Infectious Disease Flashcards
1
Q
What breeds (dog and cat) are predisposed to Mycobacterium avium?
A
- Bassetts
2. Siamese
2
Q
Where does the life cycle of Pneumocystis carinii occur?
A
The entire life cycle occurs within the alveolar spaces (trophozoites and cysts)
3
Q
Clinical disease with Pneumocystis carinii occurs in what scenarios?
A
- Immunosuppression
- Crowding
- Distemper patients
4
Q
What is the pathophysiology behind Pneumocystis carinii?
A
- Inhaled but rarely multiply in IMMUNOCOMPETENT host
- If IMMUNOSUPPRESSED → Multiply → alveolocapillary blockage and decreased gas exchange → thickened alveolar septa
* Organisms rarely invade the parenchyma and are rarely found in alveolar macrophages
5
Q
Which breeds are predisposed to Pneumocystis carinii?
A
- Mini (long-haired red) daschunds <1 year → can have a common variable immunodeficiency → absence of B cell + dysfunctional T cells
- Cavalier King Charles
6
Q
How is Pneumocystis carinii definitely diagnosed?
A
- Lung biopsy or BAL
* Low globulins may also be present on bloodwork if common variable immunodeficiency is present
7
Q
How is Pneumocystis carinii treated?
A
TMS
- more effective and less toxic than pentamidine
AZOLES ARE NOT EFFECTIVE
8
Q
If a patient is diagnosed with Pneumocystis carinii what else should you look for?
A
Immunodysfunction
9
Q
Where are pythium and lagenidium located geographically?
A
SE US
10
Q
What is the infective form of pythiosis?
A
Motile biflagellate zoospore
*Encysts in damaged skin or GI mucosa
11
Q
Pythiosis affects which layers of the GI tract?
A
Submucosal or muscular
12
Q
How are oomycetes different from true fungi?
A
- Pythiosis and Lagenidiosis
1. Produce motile, flagellate zoospores
2. Have cell walls that lack chitin
3. Cell membranes LACK ergosterol
13
Q
What segments of the GI tract are most commonly affected by pythium?
A
- Gastric outflow region
- Proximal duodenum
- Iliocecocolic junction
14
Q
Cytology and histopathology of pythium and lagenidium often reveal what kind of inflammation?
A
Eosinophilic and pyogranulomatous inflammation
15
Q
What are the best diagnostic tools for pythium?
A
- ELISA for serum antibodies → indicates active infection, high Sens and spec
- Can be used to monitor response to treatment - Culture → most successful from biopsy specimen
16
Q
How can response to treatment be monitored in pythium patients?
A
ELISA for serum antibodies
17
Q
What are the most common clinical signs associated with lagenidium?
A
Progressive cutaneous and subcutaneous lesions → typically ulcerated and edematous
18
Q
(Pythium/Lagenidium) can cause rupture of the great vessels
A
Lagenidium
19
Q
Serology for lagenidium will cross react with which other disease process?
A
Pythium
20
Q
(Pythium/Lagenidium/Both) can be observed with a GMS stain
A
Both
21
Q
(Pythium/Lagenidium/Both) can be observed on an H&E stain
A
Lagenidium
22
Q
What is the preferred treatments for lagenidium and pythium?
A
- Aggressive surgical resection
2. Itraconazole and terbinafine post-op to help prevent recurrence
23
Q
In pythiosis, complete resection should result in what % drop in ELISA?
A
50% in 3 months
24
Q
Salmonella: Gram (+/-)
A
Gram -
25
What % of dogs with salmonella are asymptomatic carriers? Cats?
1. 30%
| 2. 18%
26
When does clinically significant disease with salmonella occur?
Young, parasitized, immunocompromised animals
27
What are the possible outcomes after salmonella infection?
1. Asymptomatic carriage
2. Gastroenteritis
3. Bacteremia/Septicemia
28
When should salmonella infections be treated?
When clinical signs appear. Should not be treated if healthy.
29
What is a good starting choice for antibiotics for salmonella?
Fluoroquinolones
30
What is the most globally widespread zoonotic disease?
Leptospirosis
31
What is the most prominent leptospirosis serovar in the US today?
1. Grippotyphosa
| - Icterohemorrhagic and canicola were most prominent prior to 1960
32
Where are the following leptospirosis serovars located geographically?
1. Grippotyphosa
2. Pomona
1. East of the Mississippi
| 2. Northeast
33
Which leptospirosis serovars commonly cause
1. Liver signs
2. Renal failure
1. Icterohemorrhagica and grippotyphosa
| 2. Grippotyphosa and pomona
34
What is the most common means of leptospirosis spread?
Water contact
35
What is the maintenance host for leptospirosis?
Burrowing rodents
36
Which dog breed is at higher risk for leptospirosis?
German shepherd
37
Acute renal failure is recognized in what % of leptospirosis cases?
90%
38
How does leptospirosis cause acute renal failure?
Acute decrease in GFR due to swelling that impairs renal perfusion
39
Concurrent hepatic failure along with acute renal failure is observed in what % of leptospirosis cases?
10-20%
40
Why might PU/PD in the absence of azotemia occur in a dog with leptospirosis
Nephrogenic diabetes insipidus secondary to lepto antigen
41
When do vaccinal titers for leptospirosis start to wane?
3-4 months after vaccination
42
As antibody concentrations increase, leptospirosis is cleared from most tissues except ____
Kidneys
| *This is why the host can shed from kidneys for months to years after clinical recovery
43
What is the most common test for leptospirosis antibodies?
Microscopic agglutination test
44
MAT titers of ___ are supportive of a leptospirosis diagnosis but _____ is preferred.
1. 1:800
| 2. Fourfold rise in titer over a 2-4 week interval
45
Which immunoglobulin increases first in leptospirosis infection?
IgM → rises in the first week (before MAT titers) and peaks in 14 days
- IgG becomes positive in 2-3 weeks after infection and peaks at 1 month
46
A single IgG/IgM test is suitable to distinguish between natural vs vaccine for leptospirosis because vaccinated dogs should have high ____ and low ___
1. IgG
| 2. IgM
47
Which can identify the infective serovar for leptospirosis - MAT or PCR?
MAT
48
PCR for leptospirosis is (sensitive/specific) so you should only trust the (positive/negatives)
1. Specific
| 2. Positives
49
Which antibiotic should be used to treat ill leptospirosis patients?
Ampicillin
| *Eliminates the leptospiremic phase but does NOT eliminate the organism from the renal tubules
50
Once patients with leptospirosis are taking oral drugs or have recovered from ARF - which antibiotic should be used?
1. Streptomycin - eliminate the leptospiruric phase
OR
2. Doxycycline - eliminates both the leptospiremic and leptospiruric phases
51
When should ciprofloxacin be used in the treatment of leptospirosis? Why?
1. When meningitis or uveitis is observed
| 2. It crosses the blood brain barrier
52
What are negative prognostic factors for leptospirosis?
1. German shepherd
| 2. Pomona serovar
53
What is the prognosis for leptospirosis?
50-80% survival
54
True/False: Giardia is zoonotic
True
55
How does giardia infect the host?
