Polyneuropathy in dogs and cats
Encyclopedia
Polyneuropathy in dogs and cats is a collection of peripheral nerve
disorders that often are breed-related in these animals. Polyneuropathy
indicates that multiple nerves are involved, unlike mononeuropathy. Polyneuropathy usually involves motor nerve dysfunction, also known as lower motor neuron disease. Symptoms include decreased or absent reflexes and muscle tone, weakness, or paralysis. It often occurs in the rear legs and is bilateral. Most are chronic problems with a slow onset of symptoms, but some occur suddenly.
Peripheral nervous system
The peripheral nervous system consists of the nerves and ganglia outside of the brain and spinal cord. The main function of the PNS is to connect the central nervous system to the limbs and organs. Unlike the CNS, the PNS is not protected by the bone of spine and skull, or by the blood–brain...
disorders that often are breed-related in these animals. Polyneuropathy
Polyneuropathy
Polyneuropathy is a neurological disorder that occurs when many peripheral nerves throughout the body malfunction simultaneously. It may be acute and appear without warning, or chronic and develop gradually over a longer period of time. Many polyneuropathies have both motor and sensory...
indicates that multiple nerves are involved, unlike mononeuropathy. Polyneuropathy usually involves motor nerve dysfunction, also known as lower motor neuron disease. Symptoms include decreased or absent reflexes and muscle tone, weakness, or paralysis. It often occurs in the rear legs and is bilateral. Most are chronic problems with a slow onset of symptoms, but some occur suddenly.
Most common types of polyneuropathy
- BirmanBirmanThe Birman is a domestic cat breed. Also called the "Sacred Cat of Burma", it is not to be confused with the Burmese, which is a separate and dissimilar breed. The Birman has medium-long hair, a pale colored body and darker points with deep blue eyes. Even though the cat is pointed, the paws have...
Cat distal polyneuropathy - This is an inherited disorder caused by decreased numbers of myelinated axonAxonAn axon is a long, slender projection of a nerve cell, or neuron, that conducts electrical impulses away from the neuron's cell body or soma....
s in the central and peripheral nervous systems. AstrogliosisAstrogliosisAstrocytosis is an abnormal increase in the number of astrocytes due to the destruction of nearby neurons, typically because of hypoglycemia or oxygen deprivation .It usually takes place in prion infections...
(an increase in the number of astrocyteAstrocyteAstrocytes , also known collectively as astroglia, are characteristic star-shaped glial cells in the brain and spinal cord...
s) is also noted. The lesions are most commonly found in the lateral pyramidal tractCorticospinal tractThe corticospinal or pyramidal tract is a collection of axons that travel between the cerebral cortex of the brain and the spinal cord....
of the lumbar spinal cordSpinal cordThe spinal cord is a long, thin, tubular bundle of nervous tissue and support cells that extends from the brain . The brain and spinal cord together make up the central nervous system...
, the fasciculi graciliFasciculus gracilisThe fasciculus gracilis is a bundle of axon fibres in the posterior column of the spinal cord and carries information from the middle thoracic and lower limbs of the body...
of the dorsal column of the cervical spinal cord, and the cerebellarCerebellumThe cerebellum is a region of the brain that plays an important role in motor control. It may also be involved in some cognitive functions such as attention and language, and in regulating fear and pleasure responses, but its movement-related functions are the most solidly established...
vermian white matterWhite matterWhite matter is one of the two components of the central nervous system and consists mostly of myelinated axons. White matter tissue of the freshly cut brain appears pinkish white to the naked eye because myelin is composed largely of lipid tissue veined with capillaries. Its white color is due to...
. Symptoms start at the age of 8 to 10 weeks, and include frequent falling and walking on the hockHock (zoology)The hock, or gambrel, is the joint between the tarsal bones and tibia of a digitigrade or unguligrade quadrupedal mammal, such as a horse, cat, or dog...
. The prognosisPrognosisPrognosis is a medical term to describe the likely outcome of an illness.When applied to large statistical populations, prognostic estimates can be very accurate: for example the statement "45% of patients with severe septic shock will die within 28 days" can be made with some confidence, because...
is poor. The disease is suspected to have a recessive mode of inheritance. - BotulismBotulismBotulism also known as botulinus intoxication is a rare but serious paralytic illness caused by botulinum toxin which is metabolic waste produced under anaerobic conditions by the bacterium Clostridium botulinum, and affecting a wide range of mammals, birds and fish...
