Exam 3: Pathogenesis and lesions of the vascular system

what is arteriosclerosis

• characterized by intimal fibrosis of large elastic arteries

• age relate disease that occurs frequently in many animal species but rarely causes clinical signs

what is atherosclerosis

• characterized by intimal and medial lipid deposits in elastic and muscular arteries and fibrous tissues and calcium deposits on vascular walls

what animals are most likely to present with atherosclerosis

• aged psittacines

• male dogs with obesity, hypothyroidism, hypercholesterolemia, hypertryglycerideia, diabetes

what is arterial medial calcification

• concurrent endocardial mineralization

• caused by calcinogenic plant toxicosis, vitamin D toxicosis, renal insufficenc, severe debilitation such as Johne’s disease

• solid, dense, pipelike structures with raised, white, solid intimal plaques

• histology shows promiment basophilic granular mineral deposits

what is fibrinoid necrosis

• associated with endothelial damage

• characterized by entry and accumulation of serum proteins followed by fibrin polymerization of the vessel wall

• frequent in many acute degenerative and inflammatory diseases of small arteries and arterioles

• dogs with uremia and hypertension

what is an aneurysm

• localized dilation or outpouching of a thinned and weakened portion of a vessel

• usually large elastic arteries but also occurs in veins

• caused by copper deficiency in pigs, infection with Spirocerca lupi in dogs, infection with Strongylus vulgaris in horses

• most cases are idiopathic!

what is a dissecting aneurysm

• infrequent but seen in birds (turkeys)

• disruption of the intima → entry of blood into the media → blod dissects along the wall

• aneurysms can rupture

• rapidly fatal because rather large arteries are typically the ones involved

what is arterial hypertrophy

• response to sustained increases in pressure or volume loads

• affected vessels are generally muscular arteries, and increase in wall thickness is predominantly caused by hypertrophy of smooth muscles of the tunica media

how is hypertrophy of muscular pulomary arties described in cattle?

• hypoxia induced pulmonary arterial vasoconstriction and subsequent pulmonary hypertension associated with right sided heart vailure from high altitudes

• ascities, pulmonary edema, hydrothorax, hydropericardium, and widespread edema of dependent tissues

• high altitude disease/ high mountain disease/brisket disease

how does systemic hypertension cause arterial hypertrophy

• usually secondary to hyperthyroidism or renal dz

• causes retiopathy, renal vasculopathy

what is the major cause of arterial hypertrophy in cats

• parasites, mainly heartworms

• lesions often occur in the anscence of parasitic infections

what are viral causes of vasculities

• EVA

• africal horse sickness

• EIA

• equine morbilivirus

• malignant catarrhal fever

• BVDV

• bluetongue

• hog cholera

• african swine fever

• FIP

what are bacterial causes of vasculitis

• Salmonellosis

• Erysipelothrix rhusiopathiae

• Histophilus somni

• rocky mounted spotted fever and other tickborne diseases

what are mycotic causes of vasculitis

• Phycomycosis

• aspergilosis

  • w

what are parasitic causes of vasculitis

• equine strongyles

• heartworms

• french heartworns

• spirocercosis

what are immune mediated causes of vasculitis

• canine systemic lupus

• rheumatoid arthritis

• polyarteritis nodosa

• lymphocytic choriomeningitis

• drug induced hypersensitivity

• purapura hemorrhagica

• rabies vaccine reaction

what is Erysipelas in pigs

• Erysipelothrix rhusiopathiae

• diamond skin disease caused by vasculitis, thrombosis and ischemia

what is histophilus somni

• thrombotic meningoencephalitis

• systemic vasculitis in cattle → meningoencephalitits

• gross lesions in CNS are characteristic of infarcts

• microscopic lesions = vasculitis and vascular necrosis, which are followed by thrombosis and infarction

• also cause necrotizing myocarditis

what is rocky mountain spotted fever

• Rickettsia rickettsii

• tick born

• invade and replicate in endothelial cells causing fever, hemorrhages, and edema

what is aspergillosis

• vascular invasion of fungal hyphae results in vasculitis, thrombosis, and infarction

• systemic fungal infections in dogs are relatively uncommon but german shepards are overrepresented

• the source or route of these infections is still not well understood

what type of immune reaction causes vasculitis

type III hypersensitivity → necrotizing vasculitis by the deposition of immune complexes such as FIP

how does polyarteritis cause vasculitis

• Polyarteritis nodosa in aged rats

• beagle pain syndrome

what is Omphalophlebitis

• inflammation of the umbilical vein

• neonatal farm animals

• bacterial contamination of the umbilicus immediately after perturition → septicemia, suppurative polyarthritis, hepatic abscesses, and umbilical abscesses

what is jugular thrombophebitis

• may be associated with indwelling jugular catheters

• increased with hypoproteinemia, salmonellosis, endotoxemia, and large intestinal disease

what is Schistosomiasis (blood fluke)

• caused by Heterobilharzia americana

• granulomas in intestine and liver centered around ova and may mineralize

what is lymphangitis

• the endothelial cells lining the lymphatic vessels are subject to the same reactions to injury and inflammation as vascular system

• may be seen with specific diseases

• may be acute, subacute, granulomatous, or chronic

what are bacterial causes of lymphangitis

• Johne’s disease

• tuberculosis

• actinobacillosis

• glanders

• ulcerative lymphagngitis

• others

what are mycotic causes of lymphangitis

• epizootic lymphangitis of horses

• sporotrichosis

what is the major parasitic cause of lymphangitis

Brugia spp in dogs and cats

what is atrial thrombosis

• may occur with valvular or myocardial disease

• result of hemostatic abnormalities resulting from stasis or turbulence

• endothelial injury, turbulence, and hypercoagulability are involved in the pathogenesis

• thrombosis or embolism of coronary arteries can cause myocardial infarction

what are the most common diseases with thrombosis and embolism

• pulmonary thromboembolism secondary to PLN, spsis, hypercortisolism, IMHA

• arortic thromboembolism in cats= saddle thrombi

• aortoiliac thrombosis in horses

• septic embolism from lesions of vegetative endocarditi s

• fibrocartilaginous emboli in dogs

• conditions accompaied by DIC