Zinc Toxicity in Waterfowl and Ferrets

Disease Summary

Alternative Names (Synonyms)

• Zinc poisoning
• New Wire Disease

Disease Type

Infectious/Non-Infectious Agent associated with the Disease

Infective "Taxa"

Non-infective agents

• Zinc - excess

Physical agents

References

Disease Author

Major References / Reviews

Code and Title List

Ferrets:
B627.5.w5
J42.90.w2, J83.15.w4 J195.10.w3, J195.11.w2

Other References

Code and Title List

Detailed Clinical and Pathological Characteristics

General

Clinical Characteristics

• Weakness, anaemia, cyanosis, polyuria, polydypsia, gastro-intestinal problems, weight loss, hyperglycaemia and seizures have been reported.

Waterfowl:

• Weakness, depression, decreased ability to walk, ataxia, posterior paresis/paralysis, anorexia and weight loss, death. Infertility also reported.
• Anorexia and associated weight loss, diarrhoea, partial leg-paralysis, anaemia and deaths reported with experimental in-feed zinc poisoning. Food intake decreased from the fist day in which food containing zinc was provided and the decrease was proportional to the level of zinc.
• Note: paresis/paralysis may be related to selenium/vitamin-E responsive skeletal myopathy (J13.42.w1).

Clinical pathology:

• Serum zinc concentration 12.6-16.6 µg/ml (normal range 1.84-4.65 µg/ml)

(J2.25.w1, J40.36.w2, B11.38.w6, B13.37.w7, B13.46.w1, B15, B37.x.w1).

• Inappetance, lethargy and muscle tremors, finally coma and death. (J83.15.w4)
  • Death from renal failure after a short uremic crisis of less than 72 h. (J83.15.w4)
• Weight loss in ferrets given 1,500-3,000 ppm zinc in the diet (40 - 50% weight loss by three weeks on the lower dose); one of those on the higher dose rate died and the others were euthanased in extremis. (J42.90.w2)
• Found dead, or posterior weakness for a short time prior to death. (J195.10.w3)
• Anaemia, posterior weakness, death. (J195.11.w2)
  • Pale mucous membranes. (B627.5.w5)
• Clinical pathology: 
  • Raised BUN (blood urea nitrogen). (J42.90.w2, J195.10.w3)
  • Macrocytic hypochromic anaemia with increased reticulocytes. Also leucocytosis with a slight left shift. (J42.90.w2)

Incubation

• Death or euthanasia in extremis after 9 -14 days on 3,000 ppm; those on 1,500 ppm had lost 40 - 50% of body weight after three weeks and one was in extremis at this time. (J83.15.w4)

Mortality / Morbidity

• Variable depending on dose. (J83.15.w4)

Pathology

• Gizzard - Following metal object ingestion: Empty (except for metal object), with multifocal discolouration and roughening of lining. Experimental zinc supplementation: pale areas (myonecrosis) occasionally observed.
• Intestines: pale areas (myonecrosis) occasionally observed.
• Kidneys: may be yellow or reddish-yellow.
• Ovaries/Testes: may be smaller than expected in the breeding season.
• Skeletal muscle: sometimes pale areas (myonecrosis) observed with experimental zinc supplementation.

Histopathology:

• Gizzard - Coin ingestion: degradation and loss of koilin, necrosis of glandular epithelium, moderate heterophil infiltration into superficial mucosa. Severe coagulation necrosis of smooth muscle in one duck. Experimental zinc supplementation: occasionally necrosis of smooth muscle.
• Intestines - variable; minimal degradation to acute necro-ulcerative enteritis. Experimental zinc supplementation: occasionally necrosis of smooth muscle.
• Pancreas - Degenerative lesions. Proliferation of ducts, acinar atrophy, necrosis, fibrosis.
• Renal: mild degeneration and necrosis of tubular epithelial cells at cortico-medullary junction. Occasional hyaline casts and sloughed epithelial cells in tubules.
• Skeletal muscle: sometimes myonecrosis observed with experimental zinc supplementation.

  N.B. Lesions of myonecrosis in gizzard, intestine and skeletal muscle produced by experimental zinc supplementation were prevented if supplemental selenium or vitamin E was added (J13.42.w1).

Toxicology:

• Tissue zinc levels: increased, e.g. 212-548 µg/g (normal e.g. 35.9µg/g) in liver in coin-poisoned ducks. With experimental zinc supplementation (3,000-12,000ppm diet), pancreas zinc levels 15 to 30 times normal (control) level, kidney levels at least ten times greater than controls and liver six to nine times greater than controls.

(J2.25.w1, J13.42.w1, J40.36.w2, B13.46.w1)

Gross Pathology

• General: Pale mucous membranes. (J195.10.w3, J195.11.w2, J83.15.w4); poor body condition - absence of fat reserves. (J83.15.w4)
• Hepatic: Liver pale. (J195.10.w3, J195.11.w2) Live orange. (J83.15.w4)
• Respiratory: Pulmonary congestion (J195.10.w3). 
• Renal: Kidneys large, pale and soft; sometimes small capsular surface depressions. (J83.15.w4)
• GIT: Gastric mucosa eroded, black, granular contents. (J83.15.w4)

