Dog health 2540987 226080592 2008-07-16T19:10:00Z Sephiroth BCR 621952 Reverted edits by [[Special:Contributions/74.182.194.191|74.182.194.191]] to last version by FrancoGG (using [[WP:HG|Huggle]]) [[Image:20070114 dog with bandaged foot.jpg|thumb|right|[[Cavalier King Charles Spaniel]] with bandaged foot.]] 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. Infectious diseases are prevalent in dogs and are important not just from a veterinary standpoint but also because of the risk to public health. The most wellknown example of this is [[rabies]]. Genetic diseases are common in dogs due to the [[selective breeding]] necessary to produce individual [[dog breed]]s. Due to the popularity of both commercial and homemade [[dog food]]s, [[nutrition]] is also a heavily studied subject. ==Diseases== :''For a complete list, see [[List of dog diseases]]'' Some diseases and other health problems are common to both [[humans]] and [[dogs]]; others are unique to dogs and other animals. Dogs are susceptible to various diseases; similarly to humans, they can have [[diabetes]], [[epilepsy]], [[cancer]], or [[arthritis]]. ===Infectious diseases=== An [[infectious disease]] is caused by the presence of organisms such as [[virus]]es, [[bacteria]], [[fungi]], or [[parasite]]s (either [[animal]]ian or [[protozoa]]n). Most of these diseases are spread directly from dog to dog, while others require a [[vector (biology)|vector]] such as a [[tick]] or [[mosquito]]. Certain infectious diseases are a concern from a [[public health]] standpoint because they are [[zoonosis|zoonoses]] (transmittable to humans). ====Viral diseases==== =====Rabies=====<!-- This section is linked from [[Rabies]] --> [[Image:Rabid dog.jpg|thumb|A rabid dog]] [[Rabies]] is a viral disease commonly associated with dogs, although in recent years canine rabies has been practically eliminated in [[North America]] and [[Europe]] due to extensive and often mandatory [[vaccination]] requirements. However it is still a significant problem in [[Africa]], the [[Middle East]], [[Latin America]], and [[Asia]].<ref>{{cite web | title = Rabies:Introduction | work = The Merck Veterinary Manual | date = 2006 | url = http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/102300.htm | accessdate = 2007-08-14 }}</ref> Dogs are considered to be the main [[Natural reservoir|reservoir]] for rabies in [[developing country|developing countries]].<ref>{{cite web | last = Rupprecht | first = Charles E. | title = Prevention of Specific Infectious Diseases: Rabies | work = Traveler's Health:Yellow Book | publisher = [[Centers for Disease Control and Prevention]] | date = 2007 | url = http://wwwn.cdc.gov/travel/yellowBookCh4-Rabies.aspx | accessdate = 2007-08-14 }}</ref> Areas that are rabies-free, (usually islands) such as [[UK|Britain]], [[Ireland]], [[Australia]], and the American state of [[Hawaii]] have strict [[quarantine]] laws to keep their territories rabies-free.<ref>{{cite web | title = Rabies Epidemiology | publisher = [[World Health Organization]] | date = 2007 | url = http://www.who.int/rabies/epidemiology/en/ | accessdate = 2007-08-14 }}</ref> 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. Historically, rabies has long been linked to dogs. The earliest mention of rabies is in the Codex of [[Eshnunna]] (ca. [[20th century BC|1930 BC]]) (written prior to the [[Code of Hammurabi]]), which dictates that the owner of a dog showing symptoms of rabies should take preventative measure against bites. If a person was bitten by a rabid dog and later died, the owner was fined heavily. The sacred animal of the [[Babylonia]]n goddess of health [[Gula]] or [[Ninsun|Ninisina]] was the dog; if a person insulted a dog, Gula caused that dog to bite the person and inflict them with rabies.<ref>{{cite book | last = Dunlop | first = Robert H. | coauthors = Williams, David J. | title = Veterinary Medicine:An Illustrated History | publisher = Mosby | date = 1996 | id = ISBN 0-8016-3209-9 }}</ref> In the 1800s the infectious nature of rabies was first demonstrated by taking the saliva from a rabid dog and injecting it into another animal.<ref name=Ettinger_1995/> Rabies in dogs is a fatal disease transmitted by the bite of an infected [[mammal]], such as a [[cat]], [[raccoon]], [[bat]], or another dog. 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. Three stages of rabies are recognized in dogs and other animals. The first stage is a one to three day period characterized by behavioral changes and is known as the [[Prodrome|prodromal stage]]. The second stage is the excitative stage, which lasts three to four days. It is this stage that is often known as ''furious rabies'' due to the tendency of the affected dog to be hyperreactive to external stimuli and bite at anything near. The third stage is the paralytic stage and is caused by damage to [[motor neuron]]s. Incoordination is seen due to rear limb [[paralysis]] and drooling and difficulty swallowing is caused by paralysis of facial and throat muscles. Death is usually caused by [[respiratory arrest]].<ref name=Ettinger_1995>{{cite book|author=Ettinger, Stephen J.;Feldman, Edward C.|title=Textbook of Veterinary Internal Medicine|edition=4th ed.