BCSE Test Prep 25 Days For Test Day Flashcards
A herd from a large swine operation is presented with a severe outbreak of febrile hemorrhagic disease that appears to have affected 50% of the herd. So far, 12 animals have died. The pigs are depressed and anorexic, with temperatures as high as 104.9°F (40.5°C) [N=100-102°F (37.8-38.9°C)]. There are purple blotches on the bellies of several, and necropsy finds hemorrhaged organs. Diseases on the differential diagnosis include hog cholera, African swine fever, severe anticoagulant toxicity, and bacterial septicemias. What should be done first?
Answer: Report to the state vet
Because you suspect two REPORTABLE diseases (AFRICAN SWINE FEVER and HOG CHOLERA) with potentially disastrous consequences for the national hog industry, you should notify the authorities first.
Given your suspicions and the severity of the outbreak, depopulation could be right if tests confirm one of the reportables, but it’s probably not the first thing you should do.
Link: African Swine Fever
https://www.merckvetmanual.com/generalized-conditions/african-swine-fever/african-swine-fever?redirectid=30618
Link: Classical Swine Fever
https://www.merckvetmanual.com/generalized-conditions/classical-swine-fever/classical-swine-fever?redirectid=29630
Which one of the following procedures might make a Saddlebred horse’s tail look like this for cosmetic purposes?
Soring
Pin-firing
Dock procedure
Cutting
Alcohol block
Which two reportable diseases have a similar presentation and are caused by a closely related causative agent?
Foot and mouth disease (FMD), vesicular stomatitis (VS)
Rinderpest, peste des petits ruminants
Malignant catarrhal fever, blue tongue
Aphthous fever, bovine ephemeral fever
Pseudorabies, Aujesky’s disease
Answer: Rinderpest, peste des petits ruminants.
Rinderpest and peste des petits ruminants are both caused by a morbillivirus and both cause a syndrome characterized by fever, necrotic stomatitis, gastroenteritis/diarrhea.
In 2011, the United Nations Food and Agriculture Organization (FAO) and the World Organisation for Animal Health (OIE) officially declared that rinderpest was eradicated globally. But because it is a classic, severe, reportable, stomatitis-type disease, it’s unlikely that vets will be allowed to forget rinderpest on DDXs for years.
Canine distemper and human measles are also caused by morbilliviruses.
Pseudorabies and Aujesky’s are the same disease. Aphthous fever is just another name for foot and mouth disease (FMD).
Bluetongue is almost exclusively a sheep disease that is mild in cows. In contrast, malignant catarrhal fever (MCF) is almost 100% fatal once see clinical signs.
Ref: Pasquini’s Guide to Bovine Clinics, 4th ed. pp 8-11.
Link: Rinderpest
https://www.merckvetmanual.com/generalized-conditions/rinderpest/rinderpest?redirectid=29132
Link: Overview of Peste des Petits Ruminants
https://www.merckvetmanual.com/generalized-conditions/rinderpest/rinderpest?redirectid=29132
Link: Animal Production and Health Division (NSA)
https://www.fao.org/agriculture/animal-production-and-health/en/
Link: Canine Distemper Overview
https://www.merckvetmanual.com/generalized-conditions/canine-distemper/canine-distemper-overview
Link: Pseudorabies in Pigs
https://www.merckvetmanual.com/nervous-system/pseudorabies/pseudorabies-in-pigs?autoredirectid=14329
Link: Foot-and-Mouth Disease in Animals
https://www.merckvetmanual.com/generalized-conditions/foot-and-mouth-disease/foot-and-mouth-disease-in-animals?autoredirectid=14225
Link: Bluetongue in Ruminats
https://www.merckvetmanual.com/generalized-conditions/bluetongue/bluetongue-in-ruminants?autoredirectid=17866
Link: Malignant Catarrhal Fever in Animals
https://www.merckvetmanual.com/generalized-conditions/malignant-catarrhal-fever/malignant-catarrhal-fever-in-animals?autoredirectid=17867
You are called to a pig farm to review vaccine protocols and the farmer asks you about “electroimmobilization” as a way to restrain animals for short procedures like teeth trimming in older animals. What should you tell the farmer?
Electroimmobilization provides good plane of anesthesia for up to 20 minutes
The technique is not appropriate for animal restraint
This is illegal and you must report the farmer if you find electroimmobilization equipment on premises
Analgesia is sufficient to painful procedures
Meat form animals that have undergone this cannot be sold for human consumption
Answer: The technique is not appropriate for animal restraint.
Neither the American Veterinary Medical Association (AMA) nor Canadian Veterinary Medical Association (CVMA) condone the use of electroimmobilization for animal restraint because may cause unnecessary pain and distress and no significant analgesic effect has been demonstrated.
