Clinical and genetic assessments of hip joint laxity in the Boykin spaniel

Canine hip dysplasia (CHD) is characterized by a malformation of the hip joint that leads to joint laxity and consequential degenerative joint disease. The most widely used method for diagnosis of CHD is the ventrodorsal hip-extended radiologic view, commonly referred to as the Orthopedic Foundation for Animals (OFA) method. The method of the University of Pennsylvania Hip Improvement Program (PennHIP), an alternative technique that is based on hip joint laxity, provides a quantitative assessment, the distraction index (DI), of the likelihood of the development of CHD because of increased laxity in the hip joint. Linear regression analysis showed that, across many breeds of dog, the incidence of CHD, as defined by the OFA, is positively correlated with the mean DI, the determination coefficient (r2) being 26%. We used families of Boykin spaniels (BSs) to determine the level of joint laxity in the breed and to conduct an initial whole-genome screening to identify markers that co-segregate with increased joint laxity. Although there was a positive correlation between the incidence of hip dysplasia and increased joint laxity, we did not find significant linkage in the 28 BSs that underwent genotyping, likely owing to the small size of the pedigree.     

10 years experience with denervation of the hip joint capsule for treatment of canine hip joint dysplasia and arthrosis

Denervation of the canine hip joint capsule is described as a surgical therapy method in the treatment of canine hip joint dysplasia and arthrosis. The goal of this operation is a removal of the pain immediately and a reactivation of the dynamic active component of the hip joint in moving the body forward. Simple removal of the periosteum of the craniolateral acetabulum edge destroys the rami articulares of the cranial glutaeal nerve and the rami articulares dorsalis of the sciatic nerve. Within 10 years now we performed the denervation of the canine hip joint capsule. Evaluation of the post operative clinical course in 269 cases revealed an impressive improvement of lameness due to pain relief in almost 92% of the cases.     

Laxity of canine hip joint in two positions with computed tomography

Computed tomographic (CT) examination of 20 canine hip joints was carried out in two positions, normal-standing and weight-bearing. In normal (dorsal acetabular rim angle: DARA < 15 degrees ) or slightly abnormal (DARA, 15 degrees to 20 degrees ) hip joints, the values of parameters to laxity were evaluated as more severe in the weight-bearing position. Comparisons of results using various indicators, including the center distance (CD) index, dorsolateral subluxation score, and lateral center edge angle, revealed that the CD index may be a useful marker of functional laxity in the canine hip joint under CT scanning. Further, CT scanning in the weight-bearing position was more sensitive than in the normal-standing position for the detection of laxity in hips with normal or only slightly abnormal DARA.     

Associations between canine juvenile weight gain and coxofemoral joint laxity at 16 weeks of age

OBJECTIVE: Evaluation of the relationship between canine weight gain from 6 to 15 weeks of age and passive coxofemoral joint (CFJ) laxity at 16 weeks of age. STUDY DESIGN: Longitudinal cohort study. ANIMALS: Full- or half-sibling hounds (n = 56). METHODS: Hounds were weighed weekly from 6 to 15 weeks of age. Individual average daily gain (ADG) was calculated for each week (weekly) and for the study (overall). PennHIP distraction index (DI) was determined for each CFJ at 16 weeks. Mixed effects linear models were evaluated for associations of DI (highest and mean) with 15-week weight and ADGs (actual or normalized). Left and right DIs were compared with a Student's paired t-test. Significance was set at P<.05. Trends were considered at P<.10. RESULTS: Mean (+/-SD) 16-week DI score and 15-week weight was 0.67 +/- 0.16 and 12.5 +/- 1.8 kg, respectively. Within animal left and right DIs were not significantly different. There were no significant associations between DI and any of the weight gains evaluated. There was a trend for a negative relationship between normalized 14-week ADG and DI in one statistical model. CONCLUSIONS: Weight gain from 6 to 15 weeks of age was unrelated to 16-week PennHIP DI in a homogenous canine population with moderate-to-severe CFJ joint laxity. CLINICAL RELEVANCE: Based on our results, ad libitum feeding between 6 and 15 weeks of age does not appear to have an adverse impact on joint laxity at 16 weeks of age as measured by the PennHIP DI.     

Response of pups with maternal derived antibody to modified-live canine parvovirus vaccine

The AA reports the results of vaccination against canine parvovirus (CPV) of pups with maternal antibody, utilizing a modified-live virus (MLV) CPV vaccine having a titer of 10⁷ TCID₅₀/dose. This vaccine was shown to be effective also when HI antibody titers of pups were ≤ 1:80.     