- Botulism is very rare in dogs and usually follows feeding on carrionCarrionCarrion refers to the carcass of a dead animal. Carrion is an important food source for large carnivores and omnivores in most ecosystems. Examples of carrion-eaters include vultures, hawks, eagles, hyenas, Virginia Opossum, Tasmanian Devils, coyotes, Komodo dragons, and burying beetles...
. Symptoms include weakness, difficulty eating, acute facial nerve paralysisAcute facial nerve paralysisFacial nerve paralysis is a common problem that involves the paralysis of any structures innervated by the facial nerve. The pathway of the facial nerve is long and relatively convoluted, and so there are a number of causes that may result in facial nerve paralysis...
, and megaesophagusMegaesophagusMegaesophagus is a condition in humans, cats and dogs where peristalsis fails to occur properly and the esophagus is enlarged. Normally, when the dog's esophagus is functioning properly, it acts as a muscle and pushes the food down the esophagus into the stomach. However, when a dog has...
. Compared to other species, dogs and cats are relatively resistant to botulism. - Dancing Doberman disease - This primarily affects the gastrocnemius muscleGastrocnemius muscleIn humans, the gastrocnemius muscle is a very powerful superficial pennate muscle that is in the back part of the lower leg. It runs from its two heads just above the knee to the heel, and is involved in standing, walking, running and jumping. Along with the soleus muscle it forms the calf muscle...
in Dobermans. It usually starts between the ages of 6 to 7 months. One rear leg will flex while standing. Over the next few months it will begin to affect the other rear leg. Eventually, the dog is alternatively flexing and extending each rear leg in a dancing motion. Dancing Doberman disease progresses over a few years to rear leg weakness and muscle atrophyAtrophyAtrophy is the partial or complete wasting away of a part of the body. Causes of atrophy include mutations , poor nourishment, poor circulation, loss of hormonal support, loss of nerve supply to the target organ, disuse or lack of exercise or disease intrinsic to the tissue itself...
. There is no treatment, but most dogs retain the ability to walk and it is painless. - DiabeticDiabetes in cats and dogsDiabetes mellitus strikes 1 in 400 cats, though recent veterinary studies note that it is becoming more common lately in cats. Symptoms in cats are similar to those in humans. Diabetes in cats occurs less frequently than in dogs. 80-95% of diabetic cats experience something similar to type-2...
neuropathy - This condition is more common in cats than dogs. It is caused in part by prolonged hyperglycemiaHyperglycemiaHyperglycemia or Hyperglycæmia, or high blood sugar, is a condition in which an excessive amount of glucose circulates in the blood plasma. This is generally a glucose level higher than 13.5mmol/l , but symptoms may not start to become noticeable until even higher values such as 15-20 mmol/l...
(high blood sugar) and results in dysfunction of one or both tibial nerveTibial nerveThe tibial nerve is a branch of the sciatic nerve. The tibial nerve passes through the popliteal fossa to pass below the arch of soleus.In the popliteal fossa the nerve gives off branches to gastrocnemius, popliteus, soleus and plantaris muscles, an articular branch to the knee joint, and a...
s and a plantigradePlantigraderight|151px|thumb|Human skeleton, showing plantigrade habitIn terrestrial animals, plantigrade locomotion means walking with the podials and metatarsals flat on the ground. It is one of three forms of locomotion adopted by mammals...
stance (down on the hocks). It may resolve with treatment of the diabetes. The pathologyPathologyPathology is the precise study and diagnosis of disease. The word pathology is from Ancient Greek , pathos, "feeling, suffering"; and , -logia, "the study of". Pathologization, to pathologize, refers to the process of defining a condition or behavior as pathological, e.g. pathological gambling....
of this condition in cats has been shown to be very similar to diabetic neuropathyDiabetic neuropathyDiabetic neuropathies are neuropathic disorders that are associated with diabetes mellitus. These conditions are thought to result from diabetic microvascular injury involving small blood vessels that supply nerves in addition to macrovascular conditions that can culminate in diabetic neuropathy...
in humans. - Distal symmetric polyneuropathy - Symptoms include atrophy of the distalAnatomical terms of locationStandard anatomical terms of location are designations employed in science that deal with the anatomy of animals to avoid ambiguities that might otherwise arise. They are not language-specific, and thus require no translation...
