Dog health
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The domestic dog's health is possibly one of the best-studied areas in veterinary medicine, since the dog has had such a long and close relationship with humans.
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[edit] Diseases and ailments
Some diseases, ailments, and poisons are common to both humans and dogs; others are different.
[edit] Transferable diseases
Most diseases that affect dogs or humans are not transferable between the two species. There are some exceptions of zoonoses:
- Rabies, or Hydrophobia, is an almost invariably fatal disease which can be transmitted to dogs or humans by the bite of an infected mammal, possibly a dog's, cat's, raccoon's, or bat's. Although rodents and similar small mammals can be infected with the disease artificially, they are generally not found infected in the wild; the current hypothesis is that they are not likely to survive any attack that would infect them. Animals with rabies suffer deterioration of the brain and tend to behave bizarrely and often aggressively, increasing the chances that they will bite another animal or a person and transmit the disease. Areas that are rabies-free, (usually islands) such as Britain, Ireland, Australia, and the American state of Hawaii have strict quarantine laws to keep their territories rabies-free. These require long periods of isolation and observation of imported animals, which makes them unattractive places to move with a pet unless the pet is quite young. Areas that are not rabies-free usually require that dogs (and often cats) be vaccinated against rabies. A person or dog bitten by an unknown dog (or other animal) should always be treated without waiting for symptoms, given the potentially fatal consequences of a rabid biter: there has been only one case of someone surviving rabies when treatment was not begun until after symptoms appeared. The biter should be apprehended if possible, as only autopsy of the brain can determine if it was rabid. This should be a great incentive to dog-owners to vaccinate their dogs even if they feel the risk of their dog contracting rabies is low, since vaccination will eliminate the need for their dog to be euthanized and examined in this fashion should it bite anyone or be suspected of biting anyone. This applies to dogs that are showing neurological signs at the time of the bite. Unvaccinated healthy dogs need to be confined for ten days from the time of the bite (at home or at a veterinarian depending on state law). If the dog is not showing signs of rabies at the end of ten days, then the bitten person could not have been exposed to rabies. Dogs and cats do not have the rabies virus in their saliva until a few days prior to showing symptoms. Ten day confinement does not apply to other species. A dog or cat bitten by a wild animal in an area known to have rabies should be confined for six months, because it can take that long for symptoms to start.
- Parasites, particularly intestinal worms such as hookworms, tapeworms and roundworms, can be transmitted in a dog's feces. Some tapeworms have fleas as intermediate hosts: the worm egg must be consumed by a flea to hatch, then the infected flea must be ingested (usually by the dog while grooming itself, but occasionally by a human through various means) for the adult worm to establish itself in the intestines. The worm's eggs then pass through the intestines and adhere to the nether regions of the dog, and the cycle begins again.
- Fleas and ticks of various species can be acquired and brought home by a dog, where they can multiply and attack humans (and vice versa). This is particularly important, now that tick-borne Lyme Disease has become endemic throughout a large area, in addition to other similar diseases such as Rocky Mountain Spotted Fever. Although dogs do not seem to be as susceptible to such diseases as humans, similar rickettsial diseases have been spread by dogs to humans through such mechanisms as a dog killing an infected rabbit, then shaking itself off in the house near enough to its owners to fatally infect most of the family.
- Leptospirosis is a bacterial disease that affects humans and animals. It is caused by bacteria of the genus Leptospira. Humans and dogs become infected through contact with water, food, or soil containing urine from infected animals. This may happen by swallowing contaminated food or water or through skin contact, especially with mucosal surfaces, such as the eyes or nose, or with broken skin.
[edit] Genetic ailments
Genetic conditions are a problem in some dogs, particularly purebreeds. For this reason many of the national Kennel Clubs require dogs to not have certain genetic illnesses in order to be registered. This is most common for hip dysplasia though it has not had optimal results. Some of the most common conditions include:
- Hip dysplasia is a common problem that primarily affects larger breeds. Hip dysplasia is a defect in the hip joint which can, depending on the degree of hip luxation, be quite painful to the dog as it grows to adult size. Over time it often causes arthritis in the hips.
- Luxating patellas can be a problem for smaller breeds. It can cause lameness and pain in the hind legs.
- Genes for blindness or deafness seem to be carried by some breeds.