|publisher=W.B. Saunders Company|year=1995|id=ISBN 0-7216-6795-3}}</ref> 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 have been very few cases of someone surviving rabies when treatment was not begun until after symptoms appeared. Depending on local laws, dogs that are showing neurological signs at the time of the bite are [[animal euthanasia|euthanized]] in order to have their brain tested for rabies. Unvaccinated healthy dogs need to be confined for ten days from the time of the bite (at home or at a veterinarian depending on local 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.<ref>{{cite web | title = Questions and Answers about Rabies | publisher = [[Centers for Disease Control and Prevention]]| date = 2004 | url = http://www.cdc.gov/ncidod/dvrd/rabies/Ques&Ans/q&a.htm | accessdate = 2007-08-14 }}</ref> 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. This is an 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 or impounded should it bite anyone or be suspected of biting anyone. =====Other viral diseases===== Other canine viral diseases of note include parvovirus, distemper, infectious canine hepatitis, herpesvirus, and influenza. [[Canine parvovirus]] (caused by ''canine [[parvovirus]] type 2'', ''canine parvovirus type 1'' is also known as [[canine minute virus]]) causes a highly contagious gastrointestinal infection that is especially severe in puppies. It is spread through contact with infected feces. The virus attacks rapidly dividing cells, notably those in the [[lymph node]]s, [[Crypts of Lieberkühn|intestinal crypt]]s, and the [[bone marrow]]. There is depletion of [[lymphocyte]]s in lymph nodes and [[necrosis]] and destruction of the intestinal crypts.<ref>{{cite web | last = Lobetti | first = Remo | title = Canine Parvovirus and Distemper | work = Proceedings of the 28th World Congress of the World Small Animal Veterinary Association | date = 2003 | url = http://www.vin.com/proceedings/Proceedings.plx?CID=WSAVA2003&PID=6671&O=Generic | accessdate = 2007-04-22 }}</ref> Symptoms and signs include vomiting, bloody diarrhea, depression, severe dehydration, fever, and low [[white blood cell]] counts. Although there is no specific treatment for the canine parvovirus, aggressive [[intravenous therapy|intravenous fluid therapy]] and antibiotics for dogs with secondary bacterial infections is usually required.<ref>{{cite web | title = Canine Parvovirus | work = The Merck Veterinary Manual | date = 2006 | url = http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/23301.htm | accessdate = 2007-08-14 }}</ref> [[Canine distemper]], caused by a [[paramyxovirus]] similar to the cause of [[measles]], is a highly contagious disease that affects the respiratory, gastrointestinal, and central nervous systems. It is spread through either direct contact with respiratory excretions, through the air, or on [[fomite]]s (inanimate objects such as clothing). Symptoms and signs include discharge from the eye or nose, coughing, difficulty breathing, vomiting, diarrhea, depression, seizures, and paralysis. Similar to canine parvovirus, treatment is supportive.<ref>{{cite web | title = Information sheet: Canine distemper virus | work = UC Davis Koret Shelter Medicine Program | url = http://www.sheltermedicine.com/portal/is_canine_distempervirus.shtml | accessdate = 2006-09-26 }}</ref> [[Infectious canine hepatitis]] is caused by ''canine [[adenovirus]] type 1''. The virus is spread in the feces, urine, blood, saliva, and nasal discharge of infected dogs. It causes a liver infection and a bleeding disorder. Signs and symptoms include fever, depression, loss of appetite, coughing, tender abdomen, and spontaneous hemorrhages. Treatment is symptomatic.<ref>{{cite web | title = Infectious Canine Hepatitis: Introduction | work = The Merck Veterinary Manual | date = 2006 | url = http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/57200.htm | accessdate = 2007-08-14 }}</ref> [[Canine herpesvirus]] is a virus of the family ''[[Herpesviridae]]'' which most importantly causes a fatal hemorrhagic disease in puppies less than two to three weeks old. It is transmitted to puppies in the birth canal and by contact with infected oral and nasal secretions from the mother or other infected dogs, but it is not spread through the air. Signs and symptoms include depression, nasal discharge, and weakness. The inability of very young puppies to mount a febrile response seems to be a significant contributing factor to the high mortality rate in this age dog - it can reach 80 percent.<ref>{{cite web|author=Carter, G.R.; Flores, E.F.; Wise, D.J.|year=2006|title=Herpesviridae|work=A Concise Review of Veterinary Virology| url=http://www.ivis.org/advances/Carter/Part2Chap11/chapter.asp?LA=1|accessdate=2006-06-08}}</ref> In adult dogs, canine herpesvirus can cause [[miscarriage|abortion]]. [[Canine influenza]] usually refers to infection with [[equine influenza]] virus [[H3N8]]. This virus was found to infect dogs in 2004, and the disease was very contagious due to the dog's lack of natural [[immunity]]. Signs and symptoms include cough and nasal discharge, and in more severe cases fever and [[pneumonia]]. Canine influenza has a high [[morbidity]] but a low [[mortality]].