Canine Infectious Diseases: Lyme Disease

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Questions and Answers

What is the primary treatment for Pneumonyssoides species infestation?

Selamectin

What is another name for Linguatula Serrata?

Intestinal parasite

Nasal worm

Tongueworm (correct)

Heartworm

In the case of Pepper-Anne, what condition cleared with antibiotics but returned after withdrawal?

Cystitis

What type of lesion was identified in Pepper-Anne's right radius?

Permeative osteolytic lesion Signup and view all the answers

What was detected in the bone biopsy of Pepper-Anne?

Fungal infection Signup and view all the answers

What is the primary cause of Coccidioidomycosis?

Coccidioides immitis Signup and view all the answers

What type of therapy is recommended for coccidioidomycosis?

Azoles or amphotericin-B Signup and view all the answers

Coccidioides immitis is commonly regarded as zoonotic.

False Signup and view all the answers

Coccidioides immitis is primarily found in the __________ region of the USA.

Southwest Signup and view all the answers

What is a major route of infection for Coccidioides in dogs and cats?

Inhalation Signup and view all the answers

The protocol for treatment of coccidioidomycosis recommends therapy for a minimum of __________ months beyond clinical cure.

4-6 Signup and view all the answers

Culture of Borrelia organisms is difficult and therefore not clinically useful.

True Signup and view all the answers

PCR tests using blood or joint fluid samples are more sensitive than PCR tests on tissue samples.

False Signup and view all the answers

Levels of C6 antibodies remain high for a long time after the successful treatment of a B.burgdorferi infection.

False Signup and view all the answers

Positive serology for C6 antibodies gives a definitive diagnosis of canine Lyme disease.

True Signup and view all the answers

Dark field microscopy of body fluids to visualize B.burgdorferi is difficult as spirochaete density is usually very low.

True Signup and view all the answers

What is the drug of choice for the treatment of B.burgdorferi?

Doxycycline Signup and view all the answers

What is the recommended dosage of Doxycycline for treating B.burgdorferi?

10 mg/kg Signup and view all the answers

Doxycycline should not be used in ______ due to its cosmetic effects.

growing animals Signup and view all the answers

What type of vaccine is Merilym 3?

Non-core vaccine Signup and view all the answers

Quarantine was introduced in the UK primarily to control rabies.

True Signup and view all the answers

The PETS travel scheme requires that animals are wormed with praziquantel prior to returning to the UK.

True Signup and view all the answers

What is a common disease caused by Echinococcus multilocularis in humans?

Alveolar echinococcosis Signup and view all the answers

What is the incubation period for rabies?

2-3 months Signup and view all the answers

What are ticks good vectors for disease?

Ticks are good vectors for disease due to their life cycles. Signup and view all the answers

What are the clinical signs associated with Borrelia (Lyme disease)?

Fever, lethargy, shifting limb lameness, and joint swelling. Signup and view all the answers

What is the name of the spirochaete that is the causal agent of Lyme disease?

Borrelia burgdorferi sensu lato. Signup and view all the answers

Which of the following is NOT a potential outcome of Lyme disease?

Type II diabetes Signup and view all the answers

The type of polyarthritis that Bradley had is classified as ___ polyarthropathy.

Type II Signup and view all the answers

Ticks can fly to reach their hosts.

False Signup and view all the answers

What is the main reason for the increased incidence of Lyme disease in the UK?

Climate change Signup and view all the answers

What is the recommended treatment for Borrelia infection?

Prolonged antibiotics and in some cases, immunosuppressive doses of steroids. Signup and view all the answers

Which of these clinical signs is associated with Lyme disease?

Shifting limb lameness Signup and view all the answers

Ticks are adapted parasites that find hosts by detecting breath and body ___ .

odours Signup and view all the answers

What percentage of people with Lyme disease develop a bull's eye skin lesion?

90% Signup and view all the answers

What are ticks considered good vectors for disease?

Ticks are good vectors for disease due to their life cycles and adaptations to find and feed on hosts. Signup and view all the answers

What are the clinical signs associated with Borrelia (Lyme disease)?

Clinical signs of Lyme disease include fever, lethargy, and shifting limb lameness. Signup and view all the answers

What is a key feature of a tick's feeding process?