Ingested oocytes excyst in the upper SI and trophozoites attach to the intestinal mucosa from the duodenum to the ileum
56
Most giardia infections are (clinical/non-clinical)
Non-clinical
57
What are the options for diagnosing giardia?
1. Trophozoites in duodenal juice or fresh fecal smear
2. Oocysts on ZINC SULFATE float → shedding is intermittent
3. Giardia antigen by fecal ELISA
58
How is giardia treated?
1. Metronidazole for 5 days
| 2. Albendazole or Fenbendazole are also options (fenbendazole preferred because albendazole can cause BM suppression)
59
What compounds can help clean the environment of giardia?
1. Steam
| 2. Quaternary ammonium compounds
60
Actinomyces vs Nocardia:
| - Partial acid fast staining
Nocardia
61
Actinomyces vs Nocardia
| - Hard to culture
Actinomyces
| - Nocardia is easy to culture
62
Actinomyces vs Nocardia:
| - Long filamentous in DENSE mats
Actinomyces
| - Nocardia is in LOOSE mats or individual
63
Actinomyces vs Nocardia:
| - Present in adult hunting dogs
Actinomyces
64
Actinomyces vs Nocardia:
| - Present in young dogs (<2 years)
Nocardia
65
Actinomyces vs Nocardia:
| - Spread directly (typically plant foreign bodies)
Actinomyces
66
Actinomyces vs Nocardia:
| - Spread hematogenously
Nocardia
67
Actinomyces vs Nocardia:
| - High mortality
Nocardia
68
Actinomyces vs Nocardia
| - Sulfur granules present
Actinomyces
| - Sulfur granules variable for nocardia
69
Actinomyces vs Nocardia:
| - Treat with penicillin
Actinomyces
| - Nocardia has variable susceptibility to sulfonamides, tetracyclines, or aminoglycosides
70
Aflotoxicosis is caused by ___. Which is generated by metabolism by ____ and then conjugated with ____ by ____.
1. 8,9 epoxide
2. Cytochrome p450 enzymes
3. Glutathione
4. Phase II enzymes
71
8,9 epoxide is (highly/minimally) lipophilic and is absorbed completely in the duodenum
1. Highly
72
What is the mechanism of pathogenesis for 8,9 epoxide?
1. Binds to other molecules in the cell leading to DNA adducts.
2. Causes renal tubular and hepatic necrosis
73
What is another possible differential for aflotoxicosis?
Leptospirosis
74
What are the consequences of aflotoxicosis for patients that survive?
Fibrosis
75
How is aflotoxicosis treated?
1. Various liver protectants
| 2. Oltipraz → inhibits phase I enzymes (CYP1A2) and induces phase I enzymes including glutathione
76
What is the causative agent of feline infectious peritonitis?
Feline corona virus → enveloped ssRNA virus
77
The majority of cats infected with feline corona virus (will/will not) develop FIP
Will not
| - Only 1/10 will develop FIP
78
How soon is feline coronavirus shed in feces following infection?
2 days
79
When do most cats clear feline coronavirus infections?
After 2-3 months of fecal shedding
80
The following may associated with what disease process?
1. Rising FeCoV titers
2. Polyclonal gammopathy
3. a1-acid glycoprotein
Feline infectious peritonitis
81
How is FIP definitively diagnosed?
IHC to demonstrate presence of FCoV virus in lesions (pyogranuloma, area of vasculitis)
82
Leptospirosis PCR has (high/low) Sens and spec?
Sens: Low
Spec: High
83
Feline infectious peritonitis: Effusive vs Non-effusive forms
1. Antibody mediated immunity vs Cell mediated immunity
2. Immune reaction type
Effusive: Strong AMI, Weak CMI, Type III
| Non-Effuse: Strong AMI, Adequate CMI, Type IV
84
FIP ascites is caused by what?
Infected monocytes producing VEGF
85
What is antibody enhanced disease in the context of FIP?
If a FCoV + cat is vaccinated, it is more likely to have the effusive form of the disease and die from the disease - does not make a difference in a FCoV - cat
86
What is the gold standard for FCoV testing?
IFAT
87
What precautions should be taken if a cat has FCoV antibodies?
DO NOT STRESS THEM
88
How is pythium infection acquired?
Skin inoculation
89
Cryptosporidium vs Giardia
| Site of infection: Primarily jejunum
Cryptosporidium
90
Cryptosporidium vs Giardia
| Site of infection: Primarily small intestine
Giardia
91
Cryptosporidium vs Giardia
| Trophozoites attach to brush border of GI epithelium
Giardia
92
Cryptosporidium vs Giardia
| Type II merozoites attach to GI epithelium
Cryptosporidium
93
Cryptosporidium vs Giardia
| Very small, require oil immersion microscopy for diagnosis
Cryptosporidium
94
What is required for 95% sensitivity in testing for giardia on zinc sulfate floats?
Need to perform at least 3 floats
95
What is the preferred method of giardia diagnosis?
Fecal ELISA - detects antigen
96
Cryptosporidium vs Giardia
| Treated with paromyocin or nitazoxanide
Cryptosporidium
97
Cryptosporidium vs Giardia
| Treated with metronidazole or fenbendazole
Giardia
98
Cryptosporidium vs Giardia
| Oocysts can survive in the environment for months
Cryptosporidium
99
Cryptosporidium vs Giardia
| Can be removed from the environment with quaternary ammonium compounds
Giardia
100
Cryptosporidium vs Giardia
| Which is enteroinvasive?
NEITHER!
| - They are found on the surface of the enterocytes and pathogenesis is not likely due to direct cellular damage.
101
Cryptococcus can be identified by which stain?
India ink stain
102
What test is preferred for cryptococcus diagnosis? What does it detect?
Latex agglutination test → detects capsular antigen
| - Antibody titers are not useful due to the thick capsule keeping the body from producing a strong humoral response
103
What are sequelae that may result from canine distemper virus infection?
1. Hyperkeratosis → paw pads and nasal planum
2. Acute encephalomyelitis → occurs not long after infection
3. Chronic distemper encephalitis → neurologic signs in older dogs that do not have a history of distemper infection
4. Thymic atrophy → post-mortem finding in puppies
104
Where is canine distemper virus antigen found in dogs with hyperkeratosis?
Stratum spinosum and stratum granulosum
105
What should be ruled out before a diagnosis of distemper can be made in dogs with hyperkeratosis?
1. Familial footpad keratosis → Irish terriers and Dogue de Bourdeaux
2. Zinc responsive dermatitis → Huskies and Alaskan malamute
106
Dogs with chronic distemper encephalitis are (infectious/non-infectious)
Non-infectious
107
What is a post-mortem finding that can be found in puppies that had distemper virus?
Thymic atrophy
108
What is the organism?
1. Zoonotic
2. Found in 50% of puppies and 100% of kennels
3. Causes voluminous watery diarrhea
4. Zinc sulfate float often needed for diagnosis
5. Treated with metronidazole
Giardia
109
What is the organism?
1. Causes yellow, watery diarrhea
2. Difficult to diagnose
3. Zoonotic: Kills ~10% of AIDS patients
4. Treatment is primarily supportive therapy
Cryptosporidium sp.
