Organ Specific Patterns of Inflammation Flashcards
Infectious Arthritis
- Infection= main cause of arthritis in livestock (often arising from navel)
- Inflammation may–> joint via the bloodstream, by spread from periarticular tissues, from bone or by direct penetration (including poor aseptic sampling)
- Best are to look for inflammation is at the edges of the joint
Synovial membrane at the edges of the articular cartilage for changes in inflammation
Illustrates that the blood borne infection can arrive to the joint is one of five possible types of infection
Can spread from bone to local joint
Can spread periartricular structures (capsule)
By poor sampling techniques (sampling synovial fluid and cause infection)
Direct onocculation from outside through injury
Bite directly into joint
Non-Infectious Arthritis
- Degenerative joint disease= immune-mediated process important in adults
- Inflammation predominantly involves lymphocytes and plasma cells
Synovial tissue around cartilage–> red & swollen (acute) or duller & firmer (chronic)
Here the general principal is reversed. Likely will see this more in companion animals!
- lymphocytes and plasma cells more than neutrophils
- Much more MONONUCELAR cells
Airborne Agents–> Bronchopneumonia
((Lung inflammation))
- Infectious droplets tend to deposit in cranio-ventral portions of lobes i.e. the apical, cardiac and cranial portions of the diaphragmatic lobes
- Mainly bacterial e.g. Mannheimia haemolytica in cattle
- In certain chronic lung infections e.g. mycoplasmosis the predominant change= peribronchial & peribronchiolar cuffing with lymphocytes
- Can form lymphoid follicles, which can partial occlusion of airways
- Cuff of inflammatory cells is narrowing the airway. Cause partial occlusion of airways. Subtype of bronchopneumonia
Haematogenous Agents–> Interstitial Pneumonia
(Lung inflammation)
- Distribution tends to be throughout the lung (affected uniformly)
- Not inhaled but is arriving in the bloodstream
- Especially viral infections e.g. CDV & toxins e.g. paraquat (herbicide)- Toxin was delivered in blood stream if this was ingested
- Microscopy reveals thickening of alveolar walls (septa) due to Accumulation of inflammatory cells within them- affects gas exchange
- -sometime the interlobular septa become more prominent because the inflammatory cells are accumulating around the blood vessels in the tissue
Traumatic Implantation
(Lung inflammation)
- Fairly rare and tends to cause pleural inflammation initially with some extension to the adjacent lung tissue.
- Single area of severe inflammation, asymmetric & associated with damage to the wall of the lung
- Penetrating injury that inoculates infectious agents onto body wall
–> cat or dog fights
-lining immediately under the point of trauma is discolored, etc.
Gastroenteritis(small int.)/ Colitis(large)
(Inflammation of the GIT)
- Infections are generally controlled by the profuse gut associated lymphoid tissue (GALT), the continuous movement of ingesta & various secreted antimicrobial peptides e.g. βdefensins
- In mild infections- inflammation is usually catarrhal, particularly in the L. intestine (many goblet cells) copious mucous deposited on surface
- More severe infections may damage mucosal structure repair in which the villi are stunted or fusedSmall intestine, think about the villi being damaged which causes a reduction in SA and malabsorption (weight loss)
-diarrhea lecture
Chronic Enteritis & Malabsorption
(Inflammation: GIT)
- Chronic enteritis may –> malabsorption with progressive loss of fluid & protein across inflamed mucosa
- In a large animal, ruminant, this results in malabsorption and cobblestone gut occurs because walls are held together by macrophages
- Granulomatous enteritis e.g. Johne’s Disease (M. avium subsp. paratuberculosis)-The lamina propria of intestine is infiltrated by ↑ numbers of macrophages containing the mycobacteria
- Lymphoplasmacytic enteritis (dogs & cats)- Heavy infiltration of intestinal lamina propria by lymphocytes & plasma cells- indicates ongoing, nonspecific chronic enteritis (IBD)
- a lot of these reactions are likely a hypersensitivity to diets given today or commensal bacteria that wouldn’t affect other animals but does in these cases
Hepatitis
Inflammation of the Liver
Liver has a large capacity for regeneration & a considerable functional reserve
Acute inflammation is often due to viruses & bacteria
- Liver = swollen & perhaps hyperaemic, with rounded edges
- Small pinpoint foci of necrosis may be seen through the surface
Chronic liver damage results in fibrosis - cirrhosis
- Generally the sequel to ingestion of a toxic substance over a long period
- Ragwort poisoning (horse)- insidious deposition of fibrous tissue eventually becomes self-perpetuating–> further damage to remaining hepatocytes as it matures and contracts. Eventually neural signs, referable to loss of function of liver in converting ammonia to urea. Whether it is consumed fresh, dry, or converted in hay, still toxic. toxins in plant cause fibrosis
- more and more fibrosis tracts causing damage to the liver cells
- if you stain for collagen, you see these large bands of collagen landlocking liver cells and causing them to degenerate.
