An index was developed to measure the proportion of intramammary infections caused by environmental microorganisms on dairy farms. This environmental index can be interpreted as the probability that an intramammary infection was caused by an environmental pathogen, rather than by a contagious pathogen. Using the environmental index as the outcome variable, risk factors for environmental mastitis were studied on 10 dairy farms in New York. Turning the cows outside was associated with lower environmental index, and having cows drink from a stream increased the environmental index. Selective (rather than uniform) nonlactating cow intramammary treatment was related to a lower environmental index (apparently because the farms practicing selective nonlactating cow treatment suffered from epizootics of contagious mastitis).

Animals↗

PubMed1988

Cardiac dysrhythmias during anesthesia for cervical decompression in the dog.

In a retrospective study, the risk for cardiac dysrhythmias was evaluated in dogs undergoing ventral decompression and/or fenestration of the cervical spine (CERV) and compared with that for dogs undergoing dorsal laminectomy for decompression of the thoracic or lumbar spine (TL). The dogs in the CERV subset (48 dogs) tended to be heavier and older than the dogs in the TL subset (111 dogs). There was no apparent bias detected in treatment before anesthesia and surgery. The risk for dysrhythmias was 2.5 times greater in the CERV subset, compared with that in the TL subset (P less than 0.01). The risk for ventricular premature contraction was 3.5 times higher in the CERV group (P less than 0.05). Bradycardia was found in 6 dogs from the CERV subset and was not found in any dogs from the TL subset. A logistic model was derived from the data and may be used to evaluate the risk for dysrhythmias in similar patients undergoing similar surgery and anesthesia. This model uses age, preoperative heart rate, and site of surgery (CERV or TL) to estimate the risk.

Anesthesia↗

PubMed1987

Facial neuropathy in dogs and cats: 95 cases (1975-1985).

The medical records of 79 dogs and 16 cats admitted to the New York State College of Veterinary Medicine between January 1975 and October 1985 with facial nerve dysfunction were reviewed. In 31 dogs and 8 cats, facial neuropathy was the only abnormal finding. In 48 dogs and 8 cats, the clinical findings most often noted in the records in addition to facial neuropathy were vestibular signs. Facial neuropathy appeared unassociated with gender or right vs left sides in both dogs and cats, or with hypothyroidism in dogs. Facial neuropathy was associated with increased age, with certain breeds in both dogs and cats, and with otitis media/interna and keratoconjunctivitis sicca in dogs. Causes of facial nerve dysfunction in dogs and cats included surgical and nonsurgical trauma, neoplasia, and otitis media/interna. Facial neuropathy was judged to be idiopathic in 74.7% of dogs and 25% of cats.

Animals↗

PubMed1987

Clinicopathologic, renal immunofluorescent, and light microscopic features of glomerulonephritis in the dog: 41 cases (1975-1985).

In a 10-year retrospective study, we evaluated the clinicopathologic features and renal immunofluorescence patterns of glomerulonephritis in 41 dogs. On the basis of results of histologic examinations, the dogs were segregated into 3 groups, including membranous (n = 12), mesangioproliferative (n = 15), or membranoproliferative glomerulonephritis (n = 14). No significant differences existed among groups in regard to age or duration of illness. Most dogs had been ill for one month or longer. The proportion of dogs with azotemia, anemia, and hyperphosphatemia were not different among the disease groups. Proportion of dogs with hypoalbuminemia and the severity of hypoalbuminemia were not different among groups. Highest urine protein losses and 24-hour urine protein/creatinine ratios developed in dogs with membranous glomerulonephritis. Although hypoalbuminemia and hypercholesterolemia were common (49%), the formation of edema or ascites was not (15%) and, therefore, few dogs had all of the classic features of the nephrotic syndrome. Few dogs suffered thromboembolic complications. Antinuclear antibody titers developed in 11 dogs, the highest titers developing in dogs with polyarthritis and systemic lupus erythematosis. Cellulose acetate electrophoresis detected alpha 2 and beta 1 globulin spikes in most dogs (87%). Results of renal immunofluorescence testing were positive in 36 dogs, using polyvalent antisera for immunoglobulins (Ig)G, IgA, IgM, and/or antisera for complement factor C3. When monovalent antisera for IgG, IgA, and IgM, and fibrinogen were used, immunofluorescence was not observed as often. The major fluorescent pattern was discrete multifocal segmental granular glomerular fluorescence, consistent with immune-complex deposition. Two dogs had linear glomerular staining patterns; however, antibodies directed against normal glomerular basement membrane were not found via elution studies. A high prevalence of glucocorticoid excess (treatment with glucocorticoids and spontaneous hyperadrenocorticism) (34%), chronic inflammatory skin disease (27%), neoplasia (17%), polyarthritis (12%), and systemic lupus erythematosis (7%) were observed as clinical problems concurrent with glomerulonephritis. In 5 dogs, treatment of glomerulonephritis with prednisolone (0.5 to 1.1 mg/kg) did not result in beneficial effects and in fact appeared to be detrimental, leading to azotemia and worsening proteinuria and physical condition in some of the dogs.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

PubMed1987

The effects of periparturient events on breeding performance of dairy cows.