<ref>{{cite web | title = Media Briefing on Canine Influenza | publisher = CDC | date = Sept. 26, 2005 | url = http://www.cdc.gov/od/oc/media/transcripts/t050926.htm | accessdate = 2007-04-21 }}</ref> ====Bacterial diseases==== [[Image:Leptospira scanning micrograph.jpg|thumb|left|A number of ''Leptospira'' sp. bacteria atop a 0.1. µm [[polycarbonate]] filter]] Bacterial diseases in dogs are usually not contagious from dog to dog; instead they are usually the result of wound colonization, [[opportunistic infection]]s secondary to decreased resistance (often the result of viral infections), or secondary to other conditions ([[pyoderma]] secondary to skin allergies or [[pyometra]] secondary to cystic endometrial hyperplasia). These examples are not considered infectious diseases because they do not satisfy [[Koch's postulates]] - for example ''Staphylococcus intermedius'', a commonly isolated bacteria from skin infections in dogs, would not cause pyoderma when introduced to a healthy dog. In all likelihood that type of bacteria is already present on the skin of a healthy dog. There are some bacteria that are contagious from dog to dog. The most notable of these are ''[[Bordetella bronchiseptica]]'', one of the causes of [[kennel cough]], ''[[Leptospira]]'' sp, which cause [[leptospirosis]], and ''Brucella canis'', cause of [[brucellosis]] in dogs. There are also common tick-borne bacterial diseases, including [[Lyme disease]], [[ehrlichiosis (canine)|ehrlichiosis]], and [[Rocky Mountain spotted fever]]. Leptospirosis is a zoonotic disease 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. In dogs, transmission most commonly occurs by drinking puddle, pond, or ditch water contaminated by urine from infected wildlife such as [[squirrel]]s or [[raccoon]]s. The liver and kidney are most commonly damaged by leptospirosis. [[Vasculitis]] can occur, causing [[edema]] and potentially [[disseminated intravascular coagulation]] (DIC). [[Myocarditis]], [[pericarditis]], [[meningitis]], and [[uveitis]] are also possible sequelae. <ref>{{cite journal|author=Heuter, Kerry J.,Langston, Cathy E.|title=Leptospirosis: A re-emerging zoonotic disease|journal=The Veterinary Clinics of North America|year=2003|volume=33|pages=791–807}}</ref> [[Image:Adult deer tick.jpg|thumb|''Ixodes scapularis'']] Brucellosis in dogs is caused by ''Brucella canis''. It is a [[sexually transmitted disease]], but can also be spread through contact with aborted fetuses. The most common sign is abortion during the last [[trimester]] or [[stillbirth]]. Other symptoms include inflammation of the [[intervertebral disc]] and eye ([[uveitis]]), and inflammation of the testicle ([[orchitis]]) and [[prostate]] ([[prostatitis]]) in males.<ref>{{cite web | title = Brucellosis in Dogs: Introduction | work = The Merck Veterinary Manual | date = 2006 | url = http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/112200.htm | accessdate = 2007-08-14 }}</ref> [[Tick-borne disease]]s are common in dogs. Lyme disease, or borreliosis, is caused by ''[[Borrelia burgdorferi]]'' and spread by ''[[Ixodes pacificus]]'' on the West coast of the Umited States and by ''[[Ixodes scapularis|I. scapularis]]'' (deer tick) in the rest of the U.S. Signs and symptoms include fever, joint swelling and pain, lameness, and swelling of the lymph nodes. It has been diagnosed in dogs in all 48 states of the continental U.S.<ref>{{cite journal | title = Lyme disease recognized in 48 states | journal = Veterinary Forum | volume = 24 | issue = 5 | pages = 17 | publisher = Veterinary Learning Systems | date = May 2007 }}</ref> ''Ehrlichia canis'', which causes canine ehrlichiosis, and ''[[Rickettsia|Rickettsia rickettsii]]'', which causes Rocky Mountain spotted fever, are both spread by the American dog tick, ''[[Dermacentor variabilis]]'', and the brown dog tick, ''[[Rhipicephalus sanguineous]]''.<ref>{{cite journal | title = Forget everything you know about ticks | journal = Veterinary Forum | volume = 24 | issue = 5 | pages = 44–56 | publisher = Veterinary Learning Systems | date = May 2007 }}</ref> ====Fungal diseases==== One of the most common [[fungus|fungal]] diseases in dogs is [[ringworm]], or dermatophytosis, an infection of the skin, hair, or nails. There are three fungal species that cause ringworm in dogs. About 70 percent of infections are caused by ''[[Microsporum]] canis'', 20 percent by ''M. gypseum'', and 10 percent by ''[[Trichophyton]] mentagrophytes''. Signs include hair loss and scaling of the skin. Treatment for localized ringworm is not always necessary as the disease is self-limiting, but the cliinical course can be shortened by using topical [[miconazole]] or [[clotrimazole]]. Generalized infections, most commonly seen in [[Immunodeficiency|immunocompromised]] dogs, can be treated with oral [[antifungal drug]]s such as [[griseofulvin]] or [[itraconazole]]. Infection can spread to humans.<ref>{{cite web | title = Dermatophytosis: Dogs and Cats | work = The Merck Veterinary Manual | date = 2006 | url = http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/71303.htm | accessdate = 2007-08-18 }}</ref> [[Image:Blastomycosis cropped.JPG|left|thumb|''Blastomyces dermatitidis'']] There are several fungal diseases that are systemic in nature, meaning they are affecting multiple body systems. [[Blastomycosis]], caused by ''[[Blastomyces]] dermatitidis'', is a fungal disease that affects both dogs and humans, although it is only rarely zoonotic. It is found mainly in the United States in the [[Mississippi River]] and [[Great Lakes]] areas. Signs include weight loss, cough, fever, enlarged lymph nodes, draining skin lesions, blindness, and lameness. Because dogs are ten times more likely to become infected from the environment than humans, they are considered to be sentinels for the disease.