New concepts of coxofemoral joint stability and the development of a clinical stress-radiographic method for quantitating hip joint laxity in the dog

From mechanical principles and postmortem observations of coxofemoral joints of dogs, a hydrostatic mechanism influencing hip joint stability was discovered. This discovery led to the development of a stress-radiographic positioning method to quantitate hip joint laxity in dogs. The method incorporated 2 views with the dog in supine position and hips at neutral flexion/extension angle: a compression view, with the femoral heads fully seated in the acetabula; and a distraction view, with the femoral heads at maximal lateral displacement. An index measurement method was formulated to quantitate the relative degree of joint laxity appearing in either the compression or distraction view. Clinical evaluation of 6 dogs was done to compare the compression/distraction method with the standard hip-extended radiographic method. Also, the stress-radiographic method was performed on 16-week-old Borzoi and German Shepherd Dogs to compare the characteristics of inherent hip joint laxity in these breeds. In all dogs tested, hip joint laxity was masked by the standard hip-extended view as indicated by a 2.5-fold improvement in sensitivity to hip joint laxity of the new method (P less than 0.00001). Moreover, the mean hip joint laxity of 16-week-old German Shepherd Dogs exceeded the mean hip joint laxity of Borzois by 79% (P less than 0.00001). Reports in the literature document the incontrovertible association of hip joint laxity to the development of hip dysplasia in dogs. We believe the ability to accurately quantitate hip joint laxity will provide key diagnostic and prognostic criteria for the selection of pet dogs, and more importantly, breeding stock.     

Natural infection of captive coyote pups with a herpesvirus antigenically related to canine herpesvirus

Herpesviruses were isolated from captive coyote pups with ocular discharge and hepatomegaly. The viruses were shown to be antigenically related to canine herpesvirus on the basis of specific virus neutralization with canine herpesvirus antiserum. The epizootiology of the outbreak suggested that the herpesvirus was acquired by indirect contact with guard dogs being cared for by the same animal technicians who cared for the coyotes.     

Efficacy and toxicity of estrogens commonly used to terminate canine pregnancy

Three groups of bitches were treated with diethylstilbestrol (75 micrograms/kg) orally for 7 days (n = 12), estradiol cypionate intramuscularly once (22 micrograms/kg; n = 12), or estradiol cypionate intramuscularly once (44 micrograms/kg; n = 12). Treatments commenced during late proestrus (n = 4/group), the fourth day of behavioral estrus (n = 4/group), or the second day of diestrus (n = 4/group). All bitches were bred on alternate days throughout estrus to stud dogs of known fertility. Ovariohysterectomies were performed on day 25 of diestrus to diagnose pregnancy and to assess any pathologic changes in the uterus. Eleven bitches treated with diethylstilbestrol, 6 bitches treated with the low dosage of estradiol cypionate, and 4 bitches receiving the high dosage of estradiol cypionate were pregnant at the time of surgery. Ten of the bitches treated with estrogens during proestrus, 6 treated during estrus, and 4 treated during diestrus were pregnant. The serum concentration of progesterone in 2 bitches treated with the high dosage of estradiol cypionate decreased to less than 2 ng/ml by day 25 of diestrus, suggesting premature luteal regression. Diethylstilbestrol appeared to have little efficacy in terminating pregnancy. Estradiol cypionate appeared to have greater efficacy when administered during estrus or early diestrus; however, pyometra developed in 2 bitches treated with this estrogen during diestrus.     

Relationships among measurements obtained by use of computed tomography and radiography and scores of cartilage microdamage in hip joints with moderate to severe joint laxity of adult dogs