- In some dogs, such as collies, the blue merle or harlequin coloring is actually the heterozygote of a partially recessive gene preventing proper development of the nervous system; therefore, if two such dogs are mated, on the average one quarter of the puppies will have severe genetic defects in their nervous systems and sensory organs ranging from deafness to fatal flaws.
[edit] Parasites
Several types of parasites are commonly associated with dogs:
- Intestinal worms cause varying degrees of discomfort.
- Heartworm is a dog parasitoid. It is hard to eliminate and can be fatal; prevention, however, is easily achieved using medication.
- As the name suggests, an infected mosquito injects a larva into the dog's skin, where it migrates to the circulatory system and takes up residence in the pulmonary arteries and heart, growing and reproducing to an alarming degree. The effects on the dog are quite predictable, cardiac failure over a year or two, leading to death. Treatment of an infected dog is difficult, involving an attempt to poison the healthy worm with arsenic compounds without killing the weakened dog, and frequently does not succeed. Prevention is much the better course, via heartworm pills which are fed to the dog and contain a compound which kills the larvae immediately upon infection without harming the dog. Often they are available combined with other parasite preventives.
- Hydatidosis is caused by a cestode Echinococcus. This is usually noticed among dogs, wild dogs, foxes, etc. Due to its importance as a zoonosis, these worms are important to treat. Preventing hydatidosis is an easier task than treating the same. Anthelmintics such as praziquantel may help prevent this condition. Prohibition of the feeding of dogs with uncooked offals may be the best prophylactic measure against these tapeworms.
- Fleas and ticks are common parasites for which there are many effective preventive measures.
- Various mites cause skin problems such as mange.
[edit] Poisons
[edit] Dangerous foods
Some foods commonly enjoyed by humans are dangerous to dogs:
- Dogs love the flavor of chocolate, but chocolate in sufficient doses is lethally toxic to dogs (and horses and possibly cats). Chocolate contains theobromine, a chemical stimulant that, together with caffeine and theophylline, belongs to the group of methylxanthine alkaloids. Dogs are unable to metabolize theobromine effectively. If they eat chocolate, the theobromine can remain in their bloodstreams for up to 20 hours, and these animals may experience fast heart rate, hallucinations, severe diarrhea, epileptic seizures, heart attacks, internal bleeding, and eventually death. A chocolate bar can be sufficient to make a small dog extremely ill or even kill it. Approximately thirty grams of baking chocolate per kilogram (1/2 ounce per pound) of body weight is enough to be poisonous. In case of accidental intake of chocolate by especially a smaller dog, contact a veterinarian or animal poison control immediately; it is commonly recommended to induce vomiting within two hours of ingestion. Large breeds are less susceptible to chocolate poisoning, but still are far less tolerant of the substance than humans are.
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- Note:Carob treats are often available as dog treats; these are unrelated to chocolate and are safe.
- It has recently been confirmed that grapes and raisins can cause acute renal failure in dogs (see also grape and raisin toxicity in dogs). The exact mechanism is not known, nor is there any means to determine the susceptibility of an individual dog. While as little as one raisin can be fatal to a susceptible ten pound dog, many other dogs have eaten as much as a pound of grapes or raisins at a time without ill effects. The dog usually vomits a few hours after consumption and begins showing signs of renal failure three to five days later.
- Onions and to a significantly lesser extent garlic contain thiosulfate which causes hemolytic anemia in dogs (and cats). Thiosulfate levels are not affected by cooking or processing. Small puppies have died of hemolytic anemia after being fed baby food containing onion powder. Occasional exposure to small amounts is usually not a problem, but continuous exposure to even small amounts can be a serious threat. Garlic is also known to cause diarrhoea and vomiting.
- Macadamia nuts can cause stiffness, tremors, hyperthermia, and abdominal pain. The exact mechanism is not known. Most dogs recover with supportive care when the source of exposure is removed.
- Alcoholic beverages pose much the same temptation and hazard to dogs as to humans. A drunk dog displays behavior analogous to that of an intoxicated person. (However, beer presents another problem; see below.)
- Hops, a plant used in making beer, can cause malignant hyperthermia in dogs, usually with fatal results. Certain breeds, such as Greyhounds, seem particularly sensitive to hop toxicity, but hops should be kept away from all dogs. Even small amounts of hops can trigger a potentially deadly reaction, even if the hops are "spent" after use in brewing.
