In dogs, signs of distemper vary widely from no signs, to mild respiratory signs indistinguishable from kennel cough, to severe pneumonia with vomiting, bloody diarrhea and death.

Commonly observed signs are a runny nose, vomiting and diarrhea, dehydration, excessive salivation, coughing and/or labored breathing, loss of appetite, and weight loss. If neurological signs develop, incontinence may ensue. Central nervous system signs include a localized involuntary twitching of muscles or groups of muscles, seizures with salivation and jaw movements commonly described as "chewing gum fits", or more appropriately as "distemper myoclonus". As the condition progresses, the seizures worsen and advance to grand mal convulsions followed by death of the animal. The animal may also show signs of sensitivity to light, incoordination, circling, increased sensitivity to sensory stimuli such as pain or touch, and deterioration of motor capabilities. Less commonly, they may lead to blindness and paralysis. The length of the systemic disease may be as short as 10 days, or the start of neurological signs may not come until several weeks or months later. Those few that survive usually have a small tic or twitch of varying levels of severity. With time, this tic will usually diminish somewhat in its severity.

A dog that survives distemper will continue to have both nonlife-threatening and life-threatening signs throughout its lifespan. The most prevalent nonlife-threatening symptom is hard pad disease. This occurs when a dog experiences the thickening of the skin on the pads of its paws as well as on the end of its nose. Another lasting symptom commonly is enamel hypoplasia. Puppies, especially, will have damage to the enamel of teeth that are not completely formed or those that have not yet grown through the gums. This is a result of the virus's killing the cells responsible for manufacturing the tooth enamel. These affected teeth tend to erode quickly.

Life-threatening signs usually include those due to the degeneration of the nervous system. Dogs that have been infected with distemper tend to suffer a progressive deterioration of mental abilities and motor skills. With time, the dog can acquire more severe seizures, paralysis, reduction in sight and incoordination. These dogs are usually humanely euthanized because of the immense pain and suffering they face.

About 80% of infected dogs with H3N8 show symptoms, usually mild (the other 20% have subclinical infections), and the fatality rate for Greyhounds in early outbreaks was 5 to 8%, although the overall fatality rate in the general pet and shelter population is probably less than 1%. Symptoms of the mild form include a cough that lasts for 10 to 30 days and possibly a greenish nasal discharge. Dogs with the more severe form may have a high fever and pneumonia. Pneumonia in these dogs is not caused by the influenza virus, but by secondary bacterial infections. The fatality rate of dogs that develop pneumonia secondary to canine influenza can reach 50% if not given proper treatment. Necropsies in dogs that die from the disease have revealed severe hemorrhagic pneumonia and evidence of vasculitis.

Canine influenza (dog flu) is influenza occurring in canine animals. Canine influenza is caused by varieties of influenzavirus A, such as equine influenza virus H3N8, which in 2004 was discovered to cause disease in dogs. Because of the lack of previous exposure to this virus, dogs have no natural immunity to it. Therefore, the disease is rapidly transmitted between individual dogs. Canine influenza may be endemic in some regional dog populations of the United States. It is a disease with a high morbidity (incidence of symptoms) but a low incidence of death.

A newer form was identified in Asia during the 2000s and has since caused outbreaks in the US as well. It is a mutation of H3N2 that adapted from its avian influenza origins. Vaccines have been developed for both strains.

The incubation period is 5–7 days (with a range of 3–10). Symptoms can include a harsh, dry cough, retching, sneezing, snorting, gagging or vomiting in response to light pressing of the trachea or after excitement or exercise. The presence of a fever varies from case to case.

Rabies is a viral disease that exists in Haiti and throughout the world. It often causes fatal inflammation of the brain in humans and other mammals, such as dogs and mongooses in Haiti. The term "rabies" is derived from a Latin word that means "to rage"; rabid animals sometimes appear to be angry. Early symptoms can include fever and tingling at the site of exposure, followed by one or more of the following symptoms: violent movements, uncontrolled excitement, fear of water, an inability to move parts of the body, confusion, and loss of consciousness. Once symptoms appear, death is nearly always the outcome. The time period between contracting the disease and showing symptoms is usually one to three months; however, this time period can vary from less than a week to more than a year. The time between contraction and the onset of symptoms is dependent on the distance the virus must travel to reach the central nervous system.

