Canine

Question 1

Morph and cause. Tissue from a dog.

Answer 1

Intercostal subpleural mineralization. Metastatic mineralization from uremia (CRF). Ca x P = > 70, mineralization thorughout the body. Basement membranes, Bowman’s capsule, gastric mucosa, alveolar septa. Pulmonary edema as sequalae,

Question 2

Tissue from a dog. Name the condition.

Answer 2

Hydronephrosis.

Question 3

Tissue from a dog. Morph.

Answer 3

Malignant melanoma.

Question 4

Tissue from a dog. Morph and cause.

Answer 4

Ulcerative glossitis, bilateral, severe. Uremia.

Question 5

Tissue from a dog. Morph, pre-existing condition and causative clin path abnormality.

Answer 5

Atheroscleosis, diabetes mellitus or hypothyroidism, decreased activation of lipoprotein lipase that leads to hypertriglyceridemia. Hypercholesterolemia, hyperglycemia, hyptriglyceridemia, low T4.

Question 6

Tissue from a dog. Morph.

Answer 6

Pituitary cyst, cyst of the craniopharyngeal duct. Clinically normaly usual. Alternative, Rathe’s pouch cysts can lead to pars distalis developmental abnormality. Leads to no development of thyroid glands and adrenal glands. Autosomal recessive change leading to dwarfism in German Shepherd dogs

Question 7

Tissue from a dog. Morph. 2 other common associated lesions.

Answer 7

Right atrial hemangiosarcomas, multifocal. Also lung and spleen HSA.

Question 8

Tissue from a dog. Morph.

Answer 8

Cutaneous epitheliotropic T cell lymphoma! Has a donut shape on gross.

Question 9

Tissue from a dog. Morph.

Answer 9

Anterior uveal melanocytoma.

Question 10

Tissue from a dog. Morph. Breed of dog. Possible cause.

Answer 10

Lyssencephaly. Lhasa apso and Maltese are over-represented. Cause is a genetic defect in structural proteins that move neurons from neural crest to final resting place (double cortin, LIS-1).

Question 11

Tissue from a dog. Morph.

Answer 11

Focally extensive metaphyseal suppurative osteomyelitis with infraction. Associated with metaphyseal osteopathy (formerly hypertrophic osteodystrophy). Unknown cause. Associated with viral infection, leukocyte adhesion deficiencies). SUBPHYSEAL.

Question 12

Name the condition and give the pathogenesis.

Answer 12

Hypertrophic osteopathy. Mass in thorax –> irritation to vagal nerve –> hypertension at level of the periosteum –> triggers periosteal new bone growth.

Question 13

Tissue from a dog. Cause?

Answer 13

Ethylene glycol (antifreeze) toxicity. Tubular necrosis. Only happens if animal survives acute toxicity leading to acidosis. Calcium oxalate crystals.

Question 14

The giant kidney worm of dogs is:

Answer 14

Dioctophema renale.

Question 15

Tissue from a dog. Morph and etiology?

Answer 15

Granulomatous tracheitis. Oslerus osleri, metastrongyle nematode. Can occasionally cause occlusion of bronchi from granulomas. If in the bronchioles, consider Crenosoma vulpis, another metastrongylid nematode in canids.

Question 16

Tongue infarctions can be the result of what?

Answer 16

uremia (CKD); also look for lingual ulcers (different process but still related to elevated BUN).

Question 17

Tissue from a dog. Etiology?

Answer 17

Rhinosporidium seeberi. Gauses granulomas with little white dots in them grossly. Mesomycetozoan of the DRIP clade (neither fungus or animal).

Question 18

Etiology?

Answer 18

Pentastomes. Degenerate arthropod. Curly q’s=pentastomes. Mature form in lungs of snakes. Armillifer is a common pentastome.

Question 19

Most common breeds associated with lymphangiectasia? Common biochemical abnormalities?

Answer 19

Breeds most commonly reported to be affected by lymphangiectasia are the Basenji, the Norwegian Lundehund, Wheaten terriers, Yorkshire terriers, Shar-peis, and Rottweilers. Clin path changes are usually panhypoproteinemia, hypocalcemia and hypocholesterolemia.