OBJECTIVE: To evaluate correlations among measurements on radiographic and computed tomography (CT) images with articular cartilage microdamage in lax hip joints of dogs. ANIMALS: 12 adult mixed-breed hounds. PROCEDURES: Pelvic CT and radiography were performed. Hip joints were harvested following euthanasia. Orthopedic Foundation for Animals (OFA) and PennHIP radiograph reports were obtained. Norberg angle (NA) and radiographic percentage femoral head coverage (RPC) were determined. Center-edge angle (CEA), horizontal toit externe angle (HTEA), ventral acetabular sector angle (VASA), dorsal acetabular sector angle (DASA), horizontal acetabular sector angle (HASA), acetabular index (AI), and CT percentage femoral head coverage (CPC) were measured on 2-dimensional CT images. Femoral head-acetabular shelf percentage was measured on sagittal 3-dimensional CT (SCT) and transverse 3-dimensional CT (TCT) images. Light microscopy was used to score joint cartilage. Relationships of OFA confirmation and PennHIP osteoarthritis scores with radiography, CT, and cartilage variables and relationships of cartilage scores with radiography and CT measurements were evaluated with Spearman rank correlations. Pearson correlation was used for relationships of distraction index (DI) with radiography, CT, and cartilage variables. RESULTS: Significant relationships included PennHIP osteoarthritis score with cartilage score, CEA, HTEA, DASA, AI, CPC, and TCT; OFA confirmation score with cartilage score, NA, RPC, CEA, HTEA, DASA, AI, CPC, and TCT; cartilage score with NA, RPC, CEA, HTEA, DASA, HASA, AI, and TCT; and DI with cartilage score, CEA, HTEA, DASA, HASA, AI, and CPC. CONCLUSIONS AND CLINICAL RELEVANCE: CT appeared to be a valuable imaging modality for predicting cartilage microdamage in canine hip joints.     

Viscosity determination of synovial fluids from the canine hip and elbow joint as well as the human knee joint

The development of pathological changes in both human and canine hip joints is mainly caused by a lack of synovial fluid lubrication. This results in an increased joint abrasion. Even after implantation of joint prosthesis, inadequate lubrication can lead to abrasion in the tribological pair. This can finally result in aseptic loosening of the prosthesis. In spite of the enormous number of studies that have been performed on human, only little knowledge about the tribological properties of the joints in dogs is available in the literature. For this reason the viscosities of synovial fluid, derived from physiological and pathologically changed canine elbow joints were measured. The viscosities were determined by the use of a cone-plate viscometer at different temperatures and shear rates. The obtained values were compared with the viscosity values of pathologically changed synovial fluids from human knee joints as well as with pathological samples from the canine hip joint. The results show that the viscosity values vary within a series of measurements and are inversely proportional to the temperature of the sample and the shear rate. The differences between the average viscosities of canine and human synovial fluids taken from pathologically changed joints are below 4% (22.5 s(-1) at theta1 = 25 degrees C). The findings of this study are being implemented in a FE-Model for the computation of actual forces in the hip joint during different movements. This would represent a contribution to an improved prosthetic treatment of canine and human hips.     

Expression of relaxin receptor LRG7, canine relaxin, and relaxin-like factor in the pelvic diaphragm musculature of dogs with and without perineal hernia

OBJECTIVES: To compare the expression of canine relaxin, relaxin-like factor (RLF), and relaxin receptors within the muscles of the pelvic diaphragm of dogs with perineal hernia (PH) and clinically normal dogs. STUDY DESIGN: In vivo comparative study. ANIMALS: Fifteen client-owned intact male dogs with PH were studied. Four mature intact male dogs with no evidence of perineal pathology served as controls. METHODS: Biopsy samples from the levator ani, coccygeus, and internal obturator muscles were obtained. RNA samples were reverse transcribed and analyzed by real-time PCR for the expression of canine relaxin receptor LRG7, relaxin, and RLF. RESULTS: Significantly higher expression levels of canine relaxin receptors occurred in the musculature of the pelvic diaphragm and internal obturator muscle in dogs with PH compared with normal dogs. Expression of canine RLF revealed no significant difference between dogs with PH and controls. The difference in the expression of canine relaxin between groups was not statistically significant. CONCLUSIONS: Relaxin receptor up-regulation occurs in the coccygeus, levator ani, and internal obturator muscles of dogs with PH. CLINICAL RELEVANCE: The higher expression of relaxin receptors within the muscles of the pelvic diaphragm in dogs with PH suggests that relaxin might play a role in the pathogenesis of PH. Atrophy of these muscles, which predisposes to PH, may be attributable to increased relaxin activity.     

Pathology of the placenta and newborn pups with suspected intrauterine infection of canine herpesvirus.

Pathologic and virologic investigations were done on the fetal placenta and on pup runts which were obtained from a bitch with a medical history of canine herpesvirus (CHV) infection. Macroscopically, the placenta was poorly developed. Small grayish white foci were observed in the placental labyrinth. Characteristic lesions of CHV infection were not prominent in the pups examined. Microscopically, however, focal degenerative and necrotizing lesions were observed in the placental labyrinth. Rarely, eosinophilic or basophilic intranuclear inclusion bodies were in the trophoblastic cells in the necrotizing lesions. In the adrenal gland of one stillborn pup, focal necrosis and hemorrhages could be seen; these irregularities were essentially the same as those seen in the newborn pups with CHV infection. Focal interstitial pneumonia was also observed in some of the pups. The CHV organism was isolated from the kidney of one pup that survived for 22 days.     

