- Email: [email protected]
Bain-Fallon Memorial Lectures
~
Meeling Benon
BAIN-FALLON MEMORIAL LECTURES The Twenty-second Bain-Fallon Memorial Lectures was held at the Carlton Crest Hotel, 65 Queens Road, Melbourne from July 24-28, 2000. The speakers were Dr. C. Wayne Mcllwraith from Colorado State University and Dr. Norman Rantanen, Fallbrook, California, presenting lectures on joints and imaging. The hotel is centrally located overlooking beautiful Albert Park Lake and is only minutes from Melbourne's Central Business District, the Botanical Gardens, Port Phillip Bay and specialty shops. Prepurchase imaging Drs. McIlwraith and Rantanen collaborated in presentation of a lecture on prepurchase imaging. They emphasized that the prepurchase examination should center around the clinical examination. However, radiographs of particular areas have become the norm in many instances. In many instances one is left with problems of interpretation of the significance of an "abnormal" finding when it occurs. Radiographs at the prepurchase examination are significant with routine and complete prepurchase examinations; however they also can cause problems in association with yearling sales when radiographs are the only diagnostic examination done and their clinical relevance is a contentious issue. Both these aspects need to be addressed. The ideal situation is that a complete clinical examination is made of the horse for the prepurchase examination. Conventionally, if a horse is lame at prepurchase examination, the prepurchase examination then ceases. The option that is offered to the person requesting the examination is that a lameness examination be done. While it is usually the prospective buyerrequesting the examination, it is obviously the prerogative of the seller as to whether a detailed lameness examination is
554
carried out. Before a detailed lameness examination ensues, however, it also needs to be determined who is paying for the examination. Whenever a horse is found to be lame at prepurchase examination, they generally suggest that if the buyer is really interested in the horse that they return in two weeks for another examination in the hope that it may be a temporary problem. If there is no lameness present at the prepurchase examination but localized swelling is seen, such as synovial effusion in a fetlock or hock, then radiographs would be made at that stage. Normal radiographic requests Assuming that a horse has no lameness evident at prepurchase examination (this includes jogging on hard and soft surfaces in a straight line, as well as being lunged, and also being submitted to routine flexion tests of both fore and hind limbs), it is common to have certain radiographs requested. In a racehorse, people commonly request feet (navicular area), fetlock and carpus. Details on the problems associated with "navicular x-rays" are presented separately below. Unless an athlete has done a considerable amount of athletic exercise and if there is no synovial effusion associated with the fetlock or
carpus, we do not normally recommend radiographs of these areas. In cases of prepurchase examinations for dressage or jumping (and particularly in the Warmblood breeds), it is routine to take radiographs of the tarsus because of the incidence of distal tarsal problems. However, again it is not uncommon to have radiographic changes with no evidence of response to flexion. The other area for consideration in all prepurchase examinations is the possibility that the horse has been medicated with anti-inflammatory drugs. For this reason, when there is significant money involved, a request that a blood sample be taken and tested for the presence of anti-inflammatory drugs is becoming more popular. The sale yearling This is a major problem at the yearling sales, particularly with Thoroughbreds. It is never usually possible to examine these animals above the level of a walk. Radiographs are made and in most instances these radiographic changes are not correlated with any clinical signs. Individual veterinarians (with opinions varying markedly between sellers, veterinarians, and buyers' veterinarians) make predictions as to the significance or otherwise of individual lesions and
JOURNAL OF EQUINE VETERINARY SCIENCE
there is no data available to provide answers on how many of these lesions actually produce clinical problems. The speakers are about to take on a long-term study, looking at all the x-rays on yearlings taken at Keeneland and following them out to see how significant individual lesions are in affecting racing performance.
