Lecture 7.1: Infectious Diseases (Student) Flashcards
what is the aetiology and pathogenesis of canine brucellosis
contagious diseased caused by the bacteria. any breed/age can be affected by common in mature dogs. affects reproductive system and organs. ZOONOTIC
how is brucellosis transmitted
mucosa and broken skin. via infected fluids
what are the clinical signs of canine brucellosis
lethargy swollen lymph nodes difficulty walking back pain vaginal discharge etc
how do you diagnose canine brucellosis
spinal xray
cytology
serology
how do you treat brucellosis
ATB tests
how do you prevent brucellosis
spay and neuter
what does equine herpes virus cause
abortion 2-12 weeks after infection. if no abortion the foals have viral pneumonitis.
how is equine herpes virus transmitted
contact with aborted fetus, fetal fluids and placenta + also through aerosol secretions from coughing horse
what are the clinical signs of equine herpes virus
can be subclinical in adults. - nasal discharge - incoordination - hind limb weakness - loss of tail tone - lethargy - urine dribbling - head tilt - poor balance - inability to rise.
how do you diagnose equine herpes virus
Diagnosis: nasopharyngeal swab of the horse, blood samples for PCR or virus isolation, or tissue from the aborted fetus for detection of antibody titers.
how do you treat equine herpes virus
Treatment: Supportive care and treatment of the symptoms. NSAIDS used to reduce fever, pain and inflammation. In uncomplicated cases, will recover in a few weeks.
what is the prognosis for equine herpes virus
Prognosis: poor if the horse is recumbent for an extended period of time.
how do you prevent equine herpes virus
Prevention: 2 types of vaccines, controversial. Vaccines might actually reduce the severity and duration of the disease but it will not prevent it. There’s modified live(intra-nasal, faster protection) and killed(IM).
what is bordatella
Bordetella is a very contagious respiratory disease possible in both cats and dogs caused by a bacteria named Bordetella bronchiseptica
The bacteria will cause inflammation of the trachea and bronchi
how is bordatella transmitted
Direct contact (licking, nuzzling) Air (coughing, sneezing) Contaminated fomites (bowls, toys)
what are the mild clinical signs of bordatella
Dry, hacking cough in dogs (owners will often refer to the coughing as a foreigh material stuck in the throat)
Retching
Sneezing
Nasal discharge
what are the severe clinical signs of bordatella
Pneumonia
Fever
Lethargy
Innappetence
what is the treatment for bordatella
No medication px when an animal comes in with bordetella.
rest for 14 days and reevaluation if no improvement.
If productive cough= no anti-tussive px
If non productive cough = anti-tussive can be px
what are the risk factors for bordatella
Risk factors
Shelter animals, rescue centers animals, breeding kennel animals or pet store animals
what are the methods of preventing bordatella
vaccine once a year
what is leishmania
is an intracelluar protozoan parasite that causes the zoonotic disease Leishmaniasis.
how is leishmania spread
Spread through Sand Fly bites, with vertical transmission unlikely but possible.
who is affected by leishmaniasis
Primarily effects dogs, but humans, cats, rodents and horses can also be infected.
Leishmaniasis is a major zoonitic endemic between humans and canines
what is the pathogenesis for leishmaniasis
Predisposing factors: Age, genetics, nutrition and general immune status
Incubation period: Months to years
Parasite travels from the skin throughout the host’s body
Cutaneous and/or visceral lesions:
Skin, kidneys, spleen, liver, eyes, joints
Granulomatous inflammation
Mediated by CD4 T lymphocytes
what are the symptoms of leishmaniasis
Dermal lesions (nodules, scaling, alopecia, brittle hair coat, may be ulcerative) Lymphadenomegaly Ocular abnormalities Epistaxis Weight loss & anorexia Exercise intolerance/lethargy
what are the methods of diagnosis leishmaniasis
Clinical Signs CBC Biochem Hystology Cytology
how do you treat leishmaniasis
SC injections of Meglumine Antimoniate (4-8 wks)
PO Zyloprim (6-12 months)
Tx may only be temporary and may not eliminate the parasite, leaving the animals carriers for life, with the potential for relapse.