leg muscles and the muscles of the head, and rear limb weakness. There is no treatment and the prognosis is poor. This is most commonly seen in Chesapeake Bay RetrieverChesapeake Bay RetrieverThe Chesapeake Bay Retriever is a breed of dog belonging to the Retriever, Gundog, and Sporting breed groups. Members of the breed may also be referred to as a Chessie, CBR, or Chesapeake. The breed was developed in the United States Chesapeake Bay area during the 19th century...
s, St. BernardSt. Bernard (dog)The St. Bernard is a breed of very large working dog from the Italian and Swiss Alps, originally bred for rescue. The breed has become famous through tales of alpine rescues, as well as for its large size.-Appearance:The St. Bernard is a large dog...
s, Great DaneGreat DaneThe Great Dane , also known as German Mastiff or Danish Hound , is a breed of domestic dog known for its giant size...
s, NewfoundlandNewfoundland (dog)The Newfoundland is a breed of large dog. Newfoundlands can be black, brown, gray, or black and white. They were originally bred and used as a working dog for fishermen in the Dominion of Newfoundland, now part of Canada. They are known for their giant size, tremendous strength, calm dispositions,...
s, CollieCollieThe collie is a distinctive type of herding dog, including many related landraces and formal breeds. It originates in Scotland and Northern England. It is a medium-sized, fairly lightly built dog with a pointed snout, and many types have a distinctive white pattern over the shoulders. Collies...
s and Labrador RetrieverLabrador RetrieverThe Labrador Retriever is one of several kinds of retriever, a type of gun dog. A breed characteristic is webbed paws for swimming, useful for the breed's original purpose of retrieving fishing nets. The Labrador is the most popular breed of dog by registered ownership in Canada, the United...
s. - DysautonomiaDysautonomiaDysautonomia is a broad term that describes any disease or malfunction of the autonomic nervous system. This includes postural orthostatic tachycardia syndrome , inappropriate sinus tachycardia , vasovagal syncope, mitral valve prolapse dysautonomia, pure autonomic failure, neurocardiogenic...
- This is primarily seen in cats. Symptoms include vomiting, depression, not eating, weight loss, dilated pupils, third eyelidNictitating membraneThe nictitating membrane is a transparent or translucent third eyelid present in some animals that can be drawn across the eye for protection and to moisten it while maintaining visibility. Some reptiles, birds, and sharks have a full nictitating membrane; in many mammals, there is a small...
protrusion, sneezing, slow heart rate, and megaesophagusMegaesophagusMegaesophagus is a condition in humans, cats and dogs where peristalsis fails to occur properly and the esophagus is enlarged. Normally, when the dog's esophagus is functioning properly, it acts as a muscle and pushes the food down the esophagus into the stomach. However, when a dog has...
. There is a poor prognosis and supportive treatment is necessary. Cats can recover, but it may take up to one year. - Giant axonal neuropathyGiant axonal neuropathyGiant axonal neuropathy is a rare, autosomal recessive neurological disorder that causes disorganization of neurofilaments. Neurofilaments form a structural framework that helps to define the shape and size of neurons and are essential for normal nerve function.-Diagnosis:Giant axonal neuropathy...
- This is a rare disease in the German Shepherd DogGerman Shepherd DogThe German Shepherd Dog , also known as an Alsatian or just the German Shepherd, is a breed of large-sized dog that originated in Germany. The German Shepherd is a relatively new breed of dog, with its origin dating to 1899. As part of the Herding Group, the German Shepherd is a working dog...
. It usually becomes evident between the ages of 14 and 16 months. Symptoms include rear limb weakness, decreased reflexes, muscle atrophy, megaesophagus, and loss of bark. There is no treatment and a poor prognosis. - Hyperchylomicronemia or hyperlipoproteinemia - This a type of hyperlipidemiaHyperlipidemiaHyperlipidemia, hyperlipoproteinemia, or hyperlipidaemia is the condition of abnormally elevated levels of any or all lipids and/or lipoproteins in the blood...
that is inherited in cats. Polyneuropathy is caused by stretching or compression of nerves near bone by xanthomaXanthomaA xanthoma , from Greek xanthos, ξανθος, "yellow", is a deposition of yellowish cholesterol-rich material in tendons or other body parts in various disease states...
s, which are lipidLipidLipids constitute a broad group of naturally occurring molecules that include fats, waxes, sterols, fat-soluble vitamins , monoglycerides, diglycerides, triglycerides, phospholipids, and others...
deposits. It can cause Horner's syndromeHorner's syndromeHorner's syndrome is the combination of drooping of the eyelid and constriction of the pupil , sometimes accompanied by decreased sweating of the face on the same side; redness of the conjunctiva of the eye is often also present...