Significance of radiographic lesions Navicular "lesions" probably cause the most problem. Cystic lesions in the central area of the navicular bone, as well as "lollipops" in the vascular foramina, are usually considered significant or at least warning signs. Relative importance is affected by consideration of age. However, spurs or enthesophytes on the lateral and medial aspects of the navicular bones (at the attachments of the suspensory ligament of the navicular bone) are not considered significant. Also, enlarged but cone shaped vascular foramina (synovial fossae) are not considered significant. A caudal tangential
(skyline) radiograph showing lack of definition between cortex and medullary cavity is very significant. A small spur on the extensor process of the distal phalanx is probably of little significance-however, larger ones often are. Small rounded fragments off the extensor process always create a dilemma. I have seen these become clinically significant and break away after having passed a prepurchase examination. However, many of these are seen in the absence of clinical signs. Mild evidence of pedal osteitis on the wings is often an insignificant change. However, if feathering is seen on the solar aspects, one needs to be cautious when considering purchase. Cystic lesions in the distal phalanx are always considered significant. The presence of any cystic lesions in distal PI is significant but cysts have been seen in proximal P2 that have been unassociated with clinical signs. Spur formation is a reason for caution. However, there is a tendency for some spur formation to be seen in the pastern
We compound: • Both sterile and nonsterile prescriptions. • Dosage forms not commercially available. • Discontinued products.
joints of Warmblood breeds without any clinical problems. Rounded fragments off the proximal eminences of the first phalanx are often unassociated with clinical signs in non-racing breeds but can lead to clinical signs later and are always of concern. In most breeds, spurs on the proximal first phalanx or the apex or base of the sesamoid are indicative of some degree o! degenerative change. Palmar supracondylar lysis also is evidence of osteoarthritis developing. Cystic lesions in the distal metacarpus are usually clinically significant, whereas cystic lesions in proximal PI may not be. Carpal chip fragmentation is always a contraindication for purchase. However, small spurs on the proximal intermediate carpal or proximal radial carpal bone are usually insignificant
• Sterile hormones. • Sterile steroids.
All sales restricted to veterinarians Orders are shipped within 24 hours
Next-day delivery at minimal extra charge
1-800-759-6963 Fax 405-485-9312
CUSTOM PRESCRIPTION COMPOUNDING A division of Red Cross Drug
Volume 20, Number 9, 2000
555
in the young athlete. More chronic spurring on the distal radius in older athletes is of concern because it usually indicates osteoarthritis development. Spur formation on the distal radial carpal bone is always significant. Smooth enthesophyte formation in the carpus is generally insignificant whereas the presence of roughness on the enthesophyte depicts ongoing activity. Cystic lesions in the carpal bones will commonly be asymptomatic. The presence of full carpal flexion and absence of effusion lay question to most radiographic changes in the carpus. The undulating lines associated with the distal tarsal joints commonly create some confusion. Osteophytes off the proximal metatarsus are usually normal. Osteophytes in the distal intertarsal and proximal intertarsal
NIMAL
joints are often insignificant and should be carefully correlated with flexion tests. Spurs or fragments at the distal aspect of the medial trochlear ridge of the talus are never significant. Lucencies created by synovial fossae are also insignificant as is flattening in the central portion of the medial trochlear ridge of the talus. Osteochondritis dissecans lesions of the tarsocruraljoint, including intermediate ridge of the tibia, lateral trochlear ridge of the talus, medial trochlear ridge of the talus, and medial malleolus of the tibia, may often be seen as incidental findings on a prepurchase radiographic examination. The owner is advised that the horse may never develop clinical signs (but there are no figures on the incidence of the subsequent development of clinical signs) and that most of these cases, if they become clinical, will respond to surgery). As with all prepurchase examinations, the prospective buyer is never told that the horse "passes" or "fails". The report of any prepurchase examination should
include all findings and a prediction as to their likelihood of their being a problem. In summary, they stated, "It is very rare to find the perfect horse that has no radiographic changes whatsoever. However, it is important that all changes are communicated directly to the prospective buyer and interpretations of the significance of any radiographic lesion made as well as possible. In the meantime, Drs. McIlwraith and Rantanen are actively pursuing data on the percentage of all lesions that may likely cause problems with a given activity. Currently, the art often exceeds the science. Meeting Report is continued on page 591 with the Annual JEVS Seminar.
PRODUCTION
STEMS
Equine Artificial Insemination Equipment and Supplies
CSU Model AV KIT
DENSIMETER
E-Z MIXIN®
For Equine Semen Collection
Sperm Counter
Equine Semen Extenders
For a free catalog featuring our complete line of equine breeding supplies contact us at:
ANIMAL REPRODUCTION SYSTEMS 14395 RAMONA AVE. CHINO, CA 91710 E-MAIL: [email protected] • TEL: (909) 393-6670 • FAX: (909) 597-3043 @ 1999 DUPREE,INC.
