Dog Deaths due to Copper Toxicity: Importance of Copper in Animals
Animlas are exposed accidentally or maliciously to various toxic chemicals including copper. Copper is an integral part of many important enzymes involved in number of vital biological processes like metalloprotein enzymes, metalloporphyrin enzymes (Gaetke et al., 2003). Acute or chronic copper poisoning is encountered in most parts of the world. Sheep are affected most often, although other species are also susceptible. Acute poisoning is usually seen after accidental administration of excessive amounts of soluble copper salts, which may be present in anthelmintic drenches, mineral mixes, or improperly formulated rations. Many factors that alter copper metabolism influence copper poisoning by enhancing the absorption or retention of copper. Low levels of molybdenum or sulphate in the diet are important examples. Primary chronic poisoning is seen most commonly in sheep when excessive amounts of copper are ingested over a prolonged period. Phytogenous and hepatogenous factors influence secondary chronic copper poisoning. Incidence has increased in recent years with the intensification of the sheep industry, increased housing of ewes, increased use of breeds susceptible to copper poisoning, such as the Texel.
Role of Copper
- Copper is the integral component of enzymes namey Ceruloplasmin (ferrooxidase), Erythrocuprein, Cytochrome oxidase, Lysyl oxidase, Tyrosinase.
- Copper is the integral component Turacin, a pigment of feathers.
- Copper is required for maintenance of crimp of wool.
Deficiency
- A deficiency of copper impairs the animal’s ability to absorb iron leads to anemia
- Poor growth
- Bone disorders.
- Scouring, gastro-intestinal disturbances
- Infertility,
- Depigmentation of hair and wool,
- Lesions in the brain stem and spinal cord. The lesions are associated with muscular inco-ordination, and occur especially in young lambs – swayback condition also known as ‘enzootic ataxia‘ or neonatal ataxia.
- The signs range from complete paralysis of the newborn lamb to a swaying staggering gait, which affects, in particular, the hind limbs.
- Loss of ‘crimp’ in wool – ‘stringy’ or ‘steely’ wool
- ‘falling disease‘ – sudden death due to rupture of major blood vessels
- Copper deficiency also leads to reproductive problems in cattle.
Excess
- Continuous ingestion of copper in excess of nutritional requirements leads to an accumulation of the element in the body tissues, especially in the liver. Hence copper can be regarded as a cumulative poison.
- Chronic copper poisoning results in necrosis of the liver cells,
- Jaundice,
- Loss of appetite and
- Death from hepatic coma.
Source
- Seeds and seed by-products
- Application of copper containing fertilizer to lands
- Provision of copper containing salt licks
- Ingestion of organic complexes of Copper
What is Copper Poisoning?
Copper poisoning in dogs is most often noticed in Bedlington Terriers because they have a sensitivity to copper that is inherited, making this breed susceptible to toxicity with even low levels of copper. Because the only way copper can be removed from the body is through bile, veterinary medical experts believe it is a bile flow disorder that causes certain breeds to be more apt to get copper poisoning. There are several other breeds that also have this sensitivity, although it is not seen as often as in the Bedlington Terrier. These breeds include Doberman Pinscher, American Cocker Spaniel, Keeshond, Skye Terrier, West Highland White Terrier, and Labrador Retriever. However, copper poisoning can happen in any breed.
Copper poisoning is a serious, life-threatening emergency that causes irreversible damage to the liver, which eventually becomes fatal if not treated. Acute copper poisoning is most often reported from accidental overuse of copper salt, which is an ingredient in some parasitic deworming treatments. Chronic poisoning is caused by eating pennies or certain kinds of plants, such as certain types of clover. This causes hepatitis (liver inflammation), major gastrointestinal problems (diarrhea, vomiting, abdominal pain), and dehydration. After three days, the copper starts destroying red blood cells, tissues, and liver, so this can be fatal if not treated in the first day or two.
Symptoms of Copper Poisoning in Dogs
The symptoms of copper poisoning are usually not evident until the damage is already done to the liver, which cannot be reversed. The symptoms to watch for are:
- Abdominal pain and swelling
- Altered mental state (encephalopathy)
- Anemia
- Appetite loss (anorexia)
- Bleeding from the nose or mouth
- Blood in the urine
- Depression
- Diarrhea
- Disorientation
- Excessive thirst (polydipsia)
- Frequent urination (polyuria)
- Jaundice
- Vomiting
- Weight loss
Types
- Acute copper poisoning shows symptoms right away and is usually from an accidental overdose from parasite medication
- Chronic copper poisoning is progressive and usually caused by eating certain plants or too much copper in the diet
Causes of Copper Poisoning in Dogs
Although any breed can get copper poisoning from eating certain items or from an accidental overdose of deworming medications, several breeds are more susceptible. This is because they have a copper sensitivity giving them a much lower tolerance to copper.
- American Cocker Spaniels
- Bedlington Terriers
- Doberman Pinschers
- Keeshonds
- Labrador Retrievers
- Skye Terriers
- West Highland White Terriers
Other ways to get copper poisoning:
- Eating Mediterranean clover
- Eating pennies
- Overuse of deworming medication
Diagnosis of Copper Poisoning in Dogs
If your dog is one of the breeds mentioned above, the veterinarian will start them on chelation treatment right away to stop the damage before it gets any worse. A complete physical examination will be done next, including vital signs, reflexes, height, and weight. The veterinarian will need as much information as possible about your dog’s symptoms, medical history, recent illnesses or injuries, and abnormal behavior or appetite.
Treatment of Copper Poisoning in Dogs
If your dog is showing severe symptoms, the veterinarian will admit him to the hospital for IV fluids, oxygen therapy, antibiotics, and observation. The treatment for both acute and chronic copper poisoning is chelation with penicillamine or to excrete the copper in the urine, and zinc therapy after your dog’s copper levels are reduced. This will be done in the hospital so the veterinarian can continue to monitor your dog’s progress. A lifelong treatment of 3 mg of zinc per day can help with liver disease. Your dog will need to be monitored for the rest of his life to check zinc and copper levels in the blood. Vitamin E is often used as a supplement to reduce the damage done to the liver.
Prevention
Do not supplement with copper unless you have clear evidence of copper deficiency (or molybdenum toxicity). When supplementing sheep with copper, make sure only one source of copper is available and avoid stress during copper treatment and for a period afterwards.
Anthelmintics and any period of food deprivation around the time of copper treatment should be avoided. Do not feed excessive levels of concentrate to sheep. Do not feed concentrates high in copper levels to sheep, especially to sheep breeds susceptible to copper poisoning and housed sheep.
Compiled & Shared by- Team, LITD (Livestock Institute of Training & Development) Image-Courtesy-Google Reference-On Request.
