T. Bradley Bays
Toxin cases are common in pet birds because their small size and fast metabolic rate make them easy targets for even small amounts of exposure. The curious nature of birds makes them more likely to explore their environment with their mouths and to be attracted to shiny things. Also, the intricate and delicate air sacs in birds are easily disrupted by aerosolization of toxic fumes. Finally, not all owners are aware of the many items, foods and fumes that can be toxic to birds. According to the Pet Poison Hotline the top five toxins in birds have been lead, zinc, avocado, Teflon exposure, and other inhaled toxins.
Currently zinc is the most commonly found metal toxicity in birds. Lead and zinc toxicity diagnosis is made by history of exposure (although this is not commonly recognized by the owners), clinical signs, evidence of radiopaque material in the gastrointestinal tract and bloodwork to check for zinc and or lead levels. Blood smears may evidence hypochromic regenerative anemia, vacuoles in red blood cell cytoplasm. Increased white blood cells, and more specifically increased heterophils indicating inflammation. Elevated liver enzymes (LDH and AST), muscle enzymes (CPK), and kidney values (UA) might also be found.
Zinc toxicity sources include:
- Fertilizer
- Some paints
- Zinc pyrithione shampoos
- Zinc oxide (Desitin ointment)
- Pennies minted after 1992
- Galvanized products—98% zinc used to coat metal to keep from rusting
- Wire cages, mesh, nails, screws, wingnuts, washers, staples, toys
- Snap fasteners
- Costume jewelry
- E cigarette parts
- Containers and dishes
- Monopoly game pieces
- Hardware cloth
- Lead toxicity sources include:
- Antique or imported metal cages
- Lead based paint—old homes
- Foil wrap on some wine and champagne bottles
- Curtain weights
- Bells with lead clappers
- Imported bird toys
- Stained glass
- Sun catchers
- Tiffany lamps
- Solder—used to weld things
- Solder—jewelry
- Chandeliers
- Fishing weights
- Shotgun pellets
- Linoleum
- Plaster
- Caulking compounds
- Hardware cloth
- Batteries
- Plumbing materials
- Lead toys and bird toys with lead weights
- Mirror backs
- Improperly glazed ceramics
- Contaminated feed and bone meal
- Some welds on wrought iron cages
- Lead putty
- Golf balls
- Costume jewelry
- Imported bird toys
Lead and zinc toxicity clinical signs:
- Depression/lethargy
- Weakness
- Anorexia
- Vomiting or regurgitation
- Drinking more and increased urination (PU/PD)
- Seizures
- Incoordination/tremors
- Diarrhea
- Hemoglobin in urine
- Green or black stools
- Discolored urates
- Blindness
- Feather picking
- Weight loss
All of these signs can be seen to a varying degree and not all of the signs may be present in every case. Many times, birds are presented lethargic and weak and unable to stand as their cases are severe and chronic and earlier signs were not noted by the owners.
Treatment for lead and zinc toxicity is multimodal and determined case by case and may include:
- Removing objects via crop lavage
- Medical treatment with cathartics to empty gizzard
- Endoscopic removal
- Surgical removal
- Chelation therapy with calcium EDTA
Two cases of zinc toxicosis are described including a duck that ate coins and many metal toy parts that were removed endoscopically and a chicken that ingested 55 pellet gun pellets that were removed surgically. Both birds were also treated with calcium EDTA injections.
Avocado ingestion is also very toxic to birds and signs are believed to be caused by the compound persin. All parts of the avocado are toxic including the leaves and the bark of the avocado tree.
Signs of exposure include:
- Agitation
- Feather pulling
- Lethargy
- Food refusal or anorexia
- Dyspnea
- Pericardial effusion
- Pleural and hepatic congestion
- Sudden death
Avocado toxicity diagnosis is made based on history of exposure and clinical signs and lethal doses are fairly small including 3.5 gm in a 35-gm budgie and 20–30 gm in an 80–100 gm cockatiel. There are no known antidotes and treatment includes supportive care, fluids, sedatives, removal from the crop and proventriculus via lavage, and activated charcoal.
Teflon toxicity (polytetrafluoroethylene or PTFE) is an issue due to the delicate air sacs and respiratory system unique to birds and efficient gas exchange so that more oxygen in transferred into the blood with each breath. It is the most common aerosolized poisoning found in pet birds.
Teflon sources include:
- Stain-guard treatments for upholstered furniture
- Surfaces heated to 535°F such as when an empty pan is heated on high or when a pan boils dry
- Nonstick surfaces on Teflon cookware
- Drip pans
- Heat lamp covers
- Irons and ironing board covers
Teflon toxicity clinical signs include acute death due to respiratory failure in severe cases and dyspnea, ataxia, depression, and anxious behavior with mild exposure. Diagnosis is made based on history of exposure, clinical signs and pathological lesions found on postmortem exam including fluid and blood in lungs/air sacs.
There is no antidote for Teflon toxicity and prognosis is guarded to poor, depending on level of exposure, but treatment can include:
- Supportive care
- Oxygen
- Anti-inflammatory drugs
- Antibiotics
- Bronchodilators
- Topical ophthalmic ointments
Other inhaled toxin sources include:
- Carbon monoxide and other harmful gases
- Smoke from tobacco products
- Glues
- Paints
- Hair spray and nail polish
- Fumes from new carpets and furniture
- Air fresheners
- Scented candles
- Mothballs
- Household cleaning products
- Fumes from illicit drug production
Protection from inhaled toxins include:
- Don’t use sources of inhaled toxins around birds
- Consider how airflow in house will transfer fumes despite where bird is located in the house
- Remove bird from household as soon as fumes or fume source noted—don’t wait for signs to occur
- Use VOC (Volatile organic compounds) free paints
If using products that give off fumes:
- Remove bird from household
- Move bird to a separate room
- Open windows
- Place a towel under the door or the room bird is in
- Consider long-term effects of low-level exposure that the bird seems to do ok with when used in your household