<ref>{{cite web | last = Probst | first = Sarah | title = Blastomycosis--Fungal Disease Common in Outdoor Dogs | work = Pet Columns | publisher = [[UIUC College of Veterinary Medicine]] | date = 1999 | url = http://www.cvm.uiuc.edu/petcolumns/index.cfm?function=showarticle&id=67 | accessdate = 2007-08-18 }}</ref> [[Histoplasmosis]], caused by ''[[Histoplasma capsulatum]]'', is a disease with a worldwide distribution. In the United States it is mainly found in the Mississippi and [[Ohio River]] areas, most commonly in bird and bat feces. Signs include weight loss, cough, fever, enlarged lymph nodes, and gastrointestinal symptoms.<ref>{{cite web | title = Histoplasmosis | work = The Merck Veterinary Manual | date = 2006 | url = http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/51108.htm | accessdate = 2007-08-18 }}</ref> [[Coccidioidomycosis]], caused by ''[[Coccidioides immitis]]'', is found in [[arid]] and [[semi-arid]] regions of [[Central America|Central]] and [[South America]], [[Mexico]], and southwestern United States. Signs include weight loss, fever, cough, enlarged lymph nodes, and lameness.<ref>{{cite web | title = Coccidioidomycosis | work = The Merck Veterinary Manual | date = 2006 | url = http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/51104.htm | accessdate = 2007-08-18 }}</ref> ====Parasites==== =====External parasites===== *[[Flea]]s and [[tick]]s 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 (epidemiology)|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 [[rickettsia]]l 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. *[[Flea]]s and [[tick]]s are common parasites for which there are many effective preventive measures. *Various [[mite]]s cause skin problems such as [[mange]]. =====Internal parasites===== *[[Parasites]], particularly intestinal worms such as [[hookworm]]s, [[tapeworm]]s and [[roundworm]]s, can be transmitted in a dog's [[feces]]. Some tapeworms have [[flea]]s 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. *[[Intestinal]] [[worm]]s 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 artery|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 pill]]s 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 [[tapeworm]]s. ===Genetic diseases=== [[Image:Bilateral hip dysplasia.JPG|thumb|Bilateral hip dysplasia]] [[Genetics|Genetic]] conditions are a problem in some dogs, particularly purebreeds. For this reason many of the national [[kennel club]]s require that dogs with certain genetic illnesses or who are deemed to be carriers cannot be registered. Some of the most common conditions include [[hip dysplasia]], seen in large breed dogs, [[von Willebrand disease]], a disease that affects [[platelet]]s that is inherited in [[Doberman Pinscher]]s, [[entropion]], a curling in of the eyelid seen in [[Shar Pei]]s and many other breeds, [[progressive retinal atrophy]], inherited in many breeds, [[deafness]], and [[epilepsy in animals|epilepsy]], known to be inherited in [[Belgian Shepherd Dog (Tervuren)|Belgian Shepherd Dog]]s, [[German Shepherd Dog]]s, [[Cocker Spaniel]]s, and [[St. Bernard (dog)|St. Bernard]]s.<ref>{{cite web | title = Canine Inherited Disorders Database | publisher = University of Prince Edward Island | date = 2001 | url = http://www.upei.ca/cidd/intro.htm | accessdate = 2007-08-18 }}</ref> [[Aortic valve stenosis|Subaortic stenosis]], or SAS, is a genetic ailment that causes a narrowing of the passage of blood between the [[heart]] and the [[aorta]]. This leads to heart problems and sometimes sudden death. It affects larger breeds such as the [[Newfoundland dog|Newfoundland Dog]] and the [[Golden Retriever]].<ref>{{cite web | title = Aortic Stenosis | work = The Merck Veterinary Manual | date = 2006 | url = http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/11106.htm | accessdate = 2007-08-18 }}</ref> In some dogs, such as [[collie]]s, the [[merle (coat colour in dogs)|blue merle]] or [[Great Dane|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 system]]s and [[sensory organ]]s ranging from deafness to fatal flaws. ===Skin diseases=== {{main|Dog skin disorders}} [[Image:Canine Atopy.jpg|thumb|Canine atopy]] Skin diseases are very common in dogs. [[Atopy]], a chronic allergic condition, is thought to affect up to 10 percent of dogs.<ref>{{cite web | title = Canine Atopy | work = The Merck Veterinary Manual | date = 2006 | url = http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/70301.htm | accessdate = 2007-08-18 }}</ref> Other skin diseases related to allergies include hot spots and [[pyoderma]], both characterized by secondary bacterial infections, [[food allergy]], [[Otitis externa in animals|ear infections]], and [[flea allergy dermatitis]]. [[Canine follicular dysplasia]] is an inherited disorder of the [[hair follicle]]s resulting in [[alopecia]] (baldness). [[Mange]] is an infectious skin disease caused by [[mite]]s. [[Endocrine diseases]] such as [[hypothyroidism]] and [[Cushing's syndrome]] can also manifest as skin problems like alopecia or recurring bacterial infections. ===Orthopedic diseases=== Orthopedic diseases in dogs can be