Veterinarians should alert clients to the top 5 toxins in companion birds

Toxins can be a serious problem in companion birds due to several factors, including their size, efficient respiratory system and curious nature. In addition, many pet owners are unaware that certain substances can be toxic to their birds. The following is Pet Poison Helpline's list of the five most common toxins to be aware of for these pets.

GETTY IMAGES/KONSTANTIN ANTIPENKO

Lead

Lead poisoning has historically been the most common metal poisoning in caged birds, but due to increased knowledge of the human health problems caused by lead, its use in the home has significantly decreased.

Sources

> Lead-based paint

> Foil wrap on some champagne and wine bottles

> Curtain weights

> Bells with lead clappers

> Imported bird toys

> Stained glass.

Clinical signs

> Depression

> Weakness

> Anorexia

> Weight loss

> Vomiting or regurgitation

> Polyuria and polydipsia

> Seizures

> Hemoglobinuria

> Diarrhea.

Clinical pathology findings

> Heterophilia

> Hypochromic regenerative anemia

> Cytoplasmic vacuolization of RBCs

> Increases in hepatic enzymes (lactate dehydrogenase [LDH], aspartate transaminase [AST]), muscle enzymes (creatine phosphokinase [CPK]) and uric acid (indicator of renal function).

Diagnosis

> History

> Clinical signs

> Clinical pathology

> Blood lead concentration

> Evidence of radiopaque material in the gastrointestinal (GI) tract.

Treatment

> Remove lead object via crop lavage, cathartics or endoscopy.

> Perform chelation therapy with succimer or calcium EDTA.

Public health considerations

Pets have long served as sentinels for lead poisoning in people, especially children. If a bird or any pet in the home is diagnosed with lead poisoning, always recommend that people in the home—especially the children—be tested too.

Zinc

Zinc poisoning is now the most common metal poisoning in caged birds and occurs after ingestion of zinc-containing items.

Sources

> Galvanized products, such as wire cages, mesh, staples, nails and toys. (Galvanization is the process of coating a metal with an alloy containing more than 98 percent zinc. This is done to protect the metal against rusting.)

> Fertilizers

> Some paints

> Zinc pyrithione shampoos

> Zinc oxide

> Pennies minted after 1982.

Clinical signs

> Similar to those seen with lead poisoning, but hemoglobinuria has not been reported.

Clinical pathology findings

Blood samples should be collected in royal-blue-top tubes to avoid zinc contamination leaching into the sample.

> Elevated zinc concentrations may be found in serum, plasma or tissues.

Diagnosis

> History

> Clinical signs

> Radiographs

> Clinical pathology.

Treatment

> Removal of zinc from GI tract is typically sufficient, provided the animal is still relatively stable. If the zinc cannot be removed promptly, chelation with calcium EDTA can be performed.

Avocado

All owners of caged birds must be advised never to feed avocado, as it is extremely poisonous and can result in sudden death. Clinical signs are believed to be caused by the compound persin, which is found in all parts of avocados in the Persea genus (the most available genus for human consumption) and in the leaves and bark of their trees.

Clinical signs

> Agitation

> Feather-pulling

> Lethargy

> Food refusal or anorexia

> Dyspnea

> Pericardial effusion

> Pleural and hepatic congestion

> Death.

Diagnosis

> History

> Clinical signs.

Treatment

> No antidote exists. Supportive care includes oxygen, fluids, sedatives and removal of avocado from the crop or proventriculus with lavage and activated charcoal.

Lethal doses

The lethal dose in budgerigars is 3.5 g in an average 35 g bird. The lethal dose in cockatiels is 20 to 30 g in an average 80 to 100 g bird.

Polytetrafluoroethylene (PTFE) or "Teflon toxicity"

Birds' unique respiratory system makes them more sensitive to airborne toxins than mammals. Polytetrafluoroethylene (PTFE) or "Teflon toxicity"is one of the most common airborne poisonings in pet birds.

Sources

> Nonstick surfaces on Teflon cookware, drip pans, heat lamp covers, irons and ironing board covers. Toxic particulates and gases are produced when the surface is heated to 280 C (536 F). This can occur when a pan boils dry or an empty pan is heated on high (poisoning is not expected during routine cooking).

> Stain-guard treatments for upholstered furniture.

Clinical signs

> Acute death due to respiratory failure

> Dyspnea, ataxia, depression or anxious behavior in cases of mild exposure.

Diagnosis

> History

> Clinical signs

> Pathologic lesions (fluid- and blood-filled lungs).

Treatment

> No antidote exists. Supportive care includes oxygen, anti-inflammatory drugs, diuretics, analgesics, bronchodilators, antibiotics and topical ophthalmic ointment (if ocular irritation has occurred). Prognosis is guarded to poor.

Other inhaled toxins

Birds have a very efficient system for gas exchange. Compared to mammals, more oxygen is transferred into the blood with each breath. Unfortunately, this means more toxins are also transferred into the bird with each breath, making them more sensitive to harm from inhaled toxins. This is the reason canaries were historically used in coal mines to warn of the presence of carbon monoxide and other noxious gases.

Sources

The following can all be harmful when they are found or used in close proximity to birds. However, with appropriate ventilation and use, these substances may not be toxic.

> Carbon monoxide and other harmful gases

> Smoke from tobacco products

> Fumes from new carpets and furniture

> Air fresheners and scented candles

> Paints

> Glues

> Household cleaning products

> Mothballs

> Hair spray and nail polish.

Clinical signs

Signs are variable based on source and level of exposure.

> Acute death

> Dyspnea

> Ocular and nasal passage irritation

> Possible immunosuppression.

Diagnosis

> History

> Clinical signs.

Treatment

> Similar to the treatment for PTFE toxicosis.

How to protect companion birds

When using products that give off strong fumes, it's best to move the bird to a separate room in the home and open windows to ensure plenty of ventilation. Place a towel under the door of the bird's room to help reduce exposure to fumes. When painting walls in a home, use VOC (volatile organic compound)-free paints. Alternatively, consider boarding birds off-site during construction, remodeling or intense whole-house cleaning until odors have dissipated.

Brynne Stumpe is a 2015 DVM candidate at the University of Minnesota College of Veterinary Medicine and an extern at Pet Poison Helpline. Dr. Brutlag is the assistant director of veterinary services with SafetyCall International and Pet Poison Helpline.

For further reading

1. Burmeister CA, Yunker J. Avian avocado toxicosis. Veterinary Technician 2013;34(7).

2. Degernes L. Avian Toxicology: Common Problems. Annu Conf Assoc of Avian Vet, San Diego, Calif, Aug, 2010.

3. Jones MP. Avian Toxicology. West Vet Conf, Las Vegas, NV, Feb, 2007.

4. LaBonde J. Avian Toxicology. Annu Conf Assoc of Avian Vet, San Antonio, Texas, Aug, 2006.

5. Lightfoot TL, Yeager, JM. Pet bird toxicity and related environmental concerns. Vet Clin North Am Exot Anim Pract 2008;11(2):229-259.