110
What is the organism?
1. Occasional cause of diarrhea and death via colitis/enteritis
2. Treatment is TMS and supportive care (albon also approved)
Coccidiosis
111
Toxoplasma gondii is excreted in the feces as a (sporulated/unsporulated) oocyst
Unsporulated
112
How long does it take for unsporulated Toxoplasma oocysts to sporulate?
Sporulated in 1-5 days but can survive in the environment for over 1 year
113
```
Toxoplasma gondii
(Tachyzoites/Bradyzoites) replicate in intestinal walls
```
Tachyzoites
114
Toxoplasma gondii
| (Tachyzoites/Bradyzoites) encyst in tissue
Bradyzoites
| *Will encyst in tissue for the life of the host
115
Toxoplasma gondii
(Tachyzoites/Bradyzoites) can be the cause of reactivated infection such as after immunosuppression or can be a cause of chronic uveitis in cats
Bradyzoites
116
What is a unique feature for cats in the context of toxoplasma gondii?
They are the only species that can complete the life cycle and pass RESISTANT oocytes in feces
117
What is a consequence of immunocomprised cats being infected with toxoplasma gondii?
1. They can have FATAL DISSEMINATION and intracellular replication of tachyzoites
2. They can have transmammary infection as well
118
What tissues are most commonly affected in cats with disseminated toxoplasma gondii?
1. Hepatic
2. Pulmonary
3. CNS
4. Pancreatic
119
How does toxoplasma gondii infection occur?
1. Ingestion of sporozoites, tachyzoites, or bradyzoites in most warm blooded vertebrates
2. Transplacental is possible in most species → tachyzoites to fetus
3. Transmammary is possible in cats
120
Which cats develop the worst clinical signs from toxoplasma gondii?
Kittens that were infected transplacentally or transmammary
| - Generally die of hepatic disease or pulmonary disease
121
What is one of the most common causes of feline infectious uveitis?
Toxoplasma gondii
122
Toxoplasma gondii is (commonly/rarely) associated with clinical disease in the dog
Rarely
123
What is the duration that most cats and dogs will be Ab + with toxoplasma gondii infection?
For life → no point in repeated serum Ab titers after disease manifestations have resolved
124
Toxoplasma gondii
| 90% of cats with clinical toxoplasmosis have an elevated ___
IgM
| - Greater than 1:64 is positive
125
Toxoplasma gondii: IgG vs IgM
| ___ has a higher predictive value than ___
1. IgM
| 2. IgG
126
Toxoplasma gondii:
| Serology for IgM is indicative of what kind of infection?
Either early infection or recurrent infection
| - Detectable 2-4 weeks after infection and resolves in 16 weeks
127
Toxoplasma gondii
| Serology for IgG is indicative of what?
Indicates past exposure to toxoplasma
128
What % of cats with clinical toxoplasmosis will have an increased IgG
60%
129
Toxoplasma gondii is now correlated to what human diseases?
1. Schizophrenia
| 2. Learning disabilities
130
What precautions should be taken by households with pregnant women and cats?
1. Clean the litter box every 24 hours → will not allow toxoplasma gondii oocysts time to sporulate
131
When do cats shed toxoplasma gondii oocysts?
Days to weeks following their PRIMARY INFECTION → repeat shedding rarely occurs even if the cat relapses with immunosuppression
132
Most seropositive cats with toxoplasmosis (are/are not) shedding oocysts
Are not
| - Those shedding oocysts are usually not seropositive yet
133
What is the treatment for toxoplasmosis?
Clindamycin or TMS
| - Will not totally clear the body of the organism → recurrent disease is common
134
What is the definitive host of neospora?
The dog
135
What are the intermediate hosts for neospora?
1. Cow
2. Dog
3. Sheep
4. Goat
5. Horse
136
How is neospora transmitted?
1. Aborted fetus/placenta/raw meat ingested from intermediate host
2. Encystment in muscle and shedding of oocysts in feces
3. Intermediate host ingests feces
* Dogs and cows can also do transplacental or transmammary
137
What are the clinical signs of neospora in:
1. Puppies <6 mo
2. Dogs >6 mo
1. Ascending LMN paralysis
| 2. LMN flaccid paralysis with meningitis, encephalomyelitis, and cerellaritis
138
What is the definitive diagnostic tool for neospora? What are other options?
1. ID of tissue cysts is definitive
| 2. Serology best, fecal unrewarding
139
What is the treatment for neospora?
Clindamycin for 4-6 weeks
140
What is the organism?
1. Found in almost all puppies
2. Zoonotic - visceral larval migrans
3. Treated with Fenbendazole
Toxocara canis
141
How is toxocara canis treated?
Fenbendazole
142
What is the organism?
1. Causes cerebrospinal nematodiasis
2. Affects dogs
Baylisascaris
143
What is the organism?
1. Zoonotic - creeping eruption cutaneous larval migrans
2. Clinical effects due to blood loss (anemia, melena)
3. Treated with fenbendazole
Hookworms
| Ancylostoma, Uncinaria spp
144
How are hookworms (ancylostoma, uncinaria) treated?
Fenbendazole
145
What is the organism?
1. Difficult to diagnose due to few eggs and intermittent shedding
2. Bloody diarrhea, tenesmus
3. Diagnose based on response to treatment
4. Treated with fenbendazole
Whipworms
| Trichuris vulpis
146
How are whipworms (trichuris vulpis) treated?
Fenbendazole
147
Where do dirofilaria immitis live in teh body?
Right ventricle and pulmonary arteries
148
Which rickettsial organism is part of the disease process for dirofilaria immitis?
Wolbachia
149
How are dipylidium spp transmitted? Are they zoonotic?
1. Flea ingestion
| 2. yes
150
How are dipylidium spp treated?
Tapeworms
| Droncit (praziquantel)
151
How are Taenia spp treated?
Tapeworms
| Droncit (praziquantel)
152
Are Taenia spp zoonotic?
Yes
153
What are the results of intermediate host and definitive host infection of Taenia spp. in humans?
IH: Neural cystocercosis can lead to epilepsy
DH: Intestinal tapeworm from uncooked pork
154
What does the larval form of echinococcus granulosus cause?
Hydatid cysts in the brain, anaphylaxis
155
Which is more severe Echinococcus granulosos or Echinococcus multilocularis infection?
Multilocularis
156
What is Echinococcus multilocularis infection often thought to be?
Metastatic cancer → can cause multiloculated, thin walled, invasive cysts
157
What is the treatment for echinococcus spp?
Droncit (praziquantel)
158
How is rabies definitively diagnosed?
Direct immunoflourescence in brain tissue
159
What kind of virus is rabies?
Single stranded RNA lyssavirus
160
E. coli: Gram (+/-)
-
161
E. coli: anaerobic or aerobic
Facultative anaerobe
162
Salmonella: anaerobic or aerobic
Facultative anaerobe
163
What are the pathogenic forms of E. coli?