developmental, hereditary, traumatic, or degenerative. Because of the active nature of dogs, injuries happen frequently. One of the most common of these is an [[anterior cruciate ligament injury]], a condition which often requires surgery. [[Bone fracture]]s are a frequent occurrence in outdoor dogs due to trauma from being hit by cars. [[Osteoarthritis|Degenerative joint disease]] is common in older dogs and is one of the most likely reasons for prescription of [[non-steroidal anti-inflammatory drug]]s. Hereditary orthopedic diseases are mainly found in purebred dogs. [[Hip dysplasia (canine)|Hip dysplasia]] is a common problem that primarily affects larger breeds. Hip dysplasia is a defect in the shape of the hip joint which can, depending on the degree of hip luxation, be quite painful to the dog as it ages. Over time it often causes arthritis in the hips. [[Elbow dysplasia|Dysplasia]] can also occur in the elbow joint. [[Luxating patella]]s can be a problem for smaller breeds. It can cause lameness and pain in the hind legs. Developmental orthopedic diseases include [[panosteitis]] and [[hypertrophic osteodystrophy]]. Panosteitis occurs in large and giant breed dogs usually between the age of five and fourteen months and manifests as fever, pain, and shifting leg lameness. Hypertrophic osteodystrophy is also seen in young large and giant breed dogs and is characterized by pain, lameness, fever, and swelling of the long bone [[metaphysis]]. ===Tumors and Cancer=== [[Image:KangalWithCancer.jpg|thumb|An [[emaciated]] [[Kangal Dog|Kangal]] with cancer in the left leg.]] Both [[Benign tumor|benign]] and [[cancer|malignant]] [[tumor]]s are seen in dogs. Common benign tumors include [[lipoma]]s, non-viral [[papilloma]]s, [[sebaceous gland]] adenoma, and [[perianal gland adenoma]]s. Frequently seen cancers include [[lymphoma in animals|lymphoma]], [[melanoma]], [[mast cell tumor]]s (which are considered to be potentially malignant, even though they may have benign behavior),<ref name=MKM>{{cite web | title = Cutaneous Mast Cell Tumors | work = The Merck Veterinary Manual | date = 2006 | url = http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/72231.htm | accessdate = 2007-08-21 }}</ref> and [[osteosarcoma]] (bone cancer). Certain breeds are more likely to develop particular tumors, larger ones especially. The [[Golden Retriever]] is especially susceptible to lymphoma, with a lifetime risk of 1 in 8.<ref>{{cite journal |author=Modiano J, Breen M, Burnett R, Parker H, Inusah S, Thomas R, Avery P, Lindblad-Toh K, Ostrander E, Cutter G, Avery A |title=Distinct B-cell and T-cell lymphoproliferative disease prevalence among dog breeds indicates heritable risk |journal=Cancer Res |volume=65 |issue=13 |pages=5654–61 |year=2005 |pmid=15994938 |doi=10.1158/0008-5472.CAN-04-4613}}</ref> [[Boxer (dog)|Boxer]]s and [[Pug]]s are prone to multiple mast cell tumors.<ref name=MKM/> [[Scottish Terrier]]s have eighteen times the risk of mixed breed dogs to develop [[transitional cell carcinoma]], a type of urinary bladder cancer.<ref>{{cite journal |author=Raghavan M, Knapp DW, Dawson MH, Bonney PL, Glickman LT |title=Topical flea and tick pesticides and the risk of transitional cell carcinoma of the urinary bladder in Scottish Terriers |journal=J. Am. Vet. Med. Assoc. |volume=225 |issue=3 |pages=389–94 |year=2004 |pmid=15328714 |doi=}}</ref> ===Gastrointestinal diseases=== Due to the indiscriminate nature of a dog's appetite, gastrointestinal upset is a frequent occurrence in dogs. The most common symptoms are anorexia, vomiting, and diarrhea. [[Foreign body]] ingestion can lead to acute obstruction of the gastrointestinal tract, a very dangerous condition. [[Acute pancreatitis]] can also result from dietary indiscretion. ====Bloat and gastric torsion==== {{main|Bloat}} Breeds with deep, narrow chests, such as the [[Great Dane]] or [[St. Bernard (dog)|St. Bernard]], are susceptible to a syndrome of gastric torsion and [[bloat]]. The [[stomach]] twists on its supporting [[ligament]]s, sealing off the exits, and the contents begin to generate gas pressure which is very painful and rapidly causes [[shock (medical)|shock]] and [[necrosis]] of large areas of stomach tissue. It can be fatal within a few hours. Dogs who have experienced bloat are very susceptible to recurrences. Treatment involves stabilization and abdominal surgery to tack the dog's stomach down to prevent recurrence ([[gastropexy]]). ===Eye diseases=== [[Image:Prolapsed gland of the third eyelid.JPG|thumb|left|Cherry eye]] Eye diseases are common in dogs. [[Cataract]]s, [[glaucoma]], and [[entropion]] are seen in both dogs and humans. Canine-specific eye diseases include [[progressive retinal atrophy]], [[Collie eye anomaly]], [[sudden acquired retinal degeneration]], and [[cherry eye]]. Injury to the eye can result in [[Corneal ulcers in animals|corneal ulcers]]. The frequency of bilateral glaucoma with a genetic base in purebred dogs is higher than in any species except humans.