, facial nerve paralysis, and femoral nerveFemoral nerveThe femoral nerve, the largest branch of the lumbar plexus, arises from the dorsal divisions of the ventral rami of the second, third, and fourth lumbar nerves...
, tibial nerveTibial nerveThe tibial nerve is a branch of the sciatic nerve. The tibial nerve passes through the popliteal fossa to pass below the arch of soleus.In the popliteal fossa the nerve gives off branches to gastrocnemius, popliteus, soleus and plantaris muscles, an articular branch to the knee joint, and a...
, radial nerveRadial nerveThe radial nerve is a nerve in the human body that supplies the upper limb. It supplies the medial and lateral heads of the triceps brachii muscle of the arm, as well as all 12 muscles in the posterior osteofascial compartment of the forearm and the associated joints and overlying skin.It...
, trigeminal nerveTrigeminal nerveThe trigeminal nerve contains both sensory and motor fibres. It is responsible for sensation in the face and certain motor functions such as biting, chewing, and swallowing. Sensory information from the face and body is processed by parallel pathways in the central nervous system...
, or recurrent laryngeal nerveRecurrent laryngeal nerveThe recurrent laryngeal nerve is a branch of the vagus nerve that supplies motor function and sensation to the larynx . It travels within the endoneurium...
paralysis. - Hypertrophic neuropathy - This is also known as canine inherited demyelinative neuropathy (CIDN) and is inherited in the Tibetan MastiffTibetan MastiffThe Tibetan Mastiff is an ancient breed and type of domestic dog originating with nomadic cultures of Central Asia.-Names and etymology:...
. Symptoms usually start between the ages of 7 to 10 weeks, and include weakness, decreased reflexes, and loss of bark. Sensory fumction remains, but there may be a poor gaitGait (dog)The gait of a dog is its quality of movement. It is given a great deal of importance in the breed standard of some breeds, of lesser importance in other standards, and in some breeds gait is not described in the standard at all. A dog's gait is much similar to a horse's.A dog judge must know the...
or an inability to walk. There is no treatment and a guarded prognosis. It is inherited as an autosomal recessive trait. - HypoglycemiaHypoglycemiaHypoglycemia or hypoglycæmia is the medical term for a state produced by a lower than normal level of blood glucose. The term literally means "under-sweet blood"...
- Polyneuropathy is especially seen in conjunction with insulinomaInsulinomaAn insulinoma is a tumour of the pancreas that is derived from beta cells and secretes insulin.Beta cells secrete insulin in response to increases in blood glucose. The resulting increase in insulin acts to lower blood glucose back to normal levels at which point further secretion of insulin is...
. - Myasthenia gravisMyasthenia gravisMyasthenia gravis is an autoimmune neuromuscular disease leading to fluctuating muscle weakness and fatiguability...
- Polyradiculoneuritis - This is inflammation of the nerve roots. The most common type is CoonhoundCoonhoundA Coonhound is a type of scent hound and a member of the hound group.Coonhounds are an American style of hunting dog developed for the quarry and working conditions found in the United States. Coondogs are highly valued.-History:...
paralysis. This is similar to Guillain-Barré syndromeGuillain-Barré syndromeGuillain–Barré syndrome , sometimes called Landry's paralysis, is an acute inflammatory demyelinating polyneuropathy , a disorder affecting the peripheral nervous system. Ascending paralysis, weakness beginning in the feet and hands and migrating towards the trunk, is the most typical symptom...
in humans. Coonhound paralysis seems to be secondary to a raccoonRaccoonProcyon is a genus of nocturnal mammals, comprising three species commonly known as raccoons, in the family Procyonidae. The most familiar species, the common raccoon , is often known simply as "the" raccoon, as the two other raccoon species in the genus are native only to the tropics and are...
bite, probably due to some factor in the saliva. However, it can also occur without any interaction with a raccoon. It can happen in any breed of dog. When associated with a raccoon bite, the symptoms start 7 to 11 days after the bite, and include rear leg weakness progressing rapidly to paresisParesisParesis is a condition typified by partial loss of voluntary movement or by impaired movement. When used without qualifiers, it usually refers to the limbs, but it also can be used to describe the muscles of the eyes , the stomach , and also the vocal cords...