- often see liver disease quite late as the animal is able to compensate
- More chronic liver damage is because the liver is becoming rather fibrosed which is called cirrhosis
Pancreatitis
Inflammation of the Pancreas
Acute pancreatic necrosis in dogs –>particularly obese females
- Mechanism: pancreatic enzyme released–> surrounding fatty connective tissue–> saponification
- Sequel: Animal dies soon after the initial painful episode. Or the inflammation smoulders on, often without clinical signs, until there is little pancreatic tissue left. Diabetes mellitus or exocrine pancreatic insufficiency may occur
Chronic pancreatitis Occurs in cats & occasionally horses- a smouldering inflammation with progressive replacement of pancreatic tissue by fibrosis
Nephritis
(Inflammation of the Kidney)
Kidney- Has a great reserve i.e. only requires 30% of tissue to function properly
Only when 70% and over of the kidney has been damaged, will the animal start to present with clinical signs
- Inflammation can arise in the glomeruli, interstitial tissue or in the pelvis.
Nephrotic Syndrome
- Glomerulonephritis & amyloidosis may–> loss of substantial quantities of protein (esp albumin) urine
- Generalised oedema develops- Animal is losing large amounts of protein into the urine and consequently changes in the osmotic pressure and there is a reverse in gradient and then fluid accumulates in connective tissues of the body
- May also be loss of antithrombin III with resultant clotting problems
Inflammation of Bladder- Cystitis (common in females)
- Inflammation in the bladder–> considerable dilation of the submucosal vessels - vascular ectasia
- Bracken fern toxicity - ox initially causes vascular ectasia, inflammation and haemorrhage (enzootichaematuria), can progress to transitional cell carcinoma in the bladder.
Toxin in bracken will involve cystitis and can progress-chronic inflammation leading to the development of a cancer
Inflammation of CNS
Encephalitis- inflammation of neural tissue of the brain; it repairs by the proliferation of astrocytes, the brain’s form of fibrous tissue - called gliosis
Myelitis- inflammation of the spinal cord & often accompanies the brain i.e. encephalomyelitis
Meningitis- inflammation of the meninges: purulent meningitis follows haematogenous spread of infection from umbilical infections & certain septicaemias
Lymphoplasmacytic inflammation
- Accumulation of lymphocytes & plasma cells around blood vessels in the perivascular space
- Common in viral infections or immune-mediated disease affecting the brain or spinal cord
- BBB: will take these cells a bit longer to get past the barrier, they will be more present in the perivascular space
Metritis
(Inflammation of the Uterus)
- Inflammation of the uterus in livestock can take place at two points:
- At service where it is mild (endometritis)
- At parturition where it can be v.severe/ life threatening, particularly in assisted parturition- it causes metritis, involving the whole wall of the uterus
- Pyometra (pus in the uterus) occurs relatively commonly in bitches and is also life threatening
Mastitis
(Inflammation of the Mammary gland)
- Life- threatening mastitis occurs shortly after parturition
- Gangrenous mastitis due to Staphylococcus aureus, and coliform bacteria
- Chronic mastitis–> progressive destruction of glandular tissue & replacement by fibrous tissue e.g.Streptococcus agalactiae
Inflammation of Male Genital Tract
- Prostatitis (inflammation of the prostate) is common in dogs- Ascending infection may –> abscessation
- Orchitis (inflammation of testis)- uncommon- Brucella abortus–> granulomatous inflammation (bulls)
INFLAMMATORY CHANGES IN BLOOD SAMPLES
- Inflammatory changes in tissues are paralleled by changes in blood samples
- Examination of blood cell counts and blood smears is a valuable aid in the diagnosis of different types of inflammation & their disease processes