1. ETEC → adheres and produces toxins (but doesn't invade)
2. EIEC → invades, replicates, and destroys epithelial cells
3. EPEC → (not invasive or toxigenic) but attach and efface the brush border of enterocytes
4. EHEC → produces verocytdtoxins that induce hemorrhagic ileitis and colitis
5. EAEC → induce enterocyte pathology
164
Is salmonella enteroinvasive?
Yes
165
Where does rotavirus infect?
The villous tip in the intestine and causes sloughing and villous atrophy
166
Giardia, Crypto, Toxo: Large or small bowel diarrhea
Small
167
E. histolitica, T. foutus: Large or small bowel diarrhea
Large
168
What kind of virus is feline panleukopenia virus?
Small NONENVELOPED single stranded DNA virus
169
Feline panleukopenia is characterized by ___ and ___ with a (high/low) mortality
1. Enteritis and panleukopenia
| 2. High
170
Feline panleukopenia virus has an affinity for what kind of cell?
Rapidly dividing (lymphoid, bone marrow, and crypt epithelium)
171
Feline panleukopenia is more sever in what kind of cat?
Young kittens
172
Feline panleukopenia virus - what is the consequence of infection at the following points in pregnancy?
1. Early
2. Middle 3rd to immediately post-natally
1. Fetal death and resorption
| 2. Cerebellar hypoplasia
173
What has a good sensitivity for feline panleukopenia virus diagnosis?
Fecal viral DNA PCR
| *Antibody titers may be useful to aid diagnosis
174
What kind of lesions are seen on necropsy for feline panleukopenia virus?
Intranuclear inclusions in crypt epithelium
175
What is the prognosis for feline panleukopenia virus?
50-90% mortality
176
Why should modified live vaccines for feline panleukopenia virus not be used in pregnant queens or kittens <4 weeks old?
Risk of cerebellar hypoplasia
177
Feline panleukopenia virus environmental cleaning methods
* Very stable in the environment
| - Need bleach or glutaraldehyde
178
In utero or neonatal feline panleukopenia virus may result in what type of state?
Carrier state - but carriers play a minor role in spreading the disease
179
What kind of virus is feline herpesvirus
Double stranded DNA, ENVELOPED
180
What is the disease course for feline herpesvirus?
Initial infection is respiratory → recrudescent infections usually ocular/conjunctival
181
Where does the typical α herpes virus replicate? Where does it establish a latent infection?
1. Replicates in epithelial tissue during infection
| 2. Establishes latency in the trigeminal ganglia
182
During stress, how does feline herpesvirus spread?
Down sensory axon
183
What kind of keratitis occurs with feline herpesvirus?
STROMAL keratitis → CD4 inflammatory response to virus
184
What is the best form of PCR for feline herpesvirus? Why?
Tissue (Conjunctival/oral swabs) → serum is bad because the majority of cats have been exposed
185
What does PCR for feline herpesvirus detect?
A short sequence in the thymidine kinase gene of the virus
186
What is the effect of L-lysine for feline herpesvirus?
Inhibits replication by competitively inhibiting the incorporation of arginine into the virus
187
What can be used for treatment of acute feline herpesvirus infections?
Topical antibiotics used for Chlamydia psittici (tetracycline, chloramphenicol, or erythromycin)
*Systemic abx should not be used unless resp infection noted
188
What is produced by feline herpesvirus vaccination (humoral vs CM)? What is the result of vaccination?
1. Produces a humoral response to feline herpesvirus.
| 2. Will lessen the SEVERITY of the disease
189
What is the mechanism of imiquamod for treatment of feline herpesvirus?
Activation of TLR7
190
What is the incubation period for feline calicivirus?
2-10 days
191
What are the clinical signs associated with feline calicivirus?
1. Ocular discharge
2. Nasal discharge
3. Oral ulceration
4. Conjunctivitis
* May also have lameness from polyarthritis
192
What is the most reliable diagnostic method for feline calicivirus?
Virus isolation from nasal, conjunctiva, or oral swabs
| - >90% sensitivity in virulent systemic disease cases
193
What is feline calicivirus associated virulent systemic disease?
A more severe/hemorrhagic form of feline calicivirus
194
Are adults or kittens at higher risk of more severe feline calicivirus infection?
Adults
195
What pathologic finding is seen with feline calicvirius virulent systemic disease?
Centrilobular hepatocellular necrosis
196
How is feline calicivirus inactivated?
Bleach
| - NOT inactivated by chlorhex or quaternary ammonium compounds
197
Cutaneous horns can be seen with what diseases?
1. FeLV
2. SCC
3. Viral papillomas
- 8% of Bowen's cases (SCC in situ) are feline papilloma virus +
198
Is feline orthopox virus (feline cowpox) zoonotic?
Yes
199
How does infection of feline orthopox virus occur
Ingestion of rodents (reservoir host)
200
What is the primary lesion in feline orthopox virus?
Dermatologic lesions (ulcerating macule or plaque)
201
What kind of virus is canine parvovirus/panleukopenia virus (CPV-2)
Small ENVELOPED single strand DNA virus
202
Canine parvovirus/panleukopenia virus (CPV-2) has an affinity for what kind of cell?
Rapidly dividing cells → results in apoptotic cell death
203
CPV-1 is only pathogenic in what kind of dog?
Neonates
| - Can be isolated from healthy dogs
204
What is important about dogs <6 weeks of age in context of canine parvovirus/panleukopenia virus (CPV-2)
They are protected by maternal Abs
205
Which dogs are most at risk for canine parvovirus/panleukopenia virus (CPV-2) infection
1. >6 mo MALES are more often affected
2. More severe in black/tan dogs (Rotts, Dobs)
3. More severe in Pitts and English Springer Spaniels
206
What occurs 4-7 days after canine parvovirus/panleukopenia virus (CPV-2) infection?
Severe diarrhea
207
What is a possible sequelae to the severe diarrhea caused by canine parvovirus/panleukopenia virus (CPV-2) infection?
Intussusception → due to hypermotility
208
When does myocarditis occur with canine parvovirus/panleukopenia virus (CPV-2) infection?
If infected in utero or shortly after birth if maternal Ab is absent
209
How is canine parvovirus/panleukopenia virus (CPV-2) diagnosed?
Fecal ELISA (for viral antigen) is most sensitive in first 7-10 days
210
What is a common biochemical findings with canine parvovirus/panleukopenia virus (CPV-2)
Leukopenia in 85% of cases
| - Neutropenia due to consumption in GI tract plus destruction of progenitor cells
211
What are canine intracytoplasmic inclusion bodies diagnostic for?
Distemper
| *Intracytoplasmic EOSINOPHILIC inclusions (negri bodies) have been reported in rabies as well
212
What are canine intranuclear inclusion bodies diagnostic for?
1. Distemper
| 2. Rabies
213
What are feline intracytoplasmic inclusion bodies diagnostic for?
1. Chlamydia felis
| 2. Feline cowpox
214
What are feline intranuclear inclusion bodies diagnostic for?
1. Feline panleukopenia
| 2. Feline herpesvirus
215
What is the most common disease syndrome in chronic FIV cats? What % have this disease syndrome?
Chronic stomatitis - 50%
216
Which is more pathogenic FeLV or FIV?