Ticks have sharp mouth parts and inject tick cement to secure themselves while feeding. Signup and view all the answers

What are the different stages of a tick's lifecycle?

The stages include larva, nymph, and adult. Signup and view all the answers

Which of the following clinical signs is often associated with Borrelia (Lyme disease)?

Shifting limb lameness Signup and view all the answers

What factor contributes to the increasing incidence of tick-borne diseases?

Factors include changing climates, pet travel, and increased diagnostic techniques. Signup and view all the answers

Which Borrelia species is primarily responsible for Lyme disease in North America?

Borrelia burgdorferi sensu stricto Signup and view all the answers

Ticks can fly to find their hosts.

False Signup and view all the answers

What is the impact of the PETS travel scheme on tick-borne diseases?

The PETS travel scheme increases exposure to unusual tick vectors and diseases. Signup and view all the answers

What type of polyarthritis did Bradley have?

Type II Signup and view all the answers

What is a common diagnostic test for Lyme disease?

Serology testing for antibodies to Borrelia and PCR of joint fluid. Signup and view all the answers

What is the typical response to treatment for Lyme disease?

Gradual improvement Signup and view all the answers

What type of skin lesion is often associated with Lyme disease in humans?

Erythema migrans Signup and view all the answers

Culture of Borrelia organisms is difficult and therefore not clinically useful.

True Signup and view all the answers

PCR tests using blood or joint fluid samples are more sensitive than PCR tests on tissue samples.

False Signup and view all the answers

Levels of C6 antibodies remain high for a long time after the successful treatment of a B.burgdorferi infection.

False Signup and view all the answers

Positive serology for C6 antibodies gives a definitive diagnosis of canine Lyme disease.

True Signup and view all the answers

Dark field microscopy of body fluids to visualize B.burgdorferi is difficult as spirochaete density is usually very low.

True Signup and view all the answers

What is the drug of choice for the treatment of B.burgdorferi?

Doxycycline Signup and view all the answers

Doxycycline is administered at a dose of _____ mg/kg.

10 Signup and view all the answers

Doxycycline is contraindicated in growing animals due to its cosmetic effects.

True Signup and view all the answers

ACE inhibitors are used to reduce renal protein loss in dogs with proteinuria.

True Signup and view all the answers

The best method of reducing the risk of Lyme disease is to prevent ticks from attaching.

True Signup and view all the answers

The vaccination against Lyme disease aims to induce antibody formation to the Borrelia surface proteins, primarily OspA and _____ .

OspB Signup and view all the answers

What is the incubation period of rabies?

2-3 months Signup and view all the answers

Echinococcus multilocularis is also known as the fox tapeworm.

True Signup and view all the answers

What is the primary disease caused by Echinococcus multilocularis in humans?

Alveolar echinococcosis Signup and view all the answers

What is the species of mites that cause nasal irritation and reverse sneezing?

Pneumonyssoides species Signup and view all the answers

What is another name for Linguatula Serrata?

Tongueworm Signup and view all the answers

What type of infection was identified in the bone biopsy from Pepper-Anne?

Fungal infection Signup and view all the answers

Coccidioides immitis is a grade three pathogen that causes mild disease.

False Signup and view all the answers

What environmental conditions allow Coccidioides immitis to grow?

Alkaline sandy soils and adequate climate Signup and view all the answers

The main route of infection for Coccidioides in dogs is via __________.

inhalation Signup and view all the answers

What should be monitored during azole antifungal therapy?

Liver enzymes Signup and view all the answers

What are the potential treatments for coccidioidomycosis?

Azoles Signup and view all the answers

How long should treatment for coccidioidomycosis continue after clinical cure?

4-6 months Signup and view all the answers

Coccidioides immitis is generally regarded as a zoonosis.

False Signup and view all the answers

Study Notes

Learning Objectives

Understand the role of ticks as disease vectors due to their life cycles.
Identify clinical signs associated with Borrelia infections (Lyme disease).
Describe diagnosis methods for Borrelia infection.
Explore treatment and preventative measures for Borrelia.
Evaluate the PETS travel scheme's impact on imported diseases.