Morphometric assessment of the canine hip joint using the dorsal acetabular rim view and the centre-edge angle

The dorsal acetabular rim (DAR) view of the hip joint can be used to assess the weightbearing portion of the acetabulum and the acetabular coverage, providing an adjunct to the conventional ventrodorsal (VD) view in the radiographic evaluation of hip dysplasia in the dog. A quantitative index of acetabular coverage in the DAR view, the acetabular slope (AS) angle, was originally proposed in 1990. The aim of the present study was to make a prospective, comparative assessment of a new parameter, the centre-edge (CE) angle, with the AS angle, for the evaluation of the acetabular coverage of the femoral head in the DAR view. The reliability and repeatability of the two parameters was assessed using the r(I) value of intraclass correlation coefficient (ICC) in a prospective study of 208 hip joints in large and giant breed dogs. An estimation of the added value of using the DAR view, compared with that of the VD standard view alone, was also assessed. The CE angle showed a higher r(I) value compared with the AS angle; in 26 per cent of hips of FCI classes A, B and C, the DAR view provided additional diagnostic information compared with the VD view, with respect to lateralisation and/or initial changes to the dorsal rim. It is concluded that the CE angle is more reliable than the AS angle in the evaluation of acetabular coverage, and that the DAR view provides valuable data compared with the VD view alone in the early stages of canine hip dysplasia.     

Open reduction and stabilisation of coxofemoral joint luxation in dogs and cats, using a stainless steel rope inserted via a ventral approach to the hip joint

Open reduction and stabilisation of coxofemoral joint luxation was made via a ventral approach to the hip joint in dogs and cats, using a transarticular stainless steel rope. A feature of the procedure is transarticular penetration of the rope from the pelvic cavity to the femoral neck by guidance with a guide wire which was previously inserted from the femoral neck into the pelvic cavity and by detection of the guide wire in the pelvic cavity by use of forceps connected to an alarm-ohmmeter. Forty-seven animals (37 dogs and 10 cats) with acute and simple coxofemoral luxation were treated and postoperatively maintained in cage rest without external fixation. Most of the animals regained an almost normal gait within several days.     

Osteopontin gene polymorphism association with milk traits and its expression analysis in milk of riverine buffalo

Osteopontin gene is regarded as a plausible candidate in mammary gland differentiation and development, expressed by variety of cells, tissues, and biological fluids including milk. The current study was performed in two phases. In the first phase, Osteopontin gene polymorphisms were identified and associated with milk composition such as ash, milk fat, SNF, lactose, and protein. In the second phase, milk samples from five healthy mastitis-free Nili Ravi buffaloes were analyzed for expression of Osteopontin gene at transition (day 15), mid (day 90), and end (day 250) stage of their second lactation. Briefly, blood samples were collected from Nili Ravi buffalo to isolate the genomic DNA, specific primers were designed for PCR amplification. The amplified PCR products were sequenced bi-directionally. Six polymorphisms were identified in the coding region and four in the intronic region of the gene. The results showed that SNP g.38329758 T > C causing substitution of valine to alanine (V127A) was associated with high milk protein. For mRNA expression analysis, somatic cells were separated from milk samples for RNA isolation. Analysis of differential gene expression data has permitted us to illustrate the expression pattern of osteopontin gene in lactating buffalo. The Osteopontin gene was found to be transcribed among all three lactation stages, but expression was observed with the highest value (fold change) in peak lactation and remained elevated till the end of lactation. Identified gene marker may be helpful for the prediction of superior animal for selection. The presented study also gave an insight into the genetic screening and lactation biology of riverine buffalo, offering direction for future research in lactating buffalo.     

Immunization of pups with maternally derived antibodies to canine parvovirus (CPV) using a modified-live variant (CPV-2b)

The results of vaccination trials carried out on pups with maternally derived antibodies (MDA) to canine parvovirus (CPV), using a modified-live CPV-2b variant vaccine (29-97/40 strain), are reported. The vaccine was able to overcome the obstacle of MDA, and to elicit protective immunity in 100% of the pups whose antibody titres were 1:10-1:40, 83% of the pups with titres of 1:80, 57% of the pups with titres of 1:160, and even in 60% of the pups with antibody titres of 1:320.