Haiti is one of five remaining countries in the Americas where canine rabies is still a problem. It has the highest rate of human rabies deaths in the western hemisphere with an estimated two deaths each week. Only about seven deaths are reported to health authorities each year due to poor surveillance, limitations in diagnostic capacity, and lack of awareness and education about the disease among Haitians.

Although kennel cough is considered to be a multifactorial infection, there are two main forms. The first is more mild and is caused by B. bronchiseptica and canine parainfluenza virus infections, without complications from canine distemper virus (CDV) or canine adenovirus (CAV). This form occurs most regularly in autumn, and can be distinguished by symptoms such as a retching cough and vomiting. The second form has a more complex combination of causative organisms including CDV and CAV. It typically occurs in dogs that have not been vaccinated and it is not seasonal. Symptoms are more severe than the first form, and may include rhinitis, conjunctivitis, and fever in addition to a hacking cough.

Cat flu is the common name for a feline upper respiratory tract disease. While feline upper respiratory disease can be caused by several different pathogens, there are few symptoms that they have in common.

While Avian Flu can also infect cats, Cat flu is generally a misnomer, since it usually does not refer to an infection by an influenza virus. Instead, it is a syndrome, a term referring to the fact that patients display a number of symptoms that can be caused by one or more of the following infectious agents (pathogens):

1. Feline herpes virus causing feline viral rhinotracheitis (cat common cold, this is the disease that is closely similar to cat flu)

2. Feline calicivirus—(cat respiratory disease)

3. "Bordetella bronchiseptica"—(cat kennel cough)

4. "Chlamydophila felis"—(chlamydia)

In South Africa the term cat flu is also used to refer to Canine Parvo Virus. This is misleading, as transmission of the Canine Parvo Virus rarely involves cats.

Globally, 59,000 people die from rabies each year. This is the equivalent of one person dying every nine minutes, with half of the people who die from rabies being under the age of 15. The Pan American Health Organization (PAHO) and the Pan American Center of foot-and-mouth disease (PANAFTOSA) led a mission to eliminate dog-mediated rabies in the American region by 2015. These organizations are cognizant of the regional control of rabies. The PAHO and PANAFTOSA visited Haiti in early December, 2013, and the objectives of the mission were to assess the status of Haiti’s rabies program as delivered by the Haitian Ministry of Agriculture, Natural Resources and Rural Development (MARNDR) and the Ministry of Health (MSPP). The mission was to seek opportunities for collaboration between Haiti, Brazil, and the Centers for Disease Control and Prevention (CDC) in Haiti.

Even in 2017, rabies in Haiti is still identified as a national problem, even with PEP proposed.

The most common symptoms include headache, muscle aches, and fatigue. A rash may occur, but is uncommon. Ehrlichiosis can also blunt the immune system by suppressing production of TNF-alpha, which may lead to opportunistic infections such as candidiasis.

Most of the signs and symptoms of ehrlichiosis can likely be ascribed to the immune dysregulation that it causes. A "toxic shock-like" syndrome is seen in some severe cases of ehrlichiosis. Some cases can present with purpura and in one such case the organisms were present in such overwhelming numbers that in 1991 Dr. Aileen Marty of the AFIP was able to demonstrate the bacteria in human tissues using standard stains, and later proved that the organisms were indeed Ehrlichia using immunoperoxidase stains.

Experiments in mouse models further supports this hypothesis, as mice lacking TNF-alpha I/II receptors are resistant to liver injury caused by ehrlichia infection.

3% of human monocytic ehrlichiosis cases result in death; however, these deaths occur "most commonly in immunosuppressed individuals who develop respiratory distress syndrome, hepatitis, or opportunistic nosocomial infections."

Aleutian disease, also known as mink plasmacytosis, is a disease which causes spontaneous abortion and death in minks and ferrets. It is caused by "Carnivore amdoparvovirus 1" (also known as "Aleution diease virus", ADV), a highly contagious parvovirus in the genus "Amdoparvovirus".