Electroimmobilization is an electrical current that causes paralysis, used to restrain conscious animals. It does NOT provide analgesia or anesthesia.
The electrical current acts directly on the animal’s muscle and/or nervous system. It appears that the animals are conscious and aware of their surroundings while being unable to respond.
Refs: AVMA Policy on Electroimmobilization, and Welfare Implications of Electroimmobilization. CVMA, Electroimmobilization Position Statement.
Link: Electroimmobiliation of non-fish species
https://www.avma.org/resources-tools/avma-policies/Electroimmobilization-non-fish-species
Link: Welfare Implications of Electroimmobilization
https://www.avma.org/resources-tools/literature-reviews/welfare-implications-electroimmobilization
Comprehensive Information on Electroimmobilization for BCSE Test
1. Definitions:
• Electroimmobilization: Use of electrical current to restrain conscious animals by causing paralysis, primarily used in large livestock.
- Mechanism:
• Action: Electrical current acts on muscles and nervous system to prevent movement, causing conscious rigid paralysis.
• Application: Electrodes placed at distal ends of the spine, excluding the brain. - Physiological Impact:
• Discomfort and Distress: Loss of bodily control, muscle overstraining, labored respiration.
• Physiological Stress: Animals show aversion and stress reactions. - Usage:
• Livestock: Sheep, swine, cattle; mainly to prevent injury during handling.
• Other Animals: Insects for photography. - Limitations:
• Not Anesthetic: Does not produce analgesic or anesthetic effects; not suitable for surgical procedures.
• Ethical Concerns: Considered inhumane due to induced distress and discomfort. - Comparison with Other Procedures:
• Electrofishing: Temporary immobility in fish; not for restraint.
• Electroanesthesia: Produces unconsciousness, used prior to slaughter.
• TENS: Electrical devices like fences and collars do not cause paralysis and are not for analgesia. - Alternatives and Recommendations:
• Mechanical Restraints: Preferred over electroimmobilization due to lower distress levels.
Key Points:
• Electroimmobilization: Causes conscious paralysis, significant distress.
• Usage: Primarily in large livestock, not for anesthesia or analgesia.
• Alternatives: Mechanical restraints, proper handling techniques.
Which of the following bandaging technique prevents forelimb weight-bearing in a dog after reduction of medial shoulder luxation?
Ehmer sling
Velpau sling
Modified Thomas splint
Carpal flexion sling
Rober Jones bandage
Answer: Velpau sling.
Use the Velpeau sling to prevent weight-bearing and immobilize the joints of the affected leg following correction of a medial shoulder luxation.
Use the carpal flexion sling when weight-bearing is undesirable but the animal is able to use the shoulder and elbow joints.
Use the Ehmer sling to prevent weight bearing and immobilize the joints of the pelvic limb. It is most commonly used after closed reduction of traumatic hip luxation.
Use the modified Thomas splint in large animals to facilitate traction/reduction for treatment of fractures distal to the mid-femur or mid-humerus or to immobilize joints distal to, and including, the stifle and elbow.
Use the Robert Jones bandage to temporarily immobilize thoracic or pelvic limbs distal to the elbow or stifle.
In which stage of wound healing are neutrophils found in the largest numbers in the affected tissue?
Answer: Inflammation
Neutrophils predominate in wounded tissues during the inflammatory stage.
Wound healing occurs in most tissues of the body in three major stages: inflammation, proliferation, and remodeling (sometimes called “maturation”).
Inflammation is the first stage, when neutrophils migrate into a new wound within 30 minutes. Neutrophils phagocytize bacteria and die off, leaving monocytes (called macrophages once they exit the blood stream) to become the predominant cell type for the next phase of inflammation: wound debridement.
Monocytes are essential in this next step because they secrete growth factors that promote wound healing.
Fibroblasts predominate during the proliferative stage of wound healing, first laying down fibrin for epithelial cell migration and then collagen for wound stability.
Comprehensive Information on General Principles of Wound Healing in Small Animals for BCSE Test
1. Definitions and Stages of Wound Healing:
• Inflammatory Stage: Includes hemostasis, chemotaxis, and debridement phases.
• Hemostasis: Vasoconstriction followed by vasodilation to control hemorrhage.
• Chemotaxis: Leukocyte migration to resolve infection; neutrophils predominate initially, followed by monocytes.
• Debridement: Removal of damaged cells, pathogens, and debris by phagocytosis.
2. Proliferative Stage:
• Fibroblast Activity: Mesenchymal cells transform into fibroblasts, secreting ground substance and collagen.
• Capillary Proliferation: Delivers blood supply to the wound; granulation tissue formation.
