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in Journal of the American Veterinary Medical Association

Objective—

To measure pelvic canal diameter in dogs from a ventrodorsal radiographic view of the pelvic region, to define a normal pelvic canal diameter, to evaluate risk factors associated with stenosis of the pelvic canal secondary to sacroiliac separation, and to determine clinical signs associated with pelvic canal stenosis.

Design—

Retrospective case series.

Animals—

84 case-group and 46 control-group dogs.

Procedure—

Medical records and radiographs of dogs with conditions unrelated to pelvic fracture (control group) and dogs with sacroiliac separation (case group) in which radiographs were obtained before surgery, I after surgery, or after fracture healing were reviewed. Discriminant analysis was used to determine a normal pelvic canal diameter. An ANOVA and Dunnett's two-sided test were used to determine factors associated with pelvic canal stenosis.

Results—

Pelvic canal diameter ratio determined from control-group dogs was ≥ 1.1. Pelvic canal diameter ratios were significantly less for case-group dogs on radiographs obtained before surgery and after fracture healing than for control-group dogs, regardless of fracture type or treatment, except for dogs with ilial fractures treated conservatively. Pelvic canal diameter ratios did not differ for case-group dogs on radiographs obtained after surgery from those for control-group dogs, except when ilial fractures were surgically reduced. None of the dogs had clinical signs associated with pelvic canal stenosis.

Clinical Implications—

Pelvic canal diameter in dogs can be determined from a ventrodorsal radiographic view of the pelvic region. Dogs with pelvic fractures that have a normal pelvic canal diameter before surgery tend to have a normal pelvic canal diameter after fracture healing. (J Am Vet Med Assoc 1997; 211:75–78)

Free access
in Journal of the American Veterinary Medical Association

SUMMARY

An electronic particle counter with attached particle-size analyzer was configured to directly determine concentration, mean cell volume, and volume distribution of erythrocytes in llama blood. Blood from 38 healthy llamas was used to characterize erythrocytic measurements and serum iron values for this species. Volume distribution curves for llama erythrocytes were similar in shape to those of other species. These curves had a unimodal, symmetric shape with a tail skewed to the right. Reference ranges for directly measured mean cell volume, erythrocyte concentration, hemoglobin concentration, and mean cell hemoglobin concentration were 21 to 28 fl, 11.3 × to 17.5 × 106 cells/μl, 12.8 to 17.6 g/dl, and 43.2 to 46.6 g/dl, respectively. Reference ranges for serum iron concentration, total iron-binding capacity, and transferrin saturation were determined to be 70 to 148 μg/dl, 230 to 370 μg/dl, and 22 to 50%, respectively.

Free access
in American Journal of Veterinary Research

Abstract

Objective—To develop a method of measuring 3-dimensional kinematics of the temporomandibular joint (TMJ) in horses chewing sweet feed.

Animals—4 mature horses that had good dental health.

Procedure—Markers attached to the skin over the skull and mandible were tracked by an optical tracking system. Movements of the mandible relative to the skull were described in terms of 3 rotations and 3 translations. A virtual marker was created on the midline between the rami of the mandibles at the level of the rostral end of the facial crest to facilitate observation of mandibular movements.

Results—During the opening stroke, the virtual midline mandibular marker moved ventrally, laterally toward the chewing side, and slightly caudally. During the closing stroke, the marker moved dorsally, medially, and slightly rostrally. During the power stroke, the mandible slid medially and dorsally as the mandibular cheek teeth moved across the occlusal surface of the maxillary cheek teeth. The 4 horses had similar chewing patterns, but the amplitudes varied among horses.

Conclusions and Clinical Relevance—The TMJ allows considerable mobility of the mandible relative to the skull during chewing. The method presented in this report can be used to compare the range of motion of the TMJ among horses with TMJ disease or dental irregularities or within an individual horse before and after dental procedures.

Full access
in American Journal of Veterinary Research

Abstract

OBJECTIVE

To determine the following: (1) whether an irrigation solution that is hyperosmolar (HYPER) relative to synovial fluid decreases tissue extravasation during an arthroscopic protocol when compared to a relatively hypoosmolar solution, (2) the safety of a HYPER solution based on viability of joint tissues following joint irrigation, and (3) if the use of a HYPER solution decreases water content in stifle joint tissue.

ANIMALS

8 adult horses.

PROCEDURES

A prospective, blinded, randomized controlled trial was performed to compare lactated Ringer’s solution (LRS; 273 mOsm/L) and a HYPER (600 mOsm/L) irrigation solution for routine medial femorotibial joint (MFTJ) arthroscopy. Primary outcomes included quantification of periarticular fluid retention based on measured changes in defined stifle joint girth and ultrasonographic (US) criteria. Water content of tissue samples was assessed. The viability of articular cartilage was determined using a microscopic fluorescent cell viability staining system.

RESULTS

No significant difference in postprocedural joint swelling was observed between LRS and HYPER treatment groups. Percent increments in femorotibial joint dimensions (mean ± SD) were seen in both treatment groups based on US (LRS, 83.9 ± 84.6%; HYPER, 131.2 ± 144.9%) and caliper measurements (LRS 5.5 ± 4.3%; HYPER 7.5 ± 5.8%) (P ≤ .05). Chondrocyte viability and tissue water content were maintained in both treatment groups, and differences were not statistically significant.

