OBJECTIVE To develop a partial budget analysis of direct costs associated with bovine respiratory disease (BRD) in preweaned calves on US beef cow–calf operations and identify factors that strongly influence those costs.
DESIGN Risk analysis model.
ANIMALS US preweaned beef calf inventory from 2011 through 2015.
PROCEDURES A stochastic simulation model was developed by use of a computer spreadsheet and add-in software. Input data were obtained from the USDA, peer-reviewed literature, and a survey of beef cow–calf producers. A simulation consisting of 10,000 iterations was used to account for either uncertainty or variability in model inputs. The median (90% confidence interval) was reported for each output variable. Global and local sensitivity analyses were performed to identify the most influential factors and quantitatively evaluate the effects of inputs on the estimated costs.
RESULTS From 2011 through 2015, BRD in preweaned calves cost the US beef cow–calf industry approximately $165 million annually, of which costs associated with the death, treatment, and decreased weaning weight of BRD-affected calves were approximately $126, $25, and $15 million, respectively.
CONCLUSIONS AND CLINICAL RELEVANCE Although BRD in preweaned calves may have a fairly small effect on the total gross income for the US beef cow–calf industry as a whole, it can have a substantial adverse effect on the net profit of BRD-affected herds. The model developed provided important information regarding the cost of BRD in preweaned calves on US beef cow–calf operations and identified factors that had an import effect on those costs.
Objective—To identify, by means of 24-hour ambulatory
electrocardiography, electrocardiographic abnormalities
in overtly healthy Doberman Pinschers in
which results of echocardiography were abnormal.
Design—Clinical case series.
Animals—56 (35 male, 21 female) overtly healthy
Doberman Pinschers with echocardiographic evidence
of cardiomyopathy on initial examination that
subsequently died of cardiomyopathy.
Procedure—Twenty-four-hour ambulatory electrocardiographic
(Holter) recordings obtained at the time of
initial examination were reviewed. For all dogs, scan
quality was > 90%.
Results—Initial Holter recordings of all 56 dogs contained
ventricular premature contractions (VPC).
Thirty-six (65%) dogs had > 1,000 VPC/24 h, 17 (31%)
had > 5,000 VPC/24 h, and 11 (19%) had > 10,000
VPC/24 h. Fifty-four (96%) dogs had couplets of VPC,
37 (66%) had triplets of VPC, and 36 (64%) had
episodes of nonsustained (< 30 seconds) ventricular
tachycardia. Number of VPC/24 h during the initial
Holter recordings was positively correlated with numbers
of couplets and triplets of VPC and number of
ventricular escape beats and negatively correlated
with left ventricular fractional shortening. Twentyeight
dogs died suddenly prior to the putative onset
of congestive heart failure.
Conclusions and Clinical Relevance—Results suggested
that along with echocardiography, 24-hour
ambulatory electrocardiography can be used to help
identify overtly healthy Doberman Pinschers with
cardiomyopathy. (J Am Vet Med Assoc 2000;217:
Objective—To determine effects of sedation
achieved by xylazine (XYL) or acepromazine (ACE) on
cardiopulmonary function and uterine blood flow in
cows in late gestation.
Animals—8 cows between 219 and 241 days of gestation.
Procedure—Doses of ACE (0.02 mg/kg) or XYL (0.04
mg/kg) were administered IV. Measurements were
obtained to determine cardiopulmonary effects and
oxygen delivery to the uterus.
Results—Heart rate was not significantly affected by
administration of ACE, but it decreased markedly after
administration of XYL. Uterine artery flow was
decreased at all times by XYL and was always less
than for ACE. Xylazine increased uterine vascular
resistance through 30 minutes and caused reduced
PaO2 and increased PaCO2 at all time periods.