, and decreased reflexes. When not associated with a raccoon bite, the same symptoms occur, with the paresisParesisParesis is a condition typified by partial loss of voluntary movement or by impaired movement. When used without qualifiers, it usually refers to the limbs, but it also can be used to describe the muscles of the eyes , the stomach , and also the vocal cords...
taking about 3–4 days to reach its maximum effect. Severe cases will have a loss of bark, trouble breathing, and an inability to lift the head. Typically the duration of the paralysis is 2 to 3 months. However, the paralysis can last up to 6 months. Treatment is proper nursing care, and the prognosis is good in mild cases. In bad cases the dog doesn't completely recover their initial muscular capability but still are able to live and enjoy life for years. In very bad cases it is possible for breathing to be impaired, and unless the dog is placed on a ventilator, suffocation will occur. Polyradiculoneuritis has also been seen one to two weeks post-vaccine in dogs and cats. It can also be caused by toxoplasmosisToxoplasmosisToxoplasmosis is a parasitic disease caused by the protozoan Toxoplasma gondii. The parasite infects most genera of warm-blooded animals, including humans, but the primary host is the felid family. Animals are infected by eating infected meat, by ingestion of feces of a cat that has itself...
. - Rottweiler distal sensorimotor polyneuropathy - This is characterized by distal muscle denervation, but the cause is unknown. It affects young adult RottweilerRottweilerThe Rottweiler is a medium to large size breed of domestic dog that originated in Rottweil, Germany. The dogs were known as "Rottweil butchers' dogs" because they were used to herd livestock and pull carts laden with butchered meat and other products to market...
s. The symptoms include weakness of all four legs and decreased reflexes. The disease is gradually progressive. Treatment is possible with corticosteroidCorticosteroidCorticosteroids are a class of steroid hormones that are produced in the adrenal cortex. Corticosteroids are involved in a wide range of physiologic systems such as stress response, immune response and regulation of inflammation, carbohydrate metabolism, protein catabolism, blood electrolyte...
s, but the prognosis is poor. - Sensory neuropathies - These are inherited conditions in dogs and cause an inability to feel pain and a loss of proprioceptionProprioceptionProprioception , from Latin proprius, meaning "one's own" and perception, is the sense of the relative position of neighbouring parts of the body and strength of effort being employed in movement...
. Self mutilation is often seen. There is no treatment, and the prognosis is poor in severe cases. There are several affected breeds.- BoxerBoxer (dog)Developed in Germany, the Boxer is a breed of stocky, medium-sized, short-haired dog. The coat is smooth and fawn or brindled, with or without white markings. Boxers are brachycephalic , and have a square muzzle, mandibular prognathism , very strong jaws and a powerful bite ideal for hanging on to...
- usually occurs at around two months of age as a slowly progressive disease. - DachshundDachshundThe dachshund is a short-legged, long-bodied dog breed belonging to the hound family. The standard size dachshund was bred to scent, chase, and flush out badgers and other burrow-dwelling animals, while the miniature dachshund was developed to hunt smaller prey such as rabbits...
(longhaired) - usually occurs between 8 and 12 weeks of age, and causes urinary incontinence, loss of pain sensation all over the body, and penis mutilation. It is probably inherited as an autosomal recessive trait. - English PointerPointer (dog breed)The Pointer, often called the English Pointer, is a breed of dog developed as a gun dog. It is one of several pointing breeds.-Appearance:...
- usually occurs between the ages of 3 and 8 months and most commonly involves licking and biting at the paws. There is no treatment and a poor prognosis. It is inherited as an autosomal recessive trait.
- Boxer
- Spinal muscular atrophySpinal muscular atrophySpinal Muscular Atrophy is a neuromuscular disease characterized by degeneration of motor neurons, resulting in progressive muscular atrophy and weakness. The clinical spectrum of SMA ranges from early infant death to normal adult life with only mild weakness...