Histopathology

• Renal: 
  • Mild nephrosis. (J195.10.w3)
  • Necrosis of the proximal tubular epithelium. (J195.11.w2)
  • Diffuse subacute nephrosis: glomeruli had dilated capsular spaces and shrunken or collapsed capillary tufts; marked dilatation of the convoluted tubules, loop of Henle and collecting tubules. In some tubules, eosinophilic, proteinaceous material and in others cellular debris. In the cortical interstitium, areas of early fibrosis. Occasional mitotic figures in the tubular epithelium. (J83.15.w4)
  • Nephrosis, more severe in those surviving longer. Dilatation of the convoluted tubules, sometimes with cellular debris. In those surviving longer, glomerular capsular spaces dilated and tufts compressed. (J42.90.w2)
• Respiratory: 
  • Mild lesions such as congestion of the lungs. (J195.10.w3)
  • Pulmonary congestion (aspiration pneumonia in one individual, acute bronchopneumonia in another). (J83.15.w4)
• Hepatic: 
  • Hepatopathy. (J195.11.w2)
  • Severe lipidosis, biliary statis, haemosiderosis. (J195.10.w3)
  • Lipidosis. (J83.15.w4)
• GIT: In the gastric pits, haemorrhages; also mucosal erosions with blood loss into the gastric lumen. (J83.15.w4)
• Splenic: Marked extramedullary haematopoisis (J42.90.w2, J83.15.w4, J195.10.w3)(not necessarily associated with the zinc toxicity). (J195.10.w3)
• Bone marrow: "somewhat depressed, mainly in the erythroid series." (J83.15.w4)
• Adrenals: Moderately enlarged; cells in the zona fasciculata were swollen, some with foamy cytoplasm. (J195.10.w3)
• Thymus: in some individuals, extensive degeneration of lymphoid components. (J195.10.w3)

Human Health Considerations

Disease has been reported in either the wild or in captivity in:

• Barrow's goldeneye Bucephala islandica, Bahama (white-cheeked) pintail Anas bahamensis bahamensis, Redhead Aythya americana, Rosybilled pochard Netta peposaca American merganser Mergus merganser americana (J2.25.w1).
• Experimental toxicity in mallard Anas platyrhynchos (J13.42.w1).
• Experimental toxicity in mallard Anas platyrhynchos (J40.36.w2).
• Domestic ferrets. (J83.15.w4, J195.10.w3)

Host Species List

• Anas bahamensis - White-cheeked pintail
• Anas platyrhynchos - Mallard
• Aythya americana - Redhead
• Bucephala islandica - Barrow's goldeneye
• Mergus merganser - Common merganser
• Netta peposaca - Rosy-billed pochard

Ferrets

• Mustela putorius furo - Ferret

Disease has been specifically reported in Free-ranging populations of:

Host Species List

General Information on Environmental Factors/Events and Seasonality

Regions / Countries where the Infectious Agent or Disease has been recorded

Regions / Countries where the Infectious Agent or Disease has been recorded in Free-ranging populations

General Information on Investigation / Diagnosis

• Presumptive from radiographic evidence of recognizable zinc-containing object in gizzard, clinical recovery after removal of zinc-containing object from gizzard, confirmed (surgical or at post mortem examination) presence of zinc-containing object in gizzard.
• Confirmation by level of zinc in serum or liver.
• N.B. Must collect using glass or all-plastic syringes and tubes: contamination can occur from rubber stoppers on tubes and from grommets on plastic syringes. Royal blue stoppers to serum tubes usually indicate that they are  zinc-free.
• Comparison with sample from a clinically normal bird of the same species may assist in interpretation of results.
• Levels over 200 µg/dl (2 ppm) generally considered diagnostic.

(J2.25.w1, B11.38.w6, B13.37.w7).

• Analysis of liver and kidney zinc concentrations. (J195.11.w2) Raised liver and kidney zinc concentration. (J42.90.w2)
  • Zinc levels: in liver, mean 2,733 (range 2,300 - 3,100) µmol/kg , compared with normal mean 1,759 (1,346 - 2,371)µmol/kg ; in kidney, 6,260 (range 2,279 - 11,000) µmol/kg compared with normal 2,754 (2,111 - 4,314) µmol/kg. (J195.10.w3)
    • Note: Iron levels in the liver were lower than normal. (J195.10.w3)
  • Liver 203 - 881 ppm dry weight (normal 85 - 114); kidneys 785 - 943 ppm dry weight (normal 102 - 128). (J83.15.w4)
  • Liver 480 - 1,513 µg/g dry weight (controls 88 - 155); kidney 741 - 1,390 µg/g dry weight (controls 138 - 423). (J42.90.w2)
• High concentration of zinc confirmed in powder on the cage wire. (J83.15.w4)

• Environmental Assessment
• History & Documentation
• Physical Examination of Birds - General
• Physical Examination of Mammals
• Necropsy of Birds - General
• Necropsy of Mammals
• Chapter 2 - B36 Field Manual of Wildlife Diseases - Specimen Collection and Preservation
• Chapter 3 - B36 Field Manual of Wildlife Diseases - Specimen shipment
• Appendix A - B36 Field Manual of Wildlife Diseases - Sample specimen history form

Similar Diseases (Differential Diagnosis)

Specific Medical Treatment

• Treatment and Care - General

General Nursing and Surgical Techniques

• Treatment and Care - General

Preventative Measures

• Preventative Medicine for Mammals

Environmental and Population Control Measures

WATERFOWL

• Carefully search for and remove bits of galvanized wire, staples etc. after an enclosure has been completed.
• Regularly clean out ponds into which members of the public are able to drop or throw coins, particularly if diving ducks are displayed.

(J2.25.w1).

• Use of galvanised food and water utensils for ferrets should be avoided. (J195.11.w2)

• Environmental and Population Management - General