<ref>{{cite web | title = Glaucoma | work = The Merck Veterinary Manual | date = 2006 | url = http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/30111.htm | accessdate = 2007-08-26 }}</ref> Cataracts in dogs either have a genetic base or can also be caused by [[Diabetes in cats and dogs|diabetes]]. [[Nuclear sclerosis]] resembles a cataract but is actually a normal age-related change. ===Vestibular disease=== Elderly dogs are susceptible to an unusual form of intense [[Vertigo (medical)|vertigo]], known as old dog vestibular disease, the cause of which is unknown, or [[idiopathic]]. Signs include nausea, difficulty or the complete inability to stand, head tilt, circling, and [[nystagmus]] (the movement of the eyes in a repetitive jerking motion, usually horizontal). The signs may improve rapidly or take a few days. While most cases are idiopathic, vestibular signs can also be caused by [[otitis interna|inner ear disease]], a brain tumor, or rarely a [[stroke]]. The major risk of idiopathic cases is that the dog is often unable to eat, drink, or go outside to urinate or defecate. These cases must receive supportive therapy of [[intravenous fluid]]s and nutrition; a light [[sedative]] is sometimes administered, as the dog may be very stressed by the experience. ===Heart disease=== Older, small breeds of dogs are prone to [[congestive heart failure]] due to degeneration of the [[mitral valve]]. This condition is known to be inherited in [[Cavalier King Charles Spaniel]]s. Degenerative valve disease is the most common form of heart disease in dogs.<ref>{{cite web | title = Degenerative Valve Disease | work = The Merck Veterinary Manual | date = 2006 | url = http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/11213.htm | accessdate = 2007-09-04 }}</ref> [[Mitral regurgitation|Mitral insufficiency]] leads to turbulent blood flow and increased pressure in the [[left atrium]]. This causes increased pressure in the pulmonary blood vessels and [[pulmonary edema]] (a build-up of fluid in the lungs). Decreased output of blood by the [[left ventricle]] causes the body to compensate by increasing [[sympathetic tone]] and activating the [[renin-angiotensin-aldosterone system]] (RAAS). Increased sympathetic tone leads to increased [[peripheral vascular resistance]] and increased heart rate and [[contractility]] of the [[myocardium|heart muscle]]. Chronic elevation of sympathetic tone damages the heart muscle. Activation of the RAAS results in increased retention of water and sodium by the kidneys, [[vasoconstriction]], and other effects that result in increased blood volume. It also results in an increase in [[diastolic pressure]] and leads to pulmonary edema. Treatment for congestive heart failure nearly always includes two types of drugs that address these concerns: [[diuretic]]s (especially [[furosemide]]), which decrease blood volume, and [[ACE inhibitor]]s, which interrupt the RAAS. [[Cardiomyopathy]], or disease of the heart muscle, is also seen in dogs and is associated with large breeds (the exception being [[Cocker Spaniel]]s, a medium-sized breed). [[Dilated cardiomyopathy]] is seen in Great Danes, [[Irish Wolfhound]]s, St. Bernards, [[Dobermann]]s, [[Boxer (dog)|Boxer]]s, and other large breeds. Dobermanns, in addition to heart muscle failure, are prone to [[Cardiac arrhythmia|ventricular arrhythmia]]s. Boxers often present with weakness and fainting due solely to arrhythmias - there is no heart muscle failure at the time of diagnosis. They do, however, eventually develop congestive heart failure, if they do not die suddenly due to an arrhythmia.<ref>{{cite web | title = Cardiomyopathies | work = The Merck Veterinary Manual | date = 2006 | url = http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/11215.htm | accessdate = 2007-09-04 }}</ref> ===Other diseases=== Other diseases affecting dogs include [[endocrine system|endocrine]] diseases, [[immune-mediated disease]]s, and reproductive diseases. [[Diabetes in cats and dogs|Diabetes mellitus]], [[Cushing's syndrome]], [[Addison's disease]], and [[hypothyroidism]] are the most common endocrine diseases. [[Autoimmune hemolytic anemia|Immune-mediated hemolytic anemia]] is a devastating disease that causes severe [[anemia]] in dogs through destruction by the immune system. It has been associated with vaccinations and certain drugs, although many cases are [[idiopathic]]. A similar but less severe immune disease is [[Idiopathic thrombocytopenic purpura|immune-mediated thrombocytopenia]], characterized by destruction of [[platelet]]s by the immune system. Symptoms include bruising and [[petechia]]e (pinpoint bruising, often seen in the mouth). Common reproductive diseases include [[pyometra]] (distension of the [[uterus]] with pus), [[mammary tumor]]s, and [[benign prostatic hyperplasia]]. ==Toxic substances== ===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 [[horse]]s and possibly [[cat]]s). Chocolate contains [[theobromine]], a chemical stimulant that, together with [[caffeine]] and [[theophylline]], belongs to the group of [[methylxanthine]] [[alkaloid]]s. 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 [[tachycardia|fast heart rate]], [[hallucination]]s, severe [[diarrhea]], [[epileptic seizure]]s, [[myocardial infarction|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. ::''Note:''[[Carob]] treats are often available as dog treats; these are unrelated to chocolate and are safe. *It has recently been confirmed that [[grape]]s and [[raisin]]s can cause acute [[renal failure| kidney 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 toxic to a susceptible ten pound dog, some other dogs have eaten as much as a pound of grapes or raisins at a time without ill effects. The affected dog usually vomits a few hours after consumption and begins showing signs of renal failure three to five days later. *[[Onion]]s, and to a significantly lesser extent [[garlic]], contain [[thiosulfate]] which causes [[hemolytic anemia]] in dogs (and [[cat]]s). 