- Some dogs have food allergies much as humans do; this is particular to the dog and not characteristic of the species as a whole. An example is a dog vomiting whenever he eats salmon; many humans likewise have seafood allergies.
[edit] Common household substances
Some common household chemicals are particularly dangerous to dogs:
- Antifreeze, due to its sweet taste, poses an extreme danger of poisoning to a dog (or cat) that either drinks from a spill or licks it off its fur. The antifreeze itself is not toxic, but is metabolized in the liver to a compound which causes kidney failure, and eventual seizures, and death. By the time symptoms are observed, the kidneys are usually too damaged for the dog to survive so acting quickly is important. Immediate treatment is to administer apomorphine or peroxide solution in an effort to get the animal to vomit up as much of the antifreeze as possible. Next, it is critical to immediately get the animal to a veterinarian. Fomepizole (Antizol Vet® by Orphan Medical) is considered the preferred treatment for treating ethylene glycol toxicoses in dogs. Ethanol can also be used in cats and dogs, however it does have several unfavorable side effects. Ethanol occupies the enzymes in the dog's liver, long enough for the unmetabolized antifreeze to be passed out harmlessly through the kidneys. Dogs should not be allowed access to any place in which an antifreeze leak or spill has happened until the spill is completely cleaned out. Even a very small amount such as a tablespoon can easily prove fatal. Some brands of antifreeze that contain propylene glycol instead of ethylene glycol are marketed as being less harmful or less attractive to animals.
- Mouse and rat poison is commonly found in the house or garage. Dogs readily eat these poisons, which look like small green blocks and are very attractive to them. The poisons work by depleting stores of Vitamin K in the body, without which blood can not clot properly. Symptoms of poisoning include depression, weakness, difficulty breathing, bruising, and bleeding from any part of the body. These symptoms often take 3 to 4 days to show up. A blood test will show that the blood is not clotting properly. If the poison has only recently been ingested (within 2 to 3 hours), the dog should be given apomorphine or hydrogen peroxide to make it vomit. Activated charcoal can be given to absorb any remaining poison in the gastrointestinal tract. Then the dog is given Vitamin K supplementation for 3 to 4 weeks, depending on the type of poison. At the end of treatment, the clotting times should be tested again. The prognosis is good in these cases. However, if the dog is already showing signs of poisoning, it is too late to try and remove the poison from the body. A whole blood transfusion or plasma is given to treat the anemia and to try and control bleeding. Vitamin K is also given. The prognosis is poor in these cases.
- Mouse and rat poisons containing cholecalciferol cause hypercalcemia and hyperphosphatemia in dogs. Symptoms include depression, loss of appetite, vomiting blood, weakness, and shock. Treatment is as above for recent exposure. When hypercalcemia occurs (which can take 1 to 2 weeks), treatment is with intravenous fluids (saline), diuretics, corticosteroids, and calcitonin. Long term prognosis is good once the dog is stabilized.
- Zinc toxicity, mostly in the form of the ingestion of US pennies minted after 1982, is commonly fatal in dogs where it causes a severe hemolytic anemia. [1]
[edit] Over the counter medications
A veterinarian should be checked before any OTC medicine is used. However, poisoning with pain medications is common. Aspirin, acetaminophen (Tylenol), ibuprofen (Advil), and naproxen (Aleve) can all cause severe symptoms in dogs, including vomiting blood, diarrhea, and abdominal pain. Specifically, aspirin can cause metabolic acidosis, acetaminophen can cause liver disease, ibuprofen can cause kidney disease, and naproxen can cause ulcers in the stomach, which can perforate. Treatment depends on the symptoms.
Contact your veterinarian or the ASPCA Animal Poison Control Center in case of possible exposure.
[edit] Feeding habits and obesity
Feeding table scraps to a dog is generally not recommended, at least in excess. Dogs get ample correct nutrition from their natural, normal diet. Otherwise, just as in humans, their diet must consist of the appropriate mix of nutrients, carbohydrates, and proteins, with the appropriate mix to provide all of the minerals and vitamins that they need. A human diet is not ideal for a dog: the concept of a "balanced" diet for a facultative carnivore like a dog is not the same as in an omnivorous human. Wild and feral dogs can usually get all the nutrients needed from a diet of whole prey and raw meat. In addition, the scraps often consist of fat rather than meat protein, which is no better for dogs than it is for humans. While not all human delicacies are acutely toxic to dogs (see above), many have the same chronically unfortunate results as they do for humans.
