Clinical Examination of Farm Animals - CYF MEDICAL DISTRIBUTION

CHAPTER 4
Squamous cell carcinoma
These tumours are seen in poorly pigmented areas at
the mucocutaneous junctions of the body. The mucosa
of the third eyelid, the periorbital skin and the
vulva are common sites (Fig. 5.9). The tumours are
initially small but grow rapidly, invading adjacent
tissues.
Cutaneous lymphosarcoma
These tumours may be the precursor of generalised
lymphosarcoma or a consequence of it. The tumour
masses are mostly multiple and are found chiefly in
the skin of the neck or flanks. They are seen as grey
elevated plaques in the skin with some hyperkeratosis
of surrounding skin.
Figure 4.7 Lesions of papular stomatitis on the muzzle of a heifer. See also
Fig. 5.12.
trils and less commonly around the perineum and
scrotum. Inflammation of the upper respiratory tract
and ocular mucosa is often also seen.
Infectious vulvovaginitis/balanoposthitis The related
venereal condition of infectious vulvovaginitis/balanoposthitis
affects the genitalia of both bull
and cow. The mucosa of penis, vulva and vagina are
inflamed, painful and ulcerated. Secondary bacterial
infection may occur, and in some bulls extrusion of
the penis may be difficult.
Mucosal disease Small shallow erosions may be
seen on the oral mucosa, muzzle and less commonly
around the coronary band. Diagnosis is based on the
clinical signs, serology and antigen detection.
Malignant catarrh A superficial necrosis followed
by severe ulceration of the oral mucosa is seen. Similar
lesions may be found on the muzzle and coronary
band. Diagnosis is based on the severe clinical signs
and virus detection.
Neoplastic skin disease
The following tumours may found on the skin of
cattle.
Fibromas and fibrosarcomas
These are usually seen as large tumours arising from
the subcutaneous tissue and covered with normal
skin (Fig. 5.2).
Lipomas
Lipomas invading the soft tissues of the head have
been described. Diagnosis of tumour type can be
confirmed histologically.
Nutritional causes of skin disease
Gross deficiency of the main dietary components or a
severe shortage of food can lead to a deterioration in
skin condition. A dull, dry non-elastic skin may be
seen, with poor growth of scant and brittle hairs. The
skin may be more susceptible to bacterial infection. It
is important to ensure that no specific condition such
as chronic mucosal disease which might predispose
to similar lesions is present. Vitamins A, C and E deficiencies
have all been associated with skin disease.
Copper deficiency and excess molybdenum may produce
subtle coat colour changes, especially around
the eyes, in addition to other general symptoms of
deficiency. Diagnosis is based on the history of the
patient, dietary analysis and response to specific
therapy.
Toxic causes of skin disease
Excessive intake of some elements may produce
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