The virus has been found as a natural infection in the "Mustelidae" family within mink, ferrets, otters, polecats, stone and pine martens and within other varying carnivores such as skunks, genets, foxes and raccoons. This is most commonly explained as because they all share resources and habitats.

The acute stage of the disease, occurring most often in the spring and summer, begins one to three weeks after infection and lasts for two to four weeks. Clinical signs include a fever, petechiae, bleeding disorders, vasculitis, lymphadenopathy, discharge from the nose and eyes, and edema of the legs and scrotum. There are no outward signs of the subclinical phase. Clinical signs of the chronic phase include weight loss, pale gums due to anemia, bleeding due to thrombocytopenia, vasculitis, lymphadenopathy, dyspnea, coughing, polyuria, polydipsia, lameness, ophthalmic diseases such as retinal hemorrhage and anterior uveitis, and neurological disease. Dogs that are severely affected can die from this disease.

Although people can get ehrlichiosis, dogs do not transmit the bacteria to humans; rather, ticks pass on the "ehrlichia" organism. Clinical signs of human ehrlichiosis include fever, headache, eye pain, and gastrointestinal upset. It is quite similar to Rocky Mountain spotted fever, but rash is not seen in patients.

A lethal infection in mink, the Aleutian disease virus lies dormant in ferrets until stress or injury allows it to surface. While the parvovirus itself causes little or no harm to the ferret host, the large number of antibodies produced in response to the presence of the virus results in a systemic vasculitis, resulting in eventual renal failure, bone marrow suppression and death.

The symptoms are chronic, progressive weight loss, lethargy, splenomegaly (enlarged spleen), anemia, rear leg weakness, seizures and black tarry stool. Additional symptoms include poor reproduction and/or oral bleeding/gastrointestinal bleeding. Lesions can also be found within the pelt depending on the severity of the disease. This virus can unfortunately reduce fitness of wild mink especially, by disturbing both the productivity within adult females and the overall survivor rates of both juveniles and adults. Likewise, in the mink kits that survive, it infects the alveolar cells and ultimately causes respiratory distress, possibly leading to death.

Once symptoms show themselves, the disease progresses rapidly, usually to death within a few months.

A horse with strangles will typically develop abscesses in the lymph nodes of the head and neck causing coughing fits and difficulty swallowing. Clinical signs include fever up to 106 °F and yellow coloured nasal discharge from both the nose and eyes.

Abscesses may form in other areas of the body, such as the abdomen, lungs and brain. This is considered a chronic form of strangles called "bastard strangles" and can have serious implications if the abscesses rupture. Horses develop this form of strangles when their immune systems are compromised or if the bacteria rapidly invades the body.

Strangles has a 8.1% mortality rate. Mortality is lower in cases without complications than it is in cases of bastard strangles. The disease is very contagious and morbidity is high. Precautions to limit the spread of the illness are necessary and those affected are normally isolated. An isolation period of 4–6 weeks is usually necessary to ensure that the disease is not still incubating before ending the quarantine.

Strangles (equine distemper) is a contagious upper respiratory tract infection of horses and other equines caused by a gram-positive bacterium, "Streptococcus equi". As a result the lymph nodes swell, compressing the pharynx, larynx and trachea and can cause airway obstruction leading to death, hence the name Strangles. Strangles is enzootic in domesticated horses worldwide. The contagious nature of the infection has at times led to limitations on sporting events.

Ehrlichiosis is a tickborne

bacterial infection, caused by bacteria of the family Anaplasmataceae, genera "Ehrlichia" and "Anaplasma". These obligate intracellular bacteria infect and kill white blood cells.

The average reported annual incidence is on the order of 2.3 cases per million people.

This is the least common form of pigeon fever seen in horses. It is characterized by severe limb swelling and cellulitis in one or both hind limbs and can lead to lameness, fever, lethargy and loss of appetite. Antimicrobial and anti-inflammatory treatments are required to prevent further complications such as limb edema, prolonged or recurrent infection, lameness, weakness and weight loss.

External abscesses are the most common form of pigeon fever seen in horses. Abscesses develop on the body, usually in the pectoral region and along the ventral midline of the abdomen. However, abscesses can also develop on other areas of the body such as the prepuce, mammary gland, triceps, limbs and head. The fatality rate for this form infection is very low. The abscess is often drained once it has matured.