FeLV
217
What are the important antigens in FeLV infections? Why?
1. p27 → in plasma of infected cats → this is what IFA and ELISA test for
2. Envelope (env) → gp70 → most important for inducing immunity → vaccines are made with this
3. p15E (envelope) → causes immunosuppression
218
FeLV or FIV?
- Macrocytic normochromic anemia
- Erythroid and granulocyte hypoplasia
FeLV
219
FeLV or FIV
| - Erythroid and granulocyte hyperplasia
FIV
220
What is the effect on CD4+ T cells in FeLV and FIV?
They are decreased
221
What are the potential outcomes before BM involvement in cats infected with FeLV?
1. Immune response eliminates the virus
2. Virus may be sequestered in a latent form
3. Persistent viremia
222
How is FeLV transmitted?
Close intimate contact → licking, biting, and transplacental/transmammary
223
How is FIV transmitted?
Fighting
224
FeLV or FIV
| - Diagnostics directed toward antigen?
FeLV
225
FeLV or FIV
| - Diagnostics directed toward antibody
FIV
226
What is the primary diagnostic for FeLV infection? What is it testing for? What is the confirmatory test? What does it detect?
1. ELISA
2. p27/p30 in plasma
3. IFA
4. Detection of p27 in neutrophils and platelets
227
What are the issues with diagnostic testing for FIV?
- FIV Ag in the blood is too low to be detected → must rely on Ab testing
- ELISA has a risk of false + → must confirm with western blot or IFA
228
What is the additional risk of LSA in cats diagnosed with FeLV? FIV?
1. 62 x more likely → usually get T cell
| 2. 5 x more likely → usually get B cell
229
Can you differentiate between vaccinated and infected cats with FeLV?
1. Yes, test is for Ag so it can differentiated
230
What are the recommended management strategies for cats with FeLV? FIV?
1. Keep cats indoors and separate positive vs negative cats
| 2. Keep cats indoors but no need to separate
231
What % of FeLV cats are infected with the following and what is associated with each?
1. FeLV-A
2. FeLV-B
3. FeLV-C
1. All FeLV infected cats → Immunosuppression
2. 50% of FeLV infected cats → Neoplastic disease is more common than in cats with FeLV-A alone
3. 1% → Severe anemia
232
What is the most common cause of thrombocytopenia and neutropenia in cats?
FeLV infection
233
What does a macrocytic anemia in the absence of polychromasia strongly indicate in cats?
Strong predictor of FeLV infection
234
Tick paralysis is a (infectious/non-infectious) disease process that is associated with ____ tick species?
1. Non-infectious
| 2. Dermacentor
235
What is the vector for Ehrlichia canis?
Rhipicephalus sanguineus
236
What life stage does Rhipicephalus acquire ehrlichia and what life stage does it transmit ehrlichia to the dog?
1. Feeding on an infected dog in either the larva or nymph form
2. Transmits either in the nymph or adult form
237
What is the incubating period of Ehrlichia canis?
8-20 days
238
How long is the acute phase of infection in Ehrlichia canis? What is happening during this phase?
1. 2-4 weeks
2. The organism is multiplying within circulating mononuclear cells → cells are phagocytized in the liver, spleen, and lymph nodes
239
Where do cells infected with Ehrlichia canis adhere? What does this cause?
1. Adhere to the vascular endothelium and induce a vasculitis and subendothelial tissue infection
2. Leads to platelet consumption, sequestration, and destruction → seen as a thrombocytopenia during the acute phase of infection
240
What is the most consistent hematologic abnormality seen in both the acute and chronic phases of any ehrlichiosis?
Thrombocytopenia
241
How long does it take for dogs to become serum IFA positive in ehrlichiosis?
7-28 day
242
What is the treatment for Ehrlichia canis?
1. Doxycycline
2. Chloramphenicol
3. Imidocarb
243
Can dogs be reinfected with Ehrlichia canis?
Yes
244
Why do dogs with Ehrlichia canis have a hyperglobulinemia?
They can mount a humoral response but it is ineffective
245
What is the reservoir host for Ehrlichia canis?
Wild and domestic canids
246
Where geographically does Neorickettsia helmintheca occur?
NW coastal US
247
How is Neorickettsia helmintheca transmitted to the dog?
Trematodes (nanophytes salmincola) harbor the rickettsia → eaten by snail → fish eats snail → dog eat fish → fluke eggs passed through dog feces but rickettsia stays in the dog
248
When do clinical signs appear after being infected with neorickettsia helminthecia?
1. 1-2 weeks after eating raw fish
249
What clinical signs are associated with neorickettsia helmintheca?
1. Fever
2. V/D
3. Lymphadenomegaly
4. Thrombocytopenia
250
How long does it take for serology to become positive for neorickettsia helmintheca?
2 weeks
251
What is the treatment for neorickettsia helmintheca?
Doxycycline and praziquantel
252
What is the end result of neorickettsia helmintheca infection?
1. FATAL if not treated in 7-10 days
253
What is another name for infection with neorickettsia helmintheca?
Salmon poisoning disease
254
What is the reservoir host for Ehrlichia ewingii?
1. White tailed deer
255
What is the vector for Ehrlichia ewingii?
Amblyomma americanum (Lone star tick)
256
What are unique clinical signs associated with E. ewingii?
1. Joint swelling
2. CNS signs
* Has other clinical signs that are similar to E. canis
257
How is E. eweingii treated?
Doxycycline
258
What is the reservoir host for Anaplasma phagocytophilum?
Deer and mouse
259
What is the vector for Anaplasma phagocytophilum? What is important about this vector/host relationship?
1. Ixodes scapulars
2. Needs to feed for 24 hours to infect!
* Often co-infected with Lyme disease since it is the same vector
260
What are the clinical signs associated with Anaplasma phagocytophilum?
1. VAGUE illness
2. Arthropathy
3. Thrombocytopenia
261
What is the most common Clin path finding for both A. phagocytophilum and A. platys?
Thrombocytopenia
262
E. canis vs A. phagocytophilum
| - More likely to see morale in neutrophils
A. phagocytophilum
263
What is the treatment of Anaplasma phagocytophilum?
Doxycycline
264
What cells are infected by Anaplasma phagocytophilum? A. platys?
1. Neutrophils and eosinophils
| 2. Platelets
265
Dogs infected with Anaplasma platys are (likely/not likely) to have clinical signs?
Not likely
266
Co-infection with A. platys and what other tick borne disease is common?
E. canis → same vector
267
What is the vector for A. platys?
Rhipicephalus sanguineous
268
What is the treatment for A. platys?
Doxycycline
269
What is the vector for Leishmaniasis?
Sandfly → dont know if this is in the US
270
What is the transmission cycle for Leishmaniasis?
Sandfly injects flagellated promastigotes into host during feeding → promastigotes enter macrophages and disseminate → 1 month - 7 years later, amastigotes (non-flagellates) form and cutaneous lesions develop
271
What cells are infected by Leishmaniasis?
Macrophages and lymphocytes
272
What cells are infected by FIV during active infection?
1. T cells
2. B cells
3. Macrophages
273
What % of dogs with Leishmaniasis are clinically affected?
