Rabies Diagnosis and Treatment

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Questions and Answers

Which diagnostic test is 99% accurate and provides results in 2 to 4 hours?

Fluorescent Antibody Test (FAT) (correct)

Cell culture techniques

Histopathology

Mouse test

Which of the following is a characteristic of Ehrlichia spp. in dogs?

Infects primarily through contaminated water

Causes acute respiratory distress

Forms intracellular clusters known as morulae (correct)

Transmitted via contaminated food

What is an effective prevention strategy for rabies in communities?

Increased human exposure to wildlife

Annual vaccination of all pets

Introduction of new dog breeds

Elimination of stray dogs (correct)

Which phase of Ehrlichiosis infection may last for months to years and some dogs may clear the infection during this phase?

Subclinical phase Signup and view all the answers

What kind of cells are most likely used in modern cell culture techniques for rabies diagnosis?

Mouse neuroblastoma cells Signup and view all the answers

Which of the following factors can influence the severity of Ehrlichiosis in dogs?

Presence of co-infections Signup and view all the answers

What is the consequence of not administering rabies post-exposure vaccine before clinical signs appear?

Invariably fatal outcome Signup and view all the answers

What type of vectors are associated with the transmission of Ehrlichia spp. infections in dogs?

Ticks Signup and view all the answers

Which diagnostic technique does not show cross-reactivity with E.canis?

IFA serology Signup and view all the answers

What is the recommended oral dosage of tetracyclines for treatment?

5-10 mg/kg Signup and view all the answers

What is a potential complication seen in animals recovering from A.phagocytophilum infection?

Susceptibility to reinfection Signup and view all the answers

Which of the following statements about vaccination protocols is true?

There is currently no vaccine available for A.phagocytophilum. Signup and view all the answers

What defines the transmission dynamics of B.canis and B.Gibsoni?

Intraerythrocytic protozoan parasites Signup and view all the answers

Which of the following is a key sign seen post experimental inoculation in infected animals?

Thrombocytopenia Signup and view all the answers

Which of the following vectors is associated with the transmission of B.Canis in South Africa?

Haemaphysalis leachi Signup and view all the answers

What is the recommended duration of tetracycline therapy for treating infections?

10-28 days Signup and view all the answers

Which diagnostic technique is used commercially to detect organism-specific DNA in peripheral blood?

PCR Signup and view all the answers

What is the recommended drug for supportive care in cases of ehrlichiosis?

Doxycycline Signup and view all the answers

Which of the following reflects the prognosis of ehrlichiosis in chronic cases?

Guarded Signup and view all the answers

Which of the following is a necessary measure to control the zoonotic aspects of E. canis and E. chaffeensis?

Rigorous tick control Signup and view all the answers

Which tick is believed to be the primary vector for A. phagocytophilum?

Ixodid tick Signup and view all the answers

What condition results from immune-mediated events in ehrlichiosis, requiring the use of a specific medication?

Thrombocytopenia Signup and view all the answers

What type of gammopathy is characterized by an increase in globulins in the blood?

Polyclonal gammopathy Signup and view all the answers

In which body tissue do A. platys and A. phagocytophilum replicate primarily?

Thrombocytes Signup and view all the answers

Study Notes

Rabies

Differential diagnoses include hysteria, tetanus, alternative encephalitis, and epilepsy.
Soap and water or disinfect the wound locally.
Pre or post-exposure vaccine is available.
Antiserum can be administered.
The chance of survival is excellent if treatment is given before clinical signs appear.
Rabies is invariably fatal if treatment is not given before clinical signs appear.
Clinical signs/history: Has the patient been vaccinated?
Fluorescent Antibody Test (FAT) is 99% accurate. Results are available in 2 to 4 hours.
Histopathology - Negri bodies can be found in the hippocampus and cerebellum. Results are available in 3 to 4 days.
Mouse test: Cultivation and isolation of the virus by intracerebral inoculation of young mice. This is the standard confirmatory test and takes 3 weeks.
More recently cell culture techniques using mouse neuroblastoma cells have been shown to be capable of replacing mice and giving quicker results.
Negri bodies are found in the body of neurons and a positive IF test detects rabies antigen.

Rabies Control

Vaccination
Elimination of stray dogs
Quarantine

Canine Ehrlichiosis

Ehrlichia spp are tick-borne rickettsia that form intracellular clusters called morulae
Species that infect dogs include:
- E.canis
- E.platys
- E.ewingii
- E.Chaffeensis
Vectors include Rhipicephalous sanguinous and ixodes spp.

