Examination of superficial lymph nodes in dogs and cat

My Topic is about ………..?

Exactly Lymph-nodes

Submandibular

Prescapular

Axillary

Inguinal

Popliteal

5 major lymph

nodes on each side of

a dog

1- Basic Knowledge

2- Clinical Examination of lymph nodes

What is la lymph node

I am a gland

Part of lymph-System

Important part of immune system

Filters lymph fluid

Trapping bacteria, viruses, foreign stuff

Basic Knowledge

Can we palpate all lymph nodes?Question to Anastasia:

A: No, Lymph nodes are palpable in the loose subcutaneous tissues.

Basic Knowledge

Are they all the same size?

Question to Omri:

Basic Knowledge

A: No, their size will vary with location and species

Basic Knowledge

What shape do they have?

Question to Kyriakos:

Basic Knowledge

A: Lymph nodes are bean shaped and have a smooth contour.

Basic Knowledge

Are they difficult to locate?

Question to Bella:

Basic Knowledge

A: Yes and No. A number of superficial lymph nodes are easily

identified in domestic animals others are more difficult to locate.

Basic Knowledge

Clinical Examination of Lymph nodes

inspection palpation and if possible the course of lymphatics

Needle aspirate/biopsy

Physical examination of the lymph nodes

Physical examination of palpable lymph nodes involves:

palpation

Inspection reveals changes in normal contours caused by enlargement.

Palpation provides more critical evaluation of any changes.

inspection

Lymph nodes that are normally palpable in small animals include:

mandibular

Prescapular

Inguinal

Popliteal

- Mandibular- Prescapular- Superficial inguinal- Popliteal

Occasionally the superficial cervical, superficial inguinal and facial lymph nodes are palpable.

Lymph nodes that are not normally palpable in small animals include:

- Cervical- Retropharyngeal- Axillary- accessory

axillary- femoral

Retropharyngeal

Accessory-axillary

femoral

are palpable, disease is likely.

Cervical

Normally palpableNot normally palpable

A fine needle aspire or biopsy may also be taken.

During Examination

When examine lymph nodes we do not just look on the size of the node

There are several physical characteristics we need to check before making any diagnosis

Physical characteristics to assess include:

Size

Response to palpationTemperature of the overlying

skin

Adhesion between the lymph node and the skin or surrounding tissues

Lobulation

Consistency

Abscess formation, maturation and discharge

Physical characteristics to assess include also:

And here we still do not make any early diagnosis

Do not just look at the lymph node the owners are worrying about.

Always remember, the animal is an organism and everything is connected

Examine the whole organism

Number of palpable

lymph nodes involved is

notedLymph nodes are normally flaccid

or tensely elastic, easily

displaces and in one piece

Whether the involvement is unilateral or bilateral

Size

Lymph node enlargement can have several reasons

Let´s check them out

Lymph node size

Consider age and condition of an animal with lymphadenopathy

(Lymphadenopathy or adenopathy is disease of the lymph nodes, in which they are abnormal in size, number, or consistency)

In cachectic patient loss of fat surrounding the nodes makes them seem more

prominent

Size

Young animals are exposed to a variety of new antigenic stimuli, increased lymph node

size is a normal immunological response

As an animal ages lymph node size often decreases and the nodes

become difficult to palpate

Why?

Animal-Age + Condition

Infiltration of

inflammatory cells

response to antigenic

stimulation

Also lymph node enlargement may be due to:

Proliferation of lymphocytes + macrophages in response to antigenic stimulation

Infiltration with inflammatory cells Proliferation of hematopoietic neoplasia Infiltration by metastatic neoplastic cells

Neoplasia cellsAbundant

cytoplasm

Small, raund nucleus

Clumped and irregular

chromatin

Increased nuclear size

5. Part of a generalized neoplasia of lymphatic

tissue (myeloid leukemia)

1. Acute local inflammatory

reaction which may either

resolve completely or

lead to suppuration (equine and

puppy strangles)

2. Part of systemic

reaction to a major specific

disease (malignant

catarrhal fever)

3. Chronic inflammatory

reaction (chronic suppuration of

the sinuses)

4. Neoplasia, which may be

primary (lymphosarcoma) or metastasis as the result of

spread from neighboring

tissues (caricinoma)

When assessing lymph node, remember enlargement could be due to:

Get confidence in your touchHow?

A very important part in the differentiation of

lymphadenopathy is to interpret your palpation

Your palpation may aid in differentiation between

Reactive lympha denopathy “it react to virus, bacteria…”

neoplastic lymphadenopat

hy

Reactive lymph nodes tend to be painful

Tend to be less firm

Marked inflammatory reactions Fungal disease

Enlarged individuals are firm, freely moveable + NON PAINFUL lymphoma

If lymph nodes are extremely firm metastaic neoplasia are likely (or fibrosis)

Metastatic neoplasia or extracapsular lymphoma

Fixation of nodes to surrounding tissues

suggests:

Etiology of lymph node enlargement unknown?

Distribution of lymphadenopathy may provide you important clues to the

etiology of lymph node enlargement

If one or localized set of lymph nodes is involved these lymphatic sites

are carefully examined for

infection, inflammation or

neoplasia

Book-Page 293-294