Tick Borne Diseases

Canine tick-borne diseases are becoming more common and public awareness is increasing.
Factors influencing this trend include travel and exposure to new tick vectors, improved diagnostic techniques, and changing tick populations.
Warmer climates in northern Europe have led to expanded tick distributions and higher tick populations.
Endemic diseases, like Lyme disease, have become more prevalent in humans and canines.

Questing Behavior of Ticks

Ticks detect hosts through smell, heat, moisture, and vibrations, and wait on vegetation in a "questing" position.
They grip onto leaves and grass and extend legs to latch onto passing hosts.
Ticks have sharp mouthparts to feed on blood and secrete substances to evade the host's immune response.

Tick Life Cycles

Ticks require multiple hosts for feeding at different life stages, enhancing their abilities as disease vectors.
Global travel increases exposure to various tick species and the diseases they carry.
Climate change contributes to tick population changes and expansion into new areas, such as Dermacentor reticulatus now found in the UK.

Tick Populations in the UK

Main tick species in the UK include Ixodes ricinus (sheep tick) and Ixodes hexagonus (hedgehog tick), with some Dermacentor reticulatus (meadow tick) identified.
Younger and certain breeds of dogs (pastoral and gundog) are more likely to encounter ticks.
Rhipicephalus sanguineus (brown dog tick) is not native to the UK but poses a risk due to its reproductive capacity in heated environments.

Case Example: Bradley

Bradley, a 7-year-old Springer Spaniel, displayed symptoms including lethargy, inappetence, and shifting limb lameness.
Clinical examination revealed complications such as moderate fever and joint effusions.
Blood tests indicated inflammatory responses with mild hypoalbuminaemia and protein loss.
Imaging showed increased soft tissue opacities indicative of joint effusions, ruling out septic disease.
Joint taps showed marked neutrophilic inflammation, confirming immune-mediated polyarthritis triggered by Borrelia infection.

Lyme Disease Overview

Named after Lyme, Connecticut, following the description of infectious polyarthritis in the 1970s.
Caused by the spirochaete Borrelia burgdorferi; different isolates found in North America and Europe.
Classic canine symptoms include fever, lethargy, and shifting lameness, typically occurring within a month after tick exposure.

Clinical Signs of Borrelia Infection

Initial signs: acute fever, shifting limb lameness, potential joint swelling, and lymph node enlargement.
Lameness often correlates with the tick attachment site; symptoms may shift as the infection progresses.
Chronic non-erosive polyarthritis and kidney issues (Lyme nephropathy) have been linked to Borrelia.
In people, a characteristic "bull's eye" skin lesion, erythema migrans, appears frequently, although dogs rarely show this.

Diagnosis of Lyme Disease

Diagnosis relies on clinical signs, supportive lab data, exclusion of other conditions, and treatment response.
Blood tests may indicate an inflammatory response, and joint taps typically reveal non-degenerate neutrophils.
PCR tests and positive serology for C6 antibodies provide definitive proof of canine Lyme disease.

Treatment Insights

Neutrophilic inflammation in joints suggests immune-mediated conditions; broad antibiotic treatment may be necessary.
Prolonged antibiotic use and sometimes immunosuppressive treatment can improve patient conditions.
Awareness of co-infections is crucial, especially with pathogens like Anaplasma.

Important Notes on Borrelia

Spirochaetes evolve their outer membrane proteins to evade the immune system, complicating diagnosis.
OspC is crucial for infection establishment while the VIsE protein offers antigenic variation, hindering neutralization efforts by the immune system.
C6 antibodies are detectable 3-5 weeks after Borrelia infection and decline post-treatment, which helps monitor recovery.

Key Takeaways

Culture of Borrelia is challenging and not clinically useful, while PCR sensitivity increases with tissue samples.
Maintaining vigilant monitoring for tick-borne diseases is crucial, especially with changing environments and tick populations.### Canine Lyme Disease Diagnosis and Treatment
Positive serology for C6 antibodies provides a definitive diagnosis of canine Lyme disease.
Dark field microscopy for Borrelia burgdorferi is challenging due to low spirochaete density.

