The osseous system--differential diagnosis for young vs. old dogs (Proceedings)

Disease processes are categorized into Congenital, Degenerative, Developmental Inflammatory, Metabolic, Neoplastic, Traumatic and Miscellaneous processes.

Young animals are usually affected by Congenital, Developmental, Inflammatory, Metabolic and Traumatic processes.

Older animals are usually affected by Degenerative, Inflammatory, Metabolic and Neoplastic processes.

Neoplasia may be seen in the young and trauma may be seen in the old; thus age is not an exclusive predicting factor.

When evaluating the osseous system, it is advantageous to:

·         center the beam on the area of interest,

·         use high detail techniques

·         use table top technique unless the part is greater than 10 cm in thickness-then use a grid/bucky; may not have option with digital equipment

·         remove patient motion artifact,

·         use as many radiographic projections as needed to define the structures/lesions in the area of interest,

·         remove superimposition of unnecessary structures as much as possible, and

·         Obtain sequential radiographic studies as clinically indicated to monitor the biological behavior of the lesion/lesions.

Things to remember

·         Many osseous lesions are not defined radiographically when the animal initially presents-the tissues have not been altered sufficiently to be detected radiographically,

·         Soft tissues should always be evaluated i.e. is there joint distention, alteration in opacity of the soft tissues, mass lesions in the cranial mediastinum or pelvic canal/sublumbar region?,

·         Is there systemic disease such as renal failure, myasthenia gravis, Addison's disease, auto-immune disease, cardiovascular disease? and

·         Is there a central nervous system component-“root signature”, cauda equine, brachial plexus mass to the altered gait?.

Radiographs I receive with requested interpretation of osseous/articular disease usually involve

·         Congenital malformation of joints-especially chondrodystrophoid breeds

·         Osteochondrosis and osteochondritis dissecans-especially in large and giant breed dogs

·         “Dysplasia”-elbow and hip-especially in large and giant breed dogs

·         Trauma-any breed-usually young pets but not exclusively

·         Panosteitis-usually in male German Shepherd and Bassett Hounds

·         Osteosarcoma –Usually in the proximal humerus, distal radius, proximal and distal femur and tibia of large and giant breed dogs.

·         Avascular necrosis-usually in the femoral head of toy breed dogs

·         Immune mediate disease-usually in the Shetland sheepdog

·         Cranial cruciate disease-any breed dog-often in young Rottweiler dogs.

My presentation will review the above conditions.  The audience will be asked to participate in the presentation so that it will be a discussion rather than a monolog.

Things I have learned

Assumption

Premise: a statement that is assumed to be true and from which a conclusion can be drawnIf you make an assumption that is not supported by fact, experience, knowledge, you will eventually make a mistake.

Mistake

A wrong action attributable to bad judgment or ignorance or inattention

1.        There are only seven disease categories:

·         Congenital

·         Degeneration

·         Inflammatory

o    Infection

o    Autoimmune

·         Metabolic

·         Neoplastic

·         Toxic

·         Traumatic

2.        There are only three ways you know what something is:

·         Biological behavior-getting bigger, getting smaller, staying the same

·         Biopsy-fine needle aspirate, core, surgical/wedge

·         Disease specific clinicopathologic testing-immunological or dna testing

3.        A mass, lump, tumor-just means an accumulation of tissue either in excess of what should be present or where it should not be; it does not mean cancer!

4.        Very few people detect new diseases; most of us see what we know! So keep learning.

5.        Control the situation or the situation will control you.

6.        Know what the technology “tells you” i.e. reveals an important, know what the technology does not “tell you” i.e. does not reveal.

7.        Definitions

·         Congenital:  Present at birth

·         Degeneration: deterioration; change from a higher to a lower form, especially change of tissue to a lower or less functionally active.

·         Inflammatory: having to do with inflammation, the body's response to either invading foreign substances (such as viruses or bacteria) or to direct injury of body tissue.

·         Metabolic: refers to the chemical processes of an organ or organism.

·         Neoplastic: pertaining to malignancy, neoplasm.

·         Etymology: Gk, neos, new, plassein, to mold.

·         Toxic:  relating to, or caused by a toxin or other poison.

·         Capable of causing injury or death, especially by chemical means; poisonous.

·         Trauma:  A serious bodily injury or shock, as from violence or an accident.

·         A severely disturbing experience that leads to lasting psychological or emotional impairment.

·         Mass: A cohesive aggregate of often similar components, composition, cells or molecules.

·         Lump: A swelling or small palpable mass.

·         Tumor - an abnormal new mass of tissue that serves no purpose.

·         Biopsy: examination, esp. under a microscope, of tissue from a living body to determine the cause or extent of a disease; the sample taken for such an examination