Objective—To evaluate efficacy of topical treatment
with oxytetracycline solution among dairy cows with
papillomatous digital dermatitis (PDD) lesions on the
interdigital cleft, heels, or dewclaw.
Animals—70 dairy cows from a single herd.
Procedure—On the basis of anatomic location of
PDD lesions, cows were allocated into 1 of 3 groups
(interdigital cleft [n = 14], heels , or dewclaw )
and treated topically with oxytetracycline solution.
Cows were examined 14 and 30 days after initial treatment.
During each examination, pain and lesion size
scores were recorded.
Results—On the basis of pain and lesion size scores,
oxytetracycline appeared significantly less effective
among cows with lesions on the interdigital cleft than
for cows with lesions on the heels or the dewclaw.
Number of cows with signs of pain or visible lesions
after treatment was significantly higher for cows with
lesions on the interdigital cleft than for cows with
lesions on heels or the dewclaw.
Conclusions and Clinical Relevance—Anatomic location
of PDD lesions has an effect on the efficacy of topical
treatment with oxytetracycline solution in dairy cows
affected with PDD. Cows with lesions on the interdigital
cleft were less likely to respond to treatment, compared
with cows with lesions on the heels or the dewclaw. (J
Am Vet Med Assoc 2000;216:1288–1290)
Objective—To examine the relationship between
lameness and the duration of the interval from calving
to subsequent conception in lactating dairy cows.
Animals—837 dairy cows.
Procedure—Cows affected with lameness were
classified into 1 of 4 groups on the basis of types of
disease or lesions observed, including foot rot, papillomatous
digital dermatitis, claw lesions, or multiple
lesions. Cows not affected with lameness were classified
as healthy. Time from calving to conception
was compared between lame cows and healthy
Results—254 (30%) cows were affected with lameness
during lactation. Most lame cows (59%) had
claw lesions. Lame cows with claw lesions were 0.52
times as likely to conceive as healthy cows. Median
time to conception was 40 days longer in lame cows
with claw lesions, compared with healthy cows.
Number of breedings per conception for lame cows
with claw lesions was significantly higher than that for
Conclusion and Clinical Relevance—Claw lesions
were the most important cause of lameness, impairing
reproductive performance in dairy cows, as indicated
by a higher incidence of affected cows and a
greater time from calving to conception and a higher
number of breedings required per conception, comp ared
with healthy cows. (J Am Vet Med Assoc 2001;
Objective—To examine the relationship between
lameness and milk yield in dairy cows.
Animals—531 dairy cows.
Procedure—Cows affected with lameness were
classified into 1 of 3 groups on the basis of type of
diseases or lesions observed, including interdigital
phlegmon (foot rot), papillomatous digital dermatitis
(foot warts), or claw lesions. Cows not affected with
lameness were classified as healthy. From Dairy Herd
Improvement Association records, 305-day mature
equivalent milk yield data were collected at the end of
lactation or when the cow left the herd. Milk yield
was compared between cows affected with lameness
and healthy cows.
Results—167 (31%) cows were affected with lameness
during lactation. Lame cows had claw lesions
(60%), papillomatous digital dermatitis (31%), or interdigital
phlegmon (9%). Milk yield in lame cows with
interdigital phlegmon (mean, 17,122 lb) was significantly
less, compared with healthy cows (19,007 lb).
Conclusions and Clinical Relevance—In this herd,
interdigital phlegmon was associated with a 10%
decrease in milk production. Lame cows with claw
lesions or papillomatous digital dermatitis produced
less milk than healthy cows, but the difference was not
significant. (J Am Vet Med Assoc 2002;220:640–644)
OBJECTIVE To determine the optimal anatomic site and directional aim of a penetrating captive bolt (PCB) for euthanasia of goats.
SAMPLE 8 skulls from horned and polled goat cadavers and 10 anesthetized horned and polled goats scheduled to be euthanized at the end of a teaching laboratory.
PROCEDURES Sagittal sections of cadaver skulls from 8 horned and polled goats were used to determine the ideal anatomic site and aiming of a PCB to maximize damage to the midbrain region of the brainstem for euthanasia. Anatomic sites for ideal placement and directional aiming were confirmed by use of 10 anesthetized horned and polled goats.