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 diarrhea and vomiting. *[[Macadamia nut]]s 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 beverage]]s 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 [[Greyhound]]s, 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]]. *[[Xylitol]] is a sugar substitute used in chewing gum, chewable vitamins, candy, toothpaste, and other products. Although empirical studies ([http://www.inchem.org/documents/jecfa/jecmono/v12je22.htm 1], [http://www.inchem.org/documents/jecfa/jecmono/v13je11.htm 2], [http://www.inchem.org/documents/jecfa/jecmono/v18je16.htm 3]) indicate xylitol may be safe for dogs, there have been cases of foods, candies and gums containing xylitol causing toxic or even fatal liver damage in dogs and should be avoided ([http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15080212 1], [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=17014359 2], [http://www.aspca.org/site/DocServer/vetm0207f_095-100_.pdf?docID=10462 3]). *Some dogs have [[food allergies]] just as humans do; this is particular to the individual dog and not characteristic of the species as a whole. An example is a dog becoming physically ill from [[salmon]]; many humans likewise have seafood allergies. *If dogs eat the pits of fruits such as peaches and apricots, they can get [[cyanide]] poisoning due to [[Glycoside#Cyanogenic glycosides|cyanogenic glycosides]]. ===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 ([http://www.orphan.com/ 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. *[[Rat poison|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 carbon|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 [[coagulation|clotting time]]s 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 [[blood plasma|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 [[hypercalcaemia|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 fluid]]s (saline), [[diuretic]]s, [[corticosteroid]]s, and [[calcitonin]]. Long term prognosis is good once the dog is stabilized. *[[Zinc]] toxicity, mostly in the form of the ingestion of [[Cent (United States coin)|US pennies]] minted after 1982, is commonly fatal in dogs where it causes a severe [[hemolytic anemia]]. <ref>Stowe CM, Nelson R, Werdin R, et al: Zinc phosphide poisoning in dogs. JAVMA 173:270, 1978</ref> ===Over the counter medications=== A veterinarian should be checked before any OTC medicine is used. However, poisoning with pain medications is common. [[Aspirin]], [[paracetamol|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 [[ulcer]]s in the stomach, which can perforate. Treatment depends on the symptoms. Contact your veterinarian or the [http://www.aspca.org/site/PageServer?pagename=pro_apcc ASPCA Animal Poison Control Center] in case of possible exposure. == Public health risks == [[Image:Canine scabies mite.JPG|left|thumb|''Sarcoptes scabiei'']] Most diseases that affect dogs or humans are not transferable between the two species. There are some exceptions of [[zoonosis|zoonoses]]. The most well known zoonosis is rabies, a viral infection transmitted through a bite. A common bacterial zoonosis is leptospirosis, transmitted through urine. Some of the most important zoonoses are parasitic. Zoonotic intestinal parasites transmitted through contact with feces include ''[[Toxocara canis]]'' (the canine roundworm), which causes [[toxocariasis]], [[visceral larva migrans]], and [[ocular larva migrans]], and [[hookworm]]s, which can cause [[cutaneous larva migrans]]. Zoonotic skin parasites include [[scabies]], caused by the mite ''[[Sarcoptes scabiei]]''. The most common zoonotic fungal disease is [[ringworm]], caused in this case by ''[[Microsporum canis]]''. ==Preventive medicine== ===Vaccinations=== {{main|Vaccination of dogs}} Depending on the location of the dog, highly recommended vaccines include rabies, ''canine parvovirus'', canine distemper, and infectious canine hepatitis (using ''canine adenovirus type 2'' to avoid reaction). Vaccination for other diseases, including leptospirosis, Lyme disease, ''Bordetella bronchiseptica'', ''[[parainfluenza virus]]'', and ''[[canine coronavirus]]'', are used after determining the risk of contact with these pathogens. ===Dentistry=== [[Dental disease]] is one of the most common diseases in dogs. Accumulation of [[dental plaque|plaque]] and subsequently [[calculus (dental)|tartar]] leads to [[gingivitis]] and then [[periodontitis]] (gum disease). Periodontitis leads to loss of the bony attachment of the teeth and tooth loss. Preventive measures include [[tooth brushing]] and [[Tooth scaling|dental scaling]] and polishing. [[Dental caries (non-human)|Cavities]] are uncommon in dogs. ==Nutrition and obesity== [[Image:Bichon ice cream.jpg|thumb|right|200px|Human food such as ice cream can lead to ill health and obesity in dogs.]] 