Treatment Protocols

Early antibiotic therapy effectively reduces spirochaete numbers, leading to improvement in arthritis signs within 24-48 hours.
Doxycycline (10 mg/kg SID or BID) is the preferred antibiotic for treating B. burgdorferi.
Doxycycline has good tissue and cellular penetration due to its lipid solubility.
Treatment duration is typically 4 weeks but may require extension if dogs do not clear the infection.
Doxycycline is not recommended for growing animals due to cosmetic effects on skin, nails, and tooth enamel; alternatives include amoxicillin.
In the UK, all antibiotics used for Lyme disease treatment are administered under the cascade as no licensed product exists.

Additional Treatment Options

Doxycycline possesses immunomodulatory and chondroprotective effects, beneficial for polyarthritis.
Other antibiotics include amoxicillin, azithromycin, penicillin G, ceftriaxone, cefotaxime, and chloramphenicol for various indications and durations.

Managing Proteinuria and Glomerulonephritis

Treatment for documented proteinuria should combine antibiotics and ACE inhibitors to reduce renal protein loss.
Low-dose aspirin therapy (0.5 mg/kg BID) may prevent thromboembolism associated with anti-thrombin loss.

Case Example: Bradley

Bradley was treated successfully with doxycycline and NSAIDs; he showed significant improvement within 24 hours.
Persistent proteinuria, not treated with ACE inhibitors, returned to normal over six weeks, likely due to reactive glomerulonephritis.

Prevention of Lyme Disease

Effective tick prevention is crucial; use of acaricides like permethrin and fipronil reduces tick attachment and removal.
Spirochaete transmission occurs only after 24 hours of tick attachment; removing ticks promptly can halt transmission.
A vaccine (Merilym 3) is available to protect against borreliosis, inducing antibodies that target Borrelia surface proteins.

PET Travel Scheme and Its Impact

The PETS scheme has led to increased dog entries to the UK, from 164,836 in 2015 to over 300,000 in 2019.
The aim of the PETS scheme is to prevent rabies and tapeworms but does not require tick treatment for entering animals.

Rabies Control Measures

Rabies is a significant zoonotic disease with a fatal outcome post-symptom development, killing approximately 55,000 people annually.
Quarantine was introduced in the UK in 1897, making it rabies-free by 1922 through strict rabies control policies.
Recent vaccination programs in Europe have significantly reduced rabies prevalence, enabling several countries to achieve rabies-free status.

Echinococcus multilocularis

The PETS scheme mandates that animals be treated with praziquantel before returning to the UK to prevent the fox tapeworm.
Echinococcus multilocularis can lead to alveolar echinococcosis in humans, a serious disease with high mortality.

Travel increases exposure to diseases like tick-borne diseases, necessitating awareness and preparation for pet owners.
Tick-borne diseases such as Ehrlichia and Babesia are noted for their regional prevalence, and the potential for transmission increases with imported pets.

Nasal Mites and Linguatula Serrata

Nasal mites (Pneumonyssoides caninum) are common in Scandinavia and the USA but not in the UK.
Linguatula serrata, or tongueworm, can infest animals, predominantly found in Eastern Europe and North Africa, with a few reported cases in the UK.

Case Study: Pepper-Anne

Pepper-Anne, a dog from Arizona, presented with recurrent cystitis and forelimb lameness due to fungal osteomyelitis indicated by radiographs.
A confirmed diagnosis resulted from biopsy identifying an infection with Coccidioides immitis, prevalent in Southwest USA.

Fungal Infections and Their Distribution

Coccidioides immitis thrives in alkaline sandy soils of the Southwest USA, with its lifecycle tied to specific environmental conditions.
Coccidioidomycosis is recognized in many regions but is of major concern in specific geographical areas, often linked to rift valley fever.### Coccidioidomycosis Overview
Coccidioidomycosis is not currently endemic in the UK but can be imported.
Mycelial germination in dry soil leads to the formation of arthrospores, which become airborne.

Infection Pathway

Major infection route in dogs and cats is via inhalation; cutaneous infections from wounds are less common.
Arthrospores transform into spherules in the body, dividing and releasing endospores upon maturity.

Disease Manifestation

Severity of the disease varies with host immunocompetence, ranging from mild pulmonary infections to fatal multi-systemic diseases.
Two species identified: Coccidioides posadasii and Coccidioides immitis; both show similar disease manifestations and drug susceptibilities.

