CAT DIFFERENCES
Integument
Female cat exhibits 4 pairs of teats (thoracic, cranial abdominal, caudal abdominal, inguinal)
Male cat usually has 1 pair at the umbilicus
Female dogs exhibit 5 pairs of teats (cranial and caudal thoracic, cranial and caudal abdominal, inguinal)
Male dog also exhibits 5 pairs of teats
Muscles of the Trunk
The external abdominal oblique m.
is much more extensive in the cat than in the dog.
Transverse thoracis and abdominis mm.
appear continuous
Rectus abdominis m.
has no transverse tendinous inscriptions (“six pack”) like the dog
The diaphragm is more muscular in the cat than in the dog
Viscera
Lung
 Have one or two generations of respiratory bronchioles that open directly into alveolar sacs, whereas dog bronchi repeatedly branch
 Has a distinct cardiac notch on the left lung
 Cats are more likely to undergo acute respiratory distress syndrome if heartworm is present due to the presence of pulmonary intravascular macrophages that are absent in dog lungs
Esophagus
 Cranial 2/3 portion is composed of 2 layers of obliquely dispersed skeletal muscle (SVE)
 Distal 1/3 portion is lined by smooth muscle fibers (GVE)
Liver
 The quadrate and right medial liver lobes may appear fused
Cecum
 Small, “c”-shaped
 Common ileocecocolic orifice (cecum is directly continuous with the ascending colon
Kidneys
 Grossly pale with capsular vessels
 Left kidney is “floating” and may be palpated externally
Reproductive Organs
 No vaginal process
 Ovaries exhibit incomplete bursa
 Testes are located just ventral to the anus
 Flaccid penis points caudoventrally (cranioventrally in dog)
 Penis is covered by mucosal spines that are dependent on testosterone (disappear in neutered cats)
Lymphatics
 Young cats may demonstrate a short cervical part of the thymus
 5 cranial sternal lymph nodes may be present in the cat (1-2 in dog) ventral to the origin of internal thoracic vessels and cranial to the transversus thoracis m.
 25% of cats show a caudal sternal lymph node near the apex of the pericardium on the dorsal sternum
 It drains the cranial mediastinal structures and mammary glands
 In cats, surgical ligation of the thoracic duct to correct chylothorax is performed with a left side approach through the upper 8 th to 10 th intercostal spaces (right side approach in dog)
 Cranial and caudal epigastric lymph nodes are unique to the cat
 Found with caudal superficial epigastric vessels, cranial to the superficial inguinal lymph nodes
 Cecal lymph nodes present