556
JOURNAL OF EQUINE VETERINARY SCIENCE
Meeling Benon
BAIN-FALLON MEMORIAL LECTURES The Twenty-second Bain-Fallon Memorial Lectures was held at the Carlton Crest Hotel, 65 Queens Road, Melbourne from July 24-28, 2000. The speakers were Dr. C. Wayne Mcllwraith from Colorado State University and Dr. Norman Rantanen, Fallbrook, California, presenting lectures on joints and imaging. The hotel is centrally located overlooking beautiful Albert Park Lake and is only minutes from Melbourne's Central Business District, the Botanical Gardens, Port Phillip Bay and specialty shops. Prepurchase imaging Drs. McIlwraith and Rantanen collaborated in presentation of a lecture on prepurchase imaging. They emphasized that the prepurchase examination should center around the clinical examination. However, radiographs of particular areas have become the norm in many instances. In many instances one is left with problems of interpretation of the significance of an "abnormal" finding when it occurs. Radiographs at the prepurchase examination are significant with routine and complete prepurchase examinations; however they also can cause problems in association with yearling sales when radiographs are the only diagnostic examination done and their clinical relevance is a contentious issue. Both these aspects need to be addressed. The ideal situation is that a complete clinical examination is made of the horse for the prepurchase examination. Conventionally, if a horse is lame at prepurchase examination, the prepurchase examination then ceases. The option that is offered to the person requesting the examination is that a lameness examination be done. While it is usually the prospective buyerrequesting the examination, it is obviously the prerogative of the seller as to whether a detailed lameness examination is
554
carried out. Before a detailed lameness examination ensues, however, it also needs to be determined who is paying for the examination. Whenever a horse is found to be lame at prepurchase examination, they generally suggest that if the buyer is really interested in the horse that they return in two weeks for another examination in the hope that it may be a temporary problem. If there is no lameness present at the prepurchase examination but localized swelling is seen, such as synovial effusion in a fetlock or hock, then radiographs would be made at that stage. Normal radiographic requests Assuming that a horse has no lameness evident at prepurchase examination (this includes jogging on hard and soft surfaces in a straight line, as well as being lunged, and also being submitted to routine flexion tests of both fore and hind limbs), it is common to have certain radiographs requested. In a racehorse, people commonly request feet (navicular area), fetlock and carpus. Details on the problems associated with "navicular x-rays" are presented separately below. Unless an athlete has done a considerable amount of athletic exercise and if there is no synovial effusion associated with the fetlock or
carpus, we do not normally recommend radiographs of these areas. In cases of prepurchase examinations for dressage or jumping (and particularly in the Warmblood breeds), it is routine to take radiographs of the tarsus because of the incidence of distal tarsal problems. However, again it is not uncommon to have radiographic changes with no evidence of response to flexion. The other area for consideration in all prepurchase examinations is the possibility that the horse has been medicated with anti-inflammatory drugs. For this reason, when there is significant money involved, a request that a blood sample be taken and tested for the presence of anti-inflammatory drugs is becoming more popular. The sale yearling This is a major problem at the yearling sales, particularly with Thoroughbreds. It is never usually possible to examine these animals above the level of a walk. Radiographs are made and in most instances these radiographic changes are not correlated with any clinical signs. Individual veterinarians (with opinions varying markedly between sellers, veterinarians, and buyers' veterinarians) make predictions as to the significance or otherwise of individual lesions and
JOURNAL OF EQUINE VETERINARY SCIENCE
there is no data available to provide answers on how many of these lesions actually produce clinical problems. The speakers are about to take on a long-term study, looking at all the x-rays on yearlings taken at Keeneland and following them out to see how significant individual lesions are in affecting racing performance.