~10% → Dogs are usually not clinical for disease
274
If dogs with Leishmaniasis have cutaneous disease, what other kind of disease can you assume they have?
1. Visceral
275
What diagnostic test is used for diagnosing Leishmania in dogs?
1. IgG titers → increase 14-28 days after infection → correlated highly with infection since prevalence in US is so low → decline 45-80 days after infection
2. rk39 ELISA → amastigote antigen → does NOT cross react with T. cruzi
276
How is Leishmania treated?
1. Leishmania CANNOT be cleared from the body
| 2. Treatment with allopurinol and antimony may help prevent recurrent infections
277
What is the vector for Trypanosoma cruzi?
Kissing bug (reduvid bug)
278
What are the cellular targets for Trypanosoma cruzi?
1. Macrphages
| 2. Myocytes
279
What is the transmission cycle for Trypanosoma cruzi?
Reduvid bug defecates during feeding → EPIMASTIGOTES enter macrophages or myocytes → divide until rupture → release → TRYPOMASTIGOTE picked up by bug during blood meal
280
What is caused by Trypanosoma cruzi?
1. Cardiomyopathy → parasite damage to myocardial cells or immune mediated reaction
2. Increased creatinine kinase
281
How is Trypanosoma cruzi diagnosed?
1. Serology → positive tests correlate with infection in America
282
What is the treatment for Trypanosoma cruzi?
Nifurtimox for 2-5 months
283
B. gibsoni vs B canis
| - Occurs singly in RBCs
B. gibsoni
284
B. gibsoni vs B canis
| - Occurs in pairs in RBCs
B. canis
285
What is the vector for B. gibsoni? What is unique about tick transmission for B. gibsoni?
1. Haemophysalis spp
| 2. Transovarial tick transmission can occur
286
What is the vector for B. canis
Rhipicephalus sanguineous
287
What are common findings in dogs infected with B. gibsoni?
1. Regenerative anemia
2. Thrombocytopenia
3. Fever
4. Hyperglobulinemia
5. Some can have a positive Coombs test → 85% in one study
6. Splenomegaly
288
What are common findings in dogs infected with B. canis?
1. Usually mild disease
| 2. Anemia, thrombocytopenia, splenomegaly
289
Observing B. canis or B. gibsoni on RBCs has a (high/low) sensitivity
Low
290
What diagnostic test can be used to differentiate Babesia spp?
PCR
291
How is B. gibsoni treated?
1. Atovaquone and azithromycin → will clear the infection
2. Imidocarb → will just induce remission
* Splenectomy makes the disease worse
292
How is B. canis treated?
Imidocarb
| *Splenectomy makes the disease worse
293
How are Theileria and Babesia species differentiated?
Theileria spp first infect LEUKOCYTES before erythrocytes
294
Mycoplasma haemofelis and haemocanis attach to what?
The outside of RBCs
295
What increases the risk of M. haemofelis infection?
1. FeLV infection
2. Lack of vaccine
3. Young
4. Cat bite
4. Outdoors
296
What kind of hemolysis occurs with M. haemofelis?
Primarily extravascular but intravascular can occur
297
What % of M. haemofelis cats are FeLV +
50%
298
How can you differentiate M. haemofelis from Heinz bodies or reticulocytes?
New methylene blue staining
299
How is M. haemofelis diagnosed?
1. Visualize on blood smears (<50% of cases)
| 2. PCR readily available and can distinguish species
300
What does M. haemofelis cause in the cat?
Hemolytic anemia
301
How is M. haemofelis treated?
Doxycycline or flouroquinolone
302
When does clinical M. haemocanis infection typically occur?
Splenectomized dogs
| *Can also reactivate an infection post splenectomy
303
What kind of anemia is seen in dogs infected with M. haemocanis?
Macrocytic hypochromic anemia
304
How is M. haemocanis treated?
Doxycycline or fluoroquinolones
305
Where is Bartonella henselae found in the body?
1. Intra-RBCs
306
What is the vector of Bartonella henselae?
Fleas and flea dirt
307
Is Bartonella henselae zoonotic?
Yes, cat scratch disease
308
What are the clinical signs associated with Bartonella henselae infection?
1. Found in clinically healthy cats
- Can infect stem cell progenitors
2. Can also infect dogs
309
How is Bartonella henselae diagnosed?
- Use culture or PCR to diagnose in cats but it does not tell you if it is the cause of their clinical signs
- Diagnosis is difficult because up to 50% of all HEALTHY cats can have serologic titers and 40% are bacteremic
310
What is the treatment for Bartonella henselae?
Azithromycin
| - 2nd choice is doxycycline
311
Are dogs or cats infected by Bartonella visonii berkhoffi?
Dogs
312
What disease is associated with Bartonella visonii berkhoffi in dogs?
Endocarditis → especially aortic valves
313
What is the organism?
- Canine with subaortic stenosis
- Endocarditis present
- Culture negative
Bartonella visonii berkhoffi
314
Is serologic testing useful in the diagnosis of Bartonella visonii berkhoffi in dogs?
Yes, more useful than serologic testing in cats.
| - If antibodies are detected in a sick dog, it is safe to assume that it is the cause of the clinical signs
315
What is the treatment for Bartonella visonii berkhoffi?
Azithromycin
316
Where is Cytauxzoan felis found geographically?
Midwest and SE
317
What does Cytauxzoan felis infect?
1. Monocytes
| 2. RBC
318
What life cycle stage of Cytauxzoon felis plays a role in the tissue phase of the disease?
Schizont
319
What life cycle stage of Cytauxzoon felis plays a role in the RBC phase of the disease?
Piroplasm
320
What is a distinguishing factor between Cytauxzoon and Babesia life cycle stages?
Babesia does NOT have a tissue phase
321
What is the vector for Cytauxzoon felis?
Dermacentor variabilis
322
What is the natural host of Cytauxzoon felis?
Bobcat
| *Only Felidae are susceptible
323
When do clinical signs develop after cytauxzoon felis infection? What is the end result of the disease?
1. 13-16 days after infection
| 2. FATAL 5 days after clinical signs develop
324
What Clin path abnormalities are assoc. with Cytauxzoon felis?
1. Non-regenerative anemia → because it is so acute
2. Leukocytosis
3. THrombocytopenia
4. Hyperbilirubinemai → way more icteric than for the level of anemia
325
What is the underlying mechanism for illness in Cytauxzoon felis?
Macrophages infected → schizogeny (asexual) to form schizonts → occlude venous channels in many organs
326
What happens to cats that are exposed to only the piroplasm form of Cytauxzoon felis?
They develop protective immunity
327
How is Cytauxzoon felis diagnosed?
1. Schizonts within macrophages in tissue or LN/BM aspirate
2. Signet rings in RBCs → cats may die from schizonts before this stage occurs (piroplasm stage is in the RBC)
3. PCR is good but not commercially available
328
How is Cytauxzoon felis treated?
1. Atoviquone
| 2. Azithromycin
329
What is the causative agent of Rocky Mountain Spotted Fever?
