Pathology: Systemic - Avian Disease Flashcards
(202 cards)
Lead toxicosis
1. AKA _____ poisoning, ________
2. CAUSE: ingestion of ____
3. Species affected: ____ (not just ____)
lead, plumbism, lead, ALL, birds
Lead toxicosis
1. CAUSE: ingestion of ___
- ______ & _____ (main)
- _____ waste
- ___ pigments, etc.
Pellets, sinkers, Mine, Paint
What can be seen in this image? What does this cause?
Lead toxicosis
lead pellets
What can be seen in this image? What does this cause?
Lead toxicosis
Pellets and sinkers
Mistaken for pebbles –> ingested by animals
Lead toxicosis
- Low pH increases ___ availability
- e.g. __ + ____ = _____ toxicity
Pb, Pb, grains, higher
Birds develop lead toxicosis more than mammals because low ph increases lead absobablity
birds that eat grain have a lower ph in gizzard, alllowing lead to be abosrbed more. gizzard is grinding the sinkers or lead pellets —> lead secreted. Lead pellets enver truly go away, stay longer in GI tract –> toxicity
Lead toxicosis species main avian species affected?
- Waterfowl: Ducks, geese, swans, loons (eating stuff from bottom of lakes)
- Raptors (particularly scavengers)
- Bald eagles, other eagle sps
- water birds, upland gamebirds
- Others (other waterfowl)
- Loons
______, _______, and ______ are more commonly reported with lead poisoning.
Ducks, geese, swans
Lead toxicosis pathogenesis
Ingestion to excretion
1. Ingested
- Inhaled, transcutaneous – RARELY
2. Pb travels in blood attached to RBC membranes and albumin
- Ubiquitous, with long-term deposition in bone, liver, kidney, fat (b/c Stays longer in tissues without a lot of turnover- look here at necropsy).
- Neurotropism: likes entering brain, goes into BBB and cause nervous clinical signs.
4. Excreted in bile, urine, milk*, exfoliated skin which become sources of further toxicity to other animals.
- Potential sources of toxicity
* = Mammals
Mechanisms of pathogenicity
- Attaches to membrane of RBC
- Hemoglobin synthesis (anemia due to reduced RBC and problem with O2 transport)
- Goes through BBB and target and kills neurons and astrocytes. Directly toxic to endothelial cells –> fibrinoid necrosis of the wall of BVs.
- Pb inhibits Hb-synthesis enzymes
Microcytic hypochromic anemia
Erythrocyte fragility
Pb inhibits nucleotidase
Exacerbates anemia
Nervous system lesions – direct toxicity
Pb disrupts metabolism of neurons & astrocytes
Vascular lesions – direct toxicity
Pb disrupts metabolism of endothelium
Ischemia and/or hemorrhages
Lead toxicosis: Clinical signs
- Reluctance to fly or weakness when flying
- Unsteady gait (ataxia) (more typical with neurotropism)
- Flaccid neck (goose can walk and try to fly but can not lift its neck).
- Canada geese - Wings held in ‘roof shape’ or drooping
- Ducks, geese, swans, loons - Bile-stained feathers (& feces) around cloaca (has to do with turnover of RBC, so more pigment in feces).
none of these are exclusive to lead, but characteritic of lead txicosis
What can be seen in this image?
Wings held in ‘roof shape’ or drooping
Ducks, geese, swans, loons, etc.
What can be seen in this image?
Wings held in ‘roof shape’ or drooping
Ducks, geese, swans, loons, etc
Lead toxicosis: Gross findings
1. ______-stained feathers (& ____) around cloaca
2. ________, if chronic lead poisoning
- _____ edema (species?)
3. Impacted food in _____ GI tract +/- gastric _______
4. ____ fragments in gizzard – _____ always present
- Pb vs other metals (Fe, Al) – ______ –> lead will not be picked up with _____
Bile, feces, Emaciation, Facial, Canada geese, upper, ulceration, Lead, not, magnet, magnet
Lecture Info: chronic versus acute lead toxicosis: DOSE. When you have a little bit of lead = may develop chronic toxicity because not enough to kill you but causesa taxia, GI disturbacnes, etc. In the case of chronic –> emaciation partially necause can’t seem to eat properly. Acute lead poisoning with whomping dose = death, or absolutely nothing?
* Peracute cases with little to no gross lesions and good body condition; when very very high dose of lead, no lesions just a dead bird
What can be seen in this image? What condition is this animal suffering from?
Bile-stained feathers (& feces) around cloaca
What can be seen in this image? What condition is this animal suffering from?
Emaciation, if chronic lead poisoning
What can be seen in this image? What condition is this animal suffering from?
Impacted food in upper GI tract
What can be seen in this image? What condition is this animal suffering from?
- Lead fragments in gizzard – not always present
- Pb vs other metals (Fe, Al) – magnet
What can be seen in this image? What condition is this animal suffering from?
If not doing necropsy or have live bird, do Xray because can see lead (metal).
What can be seen in this image? What condition is this animal suffering from?
- Lead fragments in gizzard – not always present
- Pb vs other metals (Fe, Al) – magnet
What can be seen in this image? What condition is this animal suffering from?
Mature bald eagle = white head
Takes 5 years to get white head.
Good BDS b/c fat in subcutis, well deveoped pectoral muscle
What can be seen in this image? What condition is this animal suffering from?
Female bird
Ovaries
Kidneys with lead poisoning, or other diseases that cause damage to tubules look like a brain.
What can be seen in this image? What condition is this animal suffering from?
Cut open kidney
- Kidney
- ACUTE: _______________ degeneration &, sometimes, _____
- _______ convoluted tubules are most affected b/c most first tubules where urine is trying to exit.
- _______ necrosis of BV, maybe _______
- IN inclusions (well, maybe) – acid-fast [Pb bound to nuclear proteins]
- CHRONIC: _______ & ______ - Blood vessels
- Fibrinoid necrosis of the ____
- _______
- Secondary _____ or _______ lesions
Tubuloepithelial, necrosis, Proximal, fibrinoid, hemorrhage, nephropathy, fibrosis, wall, Hemorrhage, ischemic, hemorrhagic
What can be seen in this image? What condition is this animal suffering from?
Lead toxicosis - Kidney
normal tubule
Inclusion bodies are little purple circles
Ziehl Nielson stain to highlight more.