postponed, other cases may take precedence, and that his time on the stand may vary from a few minutes to hours. Most courts will try and accommodate expert witnesses, especially if extensive travel is involved, and such requests should be relayed to counsel beforehand. Lastly, it must be remembered that the judge, acting under the precedents of legal jurisprudence, exercises complete control over the admission of evidence, the designation of expert witnesses and the general proceedings of the court. An appearance as an expert witness is a recognition both of the personal accomplishments and value of the w itness and of the profession of veterinary medicine. The veterinarian should at all times act to assist the court in the exercise ofjustice, and should act with the dignity and integrity that is the hallmark of a professional.
LETTER TO THE EDITOR
Ringworm Fungi: More on Specimen Collection and Isolation Results DEAR SIR:
Dr. Dion's letter on the use of dermatophyte test medium (DTM) in veterinary medicine (CVJ, JulI, 1978) was timely. It contains much useful information, reflecting her broad experience in mvcology. While concurring with her findings I wish to comment further on specimen collection and dermatophvte isolation: 1. We do not recommend DMT. In our experience, this medium if properlIy handled, will certainly support the growth of dermatophytes. However, for reasons outlined by Dr. Dion, results are normally not satisfactorv. 2. In mycology, as in anv other area of laboratory diagnosis, the specimen is all important. To reduce contamination, the lesion must be cleaned with soap and water and dried or cleaned with an alcohol swab. The lesion can be scraped with a scalpel blade or broken-off hair roots can be plucked from the affected area. This material should be submitted to the laboratory in a small envelope or a vial with the cap loose. In our laboratory all mycology specimens from pets are examined under UV light, with a KOH wetmount and cultured on mvcosel medium.' As Dr. Dion points out, a large quantity of hair clipped or combed from the pet is a useless specimen. A swab rubbed over the lesion and submitted for mycology will invariably yield negative results since it will contain no fungal elements from the lesion. In this laboratory dermatophytes were recovered orlv once from pets in 1975. In December IMNvcosel agar, BBL, Cockevsville. Marvland. 12
R E I
R E N' C E S
I. ANN'\omot's. The veterinarian as expert witness. Can. vet. J. 18: 82-86. 1977. 2. C\MPs. F.F. The medico-legal expert. Medicine. Science. and the Law 8: 11-14. 1968. 3. ONIONS. C.T. The Oxford Universal Dictionary. 3rd Edition. London: Oxford University Press. 1955. 4. SA(; tl. E.l., Medicine in the Courtroom. Boston. Massachusetts: Continuing Legal Education. Inc. 1971. 5. SEIGAL. L.J. Forensic Medicine. New York: Grune and Stratton. 1963. 6. WAttS. H..i. Forensic Science. L ondon: Sweet and Maxwz ell. 1968. 7. w\ Im II. E.R. Legal Medicine Annual. New York: Appleton-Century-Crofts. 1973.
of that vear we sent a letter to all practitioners in the province, explaining the proper method of collecting and submitting specimens for dermatophyte isolation. Since then, 53 isolates have been recovered from cats and dogs. 3. Microsporum canis is the common cause of ringworm in cats and in our experience, it is also the common cause of ringworm in dogs. Fifteen of the last 19 dermatophyte isolates from dogs were M. canis. One was M. gypseum and three were Trichophviton mentagrophvltes. These findings are similar to a standard mycology textbook (I). These findings differ from Dr. Dion's statement that M. canis causes only one third of canine ringworm infections. However, it is known that M. canis is not a common canine isolate worldwide (I). It is important to remember that the zoophilic dermatophytes. especially M. canis are common zoonoses (2). When adults or children are diagnosed as having ringworm due to M. (canis, it usuallv has been contracted from a household pet or one in the neighbourhood. Transfer of ringworm from an infected to a noninfected host is by hair and scales either directly or indirectlv. Yours truly, JR. I-ONG. D.v.M.. Ph.D. Veterinary Diagnostic
Laboratory, Nova Scotia Department of Agriculture & Marketing, Truro, Nova Scotia B2N 5E3
Referen(ces 1. it NGERMAN. P.F' and R.M. SCHWARIZMAN. Veterinary Medical Mycology. pp. 3-28. Philadelphia: Lea and Febiger. 1972. 2. STEELE. J.H. Zoonoses as Occupational Diseases in Agriculture and Animal Related Industries. p. 24. American Medical Association. 535 N. Dearborn St.. Chicago, Illinois. 1977.
