The histological grade of 340 cutaneous mast cell tumours derived from 280 dogs was determined by an established histological grading system; 87 of the tumours (26 per cent) were well differentiated, 199 (59 per cent) were intermediately differentiated and 54 (16 per cent) were poorly differentiated. The one-year survival rates for the dogs with tumours of these three grades were significantly different (P = 0.0001), being 100 per cent, 92 per cent and 46 per cent, respectively. The median survival time for the dogs with poorly differentiated tumours was 278 days, significantly shorter than that for the dogs with either intermediately or well-differentiated tumours, which were both over 1300 days. Regrowth of the tumours was identified in 10 (19 per cent) of the dogs with poorly differentiated tumours, 12 (6 per cent) of the dogs with intermediately differentiated tumours and one of the dogs with well-differentiated tumours; only three of the tumours which regrew had initially had complete margins. The results suggest that wide surgical margins are not a prerequisite for a successful long-term outcome in dogs with well-differentiated cutaneous mast cell tumours.

Between 1956 and 1991, 8349 samples from dogs and cats were received for investigation of suspected dermatophytosis, and 1368 (16 per cent) yielded positive cultures. Cats had a significantly higher proportion of positive cultures (26 per cent) than dogs (10 per cent), and of these Microsporum canis accounted for 92 per cent in cats and 65 per cent in dogs. The other isolates were diverse but mainly sylvatic dermatophytes, and M gypseum was isolated on only four occasions. Different breeds of dog and cat had significantly different prevalences of infection, with pedigree and long-haired cats, and Jack Russell and Yorkshire terrier dogs having a particularly high proportion of positive cultures. Animals less than one year old appeared to be predisposed to infection, but there was no apparent sex predisposition and no conclusive evidence of any seasonal variation in the incidence of the disease. In comparison with the results of dermatophyte culture, examination under Wood's lamp had a positive predictive value of 90 per cent and a negative predictive value of 94 per cent in determining M canis infection, and direct microscopy had positive and negative predictive values of 93 per cent in determining the presence of dermatophytosis. However, cultural examination alone was insufficient for the diagnosis of dermatophytosis owing to the occurrence of false positive and false negative results.

Between 1997 and 1999, 280 dogs with mast cell tumours were identified, of which 59 (21 per cent) had multiple tumours. Follow-up data for survival analysis were available for 145 dogs with single tumours and 50 dogs with multiple tumours. There was no significant difference between the survival times of the two groups; the survival rates after 12 and 24 months were 88 per cent and 83 per cent, respectively, for the dogs with single tumours, and 86 per cent at both intervals for the dogs with multiple tumours. Eight of the dogs with single tumours had lymph node metastases (stage II disease) and these dogs had a median survival time of 431 days, whereas the 50 dogs with multiple tumours (classified as stage III disease) and the dogs with single tumours (classified as stage I disease) had not reached their median survival times. Golden retrievers appeared to be predisposed to developing multiple tumours in the population studied, with an odds ratio of 3.8. This study found no evidence that dogs with multiple tumours had different survival times than those with single tumours, although there was evidence that the presence of lymph node metastasis generally carried a poorer prognosis.

Vaccination is a medical procedure, and the decision to vaccinate should be based on a risk-based assessment for each cat and each vaccine.

In 65 natural cases of feline infectious peritonitis (FIP) the common clinicopathological changes included lymphopenia (77 per cent), neutrophilia (45 per cent), anaemia (37 per cent), hyperproteinaemia (39 per cent) and hyperglobulinaemia (39 per cent). There was no difference in the frequency of these abnormalities between the 38 cases of effusive disease and the 27 cases of non-effusive disease. The most consistent changes shown by serum protein electrophoresis were increases in alpha 2- and gamma-globulins. The protein content of the effusions ranged from 39 to 98 g/litre with the globulins comprising 50 to 82 per cent. Coronavirus serology showed a wide variation in antibody titres (0 to 2560) with 320 the modal titre. The diagnostic value of this information was evaluated by comparing it with data from 65 cats in which FIP was considered as a differential diagnosis, but another disease was diagnosed. None of the laboratory tests, including coronavirus serology, had good sensitivity and specificity for the diagnosis of the disease. The presence of multiple abnormalities compatible with the disease increased the specificity but decreased the sensitivity of the diagnosis.