Unit 1 - Zn, Fe, F, and Tl Flashcards
What species is most affected by zinc toxicosis?
Dogs
What are the sources of zinc toxicosis in small animals?
Galvanize wire cages, Zn game pieces, ointments, anti-dandruff shampoo, and pennies (made after 1982)
What are the sources of zinc toxicosis in large animals?
Feed supplements, galvanized feed bunks, hardware, and zinc dust (galvanized smelting)
Zn is a divalent cation so it competes with other divalent cations which are __, ___, __, ___, ___, and ____.
Ca, Fe, Pb, Cu, S, and P
What is the MOA of zinc toxicosis?
It is unknown, but what is known is that it causes hemolysis and GI irritation
When is the onset of clinical signs for zinc toxicosis in dogs?
2-4 days
What clinical signs does zinc toxicosis cause in dogs?
Depression/weakness
Anorexia, vomiting, and diarrhea
Hemolytic anemia - pale mucous membranes, icterus, and pigmenturia
When is the onset of clinical signs for zinc toxicosis in other species?
2-4 days
What clinical signs does zinc toxicosis cause in livestock species?
Decreased growth, weight, and efficiency
What clinical signs does zinc toxicosis cause in cattle?
Green/watery manure, hemolytic anemia, and pica
What clinical signs does zinc toxicosis cause in swine?
lameness
What clinical signs does zinc toxicosis cause in horses?
Lameness, weakness, ataxia, and laryngeal paralysis
What clinical signs does zinc toxicosis cause in sheep?
diarrhea
What clinical signs does zinc toxicosis cause in avian species ?
vomiting and diarrhea
What ante mortem tissue samples can be collected for zinc testing?
serum, liver biopsy, and urine
What post mortem tissue samples can be collected for zinc testing? Histo?
Liver, kidney, and pancreas
All of the above + GI tract for histo
What other methods could be used to diagnose zinc toxicosis?
Feed and radiographs
When collecting serum for zinc detection you should use a ________ top with a ____ stripe because ___ tops and _______ tubes contain Zinc.
Royal blue top with red stripe
Red tops and tiger stripes
What will your clinical pathology results be in a dog with zinc toxicosis?
Severe hemolytic anemia - hypochromic, macrocytic, regenerative, basophilic stippling Leukocytosis with heinz bodies Increased hepatic enzymes Azotemia Hemoglobinuria
What gross lesions are associated with zinc toxicity?
Icterus, enlarged pancreas, GI hemorrhage and inflammation, and enlarged and pale liver
Swine - hemorrhagic joints
Equine - osteochondrosis
What microscopic lesions are associated with zinc toxicity?
Hemorrhagic gastritis, renal tubular necrosis, centrilobular necrosis, pancreatitis/pancreatic necrosis
What differentials should you consider with zinc toxicity?
Immune mediated hemolytic anemia, onion/leek/garlic poisoning, naphthalene, copper, and lead
How is zinc toxicosis treated?
Decontamination - remove foreign bodies and eliminate further exposure
Supportive care - fluids, GI protectants, blood transfusion
Chelators (CaEDTA and D-penacillamine)
What are the sources of iron for toxicosis?
Dietary, injectable iron products, soil, and fertilizers
What does iron compete with?
Other divalent cations - Zn, Mn, Co, Cu, and P
What binds divalent cations and decreases absorption?
phytate
Iron is readily absorbed in the _____ and _______ is excreted.
GI tract, VERY LITTLE
What are the predisposing factors in swine for iron toxicity?
Vitamin E and Se deficiency
T/F - The toxicity of iron via route from most to least is: IV> IM> Oral
True
What is the MOA of iron toxicosis?
- Acutely - directly corrosive and overwhelms rate-limiting absorption
2 - Decreased cardiac output
3 - Metabolic acidosis which disrupts oxidative phosphorylation
T/F - There are 3 stages of clinical signs due to iron toxicosis
False - there are 4
What clinical signs occur during the 1st stage of iron toxicosis and when?
Hrs - 0-6
Corrosive GI effects, nausea, vomiting, diarrhea +/- blood
What clinical signs occur during the 2nd stage of iron toxicosis and when?
Hrs - 6-24
Remission phase
What clinical signs occur during the 3rd stage of iron toxicosis and when?
Hrs - 12-96
Lethargy, GI signs, acidosis, coagulopathy, CV collapse/shock
What clinical signs occur during the 4th stage of iron toxicosis and when?
Weeks later
GI scarring and strictures
In cases of mild to moderate iron toxicosis, progression ends after stage __.
1
What is the preferred sample for diagnosis of iron toxicosis? Others?
Preferred - serum
Others - Liver, feed/unknown/mineral
Radiographs
What gross lesions are associated with iron toxicosis?
GI erosion and ulceration, GI edema, brown staining at injection sites, kidneys, and LN
What microscopic lesions are associated with iron toxicosis?
Periportal necrosis in the liver and hemorrhagic gastritis
How is iron toxicosis treated?
Decontamination - cathartics, gastric lavage, and emesis
Supportive - Correct dehydration and acidosis, and GI protectants
Chelators
What chelator is used to treat iron toxicosis and how does it effect the patient’s urine?
Deferoxamine - it turns the urine wine colored red
What are the sources of flouride for toxicosis?
mineral deposits, industrial processing (aluminum and iron), Ca/P mineral mixes, and pesticides
Flouride has rapid ___ absorption, deposits in _____, and is excreted in ______.
GI, bone, urine
What is the MOA of flouride?
It replaces hydroxyapatite in crystalline structure of bone delaying/altering mineralization
What are the 2 chronic presentations of flouride?
Osteofluorosis and dental fluorosis
What are the clinical signs of osteofluorosis?
Lameness and elongated hooves
What are the lesions of osteofluorosis?
Exostoses - enlargement of the bones, medial aspect of metatarsals to others
What is dental fluorosis?
Dystrophic formation of dentin and enamel in erupting teeth only
What samples can be taken to diagnose fluorosis?
Urine - recent exposures
Bone - rib, coccygeal, metatarsals/metacarapls, and mandible
What will you see on radiographs in a patient with fluorosis?
exostosis
How is flouride toxicosis treated?
Reduce the fluoride in the diet
T/F - Thallium is the least toxic trace mineral
False - it is very toxic, however it was taken off the market in 1965 and banned as a rodenticide in 1972 so poisonings are rare
What are the old sources of thallium?
rodenticides and depilatory (hair removal)
What are the modern sources of thallium?
They are components of electrical devices, mycoplasma agar plates, and malicious poisonings
Thallium has rapid absorption in the _____, ______, and _____. It has _____ distribution.
GI tract, respiratory tract, and skin
Wide
What is the MOA of thalium?
it is similar to Pb, As, and Hg
When does the onset of clinical signs occur in thallium toxicosis?
12 hours to 4 days
What clinical signs does thallium toxicosis cause?
GI - profuse vomiting (>20x/d), bloody diarrhea, and congested mm
Neurologic - tremors, paralysis, and decreased mentation
Dermal - alopecia and sloughing of the skin
What lesions does thallium toxicosis cause?
GI - necrohemorrhagic gastritis, enteritis, and colitis
Lungs - pulmonary edema and hemorrhage
Dermal necrosis
What is the treatment for thallium toxicosis?
Prussian blue and dithizone (chelator)
They will need TLC for months
When are prussian blue and dithizone rendered ineffective in treatment of thallium toxicosis?
If clinical signs are present