• Epithelial Migration: Basal epithelial cells migrate to cover the wound; enhanced by transforming growth factors.
- Remodeling Stage:
• Collagen Reorganization: Newly laid collagen fibers and fibroblasts align along tension lines, increasing wound strength over time (up to 2 years). - Causes and Clinical Changes:
• Causes: Trauma, surgical incisions, infection.
• Symptoms: Inflammation, necrosis, granulation tissue formation. - Assessment and Treatment:
• Assessment: Monitor stages of healing; identify signs of infection or delayed healing.
• Treatment: Proper wound care, maintaining a moist environment, preventing desiccation, infection control. - Medications:
• Antibiotics: For secondary infections.
• Anti-inflammatory Drugs: To reduce inflammation and pain.
• Growth Factors: To promote healing.
Where is the best place to do a bone marrow biopsy in an adult horse?
Sternebrae
Iliac crest
Lesser trochanter
Distal femur
Scapula head
Answer: Sternebrae.
In horses, collect bone marrow from the biopsy from the sternebrae (bones where the ends of ventral ribs meet along ventrum). In horses less than four years, can collect marrow from tuber coxae of pelvis.
The iliac crest is the site of choice for a bone marrow biopsy in the dog or cat. You can also get marrow from the proximal end of the femur at the trochanteric fossa. Jamshidi, Rosenthal, or Illinois needles are most frequently used for the procedure.
Refs: Smith, Van Metre, and Pusterla’s Large Animal Internal Medicine, 6th ed., pp. 449- 59
In large animal surgery, which surgical blade fits on an #4 Bard-Parker handle?
3 blade
10 blade
20 blade
5 blade
40 blade
Answer: 20 blade.
Scalpel blades #20, #21, and #22 all fit on the Bard-Parker #4 handle.
The #3 Bard-Parker handle is used for blades #10, #11, and #15. Large animal surgeons typically use a #4 handle, while small animal surgeons typically use a #3 handle.
The major difference in the 2 handles is size. A #4 handle is larger than the #3 handle, which allows it to accommodate larger surgical blades.
To see a visual selection of scalpel handles and blades, including Bard-Parkers, go to Dr. Brigitte Brisson’s helpful website, Vet Surgery Online, hosted by the University of Guelph.
https://www.vetsurgeryonline.com/index.html
Ref: Bassert, Beal and Samples, McCurnin’s Clinical Textbook for Veterinary Technicians, gthed, p. 1062.
Link: Scalpels
https://www.vetsurgeryonline.com/scalpels/
What condition is treated using a Velpau bandage?
Cranial cruciate rupture
Elbow luxation
Shoulder luxation
Early hip dysplasia subluxation
Hip luxation
Answer: Shoulder luxation.
Use a Velpeau bandage for luxated shoulder (uncommon, but usually also caused by
trauma/HBC).
Conservatively treat hip luxation with an Ehmer sling.
Post-operatively, typically wrap a repaired cranial cruciate ligament (CCL) rupture in a bulky Robert Jones bandage with or without a fiberglass splint for 24-48 hours.
Refs: Fossum Sm An Surgery 3rd ed. pp. 946-49 and Blackwell’s 5-Minute Vet Consult Canine Feline, 4th ed. pp. 314-15.
Link: Joint Trauma in Dogs and Cats
https://www.merckvetmanual.com/musculoskeletal-system/arthropathies-and-related-disorders-in-small-animals/joint-trauma-in-dogs-and-cats
Link: Joint Trauma in Dogs and Cats
https://www.merckvetmanual.com/musculoskeletal-system/arthropathies-and-related-disorders-in-small-animals/joint-trauma-in-dogs-and-cats
Triple pelvic osteotomy is an appropriate surgical intervention for what condition?
Hip dysplasia
Aseptic necrosis of the femoral head
Acetabular osteoarthritis
Legg-Calvè-Parthes disease
Panosteitis
Answer: hip dysplasia.
Hip dysplasia. An appropriate surgical intervention for a large breed dog with subluxation but no degenerative joint disease (DJD) would be a triple pelvic osteotomy (PO), which increases coverage of femoral head by rotating the acetabulum over it more.
Transverse intertrochanteric osteotomy is another surgery that might be appropriate in younger, symptomatic dog with no JD. Choose patients with significant increased angle of anteversion and/or inclination.
Femoral head and neck excision is a salvage procedure more appropriate for dogs less than 40 pounds. This surgery is performed in dogs with vascular/aseptic necrosis of the femoral head (Legg-Calvé-Perthes disease), some fractures of the femoral head, and sometimes old hip luxations after trauma, like hit by car.
Ref: Blackwell’s 5-Minute Vet Consult Canine Feline, 4th ed. pp. 624-25.
