Incidence of some metabolic diseases in dairy cows.

The incidence of parturient paresis, nonparturient paresis, ketosis and tetany were examined from 283 herds (2,590 cows per year) over a period of eight years. These metabolic diseases made up 29.4% of the cases treated by veterinarians during the farm visits. Significant variation in annual incidences was found only in ketosis. The monthly variation in parturient paresis and ketosis differed highly significantly from the seasonal variation in calving. They were most frequent in March-April. Most of the tetany cases were diagnosed in May-June. The incidence of parturient paresis (0.095 cases per cow per year) and the incidence of ketosis (0.058) varied significantly between herds of different size. The incidence of nonparturient paresis (0.008) and tetany (0.002) did not vary significantly between herds of different size. The incidence of ketosis was significantly higher on farms with milk recording than on other farms. The type of cowshed did not affect the incidence of metabolic disease.

Field observations on the incidence of bovine clinical mastitis and teat diseases.

The incidence of bovine clinical mastitis, thelitis and teat wounds was investigated in 283 herds over a period of eight years (about 2590 cows per year). The incidence of clinical mastitis treated on farm visits was 0.102 cases per cow per year and the total incidence with cases treated by phone orders was about 0.26. The incidence of mastitis increased 6% per year. Mastitis occurred more frequently in March-April. The peak of seasonal variation of thelitis (incidence 0.032) was in April-May and that of teat wounds (incidence 0.008) in June-September. The size of herd and participating in milk recording affected the incidence of mastitis. The type of housing affected the incidence of teat diseases but not that of mastitis. Herds with a high incidence of mastitis also had a high incidence of thelitis, r = 0.41.

Staphylococcal enterotoxin and thermonuclease production during induced bovine mastitis and the clinical reaction of enterotoxin in udders.

Enterotoxin A- and C-producing strains of Staphylococcus aureus and partially and extensively purified enterotoxin A were inoculated into the udder quarters of cows. In the course of experimentally induced mastitis caused by the inoculated S. aureus strain, enterotoxin C but not A was detected in the infected udder. Enterotoxin C was observed in mastitic milk samples at very low S. aureus population levels (10(2) to 10(3) colony-forming units per ml). The results suggest that either the synthesis of enterotoxin C is stimulated in vitro or that growth of S. aureus cells in udders was, in fact, higher than the colony-forming unit values indicated. Thermonuclease was shown to be excreted into mastitic milk at a slower rate than was enterotoxin. An inoculation of 1 microgram of enterotoxin A in autogenic milk returned to the udder caused clinical reactions (swelling, palpation sensitivity, and increase in the level of somatic cells) within 6 h.

Observations on genital abnormalities in dairy cows using slaughterhouse material.

The investigated material consisted of the sexual organs of 2010 cows, collected at a slaughterhouse during the years of 1971--74. The organs were examined macroscopically, with special regard to the ovaries, ovarian bursae, oviducts, and the uterus. The genital tract was cut open and examined for anomalies and other pathological changes. The results are presented in Tables I--IV. The total frequency of abnormalities within the investigated material was 18.2%. The most common disease condition was cystic degeneration of the ovary (8.6%). Bursal adhesions, parovarian cysts, and various forms of cervical anomalies constituted respectively 2.7, 2.3, and 1.7 per cent of the cases. The percentage of genital abnormalities as a cause of infertility was estimated to 1.5. The results have been compared with those of similar investigations.

Observations on teat stenosis.

The article deals with 665 cases of teat stenosis observed over the period 1968--73 in the area covered by the Field Station of the College of Veterinary Medicine, Hautjarvi. The main attention is to the occurrence of the syndrome and the aspects associated with the clinical picture. The results are shown in Figs. 1--4. Only 12.7% of the stenoses were recorded during the pasture season. An examination of the point of time of the diagnosis revealed that 46.2% of all cases fell during the first month after calving. Of all cases of stenosis, 59.8% were found in the rear teats and, correspondingly, 50.2% in the fore teats. The location of the stenosis in the teat was known in 526 cases: 79.5% in the streak canal and tip of the teat, 8.5% in the mid-section of the cistern, 3.3% in its upper section and 8.7% affecting the entire cistern. Of the 477 cases treated surgically, 24.3% required renewed treatment. Of the 174 cases treated without surgery, 20.7% had to be treated several times. On the basis of the observations made, conclusions were drawn with regard to ethiological factors and the results examined in the light of some other studies.