Rickettsia rickettsii
330
Where is Rickettsia rickettsii located geographically
1. SE or South Central US
331
What is the cellular target of Rickettsia rickettsii?
Vascular endothelium
332
What is the vector for Rickettsia rickettsii
Dermacentor variabilis
333
What clinical signs are associated with Rickettsia rickettsii?
Rocky Mountain Spotted Fever
1. Fever
2. Depression
3. Lymphadenopathy
4. Vestibular Signs
5. Vasculitis
* Animals either get better or they die
334
What would be observed on a tissue biopsy of a dog infected with Rickettsia rickettsii?
Necrotizing vasculitis
335
Rocky Mountain Spotted Fever is a(n) (acute/chronic) disease?
Acute
| - It is never chronic!
336
How is Rocky Mountain Spotted Fever diagnosed?
1. 4x increase on IFA titer → will cross react with non-pathogenic spotted fever rickettsia group
2. DFA on skin biopsy → will also see necrotizing vasculitis
337
What is not a sensitive method for Rickettsia rickettsii diagnosis?
PCR
338
How is Rickettsia rickettsii treated?
1. Doxycycline
2. Chloramphenicol
3. Enrofloxacin
* Dogs that survive will develop long lasting immunity
* Treat BEFORE confirming diagnosis
339
Do dogs become chronic carriers for Rickettsia rickettsii?
No! They either get better or die
340
What is the causative agent for Lyme disease?
Borrelia burgdorferi
341
What is the cellular target of Borellia burgdorferi?
They are an extracellular pathogen
342
What is the vector of Lyme disease?
Ixodes spp
343
What are the clinical signs associated with Lyme disease?
1. Most dogs remain asymptomatic
2. Intermittent lameness, fever, lethargy, anorexia
3. Lyme nephritis (uncommon) → occurs without lameness and most dogs die despite therapy
* Causes a RASH in people
344
What is a good test for Lyme disease? What is it testing for specifically?
1. 4DX SNAP test
| 2. C6 peptide → good because it is not found in the vaccine
345
What is the treatment for Lyme disease?
1. Doxycycline
| 2. Ampicillin
346
What protein does the lyme vaccine contain?
OspA
347
What is the cellular target of Hepatozoon?
1. Muscle
| 2. Inflammatory cells
348
What is the vector for Hepatozoon?
Amblyomma maculatum (gulf coast tick)
349
How is Hepatozoon transmitted?
1. Dogs must INGEST the tick containing oocysts
| 2. Vertical transmission is also possible
350
What life cycle stage of hepatozoon is responsible for severe pyogranulomatous inflammation?
Merozoites being released from skeletal muscle
351
What is the organism?
| - Onion skin cysts found in skeletal muscle
Hepatozoon americanum
352
What life cycle stage of H. americanum infects inflammatory cells?
Gamonts
| *When gamonts infect inflammatory cells they can then infect ticks
353
How is H. americanum diagnosed?
1. Muscle biopsy
| 2. Serum antibodies → 93% sens and 96% spec
354
What clinical signs are associated with H. americanum?
1. Pyogranulomatous vasculitis and periostitis
2. Myositis/Pain
3. Extreme neutrophilic leukocytosis
4. Periosteal reaction of long bones
5. Liver signs → decreased albumin, glucose, and BUN, but bile acids are normal → does not indicate liver failure
355
How is H. americanum treated?
1. TMS
2. Clindamycin
3. Pyrimethamine
4. Decoquinate
356
What is the benefit of adding decoquinate to H. americanum therapy?
Prolongs MST from 10-12 months to 6 years!
357
What is the causative agent for Q fever?
Coxiella burnetti
358
Is Coxiella burnetti zoonotic?
Yes
359
What is the target of Coxiella burnetti infection?
Urogenital tract
360
What species are most commonly affected by Coxiella burnetti (Q fever)?
1. Cattle, sheep, and goats
| 2. Cats can be infected but are usually subclinical → can have abortions
361
For the 4DX SNAP test - Which portions are antigen tests vs antibody tests?
1. Dirofilaria immitis
2. Ehrlichia canis
3. Anaplasma phagocytophilum
4. Borrelia burgdorferi
1. Antigen
2. Antibody
3. Antibody
4. Antibody
362
The IFA test for Ehrlichia canis will cross react with what other diseases?
1. E. chafensis
2. E. ewingii
3. N. helminthoeca
363
The IFA test for E. chafensis will cross react with what other diseases?
1. E. canis
| 2. E. ewingii
364
The IFA test for Anaplasma phagocytophilum will cross react with what other diseases?
1. E. canis
2. E. ewingii
3. A. platys
365
The IFA test for Neorickettsia riticci will cross react with what other diseases?
1. E. canis
| 2. H. heminthoeca
366
The IFA test for Neorickettsia helminthoeca will cross react with what other diseases?
1. E. canis
| 2. N. risicii
367
What are the two forms of feline coronavirus? What do they infect?
1. Feline enteric coronavirus → enterocytes
| 2. Feline infectious peritonitis virus → macrophages
368
What percentage of cats seropositive for feline coronavirus are shedding in feces?
1/3
| - Seropositivity does not correlate with shedding
369
Cats with feline coronavirus that (do/do not) mount a humoral immune response do not develop FIP
Do not
370
What is the general underlying mechanism for pathogenesis in feline coronavirus infection?
Immune mediated disease
| *Complement fixation leads to a release of vasoactive amines → vasculitis
371
The effusive form of FIP is the (acute/chronic) form of the disease. The non-effusive form is the (acute/chroni) form.
1. Acute
| 2. Chronic
372
What other clinical signs are common with the non-effusive form of FIP?
1. Ocular
| 2. Neurologic (usually ataxia, but hydrocephalus is highly suggestive of FIP)
373
FeLV is (stable/unstable) in the environment
Unstable
| -Inactivated in seconds
374
FeLV PCR has (good/bad) sensitivity and (good/bad) specificity
1. Bad → false negatives can happen from processing, mutant strains, proviral DNA fragility
2. Good → a positive is a positive
375
Fading kitten syndrome is associated with what infectious disease process?
FeLV
376
The deleterious effects of bacteria from the gut may be secondary to (systemic endotoxin/systemic bacterial infection)
1. Systemic endotoxin
| 2. GALT may fight off bacteria → in the process LPS is released
377
What is an important amino acid for enterocytes and maintaining a mucosal barrier?
Glutamine
378
What are the mechanisms for acquired bacterial resistance to antibiotics?
1. Synthesis of enzymes that alter the antibiotic
2. Alter antibiotic target
3. Decreased entry of antibiotic into the organism
379
What is the innate antibiotic resistance associated with Pseudomonas spp.?
Very small porin channels
380
Enterococcus spp have innate resistance to what kinds of antibiotics?
1. Cephalosporins
| 2. Fluoroquinolones
381
What is the best test for FIV?
Antibody ELISA → should be confirmed by western blot
382
When should kittens be tested for FIV?
After 6 months → can be false positive due to maternal Antibodies
*If mom is positive, isolate kittens for 6 months until they can be tested
383
Cats with FIV have been shown to have a (higher/lower) prevalence of azotemia and proteinuria compared to an age-matched control group
Higher
384
Cats with neurologic disease secondary to FIV have responded well to what medication?