RESULTS Clinical observation and postmortem examination of the sagittal sections of skulls from the 10 anesthetized goats that were euthanized confirmed that perpendicular placement and firing of a PCB at the intersection of 2 lines, each drawn from the lateral canthus of 1 eye to the middle of the base of the opposite ear, resulted in consistent disruption of the midbrain and thalamus in all goats. Immediate cessation of breathing, followed by a loss of heartbeat in all 10 of the anesthetized goats, confirmed that use of this site consistently resulted in effective euthanasia.
CONCLUSIONS AND CLINICAL RELEVANCE Damage to the brainstem and key adjacent structures may be accomplished by firing a PCB perpendicular to the skull over the anatomic site identified at the intersection of 2 lines, each drawn from the lateral canthus of 1 eye to the middle of the base of the opposite ear.
To assess the extent of damage to the skull and brain of cadaveric dairy goat kids caused by a .22-caliber, 16-g pellet fired from a multipump air pistol at various power levels.
Cadavers of 8 male and 7 female dairy goat kids ≤ 5 days old.
Each cadaver was positioned in sternal recumbency with the head and neck extended on a straw bale. A multipump air pistol was held with the barrel perpendicular to and 2.5 cm from the head at the intersection of 2 imaginary lines that extended from the lateral canthus of each eye to the middle of the contralateral ear base and fired at half (5 pumps; n = 2), intermediate (7 pumps; 2), or full (10 pumps; 11) power. The head and neck were removed from the carcass for CT imaging and gross sectioning to determine the location of the pellet and extent of damage caused to the skull and brain.
The pellet successfully penetrated the skull of all 13 heads shot at full or intermediate power and 1 of the 2 heads shot at half power. The pellet did not fragment after entering the skull of any cadaver and penetrated the brainstem (necessary for instantaneous death) in only 7 cadavers.
CONCLUSIONS AND CLINICAL RELEVANCE
The described technique was insufficient for use as a stand-alone method for euthanizing young dairy goat kids. Modification of the technique warrants further research to determine whether air pistols can be used to effectively euthanize young goat kids.
OBJECTIVE To validate the effectiveness of a penetrating captive bolt device with a built-in low-pressure air channel pithing mechanism (PCBD) as a 1-step method for euthanasia of cattle.
DESIGN Clinical trial.
ANIMALS 66 feedlot steers and heifers (weight, 227 to 500 kg [500 to 1,100 lb]) that were not expected to survive or finish the feeding period with their cohorts.
PROCEDURES Cattle were transported to a university facility and euthanized with the PCBD. For each calf, clinical variables were monitored and recorded immediately before and for at least 10 minutes after application of the PCBD. Following euthanasia, the head of each calf was removed and trauma to the brain and skull was assessed and scored.
RESULTS Death was successfully achieved with the PCBD without application of an ancillary technique in all 66 cattle; however, 4 (6%) cattle required a second or third shot from the PCBD because of technical errors in its placement. All shots from the PCBD that entered the cranial vault successfully rendered cattle unconscious without a return to sensibility.
CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that the PCBD was an effective 1-step method of euthanasia for use in mass depopulation of feedlot cattle.
Objective—To determine whether ultrasound could
be used to measure sole horn thickness in dairy cattle
after claw trimming with an adaptation of the
Animals—24 adult Holstein dairy cows.
Procedure—Cows were restrained in a standing position,
and claws were trimmed with an adaptation of
the Dutch trimming method. B-mode ultrasonography
was then performed. The transducer was placed on
the sole just caudal to the apex of the toe and immediately
medial and parallel to the abaxial white zone.
The inner margin of the sole was identified as a thin
hyperechoic line. Soles were considered to be too
thin if sole horn thickness, determined by use of ultrasonography,
was < 5 mm.
Results—Sole horn, underlying soft tissues, and the
distal surface of the third phalanx were imaged in 151
claws. The inner margin of the sole could not be identified
in 4 claws, and 37 claws could not be imaged
because cows collapsed in the restraining chute.