Many periparturient events affect breeding performance in dairy cows. These events include disorders, high early lactation milk yield, other cow factors, and calf factors. The effects range in severity from "annoying" to "devastating."

Animals↗

PubMed1987

An introduction to the use of epidemiologic research methods in dairy science.

Many dairy scientists are not familiar with epidemiologic study designs and measures. The various designs (cross-sectional, case-control, cohort) are reviewed with special reference to their strengths and weaknesses. Epidemiologic measures (incidence and prevalence rates, relative risk, odds ratio, attributable fraction, and population attributable fraction) are defined, and their validity in the contexts of the different study designs is discussed. Incidence rate (risk of disease) is the number of new cases of a disease divided by the population at risk during a specified time period. Prevalence rate is the frequency of both new and old cases in a population at a specified point or period in time divided by the average population during that same period. Both incidence and duration of disease contribute to prevalence. Odds ratios and relative risks are measures of association (how much disease the exposed group experienced relative to the nonexposed group) and are used to assess the relative importance of risk factors. Attributable fraction is the proportion of the incidence in the exposed group that can be attributed to the specific exposure. Population attributuable fraction is the expected reduction in incidence in the whole population if the specific exposure were prevented. The attributable fractions are useful in planning preventive and herd health programs.

Animals↗

PubMed1987

Effect of 188-day treatment with somatotropin on health and reproductive performance of lactating dairy cows.

Health and reproductive performance were observed in a lactational study involving 188 d of treatment with bovine somatotropin. Treatments commenced 84 +/- 10 d postpartum and consisted of 27 mg/d of pituitary somatotropin and 0, 13.5, 27, and 40.5 mg/d of recombinantly derived somatotropin (six cows per treatment group). Cows were high yielding (greater than 9600 kg/305 d), and somatotropin increased milk yield by 16 to 41% depending on source and dose. Somatotropin had no discernible effect on mammary health based on somatic cell count and incidence of clinical mastitis. Cows receiving somatotropin averaged 96% conception rate, 2.0 services per conception, and 116 d open, which were comparable to controls. No subclinical or clinical evidence of ketosis or milk fever was observed. Thirty-two blood chemistry and physical examination variables were examined at several intervals during the study and no adverse treatment effects of physiologic importance for any of the variables were observed. Somatotropin treatment had no discernible effect on gestation length or birth weight and growth rate (first 28 d) of calves. Milk yields for the first 60 d postpartum were compared for the period just prior to start of treatment and the lactation subsequent to treatment; no treatment effects were observed. Overall, our results for a well-managed herd demonstrate somatotropin treatment did not cause any serious health effects. However, examination of subtle health effects will require large numbers of animals treated under a range of environmental and management conditions.

Animals↗

PubMed1987

Effects of premilking stimulation on complete lactation milk yield and milking performance.

Effects of premilking preparation on complete lactation performance were measured with two groups of multiparous Holstein cows; 1) 17 cows received full stimulation, a 60-s routine, and 2) 16 cows received minimum stimulation, a 15-s routine, before machine attachment. Actual unadjusted average lactation milk yield for cows receiving full stimulation was 5.4% less than that for cows receiving minimum stimulation. When postpeak persistencies were compared by linear regression of either 1) daily milk weights or 2) 3.5% FCM from DHI records of milk yield and milk fat percent and fitted to lactation curves using an incomplete gamma function, cows receiving full stimulation produced 1) 2.8 or 2) 2.5% more milk per lactation than did cows receiving minimal stimulation. However, none of the treatment differences in mean milk yield was significant statistically. Milk flow rates, strip yields, and machine on-times were measured at 8-wk intervals throughout lactation. Cows receiving full stimulation had significantly higher average milk flow rates and shorter machine on-times starting at wk 32. There were no significant differences in strip yields or percent residual milk between cows receiving full and minimum stimulation.

Animals↗

PubMed1987

Effects of sixty-day milk yield on postpartum breeding performance in holstein cows.

