QUALITATIVE AND QUANTITATIVE THYROID IMAGING IN FELINE HYPERTHYROIDISM USING TECHNETIUM-99M AS PERTECHNETATE

Thyroid imaging using technetium-99m as pertechnetate (^99mTcO₄) was carried out in five healthy, euthyroid and 37 hyperthyroid cats using both pinhole and parallel-hole collimators. Images of greater resolution, necessary to distinguish bilateral lobe involvement, were obtained using the pinhole collimator. Per cent thyriod ^99mTcO₄ - uptake was calculated in each cat and was significanly (P < 0.001) higher in hyperthyroid compared with euthyroid cats. In the hyperthyroid cats, per cent thyroid uptake was significantly correlated with serum total thyroxine (T4) and triiodothyronine (T3) Concentrations. Per cent thyroid ^99mTcO₄ - uptake is increased in feline hyperthyrodism and may be calculated using a pinhole collimator alone at the time of qalitative assessment of the extent of thyroid tissue involvement.     

The intestinal and serum humoral immune response of mice to systemically and orally administered antigens in liposomes: I. The response to liposome-entrapped soluble proteins.

The development of oral vaccines is of great importance in veterinary medicine and new adjuvants and carriers are essential to this aim. Liposomes are effective systemic adjuvants but the relatively little data on their potential as oral adjuvants is inconclusive. Liposomes containing ovalbumin (OA) were effective adjuvants when administered intraperitoneally to mice. Feeding mice with OA or keyhole limpet haemocyanin in liposomes in a series of priming and boosting regimes failed to elicit any significant increase in serum or intestinal antibody response compared with feeding the free antigen. Oral tolerance induction to systemic challenge was also unaffected by OA entrapment in liposomes. In vitro liposome stability assays at 37 degrees C demonstrated a substantial resistance to disruption in the presence of acidic stomach contents. However, the addition of bile caused a rapid and profound release of protein marker from the liposomes. The rate and degree of disruption was influenced by the type of phospholipid used. These results suggest that liposomes may be useful as carriers for orally administered compounds but they are ineffective as adjuvants for the non-particulate, naturally weak immunogens used in this study.     

Technique for physiological examination of canine skeletal muscle in vivo

A technique is described for studying the physiological function of canine skeletal muscle in vivo. The contractile properties of the tarsal flexor muscles were examined in three beagle dogs under general anaesthesia. The force responses to electrical stimulation of the common peroneal nerve were measured at various frequencies to determine the frequency:force relationship for this muscle group. Fatigue characteristics were also examined during intermittent stimulated activity delivered in a set pattern of frequencies. The results provide quantitative characterisation of muscle function which is repeatable. The technique described could be applied to other animals and is a potentially powerful tool for evaluating the effects of drugs on muscle performance.     

Macrophage clearance of 125I-labelled polyvinyl pyrrolidone in the horse: effect of ovarian steroids and persistent endometritis

The rate of clearance of 125I-labelled polyvinyl pyrrolidone (PVP) from blood was measured in mares as an indicator of macrophage function. In three out of four cycling mares, PVP clearance was slower during oestrus than dioestrus. Similarly, administration of oestrogen to four ovariectomised mares tended to depress PVP clearance compared with clearance from the same mares before they received oestrogen. However, the effect of oestrogen was not statistically significant. Mares susceptible to persistent endometritis had rates of PVP clearance which were similar to those of genitally normal mares.     

The diagnosis and treatment of mange in the guinea-pig caused by Trixacarus (Caviacoptes) caviae (Fain,Hovell & Hyatt, 1972)*

The clinical features exhibited by ten privately-owned guinea-pigs in nine independent outbreaks of skin disease due to Trixacarus (Caviacoptes) caviae are described. The severity of the condition was related to the duration of the clinical signs but followed a constant pattern of pruritus, increased keratinization and alopecia. The diagnosis was confirmed by the demonstration of the mite in skin scrapings. One animal died before treatment but gamma benzene hexachloride washes produced complete resolution in the remainder.     

Prevalence and risk factors associated with outcome of surgical removal of pedunculated lipomas in horses: 102 cases (1987-2002)

OBJECTIVE: To determine the prevalence of pedunculated lipomas and identify risk factors affecting postoperative complications and survival in horses at a veterinary teaching hospital undergoing surgery for colic caused by pedunculated lipomas. DESIGN: Retrospective study. ANIMALS: 102 horses with a diagnosis of pedunculated lipoma. PROCEDURE: Age, breed, weight, and sex of horses with pedunculated lipomas were compared with the total equine hospital population and the population of horses admitted for abdominal surgery during the same period. Follow-up information was obtained by reevaluation or contact with owners via telephone or written request. RESULTS: Prevalence of pedunculated lipomas as a reason for abdominal surgery in horses, compared with the population of horses with and without lipomas admitted for abdominal surgery, was 10%. Castrated male Saddlebred and Arabian horses > 14 years old were identified as being at risk for developing pedunculated lipomas. Postoperative complications were detected in 72% of horses with pedunculated lipomas. Variables associated with low survival rates included surgery before 1992, heart rate > 80 beats/min, abnormal color of abdominal fluid, pale mucous membranes, surgery requiring intestinal resection, and inability to attain a mean arterial pressure > or = 100 mm Hg. Horses undergoing surgery from 1992 to 1996, weighing < 409 kg (900 lb), or requiring jejunojejunal anastomosis had a high survival rate. CONCLUSIONS AND CLINICAL RELEVANCE: Although many of the variables reflected the health of the horse at the time of surgery, results may help veterinarians recognize risk factors associated with development of pedunculated lipomas and better predict the outcome of horses undergoing surgery for colic caused by pedunculated lipomas.