Canine limbal melanoma: 30 cases (1992-2004). Part 1. Signalment, clinical and histological features and pedigree analysis

OBJECTIVES: (1) To review the signalment, clinical, and histological features of canine limbal melanoma; (2) to perform pedigree analysis on breeds predisposed to limbal melanoma to establish if common ancestry exists; and (3) to investigate if any ancestral relationship exists between canine limbal melanoma and canine anterior uveal melanoma (CAUM). DESIGN: Retrospective study. ANIMALS STUDIED: Thirty dogs with limbal melanoma. METHODS: Medical records of patients were reviewed. Follow-up information was obtained by re-examination of patients or telecommunications with the referring veterinary surgeons or the owners. Pedigrees were analyzed for common ancestry amongst affected dogs. RESULTS The mean age (+/- SD) at diagnosis was 6.2 (+/- 2.75) years with a range from 1 to 11 years. There was a bimodal distribution of ages with a peak at 3-4 years and a peak at 7-10 years. There was no eye predilection or predisposition for sex or coat color. Twenty-five (83%) of the limbal melanomas occurred within a dorsal arc from the dorsomedial to the ventrolateral limbus. Golden retrievers were four times more common in the melanoma group compared to the Animal Health Trust population (P < 0.0001). Labrador retrievers were three times more common in the melanoma group (P=0.01). Pedigree analysis on eight Golden retrievers [limbal melanoma (n=5), CAUM (n=2) and diffuse ocular melanosis (n=1)], revealed a pattern of inter-relatedness consistent with the condition(s) being caused, at least in part, by a genetic mutation(s). A similar level of inter relatedness was evident in six Labrador retrievers (limbal melanoma (n=2) and CAUM (n=4)). In 5/22 cases (23%), histological features suggestive of malignancy were present including intratumor necrosis in 4/22 cases (18%) and cellular atypia in 1/22 cases (5%). CONCLUSIONS: In Golden and Labrador retrievers there is evidence that limbal melanomas, CAUM and ocular melanosis are at least in part heritable and that the same genetic mutation(s) may be causally associated with melanocytic disease at different ocular sites. The same genetic mutation(s) may be present in these two breeds. Histology should be performed on all cases to identify those with greater malignant potential.     

Surgical technique to cannulate the rete testis of the goat

A surgical technique was devised to collect rete testis fluid from 14 mature goats. The tubular portion of the extratesticular rete testis was cannulated where it penetrated the tunica albuginea of the testis under the center of the head of the epididymis. The tip of the cannula was sutured in place in the extratesticular rete testis and the opposite end was passed through the scrotum and into a plastic collection bottle. The bottle was glued to pillow ticking, which was sutured to the scrotum. Continuous flow of rete testis fluid occurred for 0 to 14 days and was usually terminated by a sperm clot in the cannula. The flow rate was 0.59 +/- 0.37 ml/hr.     

Long distance transport of foot-and-mouth disease virus over the sea

The conditions required for the transport of foot-and-mouth disease (FMD) virus in the atmosphere over long distances and in sufficient concentrations to cause infection in exposed animals are described. Using these factors a series of 23 outbreaks of FMD in Europe, where the original outbreaks were separated from later outbreaks by sea passage, have been investigated. The findings obtained support the hypothesis that under certain conditions the airborne transmission of FMD over a long sea passage is possible.     

Model field study of Sumithion 50 EC and Fusilade S on pheasants.

Toxicological studies on wild animals play an important role in the ecotoxicological examination of pesticides. The applied model tests enable the assessment of toxicological consequences with particular regard to the life and nutrition of wild animals in the ploughed field among plants treated with pesticides. The application of different pesticide formulations on plough-land may pose a simultaneous chemical burden to wild birds. In this model study, manifestations of the interaction between an insecticide and a herbicide were studied in pheasants. The birds were placed on lucerne in cages (48 m2) and sprayed once. The applied doses were: Sumithion 50 EC 1 litre/ha + Fusilade S 6 litres/ha (practical doses) and Sumithion 50 EC 5 litres/ha + Fusilade S 30 litres/ha. The analytically determined pesticide concentration of the lucerne was taken as a basis in the further treatment of fodder. The fodder of pheasants contained the following chemicals: 85 mg/kg Sumithion 50 EC + 510 mg/kg Fusilade S and 425 mg/kg Sumithion 50 EC + 2250 mg/kg Fusilade S. Sporadic deaths observed among the pheasants were of traumatic origin and not due to a toxic effect. The decrease of body weight was significant only at the higher dose levels. Acetylcholinesterase (AChE) activity of the blood decreased significantly in both dose groups. On the basis of the results obtained it can be established that at the dose level used in the practice the pesticides studied do not give rise to a toxic interaction in pheasants.