Acepromazine caused a 5% decrease in PaO2 only at
5 minutes. Xylazine reduced oxygen delivery by 59%
at 5 minutes and 32% at 45 minutes. In contrast, ACE
caused a nonsignificant reduction of oxygen delivery
by 16% at 15 minutes and a return to baseline values
by 45 minutes
Conclusions and Clinical Relevance—Xylazine
markedly reduces flow and availability of oxygenated
blood to the uterus, which may critically impair delivery
of oxygen to the fetus at a stressful and important time
of development or delivery. Acepromazine was associated
with slight reductions of much shorter duration.
When XYL is used to sedate pregnant cows, it could
impose physiologic distress on the fetus and potentially
increase fetal morbidity and mortality. When sedation
of the dam is desirable, ACE could be an alternative
to XYL. (Am J Vet Res 2002;63:1695–1699)
Objective—To determine herd-level prevalence of Mycoplasma spp mastitis in Utah dairy herds and characterize farms and management practices for positive herds.
Sample Population—Bulk tank milk samples from 222 of 285 (78%) dairy farms in Utah.
Procedures—Milk haulers or dairy producers collected 5 milk samples from all bulk tanks at 3- to 4-day intervals for mycoplasmal culture. Owners of all positive herds were offered follow-up visits.
Results—Milk samples from 16 of 222 (7%) herds had positive mycoplasmal culture results. Follow-up information was obtained from 14 of 16 herds; 12 provided complete data. Some characteristics of mycoplasma-positive herds included the following: 8 of 14 herds had > 750 lactating cows, 9 of 11 had bulk tank milk somatic cell count of 140,000 to 240,000 cells/mL, 7 of 11 had actual milk production of 9,535 to 11,622 kg (21,000 to 25,600 lb)/305 d, 11 of 12 had cows with clinical mastitis that was nonresponsive to treatment and involved ≥ 2 mammary gland quarters, 9 of 12 had cows with clinical mastitis that spread from 1 mammary gland quarter to another, 8 of 12 had cows with droopy ears, 7 of 12 had cows with a head tilt, 7 of 12 used common milking towels, 2 of 12 were closed to replacement cattle for > 1 year, and 2 of 12 purchased bulls only.
Conclusions and Clinical Relevance—Herd-level prevalence of mycoplasma mastitis in Utah was relatively high, compared with other areas of the United States.
Objective—To evaluate trends in feedlot cattle mortality
ratios over time, by primary body system affected,
and by type of animal.
Design—Retrospective cohort study.
Animals—Approximately 21.8 million cattle entering
121 feedlots in the United States during 1994 through
Procedures—Yearly and monthly mortality ratios
were calculated. Numbers of deaths were modeled
by use of Poisson regression methods for repeated
measures. Relative risks of death over time and by
animal type were estimated.
Results—Averaged over time, the mortality ratio
was 12.6 deaths/1,000 cattle entering the feedlots.
The mortality ratio increased from 10.3
deaths/1,000 cattle in 1994 to 14.2 deaths/1,000
cattle in 1999, but this difference was not statistically
significant (P = 0.09). Cattle entering the feedlots
during 1999 had a significantly increased risk
(relative risk, 1.46) of dying of respiratory tract disorders,
compared with cattle that entered during
1994, and respiratory tract disorders accounted for
57.1% of all deaths. Dairy cattle had a significantly
increased risk of death of any cause, compared with
beef steers. Beef heifers had a significantly
increased risk of dying of respiratory tract disorders,
compared with beef steers.
Conclusions and Clinical Relevance—Results suggested
that although overall yearly mortality ratio did
not significantly increase during the study, the risk of
death attributable to respiratory tract disorders was
increased during most years, compared with risk of
death during 1994. The increased rates of fatal respiratory
tract disorders may also reflect increased rates
of non-fatal respiratory tract disorders, which would
be expected to have adverse production effects in
surviving animals. (J Am Vet Med Assoc 2001;219:1122–1127)
Objective—To assess the effect of dietary potassium
citrate supplementation on the urinary pH, relative
supersaturation of calcium oxalate and struvite
(defined as the activity product/solubility product of the
substance), and concentrations of magnesium, ammonium,
phosphate, citrate, calcium, and oxalate in dogs.
Animals—12 healthy adult dogs.