AZT (zidovudine) → blocks reverse transcriptase
385
What changes to the lymphocyte population have been seen experimentally with Bartonella infection in dogs?
1. Decreased number of CD8 T lymphocytes
| 2. Increase in CD4 lymphocytes but with altered surface phenotypes
386
What general type of disease is associated with Bartonella infection in dogs?
1. Granulomatous disease
- 2 dogs with granulomatous lymphadenitis reported
2. Endocarditis also possible
387
Ehrlichia: Gram (+/-)
Gram -
388
What is the gold standard diagnostic test for E. canis?
IFA
| - ELSIA is also good (96% Sens, 100% spec)
389
What is unique about the thrombocytopenia associated with Anaplasma platys?
1. It is typically severe (A. phagocytophilum is usually mild)
2. Chronic, cyclical thrombocytopenia can be seen following the initial event every 7-14 days
390
How long does it take for infection to occur during a tick bite for Rocky Mountain spotted fever?
<24 hours
391
True/False
| - Dermacentor ticks can pass infection of R. rickets to their offspring (transovarial)
True
392
What is the only gram - intracellular bacteria that is transmitted by trematodes (flukes)
Neorickettsia helminthoeca
393
How is Nanophyteus salmincola (trematode in salmon poisoning disease) diagnosed?
Fecal flotation and sedimentation for ova
394
What % mortality occurs with treatment for Rickettsia ricketsii infection?
15-30%
395
What is the causative agent of tetanus? What kind of organism is it? Where is it located?
1. Clostridium tetani
2. Gram + anaerobic spore forming bacilli
3. Soil
396
Clinical signs of clostridium tetani develop secondary to what?
1. Secondary to active infection of a penetrating wound with tetanus
397
What is the cause of the neurologic signs seen with clostridium tetani? Why?
1. Develop due to toxin tetanospasmin
2. Attaches to the presynaptic nerve terminal of LMN and is taken up by phagocytosis → moves by retrograde axonal transport → cleaves docking protein (synaptobrevin) needed for exocytosis of the inhibitory neurotransmitter GABA
398
What is important about the docking protein cleaved by Clostridium tetani?
Synaptobrevin
| - Part of the SNARE complex needed for exocytosis of GABA
399
Clinical signs of tetanus develop how long after infection?
3 days to 3 weeks
400
How is Clostridium tetani diagnosed?
ELISA toxin assay available
401
What are the clinical signs associated with Clostridium tetani?
1. Hyperthermic
| 2. Spastic paralysis → may be localized near the wound but can become generalized
402
How is tetanus treated?
1. One dose of tetanus antitoxin
| 2. Metronidazole
403
What is the prognosis for tetanus?
1. Mild
2. Severe
1. 100% survival
| 2. 60% survival
404
What is the causative agent for botulism? What kind of organism is it?
1. Clostridium botulinum
| 2. Gram + anaerobic spore forming bacillus
405
Clinical signs of Clostridium botulinum occur secondary to what?
Secondary to ingestion of botulinum toxin produced within infected carrion
*ACTIVE INFECTION DOES NOT OCCUR
406
What is the cause of the neurologic signs seen with Clostridium botulinum? Why?
1. Develop due to ingestion of botulinum toxin C
2. Attaches to the presynaptic nerve terminal of peripheral CHOLINERGIC synapses (neuromuscular junction and autonomic nervous system) → taken up by phagocytosis → cleaves docking proteins (synaptotaxin and syntaxin) needed for exocytosis of ACh
407
What are the clinical signs associated with botulism? How quickly do they develop?
1. LMN signs including loss of tone and reflexes
- Death is common secondary to aspiration pneumonia or diaphragmatic paralysis
2. Within 12-72 hours after ingestion
408
How is botulism diagnosed?
ELISA toxin assay available
409
How is botulism treated?
Supportive care
410
What is important about the following stages of the heart worm life cycle?
1. L1
2. L3
3. L5
1. Microfilaria - produced by the adult heart worms in the pulmonary artery
2. L3 larvae can infect dogs → live in the tissue for 2-3 months and when they have matured to L5 they will invade the vasculature
3. Immature adult → takes 4-5 months to fully mature
411
What is the total time from infection to adult heart worms?
6-9 months
412
Where and how long do adult heart worms live?
Pulmonary artery for 5-7 years
413
The pulmonary effects seen in heart worm disease are secondary to what?
1. Eosinophilic pneumonia
| 2. Pulmonary thromboembolism
414
The cardiac effects seen in heartworm disease are secondary to what?
1. Fibrosis of the vasculature leading to severe pulmonary fibrosis
2. Right sided heart failure secondary to pulmonary hypertension
415
Canine heartworm testing is an (antigen/antibody) test? What is detected in this test?
1. Antigen
| 2. Only detects antigen from adult female worms
416
What is the mechanism behind prophylactic heartworm therapy?
Macrocyclic lactones
1. Cause irreversible opening of glutamate gated chloride channels leading to neuronal depolarization → parasitic paralysis
417
What is adulticideal therapy for heartworm disease?
1. Should only progress after clearing circulating microfilaria for 1-3 months
2. Melarsomine is an organoarsenic and is the most effective adultacide
418
What are risks associated with melarsomine therapy?
1. Thromboembolic disease
| - Occurs in 30% of dogs treated
419
The following organism is a vector for what diseases?
| - Rhipicephalus
* Tick
1. Hepatauxzoon canis (ingestion)
2. Babesia canis
3. Ehrlichia canis
4. Anaplasma platys
5. Rickettsia rickettsii
420
The following organism is a vector for what diseases?
| - Dermacentor
* Tick
1. Cytauxzoon
2. Rickettsia rickettsii
421
The following organism is a vector for what diseases?
| - Amblyomma
* Tick
1. Rickettsia rickettsii
2. E. ewingii
3. E. chaffensis
4. Cytauxzoon
5. Hepatauxzoon americanum (ingestion)
422
The following organism is a vector for what diseases?
| - Ixodes
* Tick
1. Borellia burgdorferi
2. Anaplasma phagocytophilum
423
The following organism is a vector for what diseases?
| - Reduviid
1. Trypanosoma
424
The following organism is a vector for what diseases?
| - Sand Fly
1. Leishmania
425
The following organism is a vector for what diseases?
| - Mosquito
1. Dirofilaria immitis
426
The following organism is a vector for what diseases?
| - Fleas
1. Mycplasma hemophelis
2. Bartonella hensilae
3. Diplidium caninum
427
What is the most common form of canine influenza? Where did it come from?
1. H3N8
| 2. Jumped species from equine to dogs without genetic reassortment
428
What is a zoonotic pathogen present in both dogs and horses?
1. Staph aureus → clinical infections in vet med uncommon
| * H3N8 has not been shown to transmit to humans
429
When is antibody testing used for heartworm disease?
1. In cats
2. May be helpful if an antigen test is negative due to a low worm burden
3. Specific but not sensitive
430
Rectal scraping is helpful in diagnosing which organism in dogs?
Histoplasmosis