Pulmonary and Disseminated Disease

Pulmonary infections occur through bronchioles and alveoli, spreading to peribronchial tissues and lymph nodes.
Disseminated disease can affect various organs, including bones, skin, central nervous system, abdomen, heart, and prostate.

Transmission and Containment

No direct transmission reported between infected individuals (human or veterinary).
Human inoculated infections may happen due to sharps injuries during procedures involving infected tissues.

Laboratory Handling and Diagnosis

Tissue samples suspected of containing Coccidioides immitis should be handled cautiously.
Fungal culture can be submitted to Health Protection Agency; serological testing is limited to the USA.

Treatment Protocols

Treatment typically involves azoles or amphotericin-B, with a recommended duration of 4 to 6 months post-clinical cure.
Prolonged treatment may be required for disseminated cases, sometimes exceeding one year or necessitating lifelong therapy.

Drug Specifics and Monitoring

Azoles, such as itraconazole, inhibit ergosterol synthesis—essential for fungal cell membrane integrity.
Itraconazole is preferred for cases with bony involvement, while fluconazole may be used for CNS infections.
Regular monitoring of liver enzymes is advised due to potential hepatotoxicity associated with azoles.

Risks and Precautions

All azole drugs may be teratogenic; caution is necessary in pregnant animals.
Proper protective measures should be taken when handling infected tissues.

Conclusion

Understanding coccidioidomycosis and its related risks can aid in correctly diagnosing and treating canine infectious diseases.
Future lessons will cover diseases associated with pet travel, including Babesia, Ehrlichia, Leishmania, and Dirofilaria.

Learning Objectives

Understand ticks as effective disease vectors due to their complex life cycles.
Recognize clinical signs of Borrelia infection (Lyme disease).
Outline diagnostic methods for Borrelia.
Explore treatment and prevention strategies for Borrelia infection.
Discuss the impact of the PETS travel scheme on the introduction of infectious diseases.

Tick Borne Diseases

Canine tick-borne diseases are rare but increasingly noted, influenced by pet travel and changes in tick populations.
Warmer climates in northern Europe are fostering tick population growth and geographic spread.
Endemic diseases like Lyme disease have seen a rise in human cases and canine infections in the UK.
Diseases such as Borrelia and Ehrlichia are reported in both traveled and non-traveled dogs.

Questing Behavior of Ticks

Ticks locate hosts using sensory cues such as breath, body odor, heat, and vibrations.
"Questing" involves the tick positioning itself on vegetation, awaiting a host to pass by.
Feeding adaptations include sharp mouthparts for blood access and salivary components for immune evasion, including anticoagulants and immunomodulators.

Tick Life Cycles

Ticks undergo several life stages requiring multiple hosts, making them efficient disease transmitters.
Increased pet travel through the PETS scheme raises exposure to unusual tick types and associated diseases.
Ticks' geographic range is expanding due to climate changes, exemplified by Dermacentor reticulatus moving into the UK.
Infestations can occur unnoticed; a study found 15% of dogs had undetected ticks.

Tick Populations in the UK

Common hard-shelled tick species in the UK include Ixodes ricinus and Dermacentor reticulatus.
Increased pet travel leads to the introduction of non-native ticks like Rhipicephalus sanguineus, which can reproduce in heated environments, posing disease risks.

Case Example – Bradley

Bradley, a 7-year-old neutered Springer Spaniel, presented with lethargy, listlessness, and shifting leg lameness.
Clinical examination revealed high fever and palpable joint effusions; blood tests indicated inflammatory responses.
Imaging yielded normal results, and joint taps showed neutrophilic inflammation, leading to a diagnosis of immune-mediated polyarthritis triggered by Borrelia infection.

Lyme Disease Overview

Lyme disease originates from Lyme, Connecticut, identified in the mid-1970s.
Causal agent: Borrelia burgdorferi sensu lato, which causes diverse symptoms across species.
Initial signs in dogs include fever, lethargy, and shifting lameness, typically following a tick bite.

Clinical Signs of Borrelia

Early signs consist of high fever, limb lameness, joint swelling, and lymph node enlargement, with severity often in younger or immunocompromised dogs.
Chronic cases may develop into non-erosive polyarthritis or protein-losing nephropathy, particularly in the USA and the UK.
Diagnosis challenges arise from overlapping signs with other diseases; "bull's-eye" lesions, typical in humans, are rare in dogs.

