This Month's Highlight on Health
Basal Cell Tumor
This slow-growing tumor is a disordered overgrowth of cells of the epidermis, or outer layer of skin. It gets its name from its resemblance under the microscope to the basal cell layer of epithelium (see illustration). The tumor cells show minimal organisation into the local specialized skin structures (such as hair follicles and their glands). Basal cell tumors merge in their classification into the closely related benign (non-life threatening and non-spreading) tumors of hair follicles and their accompanying sebaceous and sweat glands, called sebaceous gland tumors. Usually, basal cell tumors are permanently cured by full surgical removal. Spread to other parts of the body (metastasis) is extremely rare. Read more...
Sebaceous Gland Tumors
This tumor is a disordered and purposeless overgrowth of sebaceous gland cells. These glands are attached to the hair follicles where their function is to lubricate the hairs and skin. Almost all sebaceous gland tumors are benign and can be permanently cured by total surgical removal. Many are multiple. Malignant tumors, which have the potential to spread to other parts of the body, are extremely rare. Read more...
Sweat Gland Tumor
This tumor is a disordered and purposeless overgrowth of sweat gland cells. Most sweat glands are attached to the hair follicles ("paratrichial", or beside the hair) but a few are not associated with follicles (atrichial). Most sweat gland tumors are benign and can be permanently cured by total surgical removal. Malignant tumors that spread to other parts of the body are rare. Read more...
Hair Follicle Tumor
This is one of many similar tumors that arise by disordered growth of the hair follicles. Almost all of these tumors are benign and can be permanently cured by total surgical removal. Sometimes these tumors occur at multiple sites within the same animal. Precise nomenclature or naming of the type of hair follicle tumor is usually irrelevant, as almost all are benign. Read more...
This is a tumor of pigment producing melanocytes. In humans, the classification of melanocytic tumors is very complex. The names are confusing and used in different ways by human and veterinary pathologists.
Melanocytoma (dermal melanoma, benign melanoma) is a benign tumor. It may be described as compound or simple, meaning with or without tumor melanocytes in the overlying epidermis (see diagram above); there are other subclassifications which indicate its microscopic appearance.
A malignant tumor may also be called melanoma but can also be more clearly identified by the terms malignant melanoma or melanosarcoma. Melanocytic hyperplasias (non-cancerous cell overgrowths) are benign and may be called 'lentigo' or 'lentigo simplex'.
On the hairy parts of the skin of dogs and cats, most melanocytic tumors are benign but those on mucocutaneous junctions (such as nail beds and lips) are often malignant. The exception to this rule is eyelid melanocytic tumors, which are usually benign. Read more...
The reason why a particular pet may develop this, or any cancer, is not straightforward. Cancer is often the culmination of a series of circumstances that come together for the unfortunate individual. It is the result of non-lethal genetic damage to cells, with "external" contributory factors such as radiation, chemicals, hormones and infections. The mutated cells upset the normal regulation of cell death and replacement. They do this by activating growth-promoting oncogenes (cancer genes), inactivating suppressor genes and altering the genes that regulate normal, programmed cell death (apoptosis).
Lymphocytosis is a term used to describe abnormal accumulations of lymphoid cells in the dermis or subcutaneous tissue of the skin. Occasionally, the term "pseudolymphoma" is used for these. They are non-cancerous but some may progress to be cancerous (neoplasia).
Dermal cutaneous lymphosarcoma is a malignant proliferation of abnormal lymphocytes, usually visible as nodules in the skin. It is often rapidly progressive. The disease spreads to the lymph nodes ("glands") and later to other organs of the body.
Epitheliotropic lymphoma, (sometimes described by human terms including mycosis fungoides, pagetoid reticulosis and Sezary syndrome) has a very variable clinical presentation. Sometimes there are skin nodules but the lesion may resemble an inflammatory skin disease with scaling, hair loss or secondary infection. It is progressive and spreads to lymph nodes. Read more...
The Come Command
For dogs, learning to come when called is not only a behavior issue. It's a safety issue. For instance, if your dog slips out the front door and races down across the yard, you must be able to get him to stop and come back before he runs into the street.
Bear in mind that the "come" command isn't always the best option when you want your dog by your side. For instance, if you haven't fully trained your dog to understand what you want when you say "come," don't use that command and expect results. It's better to go and get him than to say "come" repeatedly.
Keep practicing the "come" command until you are certain your dog will respond immediately the first time you call. Read more...