Question 20

Etiology?

Answer 20

Mesocestoides. Dog cestode that causes peritonitis. Moving tapioca pudding.

Question 21

Tissue from a German Shepherd Dog. Cause?

Answer 21

Autoimmunity causes pancreatic atrophy of what once was a normal pancreas. No fibrosis. Get exocrine pancreatic insufficiency. Also found in rough coated collies.

Question 22

Tissue from a dog. Morph and name the cell of origin.

Answer 22

TVT. Histiocytes are cell of origin, don’t express MHC which allows them to escape detection and be xenotransplanted. Don’t express correct # of chromosomes.

Question 23

Most common subepidermal bullous disease in dogs and cats?

A. Bullous pemphigoid

B. Mucous membrane pemphigoid

C. Epidermolysis bullosa acquisita

Answer 23

B. Mucous membrane pemphigoid (caused by autoantibodies to different epitopes including collagen XVII (17) and laminin V

bullous pemphigoid is more common in horses and Yucatan pigs (autoantibodies target BP 1 and 2 also called collagen 17)

Epidermolysis bullosa acquisita autoantibodies target collagen VII (rare disease)

Question 24

Tissue from a Pembroke Welsh Corgi, affected regions are axilla, groin, pawpads, and pinnae. What is the most specific diagnostic change on histology?

A. Apoptotic cells in the basal keratinocytes

B. Interface dermatitis

C. Apoptotic cells throughout all layers of epidermis

D. Fading follicles/hair follicle atrophy

Answer 24

This is erythema multiforme (commonly affected breed, axilla/groin/ventrum affected is most likely this rather than pemphigous diseases). C. apoptotic cells throughout all layers of epidermis is correct

interface dermatitis is less specific (DLE, EM, ID, ED) and includes exocytosing cells, true interface dermatitis is associated with lupus erythematosus (DLE, but also VCLE, SLE). apoptotic cells in the basal keratinocytes only is more indicative of lupus erythematosus

fading hair follicle atrophy is seen in ischemic dermatopathy

Question 25

Exfoliative dermatitis in cats is associated with what type of neoplasm? A. Thymoma B. Glucogonoma C. Exocrine Pancreatic adenoma D. Hepatocellular carcinoma

Answer 25

A **thymoma** is correct - abnormal thymus thought to help activate T-cells that are self reactive and then go attack skin (like graft-vs-host disease). Exfoliative dermatitis is most common in middle aged to old dogs and cats. glucogonomas are a common tumor reported in hepatocutaneous syndrome aka superficial necrolytic dermatitis liver tumors or diffuse hepatic disease are commonly associated with superficial necrolytic dermatitis in dogs pancreatic tumors in dogs or cats could be associated with SND/hepatocutaneous syndrome (amino acid metabolism issue), but NOT exfoliative dermatitis (which is a T-cell mediated problem)

Question 26

Which immune-mediated skin disease is most commonly seen in young dogs? A. Ischemic dermatomyositis B. Discoid lupus erythematosus C. Exfoliative dermatitis D. Erythema multiforme

Answer 26

A. ischemic dermatomyositis occurs in YOUNG animals DLE and erythema multiforme have no real age predilections. Exfoliative dermatitis tends to happen in old animals (since it is a paraneoplastic syndrome and associated with neoplasms like thymoma)

Question 27

Which feature is the most diagnostic for this disease? A. breed of dog B. loss of sebaceous glands C. histiocytic inflammation D. hyperkeratosis

Answer 27

This is nodular sebaceous adenitis, seen in Vislas (similar but distinct from regular sebaceous adenitis seen in several breeds, most commonly Standard Poodle) B **loss of sebaceous glands** is CORRECT this is THE diagnostic feature for sebaceous adenitis and nodular sebaceous adenitis Vislas could be affected by other nodular histiocytic diseases (reactive histiocytosis, demodex mites, sterile pyogranuloma, etc) so breed and histiocytic inflammation are not the most diagnostic. Hyperkeratosis is really not specific Primary seborrhea and vitamin A responsive dermatosis could have follicular hyperkeratosis for instance - but their sebaceous glands would be PRESENT