Objective—To determine in dogs what effect using
hip conformation scores assigned by the Orthopedic
Foundation for Animals (OFA) as a criterion for breeding
selections would have on hip conformation scores
of the progeny.
Animals—English Setters, Portuguese Water Dogs,
Chinese Shar-peis, and Bernese Mountain Dogs for
which OFA hip conformation scores were known.
Procedure—Pedigree data were obtained from the
national breed clubs and the American Kennel Club and
merged with data from the OFA hip conformation score
database. An ANOVA was used to evaluate the effects
of sex, age at the time of radiographic evaluation, and
year of birth on the variation in hip conformation scores
among the progeny. Heritability was estimated by use
of within-year midparent offspring regression analyses.
Results—Significant differences in progeny hip conformation
scores between sexes were not detected,
but age at the time of radiographic evaluation and year
of birth had a significant effect on hip joint conformation
of the progeny. Estimated heritability (mean ± SE)
was 0.26 ± 0.03, and dam and sire hip conformation
scores had a significant effect on progeny hip conformation
scores. Annual decreases in percentage of
dysplastic progeny and increases in percentages of
progeny and breeding dogs with phenotypically normal
hip joint conformation were detected.
Conclusions and Clinical Relevance—Results indicated
that hip conformation scores have moderate
heritability in dogs and selection of breeding stock
with better hip conformation scores will increase the
percentage of progeny with phenotypically normal hip
joint conformation. (J Am Vet Med Assoc 2000;
Objective—To describe effects of lifetime food
restriction on causes of death and the association
between body-mass characteristics and time of death
Animals—48 dogs from 7 litters.
Procedures—Dogs were paired, and 1 dog in each
pair was fed 25% less food than its pair mate from 8
weeks of age until death. Numerous morphometric
and physiologic measures were obtained at various
intervals throughout life. Associations of feeding
group to time and causes of death were evaluated,
along with important associated factors such as body
composition components and insulin-glucose
Results—Median life span was significantly longer
for the group that was fed 25% less food, whereas
causes of death were generally similar between the 2
feeding groups. High body-fat mass and declining
lean mass significantly predicted death 1 year prior to
death, and lean body composition was associated
with metabolic responses that appeared to be integrally
involved in health and longevity.
Conclusions and Clinical Relevance—Results were
similar to results of diet restriction studies in rodents
and primates, reflecting delayed death from species-
and strain-specific intrinsic causes. Clinicians should
be aware that unplanned body mass changes during
mid- and later life of dogs may indicate the need for
thorough clinical evaluation. (J Am Vet Med Assoc 2005;226:225–231)
To evaluate distribution and intensity of 99mTc-methylene diphosphonate (99mTc-MDP) uptake in the navicular area in horses with forelimb lameness isolated to the palmar aspect of the foot.
Prospective, case-controlled study.
7 horses with clinical signs of navicular syndrome and 7 control horses.
Palmar view, soft tissue-phase scintigraphic images of the foot were obtained between 7 and 12 minutes after injection of 120 to 170 mCi of 99mTc-MDP. Lateral and palmar view, bone-phase images were obtained at 30 minutes and 1, 2, and 4 hours after injection. Palmar views were evaluated by determining the ratio of image density in the navicular area to mean image density in the distal phalangeal area. Palmar and lateral view, bone-phase images were also scored on the basis of navicular area intensity (intense = 3, moderate = 2, mild = 1, and no uptake = 0). Density ratios and mean scores were evaluated as a three-way ANOVA.
Mean navicular-to-distal phalangeal density ratio for affected horses (1.77) was significantly (P = 0.003) greater than that for control horses (0.97). The mean subjective score for affected horses when evaluating palmar views only (1.85) and when evaluating palmar and lateral view pairs together (1.99) was significantly (P < 0.01) higher than scores for control horses (0.51, 0.62). Images obtained 1 hour after injection were as good at differentiating affected from control horses as images obtained between 2 to 4 hours after injection.
A substantial number of horses with palmar foot pain have increased scintigraphic uptake within the navicular bone 1 to 4 hours after injection of 99mTc-MDP. Lateral view, bone-phase images are less sensitive than palmar view, bone-phase images in revealing navicular area uptake.
A combination of lateral and palmar view scintigraphic images obtained between 1 and 4 hours after injection of 99mTc-MDP is a useful diagnostic aid in evaluating navicular bone involvement in horses with forelimb lameness isolated to the palmar aspect of the foot. (Am J Vet Res 1996;57:415–421)
To evaluate the distribution of mepivacaine hydrochloride after distal interphalangeal (DIP) joint injection in horses.
Prospective, uncontrolled study.
10 adult horses.
30 minutes before euthanasia, 8 ml of 2% mepivacaine hydrochloride was injected into the dorsal pouch of a forelimb DIP joint. Synovial tissue from the DIP joint and podotrochlear (navicular) bursa and bone tissue from the medullary cavity of the distal sesamoid (navicular) bone were taken from both forelimbs immediately after death. All synovial and bone specimens were analyzed for tissue concentration of mepivacaine by high-performance liquid chromatography. Synovial tissue and bone specimen concentrations from the injected forelimb were compared with corresponding specimens from the noninjected forelimb. All synovial tissue and bone specimen concentrations were compared with an estimated effective tissue concentration of mepivacaine (0.3 µg/mg) for local anesthesia.
Specimen concentrations of mepivacaine from the injected forelimb were significantly greater (P < 0.05) than those in the corresponding tissues of the contralateral noninjected forelimb. All DIP joint and navicular bursa synovial tissue specimens from the injected forelimb had greater than the estimated effective tissue concentration of mepivacaine for local anesthesia. Of the 10 navicular bone specimens from the injected forelimb, 4 were higher and 2 were within 20% of the estimated effective tissue concentration of mepivacaine for local anesthesia.
Mepivacaine hydrochloride deposited into the DIP joint should anesthetize pain arising from navicular bursa synovia and may decrease pain arising from the medullary cavity of the navicular bone.
DIP joint injection of mepivacaine hydrochloride is not specific for DIP joint pain. (Am J Vet Res 1996;57:422–426)