CLINICAL RELEVANCE

Doubling the osmolarity of an irrigation solution used routinely for arthroscopy does not result in detrimental effects on chondrocyte viability or tissue water content. However, use of a relatively HYPER irrigation solution did not attenuate procedural tissue swelling of the equine stifle joint.

Open access
in American Journal of Veterinary Research

SUMMARY

Objective

To determine effect of electrical muscle stimulation (EMS) on rate and degree of return to function of the limb and development of degenerative joint disease (DJD) after surgical creation and subsequent stabilization of the cranial cruciate ligament (CrCL)-deficient stifle.

Animals

12 clinically normal adult large (19.5 to 31.5 kg) dogs.

Procedure

Dogs were anesthetized, and the right CrCL was severed via arthrotomy, destabilizing the stifle. After 3 weeks, the stifle was surgically stabilized. Three weeks later, 6 dogs were subjected to an EMS treatment protocol for the thigh muscles. At 5, 9, 13, and 19 weeks after stifle destabilization, treated (n = 6) and control (n = 6) dogs were evaluated for return of stifle function. Gross and histologic evaluations of the stifles were performed at 19 weeks after stifle destabilization.

Results

Treated dogs had significantly (P = 0.001) better lameness score than did control dogs. There was less palpable crepitation of the stifle in treated dogs (P = 0.06); treated dogs also had significantly (P = 0.01) fewer radiographic signs of bone changes. Thigh circumference was significantly (P = 0.02) larger in treated dogs.There was less gross cartilage damage (P = 0.07) in the EMS-treated dogs, but more medial meniscal damage (P = 0.058, cranial pole; P = 0.051, caudal pole).

Conclusions

Improved lameness scores, larger thigh circumference, and decreased radiographically apparent bony changes observed for the treated group of dogs support the hypothesis that dogs treated by EMS after surgical stabilization of the CrCL-deficient stifle had improved limb function, with less DJD, than did dogs treated with the currently accepted clinical protocol of cage rest and slow return to normal activity. However, results of force plate evaluation did not support the hypothesis. Increased meniscal damage in dogs treated by EMS may be cause for concern. (Am J Vet Res 1997;58:1473–1478)

Free access
in American Journal of Veterinary Research
in Journal of the American Veterinary Medical Association

Abstract

OBJECTIVE

To retrospectively describe ocular abnormalities reported in dogs with presumed dysautonomia.

ANIMALS

79 dogs with dysautonomia.

METHODS

Medical records from the Kansas State University Veterinary Health Center from 2004 to 2021 were reviewed for dogs with a clinical or histopathologic diagnosis of canine dysautonomia (CD). Ophthalmic exam abnormalities, nonocular clinical signs, and outcomes were recorded.

RESULTS

Most dogs (73/79 [92.4%]) with CD exhibited at least 1 ocular abnormality. The most common ocular abnormalities were diminished pupillary light reflexes (PLRs) in 55 of 79 (69.6%) dogs and elevation of the third eyelids in 51 of 79 (64.6%) dogs. Schirmer tear test values were bilaterally decreased in 32 of 56 (57.1%) dogs. Other ocular abnormalities included resting mydriasis, ocular discharge, photophobia, blepharospasm, corneal ulceration, and conjunctival vessel pallor. The most common nonocular clinical signs were vomiting or regurgitation in 69 of 79 (87.3%) and diarrhea in 34 of 79 (43.0%) dogs. Pharmacologic testing with dilute 0.01%, 0.05%, or 0.1% pilocarpine yielded pupillary constriction in 42 of 51 (82.4%) dogs. Thirty-two of 79 (40.5%) dogs survived to discharge. Resolution of ocular abnormalities was variable.

CLINICAL RELEVANCE

Ophthalmic abnormalities such as diminished PLRs, elevation of the third eyelids, and decreased tear production are commonly associated with CD and provide support for its antemortem clinical diagnosis, though dogs with normal PLRs can be diagnosed with the disease. Pharmacologic testing with dilute topical pilocarpine in dogs with clinical signs suggestive of dysautonomia supports a diagnosis of CD. Ophthalmic abnormalities may improve or resolve over time.

Full access
in Journal of the American Veterinary Medical Association

Abstract

Objective

To test the hypothesis that endothelium-derived nitric oxide modulates vasomotor reactivity in equine digital arteries.

Design

Digital arteries were isolated from adult horses, and their vasodilator properties were examined in an in vitro controlled environment.

Animals

Five adult horses (1 gelding, 4 mares) without evidence of hoof or vascular disease were studied.

Procedure

Arterial rings with or without endothelium were exposed to endothelium-dependent vasodilator drugs in the presence or absence of a pharmacologic inhibitor of the enzyme nitric oxide synthase.

Results

Vasodilator effects of 3 endothelium-dependent vasorelaxant agents were significantly greater in endothelium-intact vessels than in endothelium-denuded vessels. Moreover, a nitric oxide synthase inhibitor reduced vasodilator responses to endothelium-dependent vasodilators in endothelium-intact arteries, but had no discernable effects in endothelium-denuded arteries.

Conclusions

These findings indicate the presence of endothelium-derived relaxing factor/nitric oxide in blood vessels of horses, and identify vascular endothelium as an endogenous modulator of vasomotor tone in the digital arteries of this species.

Free access
in American Journal of Veterinary Research