Significance of radiographic lesions Navicular "lesions" probably cause the most problem. Cystic lesions in the central area of the navicular bone, as well as "lollipops" in the vascular foramina, are usually considered significant or at least warning signs. Relative importance is affected by consideration of age. However, spurs or enthesophytes on the lateral and medial aspects of the navicular bones (at the attachments of the suspensory ligament of the navicular bone) are not considered significant. Also, enlarged but cone shaped vascular foramina (synovial fossae) are not considered significant. A caudal tangential
(skyline) radiograph showing lack of definition between cortex and medullary cavity is very significant. A small spur on the extensor process of the distal phalanx is probably of little significance-however, larger ones often are. Small rounded fragments off the extensor process always create a dilemma. I have seen these become clinically significant and break away after having passed a prepurchase examination. However, many of these are seen in the absence of clinical signs. Mild evidence of pedal osteitis on the wings is often an insignificant change. However, if feathering is seen on the solar aspects, one needs to be cautious when considering purchase. Cystic lesions in the distal phalanx are always considered significant. The presence of any cystic lesions in distal PI is significant but cysts have been seen in proximal P2 that have been unassociated with clinical signs. Spur formation is a reason for caution. However, there is a tendency for some spur formation to be seen in the pastern
We compound: • Both sterile and nonsterile prescriptions. • Dosage forms not commercially available. • Discontinued products.
joints of Warmblood breeds without any clinical problems. Rounded fragments off the proximal eminences of the first phalanx are often unassociated with clinical signs in non-racing breeds but can lead to clinical signs later and are always of concern. In most breeds, spurs on the proximal first phalanx or the apex or base of the sesamoid are indicative of some degree o! degenerative change. Palmar supracondylar lysis also is evidence of osteoarthritis developing. Cystic lesions in the distal metacarpus are usually clinically significant, whereas cystic lesions in proximal PI may not be. Carpal chip fragmentation is always a contraindication for purchase. However, small spurs on the proximal intermediate carpal or proximal radial carpal bone are usually insignificant
• Sterile hormones. • Sterile steroids.
All sales restricted to veterinarians Orders are shipped within 24 hours
Next-day delivery at minimal extra charge
1-800-759-6963 Fax 405-485-9312
CUSTOM PRESCRIPTION COMPOUNDING A division of Red Cross Drug
Volume 20, Number 9, 2000
555
in the young athlete. More chronic spurring on the distal radius in older athletes is of concern because it usually indicates osteoarthritis development. Spur formation on the distal radial carpal bone is always significant. Smooth enthesophyte formation in the carpus is generally insignificant whereas the presence of roughness on the enthesophyte depicts ongoing activity. Cystic lesions in the carpal bones will commonly be asymptomatic. The presence of full carpal flexion and absence of effusion lay question to most radiographic changes in the carpus. The undulating lines associated with the distal tarsal joints commonly create some confusion. Osteophytes off the proximal metatarsus are usually normal. Osteophytes in the distal intertarsal and proximal intertarsal
NIMAL
joints are often insignificant and should be carefully correlated with flexion tests. Spurs or fragments at the distal aspect of the medial trochlear ridge of the talus are never significant. Lucencies created by synovial fossae are also insignificant as is flattening in the central portion of the medial trochlear ridge of the talus. Osteochondritis dissecans lesions of the tarsocruraljoint, including intermediate ridge of the tibia, lateral trochlear ridge of the talus, medial trochlear ridge of the talus, and medial malleolus of the tibia, may often be seen as incidental findings on a prepurchase radiographic examination. The owner is advised that the horse may never develop clinical signs (but there are no figures on the incidence of the subsequent development of clinical signs) and that most of these cases, if they become clinical, will respond to surgery). As with all prepurchase examinations, the prospective buyer is never told that the horse "passes" or "fails". The report of any prepurchase examination should
include all findings and a prediction as to their likelihood of their being a problem. In summary, they stated, "It is very rare to find the perfect horse that has no radiographic changes whatsoever. However, it is important that all changes are communicated directly to the prospective buyer and interpretations of the significance of any radiographic lesion made as well as possible. In the meantime, Drs. McIlwraith and Rantanen are actively pursuing data on the percentage of all lesions that may likely cause problems with a given activity. Currently, the art often exceeds the science. Meeting Report is continued on page 591 with the Annual JEVS Seminar.
PRODUCTION
STEMS
Equine Artificial Insemination Equipment and Supplies
CSU Model AV KIT
DENSIMETER
E-Z MIXIN®
For Equine Semen Collection
Sperm Counter
Equine Semen Extenders
For a free catalog featuring our complete line of equine breeding supplies contact us at:
ANIMAL REPRODUCTION SYSTEMS 14395 RAMONA AVE. CHINO, CA 91710 E-MAIL: [email protected] • TEL: (909) 393-6670 • FAX: (909) 597-3043 @ 1999 DUPREE,INC.
556
JOURNAL OF EQUINE VETERINARY SCIENCE