Scintigraphic and clinical findings in the Standardbred metatarsophalangeal joint: 114 cases (1993-1995).

To correlate scintigraphic and clinical findings of the metatarsophalangeal joint (MTPJ) in Standardbreds, radiographic findings in horses with confirmed MTPJ lameness, and determine if stress reaction and more advanced bone remodelling occurred in the MTPJ, medical records of 114 Standardbreds admitted between September 1993 and April 1995 in which bone scintigraphy included standing lateral and plantar views of the metatarsophalangeal joint (MTPJ) were reviewed. Images obtained using a large field of view gamma camera were evaluated visually for location, definition and intensity of increased radioisotope uptake (IRU), which was graded as mild, moderate, or intense. Clinical history and lameness examination findings were recorded and, in horses with documented MTPJ lameness, radiographic examination included the 30 degree (down-angled) dorsolateral 45 degree plantaromedial view thought to be useful in evaluation of the plantarolateral condyle of the third metatarsal bone (MtIII). The most common abnormality, IRU of the plantarolateral aspect of MtIII, was seen in 67 horses, and horses were further classified according to scintigraphic and clinical findings. In 43 horses in which lameness was not localised to the MTPJ, mild (32 horses), moderate (10 horses), and intense (one horse) IRU of MtHII was found. In 24 horses with lameness localised to the MTPJ, moderate (18 horses) and intense (6 horses) IRU was found. Of 18 horses with moderate IRU of MtIII, 9 had radiographic evidence of abnormal bony remodelling of MtIII, whereas 5 of 6 horses with intense IRU had radiographic changes. In 12 horses with MTPJ lameness and radiographic evidence of bony remodelling without fracture, radiographic changes consisted of plantarolateral subchondral radiolucency and sclerosis (7 horses), radiolucency and osteochondrosis (one horse), and plantar MtIII sclerosis without radiolucency (4 horses). In 2 horses with moderate IRU and MTPJ lameness, radiographic evidence of radiolucency and MtIII fracture was found. Of 19 starters with MTPJ lameness and IRU of MtIII, 18 horses raced after diagnosis, but only 13 remained at the same racing class or improved. The results of this study suggest the most common scintigraphic abnormality of the MTPJ, IRU of the plantarolateral aspect of MtIII, may precede other stress-related changes, and in some horses is associated with a continuum of stress-related subchondral bone remodelling which results in lameness and later radiographic changes. Since 24 of 35 horses with moderate or intense IRU of MtIII had MTPJ lameness, and 5 of 7 horses with intense IRU of MtIII had lameness and radiographic evidence of abnormal remodelling, it was concluded that horses with advanced, scintigraphic findings are more likely to have lameness and radiographic evidence of subchondral bone damage.

Postoperative evaluation of the surgical treatment of accessory teat and gland cistern complexes in dairy cows.

The purpose of this study was the long-term evaluation of a method of surgically repairing the abnormal condition of accessory teat and gland cistern complexes in dairy cattle. A prospective evaluation of three cows that had undergone the procedure was done. These cows were evaluated from four months to one year, postoperatively. A thorough history, physical examination, contrast radiography, and ultrasonic examination were done on each cow. A retrospective evaluation of an additional 13 cows that had also undergone the procedure was obtained four months to three years following the surgery, via owner communication. The prospective portion of this study demonstrated patency of the communication between main and accessory teat cisterns. Postoperative complications included initial slow milking and mild swelling of the involved teat. These problems resolved in all cows one to two months postoperatively. None of the 16 cows that had undergone the surgery either developed or was treated for mastitis. Likewise, none of these cows was sold or slaughtered as a result of postoperative teat problems or unsatisfactory milk production. Our study demonstrated that this particular method of surgical correction of accessory teat and gland cistern complexes is effective, is esthetically acceptable, produces minimal associated complications, and preserves the milk production capacity of the gland.

Comparison of radiologic imaging techniques for diagnosis of fragmented medial coronoid process of the cubital joint in dogs.

Thirty cubital joints from 16 dogs suspected of having a fragmented medial coronoid process were examined. Four breeds accounted for 87.5% of the cases: German Shepherd Dog (25%), Labrador Retriever (25%), Rottweiler (18.75%), and Golden Retriever (18.75%). Seventy-five percent of the dogs were male. Mean age of affected dogs was 13.6 months. Plain-film radiography, xeroradiography, linear tomography, arthrography, and computed tomography were performed on each cubital joint prior to surgical exploration of the joint. Three reviewers evaluated each diagnostic study and independently determined whether a fragment from the medial coronoid process could be seen. The consensus opinion was compared with the finding at surgery. Abnormalities of the medial coronoid process were detected in 25 of 30 joints at surgery. Fragmented coronoid process was found in 17 of 30 joints, and wear lesions were observed in 8 of 30 joints. Computed tomography had the highest accuracy (86.7%), sensitivity (88.2%), and negative-predictive value (84.6%) of the 5 imaging modalities evaluated (P < 0.05). Specificity and positive-predictive value of all imaging techniques were high. There was no significant difference between the diagnostic ability of plain-film radiography, xeroradiography, or linear tomography of the cubital joint. The combination of plain-film radiography and linear tomography provided an improvement in accuracy, approaching that of computed tomography.

Xeroradiographic evaluation of the equine larynx.

The normal radiographic anatomy of the equine larynx was determine by use of xeroradiography and dissection. The body and laminae of the thyroid cartilage, the muscular process of the arytenoid cartilages, and the dorsal lamina and arch of the cricoid cartilage had radiographic evidence of mineralization (calcification) and/or ossification in clinically normal horses. There was a significant (P less than 0.01) increase in the degree of mineralization of the thyroid and arytenoid cartilages with advancing age. Horses with diagnosis of arytenoid chondrosis (arytenoid chondral dysplasia, arytenoid chondropathy) by use of endoscopy had radiographic changes that included: enlargement with increased density of the arytenoid cartilage region, abnormal patterns of mineralization (dystrophic mineralization or osseous metaplasia), abnormal contour of the corniculate process(es) and laryngeal masses, sometimes obliterating part or all of the lateral laryngeal ventricles.

Ancillary diagnostic imaging. Angiography, ultrasonography, scintigraphy, and xeroradiography.

Veterinary medical imaging is now accepted as including a number of imaging modalities other than conventional radiography. Although the wide availability and relatively low cost of conventional radiography will keep it in the forefront of veterinary medical imaging, other imaging modalities or techniques such as those discussed in this article will, where available, be of significant value in selected cases of bovine lameness.