- This occurs in cats and dogs both, and is caused by the death of nerve cells in the spinal cord. This progressive disease has no treatment and a poor prognosis. Affected dog breeds include the Swedish Lapland Dog, Brittany SpanielBrittany (dog)The Brittany is a breed of gun dog bred primarily for bird hunting. Although the Brittany is often referred to as a Spaniel, the breed's working characteristics are more akin to those of a pointer or setter.-History:...
, English PointerPointer (dog breed)The Pointer, often called the English Pointer, is a breed of dog developed as a gun dog. It is one of several pointing breeds.-Appearance:...
, German Shepherd DogGerman Shepherd DogThe German Shepherd Dog , also known as an Alsatian or just the German Shepherd, is a breed of large-sized dog that originated in Germany. The German Shepherd is a relatively new breed of dog, with its origin dating to 1899. As part of the Herding Group, the German Shepherd is a working dog...
, RottweilerRottweilerThe Rottweiler is a medium to large size breed of domestic dog that originated in Rottweil, Germany. The dogs were known as "Rottweil butchers' dogs" because they were used to herd livestock and pull carts laden with butchered meat and other products to market...
, and Cairn TerrierCairn TerrierThe Cairn Terrier is the oldest of the terrier breeds, originating in the Scottish Highlands and recognized as one of Scotland's earliest working dogs...
. Maine CoonMaine CoonThe Maine Coon is a breed of domestic cat with a distinctive physical appearance and valuable hunting skills. It is one of the oldest natural breeds in North America, specifically native to the state of Maine, where it is the official State Cat....
cats are one of the affected cat breeds. - Tick paralysisTick paralysisTick paralysis is the only tick-borne disease that is not caused by an infectious organism. The illness is caused by a neurotoxin produced in the tick's salivary gland. After prolonged attachment, the engorged tick transmits the toxin to its host...
- This is an acute, ascending motor paralysis that occurs in dogs; cats seem to be resistant. The cause is a neurotoxinNeurotoxinA neurotoxin is a toxin that acts specifically on nerve cells , usually by interacting with membrane proteins such as ion channels. Some sources are more general, and define the effect of neurotoxins as occurring at nerve tissue...
in the saliva of certain species of adult tickTickTicks are small arachnids in the order Ixodida, along with mites, constitute the subclass Acarina. Ticks are ectoparasites , living by hematophagy on the blood of mammals, birds, and sometimes reptiles and amphibians...
s. DermacentorDermacentorDermacentor is a genus of hard-bodied ticks.-Species:* Dermacentor abaensis Teng, 1963* Dermacentor albipictus Packard, 1869* Dermacentor andersoni Stiles 1908* Dermacentor asper Arthur, 1960...
species predominate as a cause in North America, while IxodesIxodesIxodes is a genus of hard-bodied ticks . It includes important disease vectors of animals and humans . Some ticks in this genus may transmit the pathogenic bacterium Borrelia burgdorferi responsible for causing Lyme disease...
mainly causes the disease in Australia. The onset of symptoms is 5 to 9 days after tick attachment, and include incoordination progressing to paralysis, changed voice, and difficulty eating. Death can occur secondary to paralysis of the respiratory muscles, but in North America there is a good prognosis once the ticks are removed. Recovery is usually in 1 to 3 days. In Australia, however, it is a more severe disease with cranial nerveCranial nervesCranial nerves are nerves that emerge directly from the brain, in contrast to spinal nerves, which emerge from segments of the spinal cord. In humans, there are traditionally twelve pairs of cranial nerves...
effects, and death can occur in 1 to 2 days. - Toxic neuropathies - The most common causes are vincristineVincristineVincristine , formally known as leurocristine, sometimes abbreviated "VCR", is a vinca alkaloid from the Catharanthus roseus , formerly Vinca rosea and hence its name. It is a mitotic inhibitor, and is used in cancer chemotherapy.-Mechanism:Tubulin is a structural protein that polymerizes to...
, thalliumThalliumThallium is a chemical element with the symbol Tl and atomic number 81. This soft gray poor metal resembles tin but discolors when exposed to air. The two chemists William Crookes and Claude-Auguste Lamy discovered thallium independently in 1861 by the newly developed method of flame spectroscopy...
, and leadLeadLead is a main-group element in the carbon group with the symbol Pb and atomic number 82. Lead is a soft, malleable poor metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed...
. In cats, the symptoms include paresis, hyporeflexia, and muscle tremors.