Carriers can be infectious to sand flies, restarting the cycle.
what is erysipelas caused by
Caused by a bacteria called Erysipelothrix rhusiopathiae that is:
Gram-positive
who does erysipelas effect
Affects swine
50% of pigs in production are affected
where is the erysipelas bacteria found
The organism commonly resides in the tonsillar tissue
how is erysipelas transmitted
Organism is shed by carriers in the feces
Oronasal secretions
what are the clinical signs of an acute erysipelas infection
Sudden and unexpected death from septicemia
Painful joints
Skin lesions often described as diamond skin
what are the signs of a chronic erysipelas infection
Tends to follow acute infections
One form is characterized by enlarged joints and lameness
Also has diamond skin disease that can progress to necrosis
how do you diagnose erysipelas
Skin lesions
Skin discoloration and erythema of the ears, snout, and lateral or dorsal regions of the body
Gram stain the tissue sample of affected tissue
Acute more difficult to diagnose
how do you treat/prognosis of erysipelas
Penicillin treatment at 12 hour intervals for a minimum of 3 days
Fever associated with acute infections treated with NSAIDS
Treatment usually ineffective and costly (Poor prognosis)
what is ehrlichia
Ehrlichia is an obligate intracellular bacterium
what is ehrlichia responsible for the transmission of
a group of tick-borne illnesses known as Ehrlichiosis (zoonosis)
describe the ethiology of ehrlichia
Once transmitted, Ehrlichia most commonly infects monocytes.
They are able to guarantee their survival because they possess the capability to reprogram the systems and mechanisms of defense employed by the host cell.
Ehrlichia can cause an acute or chronic infection.
Is zoonotic passed through tick bites, causes similar symptoms as in dogs, but can
be fatal in immune compromised
patients
what are the signs and symptoms of ehrlichia
Fever, Lethargy, Loss of appetite, Weight Loss
abnormal bleeding (e.g., nosebleeds, bleeding under skin – looks like little spots or patches of bruising)
enlarged lymph nodes, enlarged spleen
pain and stiffness (due to arthritis and muscle pain)
Coughing, Discharge from the eyes and/or nose
vomiting and diarrhea
inflammation of the eye
neurological symptoms
(e.g., incoordination,
depression, paralysis, etc.)
how do you diagnose ehrlichia
Blood counts and hematological tests are crucial to the diagnosis of Canine monocytic ehrlichiosis.
Critical signs of ehrlichia infections are:
- Low blood counts
- thrombocytopenia
what is the etiology of distemper
Direct or indirect (fomite), inhalant transmission
Improper attenuated vaccines in rare cases
Most common cause is coming in direct contact with infected animals such as raccoons, foxes and skunks.
what is the pathogenesis of distemper
Initially attacks tonsils and lymph nodes and replicates in those specific tissue for about a week.
Then attacks the Respiratory, urogenital, gastrointestinal & nervous system
who does distemper affect
Dogs Ferrets Wolves Foxes Skunks Racoons
Unvaccinated dogs are more at risk for contracting the disease
what are the clinical signs of the first stage of distemper
Early symptoms include
High fever 39.7°C
Red eyes
Watery discharge from the nose and eyes
Following Symptoms
Lethargic and weak
Usually become anorexic
May have persistent coughing, vomiting and/or diarrhea
what are the clinical signs of the later stages of distemper
The virus attacks the nervous system effecting the brain and spinal cord
May start having fits, seizures, paralysis, and attacks of hysteria
In some strains it can cause abnormal thickening of the pads of feet AKA Hard Pad Disease
Secondary bacterial infection may increase the animals vulnerablity to the disease
what is the prognosis for distemper
No cure
Recovery is possible but seizures and other severe changes to the CNS may be fatal 2-3 months after recovery
Chance of survival depends on the strain and the dogs immune system
Young unvaccinated puppies and non-immunized older dogs are more susceptible.