Diagnosis and Laboratory Findings

Diagnosis hinges on clinical signs, lab data, differential diagnosis exclusion, and treatment response.
Common findings include inflammatory changes in blood tests, high neutrophil counts in joint taps, and increased urine protein suggesting nephropathy.
The changing surface proteins of Borrelia complicate detection; C6 antibodies indicate infection, correlating well with actual presence.

Diagnostic Techniques

PCR tests are sensitive and applicable for confirming Borrelia in tissue and fluid samples.
Joint fluid will show high non-degenerate neutrophils, while culture methods remain ineffective.
Prompt and accurate diagnostics are critical due to the diverse clinical manifestations of Lyme disease.

Knowledge Check

Culturing Borrelia is clinically impractical.
PCR tests on tissue are more sensitive than those on blood or fluids.
Persistent high levels of C6 antibodies can occur following treatment and are not indicative of ongoing infection.### Canine Lyme Disease and Diagnosis
Positive serology for C6 antibodies indicates a definitive diagnosis of canine Lyme disease.
Dark field microscopy of body fluids for B.burgdorferi is challenging due to low spirochaete density.

Treatment Protocol

Early antibiotic therapy effectively reduces B.burgdorferi numbers, improving arthritis signs within 24-48 hours.
Doxycycline (10 mg/kg SID or BID) is the primary treatment, although other antimicrobials are also effective.
Treatment duration is typically 4 weeks, but not all dogs may clear the infection within this timeframe.
Doxycycline's lipid solubility allows good tissue and cellular penetration.
In growing animals, doxycycline is contraindicated due to cosmetic effects; alternative antibiotics like amoxicillin are recommended.
In the UK, antibiotics are used under the "cascade" since no licensed product for canine Lyme disease exists.
Doxycycline provides additional immunomodulatory and chondroprotective benefits for polyarthritis treatment.

Antibiotic Dosage and Administration

Doxycycline: 10 mg/kg PO, every 12-24 hours for 30 days (not for young animals).
Amoxicillin: 20 mg/kg PO every 8 hours for 30 days (suitable for young patients).
Other options include azithromycin, penicillin G, ceftriaxone, cefotaxime, and chloramphenicol for various indications.

Managing Associated Conditions

If proteinuria is detected and causes of PLN excluded, treat for glomerulonephritis alongside antibiotics.
ACE inhibitors reduce renal protein loss by altering glomerular filtration pressure.
Ultra-low aspirin (0.5 mg/kg BID) may help prevent thromboembolism due to anti-thrombin loss and platelet dysfunction.

Case Study: Bradley

Treated with doxycycline and NSAIDs (meloxicam); improvement was seen within 24 hours.
Persistent but mild proteinuria was noted, with a normal UPC ratio achieved over 6 weeks.
Likely a reactive glomerulonephritis due to infection rather than Lyme nephritis, which is uncommon in the UK.

Prevention Strategies

Preventing ticks from attaching is crucial to reducing Lyme disease risk.
Effective acaricides like permethrin and fipronil can repel or kill ticks.
Regular use of acaricides is recommended for dogs in high-tick areas, particularly in spring and autumn.
Immediate tick removal within 24 hours of attachment stops spirochaete transmission.
A vaccine (Merilym 3) induces antibodies targeting Borrelia surface proteins to protect against borreliosis, used mainly in high-risk areas.

Pet Travel Scheme (PETS)

The PETS scheme allows for easier pet travel, with over 300,000 dogs crossing into the UK in 2019.
Requirements for travel include microchipping, rabies vaccination, and tapeworm treatment.
The scheme aims to prevent importing rabies, Echinococcus multilocularis, and tick-borne diseases.
Tick treatment is no longer mandatory, raising risks of exotic diseases.

Rabies Awareness

Rabies poses a significant zoonotic risk, with approximately 55,000 human fatalities annually.
Incubation period is typically 2-3 months; hence, a quarantine period of 6 months helps to monitor imported animals.
The UK achieved rabies-free status in 1922, largely due to successful rabies control measures including vaccination.