Canine Ehrlichiosis - Pathology

Infected mononuclear cells marginate in small vessels or migrate into endothelial tissues inducing vasculitis during the acute phase (Begins 1-3 weeks PI and lasts 2-4 weeks). Most immunocompetent animals survive.
Subclinical phase lasts months to years. Some dogs may clear infection during this phase.
The organism may persist intracellularly leading to the chronic phase of infection. Most clinicopathological changes in the chronic phase are due to immune reaction against the organism.

Canine Ehrlichiosis - Clinical Severity

Severity depends on:
- Organism
- Host factors (dogs with depressed cell-mediated immunity develop severe disease)
- Presence of co-infections

Canine Ehrlichiosis - Clinical Findings

Thrombocytopenia and recovery seen cyclically at 1-2 week intervals (thrombocytopenia lessens with each cycle).
Signs related to thrombocytopenia are occasionally reported.

Canine Ehrlichiosis - Diagnosis

Identification of morulae:
- A.Platys- seen in platelets
- A.phagocytophilum seen also in granulocytes (seen 4-18 days post infection)
Thrombocytopenia
Serology- IFA available and no cross-reactivity seen with E.canis
PCR has also been used

Canine Ehrlichiosis - Treatment

Tetracyclines are the mainstay of therapy.
- 5- 10 mg/kg orally, q12- 24hr. Optimal duration of therapy: 10-28 days.
There is no vaccine.
Recovered animals are susceptible to reinfection with A.phagocytophilum.
Tick control is important.

Canine Babesiosis

Etiology and epidemiology:
- Piroplasma are intraerythrocytic protozoan parasites of the phylum Apicomplexa
  - Include babesiidae and Theileridae.
  - Babesia have no pre-erythrocytic stage whereas Theileria first infect leukocytes then RBCs
- Most commonly associated with B.canis and B.Gibsoni, protozoan parasites that parasitise RBCs leading to progressive anemia.
- Has worldwide distribution.

Canine Babesiosis - Genotype/Species Distribution

Genotype/Species	Distribution	Vector	Risk factors	Virulence
B.Canis vogeli	Worldwide	R.sanguinous	Greyhounds, dog bites, transfusion	+
B.Canis rossi	South Africa	Haemaphysalis leachi	Ticks	+++
B.Canis canis	Europe	Dermacenter reticulates	Ticks	++

Canine Babesiosis - Clinical Findings

Signs seen 1-2 weeks post experimental inoculation.

Canine Babesiosis - Laboratory Findings

Anemia
Increased ALT, ALP
Hyperglobulinemia
Positive Ehrlichia titer
PCR positive
Hypocellular bone marrow
Hypoalbuminemia

Canine Babesiosis - Serum Protein Electrophoresis

Polyclonal gammopathy
Normal
Monoclonal gammopathy

Canine Babesiosis - Diagnosis

IFA tests
Buffy coat from ear vein blood can increase the chances of finding morulae.
Cultures; some ehrlichia can be cultured but this procedure is low yield and expensive.
PCR; used commercially to detect organism specific DNA in peripheral blood.

Canine Babesiosis - Treatment

Supportive care, including:
- Doxycycline (10 mg/kg PO q24 h for 28 days) is the recommended drug. Clinical signs should resolve within 7 days.
- Other's include: Tetracycline, chloramphenicol and imidocarb dipropionate.
- Immune mediated events in this disease lead to the use of Prednisolone (2.2 mg/kg PO divided q12 during the first 3-4 days).

Canine Babesiosis - Prognosis

Good in acute cases, guarded in chronic cases.

Canine Babesiosis - Zoonotic/Control Aspects

E.canis, chaffeensis are zoonotic.
Rigorous Tick control
Screen potential blood donors

Canine Anaplasmosis - Etiology and Epidemiology

The Organisms:
- A.Platys and A.phagocytophilum are small obligate intracellular bacteria that replicate within canine thrombocytes.
- A.phagocytophilum also resides in granulocytic white blood cells (neutrophils).
- May cause infection in dogs, cats, horses, small ruminants and humans.

Canine Anaplasmosis - Transmission

Ticks are believed to be the primary vector.
- A.phagocytophilum by ixodid ticks
- A.platys transmitted by R.

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Description

This quiz covers essential information regarding the diagnosis, treatment, and preventative measures for rabies. It includes details on differential diagnoses, vaccination options, and the significance of tests like the Fluorescent Antibody Test. Understand the critical importance of timely intervention in rabies management.