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 [[wikt:facultative|facultative]] [[carnivore]] like a dog is not the same as in an [[omnivore|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 in excess 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 table scraps and human food such as ice cream. Dogs will usually eat all the scraps and treats they are fed, which is more than often too much food..[[Image:Lightblueheeler.jpg|thumb|left|This [[Australian Cattle Dog]]'s obesity is a sign of [[Cushing's disease]].]] The result of too much food is [[obesity]], an increasingly common problem in dogs in Western countries, 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. Obesity can be a sign of other serious ailments such as [[Cushing's Disease]] which is characterized by weight gain, appetite increase and lethargy in primarily older dogs. A modern trend in canine diets is [[raw feeding]] of whole meats, bones and little filler material. ===Coprophagia=== {{main|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. ==Reproductive health== {{main|Canine reproduction}} ===Spaying and neutering=== {{main|Neutering}} Spaying (females only) and neutering (both genders but more usually males) refers to the [[Sterilization (surgical procedure)|sterilization]] of animals, usually by removal of the male's [[testicle]]s or the female's [[ovary|ovaries]] and [[uterus]], in order to eliminate the ability to procreate, and reduce sex drive. Neutering has also been known to reduce aggression in male dogs, but has been shown to occasionally increase aggression in female dogs.<ref>{{cite journal |author=Heidenberger E, Unshelm J |title=[Changes in the behavior of dogs after castration] |language=German |journal=Tierärztliche Praxis |volume=18 |issue=1 |pages=69–75 |year=1990 |pmid=2326799 |doi=}}</ref> Animal control agencies in the United States and the [[ASPCA]] advise that dogs not intended for further breeding should be spayed or neutered so that they do not have undesired puppies.<ref>{{cite web |url=http://www.aspca.org/site/PageServer?pagename=adopt_spayneuter |title=Top 10 reasons to spay/neuter your pet |publisher=American Society for Prevention of Cruelty to Animals |accessdate=2007-05-16}}</ref> Because of the overpopulation of dogs in some countries, puppies born to strays or as the result of accidental breedings often end up being killed in animal shelters. Spaying and neutering can also decrease the risk of hormone-driven diseases such as mammary cancer, as well as undesired hormone-driven behaviors. However, certain medical problems are more likely after neutering, such as [[urinary incontinence]] in females<ref>{{cite journal |author=Arnold S |title=[Urinary incontinence in castrated bitches. Part 1: Significance, clinical aspects and etiopathogenesis] |language=German |journal=Schweiz. Arch. Tierheilkd. |volume=139 |issue=6 |pages=271–6 |year=1997 |pmid=9411733 |doi=}}</ref> and [[prostate cancer]] in males.<ref>{{cite journal |author=Johnston SD, Kamolpatana K, Root-Kustritz MV, Johnston GR |title=Prostatic disorders in the dog |journal=Anim. Reprod. Sci. |volume=60-61 |issue= |pages=405–15 |year=2000 |pmid=10844211 |doi=}}</ref> The hormonal changes involved with sterilization are likely to somewhat change the animal's personality, however, and some object to spaying and neutering as the sterilization could be carried out without the excision of organs. It is not essential for a female dog to either experience a heat cycle or have puppies before spaying, and likewise, a male dog does not need the experience of mating before neutering. Female cats and dogs are seven times more likely to develop [[mammary tumor]]s if they are not spayed before their first [[estrus cycle|heat cycle]]. <ref>{{cite book|author=Morrison, Wallace B.|title=Cancer in Dogs and Cats (1st ed.)|publisher=Williams and Wilkins|year=1998|id=ISBN 0-683-06105-4}}</ref> The high dietary estrogen content of the average commercial pet food as well as the estrogenic activity of topical pesticides {{Fact|date=June 2007}} may be contributing factors in the development of mammary cancer, especially when these exogenous sources are added to those normal estrogens produced by the body. Dog food containing [[soybean]]s or soybean fractions have been found to contain [[phytoestrogens]] in levels that could have biological effects when ingested longterm.<ref>{{cite journal |author=Cerundolo R, Court MH, Hao Q, Michel KE |title=Identification and concentration of soy phytoestrogens in commercial dog foods |journal=Am. J. Vet. Res. |volume=65 |issue=5 |pages=592–6 |year=2004 |pmid=15141878 |doi=}}</ref> ==Tobacco smoke== Dogs, just like humans, are affected by [[Passive smoking#Studies of passive smoking in animals|passive smoking]]. ==See also== *[[Aging in dogs]] ==References== {{reflist|2}} ==External links== *[http://petdiabetes.wikia.com/ Pet Diabetes Wiki] *[http://www.vetinfo.com/dencyclopedia/deindex.html Encyclopedia of Canine Veterinary Medical Information] *[http://www.the-bulldog.com/congenital_heritable_disorders_in_dogs.html Congenital and Heritable Disorders in dogs ] *[http://www.avma.org/careforanimals/animatedjourneys/livingwithpets/poisoninfo.asp List of substances toxic to dogs] from the [[American Veterinary Medical Association]] *[http://www.stopcanineobesity.com Spotlight on the issue of canine obesity] *[http://www.mydogsage.com My Dogs Age - An Online Dog Age Calculator] *[http://www.petside.com/pet-vet Pet Vet Symptom and Condition Finder] {{Dog nav}} [[Category:Dog health| ]]