Echinococcus multilocularis

The PETS scheme mandates praziquantel treatment prior to returning to the UK to prevent tapeworm contamination.
This tapeworm is endemic in various parts of Europe and poses a risk to humans through ingestion of eggs from infected hosts.

Emerging Pet Travel Diseases

Increased travel leads to encounters with unfamiliar diseases; guidance is essential for pet owners.
Pet travel may expose animals to tick-borne diseases like Babesia and Ehrlichia, reported through DEFRA.

Nasal Mites and Other Infections

Nasal mites (Pneumonyssoides caninum) are common in Scandinavia and the USA but rare in the UK.
Linguatula Serrata, a tongueworm parasite, is also rarely reported in the UK but can affect imported dogs.

Case Study: Pepper-Anne

Pepper-Anne presented with cystitis and lameness, revealing osteolytic bone lesions through radiographs.
A bone biopsy confirmed a fungal infection from Coccidioides immitis, endemic to Arizona.
The environment of southwestern USA supports the growth of Coccidioides due to its unique soil conditions.### Coccidioidomycosis Overview
Coccidioidomycosis, caused by Coccidioides posadasii and Coccidioides immitis, is not commonly found in the UK but can be imported.
Mycelia germinate into arthrospores in dry soil and become airborne, primarily infecting dogs and cats through inhalation.
Infection can occur via cutaneous contamination but is less frequent than inhalation.
Arthrospores develop into spherules within the body, which then release endospores, continuing the infection cycle.

Disease Manifestations

Severity of coccidioidomycosis varies based on host immunocompetence, ranging from mild pulmonary symptoms to fatal systemic dissemination.
Pulmonary infections target bronchioles and alveoli, spreading to associated lymph nodes.
Disseminated diseases can affect bones, skin, central nervous system, and internal organs, including the heart and digestive system.

Transmission and Infection Control

No direct transmission between infected patients (humans or animals) has been documented, and it is not typically regarded as a zoonosis.
Human infections can occur through sharps injuries during procedures involving infected tissues; proper protective equipment is essential when handling samples.

Diagnostic Methods

Culture samples must be handled with care; submission is advised if coccidioidomycosis is suspected.
Serological testing for Coccidioides immitis is available, though limited to the USA.

Treatment Protocols

Treatment options include azoles or amphotericin-B, with a recommended duration of 4-6 months post-clinical cure.
Disseminated cases may require prolonged treatment exceeding one year or even lifelong therapy.
Relapse rates are high, and it remains unclear if prior infections provide lifelong immunity.

Azole Antifungal Agents

Azoles function by inhibiting ergosterol synthesis, impacting the fungal cell membrane and growth.
Itraconazole is preferred for cases with bony involvement, while fluconazole is suggested for central nervous system cases.
Monitoring liver enzymes is essential during azole treatment due to potential hepatotoxicity.

Additional Considerations

Azole drugs may be teratogenic and should not be used during pregnancy; specific handling instructions for owners are necessary.
Local knowledge and travel histories are crucial for identifying differential diagnoses related to imported diseases in pets.

Learning Objectives Recap

Understanding why ticks are effective disease vectors based on their life cycles.
Recognizing clinical signs of Borrelia (Lyme disease).
Outlining diagnostic approaches for Borrelia infection.
Considering treatment options and preventive measures for Borrelia infections.
Reflecting on the effects of the PETS travel scheme on imported diseases.

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Description

This lesson focuses on Lyme disease and explores the role of ticks as vectors for various diseases. By the end of the lesson, you'll understand tick life cycles and the clinical signs associated with Lyme disease and other tick-borne illnesses.

Canine Infectious Diseases: Lyme Disease

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Questions and Answers

What is the primary treatment for Pneumonyssoides species infestation?

What is another name for Linguatula Serrata?

In the case of Pepper-Anne, what condition cleared with antibiotics but returned after withdrawal?

What type of lesion was identified in Pepper-Anne's right radius?

What was detected in the bone biopsy of Pepper-Anne?

What is the primary cause of Coccidioidomycosis?

What type of therapy is recommended for coccidioidomycosis?

Coccidioides immitis is commonly regarded as zoonotic.

Coccidioides immitis is primarily found in the __________ region of the USA.