LETTER TO THE EDITOR
Ringworm Fungi: More on Specimen Collection and Isolation Results DEAR SIR:
Dr. Dion's letter on the use of dermatophyte test medium (DTM) in veterinary medicine (CVJ, JulI, 1978) was timely. It contains much useful information, reflecting her broad experience in mvcology. While concurring with her findings I wish to comment further on specimen collection and dermatophvte isolation: 1. We do not recommend DMT. In our experience, this medium if properlIy handled, will certainly support the growth of dermatophytes. However, for reasons outlined by Dr. Dion, results are normally not satisfactorv. 2. In mycology, as in anv other area of laboratory diagnosis, the specimen is all important. To reduce contamination, the lesion must be cleaned with soap and water and dried or cleaned with an alcohol swab. The lesion can be scraped with a scalpel blade or broken-off hair roots can be plucked from the affected area. This material should be submitted to the laboratory in a small envelope or a vial with the cap loose. In our laboratory all mycology specimens from pets are examined under UV light, with a KOH wetmount and cultured on mvcosel medium.' As Dr. Dion points out, a large quantity of hair clipped or combed from the pet is a useless specimen. A swab rubbed over the lesion and submitted for mycology will invariably yield negative results since it will contain no fungal elements from the lesion. In this laboratory dermatophytes were recovered orlv once from pets in 1975. In December IMNvcosel agar, BBL, Cockevsville. Marvland. 12
R E I
R E N' C E S
I. ANN'\omot's. The veterinarian as expert witness. Can. vet. J. 18: 82-86. 1977. 2. C\MPs. F.F. The medico-legal expert. Medicine. Science. and the Law 8: 11-14. 1968. 3. ONIONS. C.T. The Oxford Universal Dictionary. 3rd Edition. London: Oxford University Press. 1955. 4. SA(; tl. E.l., Medicine in the Courtroom. Boston. Massachusetts: Continuing Legal Education. Inc. 1971. 5. SEIGAL. L.J. Forensic Medicine. New York: Grune and Stratton. 1963. 6. WAttS. H..i. Forensic Science. L ondon: Sweet and Maxwz ell. 1968. 7. w\ Im II. E.R. Legal Medicine Annual. New York: Appleton-Century-Crofts. 1973.
of that vear we sent a letter to all practitioners in the province, explaining the proper method of collecting and submitting specimens for dermatophyte isolation. Since then, 53 isolates have been recovered from cats and dogs. 3. Microsporum canis is the common cause of ringworm in cats and in our experience, it is also the common cause of ringworm in dogs. Fifteen of the last 19 dermatophyte isolates from dogs were M. canis. One was M. gypseum and three were Trichophviton mentagrophvltes. These findings are similar to a standard mycology textbook (I). These findings differ from Dr. Dion's statement that M. canis causes only one third of canine ringworm infections. However, it is known that M. canis is not a common canine isolate worldwide (I). It is important to remember that the zoophilic dermatophytes. especially M. canis are common zoonoses (2). When adults or children are diagnosed as having ringworm due to M. (canis, it usuallv has been contracted from a household pet or one in the neighbourhood. Transfer of ringworm from an infected to a noninfected host is by hair and scales either directly or indirectlv. Yours truly, JR. I-ONG. D.v.M.. Ph.D. Veterinary Diagnostic
Laboratory, Nova Scotia Department of Agriculture & Marketing, Truro, Nova Scotia B2N 5E3
Referen(ces 1. it NGERMAN. P.F' and R.M. SCHWARIZMAN. Veterinary Medical Mycology. pp. 3-28. Philadelphia: Lea and Febiger. 1972. 2. STEELE. J.H. Zoonoses as Occupational Diseases in Agriculture and Animal Related Industries. p. 24. American Medical Association. 535 N. Dearborn St.. Chicago, Illinois. 1977.