The relationship between breeding performance and postpartum milk yield was evaluated using data collected in a prospective field project from 33 New York Holstein herds. Herds selected were enrolled in the New York Dairy Herd Improvement Cooperative program and received monthly or biweekly herd health visits from the New York State College of Veterinary Medicine. Factors other than milk yield (e.g., postpartum reproductive disorders, inseminator, housing) that influence breeding performance were controlled in multiple regression analyses. Milk yield had a slight linear antagonistic relationship with conception at first service, services per conception, and days open but not with interval from parturition to first service, interval between first and second services, or interval between second and third services. Services per conception and days open increased by .009 and .6, respectively, for each 100-kg increase in cumulative milk yield during the first 60 d of lactation. Postpartum reproductive disorders, service method (artificial vs. natural), inseminator (farmer vs. technician), and calving interval of the previous lactation had more important relationships than milk yield with measures of breeding performance.

Animals↗

PubMed1987

Early pregnancy loss in brood mares.

During 1985, linear-array ultrasonography was used to study early pregnancy loss in commercial brood mares: 600/1115 (54%) of the cycles resulted in detected pregnancy at Week 2 after ovulation and 80 (13%) of these pregnancies resulted in early pregnancy loss. The pregnancy loss rate was significantly higher (P less than 0.05) for twin pregnancies (10/41) than for singleton pregnancies (70/559). The pregnancy loss rate was significantly higher (P less than 0.05) at 2-4 weeks (29/60) than at 6-8 weeks (12/60). The pregnancy rate was significantly less (P less than 0.05) for post-partum mares inseminated at the foal heat (157/302) than for those inseminated at a subsequent oestrus (203/334). Mares with a history of endometritis had a significantly higher (P less than 0.05) per cycle pregnancy loss rate (7/26) than did mares with a history of not having endometritis (64/498). When mares that had lost pregnancies were re-mated, 37/75 (49%) detectable pregnancies resulted and 7 (19%) of these pregnancies were again lost. The per cycle pregnancy rate was 56% (153/273), 55% (177/319), 60% (130/216), 51% (72/142), 45% (34/76) and 33% (12/36) for mares aged 2-5, 6-9, 10-13, 14-17, 18-21 and greater than 21 years, respectively. The corresponding per cycle pregnancy loss rates were 12%, 14%, 9%, 14%, 24% and 33%.

Animals↗

PubMed1987

Healing of experimentally induced corneal ulcers in horses.

Corneal ulcers to the depth of the anterior third of the stroma were created surgically in both eyes of 10 ponies. One eye in each pony was treated topically with chloramphenicol and 1% atropine ophthalmic ointments 3 times per day; the contralateral eye was not treated topically. All ponies were given phenylbutazone orally for relief of ocular pain. Fluorescein-stained ulcers were measured once a day. The median healing time of the treated eyes (11 days) and the median healing time of the nontreated eyes (13.5 days) were found not to be significantly different. Clinically, however, more severe complications arose in the nontreated eyes.

Animals↗

PubMed1986

Cecal dilatation and volvulus in dairy cows: 84 cases (1977-1983).

The records of 84 cows with cecal dilatation or cecal volvulus were reviewed. The diagnosis was made by exploratory laparotomy or necropsy in 21 cows with cecal dilatation, and in 45 cows with cecal volvulus. Eighteen of the cows with cecal dilatation responded to medical management and the diagnosis was made by physical examination alone. The most useful criteria for determining that surgery was necessary were the presence of a high heart rate, apparent abdominal pain, scant or absence of feces, and the apex of the cecum rotated cranially on rectal examination. The prognosis for cattle with cecal dilatation and volvulus was good following medical therapy or decompression at surgery unless there was severe vascular compromise of the cecum. There was a 10% recurrence rate, and in these cows a partial typhlectomy was performed.

Animals↗

PubMed1986

Effects of risk factors and prophylactic treatment on primary glaucoma in the dog.

Seventy dogs from 26 breeds were admitted with primary glaucoma between January 1979 and December 1983. Compared with mixed-breed dogs, 8 breeds were at higher risk (P less than 0.01) of developing glaucoma: Basset Hound, Beagle, Boston Terrier, Cocker Spaniel, Dalmatian, Miniature Poodle, Norwegian Elkhound, and Siberian Husky. Dogs between the ages of 5 and 10 years were at increased risk (P less than 0.001). There was no predisposition for either eye to be affected first (P greater than 0.55). Females were at twice the risk of males (P less than 0.01). Fourteen dogs had bilateral glaucoma. Among 46 dogs for which the number of months that the second eye remained normal was available, 24 were treated prophylactically and 22 were not treated or had treatment stopped. Prophylactic treatment significantly extended the interval between diagnosis in the first eye and development of glaucoma in the second eye for dogs in predisposed breeds (P less than 0.01). Prophylactic treatment did not make a difference when all breeds were considered (P greater than 0.19), nor did gender affect this interval (P greater than 0.37).

Animals↗