What is a major route of infection for Coccidioides in dogs and cats?

The protocol for treatment of coccidioidomycosis recommends therapy for a minimum of __________ months beyond clinical cure.

Culture of Borrelia organisms is difficult and therefore not clinically useful.

PCR tests using blood or joint fluid samples are more sensitive than PCR tests on tissue samples.

Levels of C6 antibodies remain high for a long time after the successful treatment of a B.burgdorferi infection.

Positive serology for C6 antibodies gives a definitive diagnosis of canine Lyme disease.

Dark field microscopy of body fluids to visualize B.burgdorferi is difficult as spirochaete density is usually very low.

What is the drug of choice for the treatment of B.burgdorferi?

What is the recommended dosage of Doxycycline for treating B.burgdorferi?

Doxycycline should not be used in ______ due to its cosmetic effects.

What type of vaccine is Merilym 3?

Quarantine was introduced in the UK primarily to control rabies.

The PETS travel scheme requires that animals are wormed with praziquantel prior to returning to the UK.

What is a common disease caused by Echinococcus multilocularis in humans?

What is the incubation period for rabies?

What are ticks good vectors for disease?

What are the clinical signs associated with Borrelia (Lyme disease)?

What is the name of the spirochaete that is the causal agent of Lyme disease?

Which of the following is NOT a potential outcome of Lyme disease?

The type of polyarthritis that Bradley had is classified as ___ polyarthropathy.

Ticks can fly to reach their hosts.

What is the main reason for the increased incidence of Lyme disease in the UK?

What is the recommended treatment for Borrelia infection?

Which of these clinical signs is associated with Lyme disease?

Ticks are adapted parasites that find hosts by detecting breath and body ___ .

What percentage of people with Lyme disease develop a bull's eye skin lesion?

What are ticks considered good vectors for disease?

What are the clinical signs associated with Borrelia (Lyme disease)?

What is a key feature of a tick's feeding process?

What are the different stages of a tick's lifecycle?

Which of the following clinical signs is often associated with Borrelia (Lyme disease)?

What factor contributes to the increasing incidence of tick-borne diseases?

Which Borrelia species is primarily responsible for Lyme disease in North America?

Ticks can fly to find their hosts.

What is the impact of the PETS travel scheme on tick-borne diseases?

What type of polyarthritis did Bradley have?

What is a common diagnostic test for Lyme disease?

What is the typical response to treatment for Lyme disease?

What type of skin lesion is often associated with Lyme disease in humans?

Culture of Borrelia organisms is difficult and therefore not clinically useful.

PCR tests using blood or joint fluid samples are more sensitive than PCR tests on tissue samples.

Levels of C6 antibodies remain high for a long time after the successful treatment of a B.burgdorferi infection.

Positive serology for C6 antibodies gives a definitive diagnosis of canine Lyme disease.

Dark field microscopy of body fluids to visualize B.burgdorferi is difficult as spirochaete density is usually very low.

What is the drug of choice for the treatment of B.burgdorferi?

Doxycycline is administered at a dose of _____ mg/kg.

Doxycycline is contraindicated in growing animals due to its cosmetic effects.

ACE inhibitors are used to reduce renal protein loss in dogs with proteinuria.

The best method of reducing the risk of Lyme disease is to prevent ticks from attaching.

The vaccination against Lyme disease aims to induce antibody formation to the Borrelia surface proteins, primarily OspA and _____ .

What is the incubation period of rabies?

Echinococcus multilocularis is also known as the fox tapeworm.

What is the primary disease caused by Echinococcus multilocularis in humans?

What is the species of mites that cause nasal irritation and reverse sneezing?

What is another name for Linguatula Serrata?

What type of infection was identified in the bone biopsy from Pepper-Anne?

Coccidioides immitis is a grade three pathogen that causes mild disease.

What environmental conditions allow Coccidioides immitis to grow?

The main route of infection for Coccidioides in dogs is via __________.

What should be monitored during azole antifungal therapy?

What are the potential treatments for coccidioidomycosis?

How long should treatment for coccidioidomycosis continue after clinical cure?

Coccidioides immitis is generally regarded as a zoonosis.

Study Notes

Learning Objectives

Tick Borne Diseases

Questing Behavior of Ticks