how do you diagnose distemper
Biochemical tests
Urinalysis
Low lymphocytes
Serology test : won’t be able to differentiate between vaccinated antibodies or exposure to virus
Viral antigens may be detected in urine sediment or vaginal imprints
Skin with hair, nasal mucous and foot pad epithelium may be tested for antibodies
CT and MRI can be used to examine the brain to view any lesions that may have developed
how do you treat distemper
Supportive treatment
Iv fluids
Antibiotics to control secondary bacterial infection
Phenobarbital and potassium bromide to control convulsions
and seizures
No antiviral drugs that are effective in treating the disease
how do you prevent distemper
Vaccination
Rarely seen in pet dogs because of judicious vaccine protocols
Part of core vaccinations
what is the aetiology and pathogenesis of the avian newcastle disease
RNA virus
Most important virus in poultry
Chickens are most susceptible, waterfowl are least susceptible
what is the epidemiology and transmission of newcastle disease
Endemic in poultry in most of Asia, Africa, and some countries of North/South America
USA and Canada are free of the virulent strains poultry (import restrictions and destruction of infected poultry)
Infected birds shed virus in exhaled air, respiratory discharges, and feces
Shed during incubation, clinical stage
Chickens are often infected by aerosols and ingesting contaminated food and water
Young chickens are most susceptible
what are the clinical signs of newcastle disease
Rapid onset, symptoms appear throughout the flock within 2-12 days (avg 5) after aerosol exposure
Onset is slower if contracted through fecal-oral route
Signs depend on whether the virus has affected the respiratory, digestive, or nervous system
Respiratory: gasping, sneezing, coughing, rales
Nervous: tremors, paralyzed wings and legs, twisted necks, circling, clonic spasms, complete paralysis
GI: diarrhea, inappetence
May see complete or partial cessation of egg production
Mortality is variable but can be as high as 100% with virulent infections
what is the diagnosis and prevention of newcastle disease
Diagnosed through oropharyngeal or cloacal swabs
Vaccine available, but the vaccines do not provide sterile immunity
ZOONOTIC RISK
All strains can produce a transitory conjuctivitis in humans, usually only when exposed to high quantities of the virus (lab workers and vaccination teams)
what is foot and mouth disease
A reportable, zoonotic, highly contagious viral disease (7 strains) of cattle and swine, which also affects sheep, goats, deer, and other cloven-hoofed ruminants. Giraffes and elephants can also be affected.
Mostly found in endemic countries like the Middle East, Africa, Asia, and in parts of South America
The disease is characterized by fever and vesicles in the mouth and on the muzzle, teats, and feet
It can be spread by direct (milk, semen, secretions) and indirect contact (people, air current)
what is the pathogenicity of foot and mouth disease
In endemic countries, there is 100% morbidity with low mortality, except in the case of young animals
The primary site of infection is in the mucosa of the pharynx, the virus then goes through the lymphatics and replicates in the mouth, muzzle, feet, teats, and damaged skin.
Animals that are infected and vaccinated can still carry the disease (cattle up to 3.5 years)
what are the symptoms and treatment of foot and mouth disease
Lameness, pyrexia, vesicles in mouth cavity and feet, decreased milk production, frothing of mouth, teat blisters, and decreased appetite
There is no treatment, only supportive care
Ill animals can recover, however they are usually culled, as so the ones who are susceptible. They must be incinerated.
how do you prevent foot and mouth disease
Export restrictions can be instilled to reduce risk of infection in endemic countries
A full quarantine must be implemented
Full disinfection of infected areas must be performed immediately
Infected milk can be disinfected by boiling for 20 minutes
Vaccination may be provided, however must closely match the strain of the virus, as there is no universal vaccine.
The inactivated vx only protects for 4-6 months against clinical signs only
what is helicobacter
Affects cats and dogs
Found in gastric tissues and intestinal tract
Transmission is unknown, reservoirs unknown
Concern of zoonotic transmission
what are the clinical signs of helicobacter
100% of healthy cats and dogs are positive.
Infection reported in vomiting cats and dogs
Signs: Gastritis, vomiting and diarrhea
No direct relationship between symptoms and infection has been identified
how do you diagnose helicobacter
Upper GI endoscopy ( taking brush samples) or laparotomy
Brush samples: Can cover large area of the stomach therefore high sensitivity. Sample viewed under 100x magnification.
Multiple biopsies must be taken in the stomach and stained with H&E stain to identify organism.
Cytology and histopathology cannot identify specific species but high sensitivity and specificity for Helicobacter.
how do you treat helicobacter
Very little knowledge of pathogenicity
Treatment will be based off the presence of species and clinical signs.
Some animals don’t experience long term eradication of infection
