Lead Toxicity in Dogs

Lead poisoning (toxicity), a condition in which increases levels of the metal lead is found in blood, can afflict both humans and dogs through both sudden (acute) and long-term (chronic) exposure to the metal. Through the ability to substitute itself for calcium and zinc (both important minerals for normal cell functions), lead damages the cell and affects normal biological processes.

Although a high number of lead poisoning cases are seen during the warmer months of the year, there is a wide variety of sources of lead -- many of which vary between different geographical and ecological locations. Older homes and buildings, for instance, are common sources of lead poisonings, as they can be riddled with lead dust or chips from lead paint.

Lead poisoning is more common in young animals and in dogs living in poor areas. However, cats also succumb to lead poisoning.

Symptoms and Types

The symptoms for lead poisoning mostly relate with the gastrointestinal (GI) and central nervous system (CNS). GI systems, for example, are seen with chronic and low-level exposure, whereas CNS symptoms are more common in acute exposure in young animals. Some of the more common symptoms include:

• Vomiting
• Diarrhea
• Lethargy
• Poor appetite
• Abdominal pain
• Regurgitation (due to megaesophagus)
• Weakness
• Hysteria, extreme anxiety
• Seizures
• Blindness

Causes

• Ingestion of lead – sources can include paint chips, car batteries, solder, plumbing material, lubricating material, lead foil, golf balls, or any other material containing lead
• Use of improperly glazed ceramic food or water utensil
• Lead-contaminated water

Diagnosis

You will need to give a thorough history of your dog’s health leading up to the onset of symptoms, including a history of any contact with material containing lead, if possible. After recording your dog’s history, your veterinarian will perform a complete physical examination. Laboratory tests will include complete blood count, biochemistry profile, and urinalysis -- the results of which may reveal valuable information for initial diagnosis.

Blood testing may reveal red blood cells of unequal size (anisocytosis), abnormally shaped red blood cells (poikilocytosis), variations in red blood cell coloring (polychromasia, hypochromasia), and increased number of neutrophils (type of white blood cells). Urinalysis results are often non-specific and in some patients, abnormal concentrations of glucose may be seen in urine.

If your dog is showing all of the appearances of lead poisoning, your doctor will use more specific tests available which will help your veterinarian to determine the levels of lead in both blood and body tissues.