Abstract
The report by de Melo Ocarino et al (2006) details an ‘idiopathic’ case of hypertophic osteopathy (HO) in a cat. The authors discuss the rarity of this condition in the cat and although they do not state categorically that there are only four reports in the cat, the introductory comments suggest that this is so. Three cases of pulmonary HO (Gram et al 1990, Grierson et al 2003, Rohr 2003) and one case secondary to a malignant tumour of the adrenal gland (Becker et al 1999) are cited. The paper by Becker et al (1999) actually includes references to another four cases (Carr 1971, Richards 1977, Roberg 1977, Nafe et al 1981), not mentioned by de Melo Ocarino and coauthors, making a minimum of eight cases. These same four cases are also referenced in Sherding's The Cat Diseases and Management (Couto and Hammer 1994, Schrader and Sherding 1994) and three of them are also referenced in Holzworth's Diseases of the Cat (Carpenter et al 1987). The latter textbook also revealed another case of HO, secondary to tuberculosis (Houdemer 1928 cited by Biberstein and Holzworth 1987). Thus, with a very quick, and by no means thorough, check of the literature, there would appear to be at least nine previously published cases in cats. A more extensive literature search would be required to give the exact number of publications on this topic.
Of the nine cases, at least three were not associated with pulmonary lesions: one due to thymoma (Richards 1977), one due to adrenocortical carcinoma (Becker et al 1999) and one due to a renal papillary carcinoma (Nafe et al 1981) suggesting that lesions in other organs need to be checked thoroughly. This latest case report by de Melo Ocarino and coauthors only details partial histopathology: bone, liver, kidneys, heart, lungs, brain, bladder, lymph node and spleen. It is not mentioned whether adrenal glands were checked grossly and similarly there was no mention of other organs such as thyroid glands, pancreas, etc. In order that this case be described as a case of idiopathic HO, a thorough gross and histopathological examination was imperative. Whilst it is another case to add to the literature, it cannot rightly be described as idiopathic HO, except in very loose terms, ie, that the underlying pathology was not discovered in a partial investigation.
The most significant problems with this paper stem from lack of appropriate referencing and this is not uncommon. Whilst use of electronic databases is very convenient, references retrieved from these sources are dependent entirely on the journals accessed by each database, ie, both title and year of publication. Many of the more convenient databases do not access smaller peer-reviewed, case-based journals such as Australian Veterinary Practitioner and Feline Practice (no longer in publication) and many do not access journals prior to 1960 or 1970. When checking for prior cases of rare conditions, literature searches should include extensive veterinary databases such as CAB Abstracts (1910–present). In addition, when checking for conditions that have been described for 50–100 years (such as HO) pathology textbooks, feline textbooks and pre-electronic veterinary data catalogues such as Index Veterinarius should really be searched.
As a general comment, authors and reviewers of any paper detailing neoplasia or paraneoplastic syndromes in cats should check Holzworth's Diseases of the Cat (1987). Whilst this textbook is now very old, it is still an invaluable reference on many feline conditions, especially neoplasia, as it is extensively referenced and includes many cases that pre-date electronic databases, enabling a reliable literature search of old papers without having to resort to manual searches. In fact, the preface actually cites this as one of its aims. In addition, many sections include collated case series from Angell Memorial Animal Hospital and other institutions that have never been published. As such, it offers a wealth of information and should be checked for any case-based feline paper. Similarly, whilst Sherding's The Cat Diseases and Clinical Management (1994) is now also ‘out of date’ it remains a wonderful database for literature research. As these classic textbooks steadily disappear from veterinarian's bookshelves, we are losing very valuable resources of case-based material. I would urge any JFMS author to check these texts when contributing to case-based material and similarly, any JFMS reviewer reviewing such papers. It took me less than five minutes to locate five extra cases of HO and I did not even have to turn on a computer!