Mean ± SD sole thickness for all claws was 7.1 ± 1.3
mm. Only 1 sole was < 5 mm thick. The lateral front
claws were significantly thicker than the medial hind
Conclusions and Clinical Relevance—Results suggest
that ultrasound imaging can be used to determine
sole thickness in dairy cattle after routine claw
trimming. (J Am Vet Med Assoc 2003;223:492–494)
Objective—To assess the efficacy of prophylactic hoof health examination and trimming during midlactation at reducing the incidence of lameness during late lactation in dairy cows.
Design—Randomized field trial.
Animals—333 Holstein cows.
Procedures—Cows without apparent lameness were randomly allocated into 1 of 2 groups approximately 204 days after calving. Cows allocated to the treatment group (n = 161) were examined on a tilt table for diagnosis and underwent hoof-trimming procedures, if needed, for treatment of hoof disorders or lesions. Cows in the control group (n = 172) were not examined. Cows were assigned a locomotion score weekly for 28 weeks after allocation to a group. The number of cows classified as lame during late lactation (approx 205 to 400 days after calving) was compared between groups to assess the efficacy of prophylactic examination and trimming.
Results—Incidence of lameness during late lactation was 24% in cows in the control group and 18% in cows in the treatment group.
Conclusions and Clinical Relevance—The 25% decrease in number of new cases of lameness in cows undergoing prophylactic hoof health examination and trimming during midlactation may be relevant for the well-being of dairy cows and should not represent a major economic burden to producers.
Objective—To compare calving-to-conception intervals
among cows classified as nonlame, moderately
lame, or lame during the prebreeding postpartum
period and to examine the relationship between
severity of lameness and time to conception in cows
that were classified as lame.
Animals—499 Holstein cows.
Procedure—Cows in the prebreeding postpartum
period were classified as nonlame, moderately lame,
or lame by use of a 6-point locomotion scoring system.
Time to conception (days) was compared among
cows. A low, medium, or high cumulative locomotion
score was assigned to lame cows, and time to conception
among those cows was compared. Cows
classified as lame were examined on a tilt table for
diagnosis and treatment of lameness.
Results—154 (31%), 214 (43%), and 131 (26%) cows
were classified as nonlame, moderately lame, and
lame, respectively. Most cows classified as lame had
laminitis (54%) or disorders of the claw (33%).
Median time to conception was 36 to 50 days longer
in lame cows than in nonlame cows. Among lame
cows, the median time to conception was 66 days
longer in cows with high cumulative locomotion
scores than in cows with low scores.
Conclusion and Clinical Relevance—Nonlame cows
became pregnant more quickly than lame cows. Lame
cows with low cumulative locomotion scores during the
prebreeding postpartum period became pregnant sooner
than lame cows with high scores. Early diagnosis and
intervention may mitigate the effects of lameness and
improve reproductive performance in lame dairy cows.
(J Am Vet Med Assoc 2005;227:1284–1291)
Objective—To compare milk yield among cows classified
as nonlame, moderately lame, and lame and to
examine the relationship between severity of lameness
and milk yield in cows classified as lame during
the first 100 days after parturition.
Animals—465 Holstein cows.
Procedure—Cows were examined weekly during the
first 100 days after parturition and assigned a lameness
score by use of a 6-point locomotion scoring
system (ie, 0 to 5). Milk yield was compared among
cows classified as nonlame, moderately lame, and
lame. Among cows classified as lame (locomotion
score ≥ 4), milk yield was compared for cows with
low, medium, and high cumulative locomotion scores.
Cows classified as lame were further examined on a
tilt table for diagnosis and treatment of lameness.
Results—84 (18%), 212 (46%), and 169 (36%) cows
were classified as nonlame, moderately lame, and
lame, respectively. Among cows in their second or
later lactations, milk yield in lame cows was significantly
lower than that in moderately lame and nonlame
cows. In addition, among cows classified as
lame, milk yield was significantly lower in cows with
high locomotion scores during the first 100 days after
parturition, compared with cows with low scores.
Most (58%) cows classified as lame had laminitis.
Conclusions and Clinical Relevance—Results indicate
a linear relationship between increasing degree
of lameness and decreasing milk yield among cows in
their second or later lactations. The locomotion scoring
system used in this study may be a useful management
tool that veterinarians and dairy farmers
could adopt for early detection of lameness in dairy
cows. (J Am Vet Med Assoc 2005;227:1292–1296)