Ehrlichiosis (; also known as canine rickettsiosis, canine hemorrhagic fever, canine typhus, tracker dog disease, and tropical canine pancytopenia is a tick-borne disease of dogs usually caused by the organism "Ehrlichia canis". "Ehrlichia canis" is the pathogen of animals. Humans can become infected by "E. canis" and other species after tick exposure. German Shepherd Dogs are thought to be susceptible to a particularly severe form of the disease, other breeds generally have milder clinical signs. Cats can also be infected.

Death rates during outbreaks were usually extremely high, approaching 100% in immunologically naïve populations. The disease was mainly spread by direct contact and by drinking contaminated water, although it could also be transmitted by air.

Initial symptoms include fever, loss of appetite, and nasal and eye discharges. Subsequently, irregular erosions appear in the mouth, the lining of the nose, and the genital tract. Acute diarrhea, preceded by constipation, is also a common feature. Most animals die six to twelve days after the onset of these clinical signs.

Canine leishmaniasis (LEESH-ma-NIGH-ah-sis) is a zoonotic disease (see human leishmaniasis) caused by "Leishmania" parasites transmitted by the bite of an infected phlebotomine sandfly. Canine leishmaniasis was first identified in Europe in 1903, and in 1940, 40% of all dogs in Rome were determined to be positive for leishmaniasis. Traditionally thought of as a disease only found near the Mediterranean basin, 2008 research claims new findings are evidence that canine leishmaniasis is currently expanding in continental climate areas of northwestern Italy, far from the recognized disease-endemic areas along the Mediterranean coasts. Cases of leishmaniasis began appearing in North America in 2000, and, as of 2008, "Leishmania"-positive foxhounds have been reported in 22 U.S. states and two Canadian provinces.

Cutaneous

- Alopecia

- Skin lesions

- Ulcerative or exfoliative dermatitis

Visceral

- Epistaxis (nose bleeds)

- Kidney failure > increased urination and drinking

- Ocular signs

- Progressive loss of weight with decreased appetite

- Swollen lymphnodes

Epizootic catarrhal enteritis (ECE) is a viral disease that first appeared in the northeastern US in 1994, is an inflammation of the mucous membranes in the intestine. The condition manifests itself as severe diarrhea (often of a bright green color), loss of appetite, and severe weight loss. The virus can be passed via fluids and indirectly between humans. Although it was often fatal when first discovered, ECE is less of a threat today.

Coccidiosis is a parasitic disease of the intestinal tract of animals caused by coccidian protozoa. The disease spreads from one animal to another by contact with infected feces or ingestion of infected tissue. Diarrhea, which may become bloody in severe cases, is the primary symptom. Most animals infected with coccidia are asymptomatic, but young or immunocompromised animals may suffer severe symptoms and death.

While coccidia can infect a wide variety of animals, including humans, birds, and livestock, they are usually species-specific. One well-known exception is toxoplasmosis caused by "Toxoplasma gondii".

Humans may first encounter coccidia when they acquire a puppy or kitten that is infected. Other than "T. gondii", the infectious organisms are canine and feline-specific and are not contagious to humans, unlike the zoonotic diseases.

Lymphoma/lymphosarcoma is the most common malignancy in ferrets. Ferret lymphosarcoma occurs in two forms -- "juvenile lymphosarcoma", a fast-growing type that affects ferrets younger than two years, and "adult lymphosarcoma", a slower-growing form that affects ferrets four to seven years old.

In juvenile ferret lymphosarcoma, large, immature lymphocytes (lymphoblasts) rapidly invade the thymus or the organs of the abdominal cavity, particularly the liver and spleen. In adult ferret lymphosarcoma, the lymph nodes in the limbs and abdominal cavity become swollen early on due to invasion by small, mature lymphocytes. Invasion of organs, such as the liver, kidney, lungs, and spleen, occurs later on, and the disease may be far advanced before symptoms are noticeable.

As in humans, ferret lymphosarcoma can be treated surgically, with radiation therapy, chemotherapy or a combination thereof. The long-term prognosis is rarely bright, however, and this treatment is intended to improve quality of life with the disease.