Lastly, many people overfeed their dogs by giving them all the table scraps that the dogs will eat—which is usually all the table scraps they are fed, which is often too much food.
The result of too much food is obesity, an increasingly common problem in dogs, which can cause numerous health problems just as it does in humans, although dogs are much less susceptible to the common cardiac and arterial consequences of obesity than humans are.
Additionally, the feeding of table scraps directly from the table (as opposed to taking scraps after the meal, and giving them in the dog's food dish as a treat) can lead to trained begging behavior on the part of the dog, or even encourage the dog to reach up and take food directly from the table (another trained response). These are normally seen as undesirable behavioral traits in a dog.
[edit] Coprophagia
Many dogs have a fondness for eating feces. Some consume their own or other dogs' feces; others seem to prefer cat feces (which, due to the feline digestive system, are high in protein and consumed by many animals in the wild), and will raid a kitty litter box for "treats". This can be unsafe for the dog's health if the animal producing the feces has any diseases or parasites or has recently ingested drugs that might be poisonous. For more information, see coprophagia.
[edit] Additional health information
Dogs are susceptible to various diseases; similarly to humans, they can have diabetes, epilepsy, cancer, or arthritis. Other diseases are more specific to canines.
[edit] Bloat and gastric torsion
Breeds with deep chests and narrow waists, such as the Bouvier des Flandres or Doberman Pinscher, for instance, are susceptible to a syndrome of gastric torsion and bloat, where the stomach twists on its supporting ligaments, sealing off the exits, and the contents begin to generate gas pressure which is not only terribly painful (as can be imagined by anyone who has experienced even mild gas pains), but kills large areas of stomach tissue fairly quickly, resulting in a painful death within a very few hours. A similar disease is seen in cattle and horses; and a similar home remedy has sometimes been effective when a veterinarian is not at hand, i.e. puncturing the stomach from outside with a sharp object to relieve the pressure. Obviously, such a remedy must only be attempted as a last resort. Dogs who have experienced such an attack are very susceptible to another which is usually more severe, and this is one case where the most medical intervention usually proves the best choice, normally involving abdominal surgery to tack the dog's stomach down in several places to prevent recurrence.
[edit] Vertigo
Elderly dogs are susceptible to an unusual form of intense vertigo, the cause of which is unknown; the affected dog is unable to stand up and remains sprawled on the floor, the eyes displaying intense nystagmus, for typically a few days. While terrifying in appearance, owners often fearing that the dog has had a fatal stroke (which is actually uncommon in dogs), the vertigo passes within a few days and by the end of a week the dog is staggering around upright, and within another week there is no evidence that anything at all had happened. The only risk of the disease is that the dog is unable to eat or drink in that condition, and must receive supportive therapy of intravenous fluids and nutrition; a light sedative is usually also administered, as the dog naturally seems terrified during the experience.
[edit] Tobacco smoke
The Passive smoking article has information on the effects of second-hand smoke on dogs.
[edit] Other Health-related topics
[edit] See also
- List of dog diseases
- Aging in dogs
- Category:Dog health
- Category:Veterinary medicine images
- Puppy breath
[edit] References
- Information about the third eyelid of dogs, and the problem of Kertao, or "dry eye".
- How to keep a dog healthy
- Why chocolate is poisonous to dogs from the American Veterinary Medical Association
- Information about grapes and raisins
- Petalia: Human foods that poison pets
- Common household items that can poison pets
- Pros and Cons of Inbreeding
- Information about dog vaccinations
- Dog skin disorders
- About the new weight loss drug for dogs from Pfizer
- Low allergen producing dog breeds for allergy sufferers
- Eliminating dog roundworms (toxocara canis)
- Dog Obesity Health Issues
- Free Online Veterinarian Advice Free online veterinary advice and lots of dog health articles.
- Ettinger, Stephen J.;Feldman, Edward C. (1995). Textbook of Veterinary Internal Medicine, 4th ed., W.B. Saunders Company. ISBN 0-7216-6795-3.
- Free Dog Health Book "Keeping Your Dog Healthy" by A. Barton
[edit] Footnotes
- ^ Stowe CM, Nelson R, Werdin R, et al: Zinc phosphide poisoning in dogs. JAVMA 173:270, 1978