Procedure—Canned dog food was fed to dogs for 37
days. Dogs were randomly allocated to 3 groups and
fed test diets for a period of 8 days. Study periods
were separated by 6-day intervals. During each study
period the dogs were fed either standard diet solus
(control) or standard diet plus 1 of 2 types of potassium
citrate supplements (150 mg potassium citrate/kg
of body weight/d) twice daily. Urinary pH, volume and
specific gravity, relative supersaturation of calcium
oxalate and struvite, and concentrations of magnesium,
ammonium, phosphate, calcium, oxalate, and
citrate were assessed for each treatment.
Results—Mean urine pH was not significantly affected
by dietary potassium citrate supplementation,
although urine pH did increase by 0.2 pH units with
supplementation. Diets containing potassium citrate
maintained a higher urine pH for a longer part of the
day than control diet. Three Miniature Schnauzers had
a significantly lower urinary relative calcium oxalate
supersaturation when fed a diet supplemented with
potassium citrate, compared with control diet.
Conclusions and Clinical Relevance—Dietary
potassium citrate supplementation has limited
effects on urinary variables in most healthy dogs,
although supplementation results in maintenance of a
higher urine pH later in the day. Consequently, if supplementation
is introduced, dogs should be fed twice
daily and potassium citrate should be given with both
meals or with the evening meal only. (Am J Vet Res 2000;61:430–435)
Objective—To determine whether kinematic changes
induced by heel pressure in horses differ from those
induced by toe pressure.
Animals—10 adult Quarter Horses.
Procedure—A shoe that applied pressure on the
cuneus ungulae (frog) or on the toe was used.
Kinematic analyses were performed before and after 2
levels of frog pressure and after 1 level of toe pressure.
Values for stride displacement and time and joint angles
were determined from horses trotting on a treadmill.
Results—The first level of frog pressure caused
decreases in metacarpophalangeal (fetlock) joint extension
during stance and increases in head vertical movement
and asymmetry. The second level of frog pressure
caused these changes but also caused decreases in
stride duration and carpal joint extension during stance
as well as increases in relative stance duration. Toe pressure
caused changes in these same variables but also
caused maximum extension of the fetlock joint to occur
before midstance, maximum hoof height to be closer to
midswing, and forelimb protraction to increase.
Conclusion and Clinical Relevance—Decreased fetlock
joint extension during stance and increased head
vertical movement and asymmetry are sensitive indicators
of forelimb lameness. Decreased stride duration,
increased relative stance duration, and decreased
carpal joint extension during stance are general but
insensitive indicators of forelimb lameness. Increased
forelimb protraction, hoof flight pattern with maximum
hoof height near midswing, and maximum fetlock joint
extension in cranial stance may be specific indicators
of lameness in the toe region. Observation of forelimb
movement may enable clinicians to differentiate lameness
of the heel from lameness of the toe. (Am J Vet Res 2000;61:612-619)
Case Description—A 6-month-old male Bactrian camel was examined because of a 3-week history of lameness of the left hind limb.
Clinical Findings—Lameness was initially detected in the left hind limb but resolved and was detected in the right hind limb during treatment. Lameness increased during periods of rapid growth. Radiography revealed multiple small opacities of the medullary cavity of several long bones throughout treatment. Core bone biopsies of lesions in the tibiae revealed lamellar bone with areas of loose connective tissue, osteoblasts in the medullary cavity, and periosteal new bone formation, all which were consistent with panosteitis.
Treatment and Outcome—Palliative treatment was attempted with epidural and transdermal administration of analgesics. Flunixin meglumine was administered PO, which coincided with an abrupt increase in serum creatinine concentration. Performance of multiple diagnostic bone biopsies led to remission of clinical signs of pain.
Clinical Relevance—Panosteitis should be a differential diagnosis for shifting limb lameness in young camels. Bone biopsies can be useful for diagnosis of panosteitis and possible relief of pain associated with the disease. Bactrian camels may be susceptible to the renal toxicity of flunixin meglumine, especially when dehydrated.