between experienced and inexperienced readers increased.
C linical S ignificance : LAE, not HE, should be used to evaluate the heart size and indirectly the severity of MR on radiographs. For HF, agreement among individual readers was only moderate. Studies of reader accuracy should consider the effects of interreader variability.     

Effect of Oxytocin Treatment on Artificial Insemination with Frozen–Thawed Semen in Murciano–Granadina Goats

The site where the semen is deposited appears to be one of the most important factors affecting pregnancy of inseminated goats. In Murciano–Granadina (MG) goats, post-cervical insemination is achieved in a limited number of females. An effective way to increase fertility rate could be by increasing post-cervical inseminations. Effect of exogenous oxytocin application to facilitate the cervical penetration and its effect on kidding rate and prolificacy in MG goats were investigated. Oestrus was synchronized using progesterone-impregnated sponges for 11 days. Females were randomly divided into three groups (n = 190) and received either an i.v. injection of 100 or 200 IU of oxytocin or saline solution 15 min before being inseminated. Data on semen deposition depth were recorded for each animal using a catheter scaled in centimetres (up to 4 cm). Depth of semen deposition was affected by the oxytocin treatment (p < 0.05). Oxytocin enhanced cervical passage only with the dose of 200 IU compared with the control group, increasing the deposition depth (2.9 cm vs 1.9 cm). No significant effect of oxytocin treatment on kidding rate and prolificacy was detected. Depth of semen deposition affected kidding rate (p < 0.01). In conclusion, oxytocin treatment improved the depth of semen deposition in AI of MG goats, but kidding rate and prolificacy was not affected. More studies must be conducted to assess the minimal effective dose required for sufficient cervical dilation, and to determine the effects of such doses of oxytocin on uterine motility, sperm transport and fertility in goats.