Link: Hip Dysplasia in Dogs
https://www.merckvetmanual.com/musculoskeletal-system/arthropathies-and-related-disorders-in-small-animals/hip-dysplasia-in-dogs
Link: Aseptic Necrosis of the Femoral Head in Dogs
https://www.merckvetmanual.com/musculoskeletal-system/arthropathies-and-related-disorders-in-small-animals/aseptic-necrosis-of-the-femoral-head-in-dogs
Centaurea spp (Russia knapweed, yellow star thistle) toxicity is most commonly observed in the western U.S. in which one of the following animals?
Cattle
Sheep
Pigs
Horses
Goats
Answer: Horses.
Horses are affected by ingestion of Centaurea spp.; common names are yellow star thistle and Russian knapweed. These plants are weeds normally found in the Mediterranean area and Russia, but have been introduced into the United States, primarily in the western U.S.
The toxic agents) of Centaurea spp. are found in fresh and dry plants. Toxicity develops only with chronic ingestion of large volumes; unfortunately, horses may develop a taste for the plant. Ruminants are NOT affected and can be used to control the spread of these weeds.
Sometimes called “chewing disease,” the signs of toxicity are quite characteristic - involuntary chewing movements, twitching/curling of the lips, and facial hypertonicity.
Affected horses cannot prehend or chew, but they are still able to swallow. They can be seen with their head deep into a water bucket trying to drink.
A dopaminergic neurotoxin causes malacia of neurons in the globs pallidus and the
substantia nigra, hence the name “nigropallidal encephalomalacia.” The brain damage irreversible, and euthanasia is recommended.
Click here to see an image of Centaurea spp.
https://www.merckvetmanual.com/multimedia/v4741511
Click here (scroll down) to see a Merck table of Poisonous Range Plants of Temperate
North America.
https://www.merckvetmanual.com/toxicology/poisonous-plants/range-plants-of-temperate-north-america
Which drug can predispose an animal to develop Tyzzer disease?
Answer: Sulfonamides
Immunosuppressive drugs and sulfonamide antibiotics predispose to Tyzzer disease caused by Clostridium piliforme.
Think of sporadic fatal infection in well-nourished but stressed young foals and acute fatal epidemics in lab animals. Rare in dogs, cats and calves.
Link: Tyzzer Disease in Animals
https://www.merckvetmanual.com/digestive-system/tyzzer-disease/tyzzer-disease-in-animals?autoredirectid=14186
Comprehensive Information on Tyzzer Disease in Animals for BCSE Test
1. Definitions:
• Tyzzer Disease: A highly fatal disease caused by Clostridium piliforme, affecting various animals with characteristic lesions in the liver, intestines, and heart.
- Causative Agent:
• Clostridium piliforme: A gram-variable, motile, spore-forming, rod-shaped bacterium. - Pathophysiology:
• Transmission: Fecal-oral route; ingestion of spores.
• Disease Process: Replication in intestinal mucosa, systemic spread via portal circulation, leading to hepatic necrosis and other organ involvement.
• Predisposing Factors: Stress, immunosuppression, high-protein diets. - Clinical Findings:
• Symptoms in Foals: Depression, anorexia, fever, jaundice, diarrhea, recumbency, convulsions, coma.
• Laboratory Animals: Sudden death, depression, ruffled coat, watery diarrhea. - Diagnosis:
• Clinical Signs: Consistent with liver failure.
• Laboratory Tests: PCR assay, histopathologic analysis of tissue sections.
• Post-Mortem Examination: Gross liver lesions, histopathologic confirmation with special stains. - Treatment:
• Supportive Care: IV fluids, antibiotics (tetracycline, penicillin).
• Prognosis: Poor; high fatality rate, especially in foals. - Prevention and Control:
• Hygiene: Proper sanitation, reducing stress and immunosuppression.
• Dietary Management: Avoid high-protein diets for nursing mares.
Eastern tent caterpillars have been associated with which disease?
Contagious agalactia of sheep
Postpartum dysgalactia syndrome of swine
Mare reproductive loss syndrome
Prolonged gestation association with fetal deformity
Ulcerative posthitis and vulvitis
Answer: Mare reproductive loss syndrome.
Mare reproductive loss syndrome (MRLS) is poorly understood, but has been associated with wild cherry trees, Eastern tent caterpillars and weather changes that affect pasture conditions.
Click here to see Eastern tent caterpillars and a wild cherry tree, Prunus avium.
Refs: Dwyer, etal., Case-control study of factors associated with early fetal losses associated with mare reproductive loss syndrome in central Kentucky during 2001 , JAVMA, Vol 222, No. 5, March 1, 2003.
Link: Abortion in Horses
https://www.merckvetmanual.com/reproductive-system/abortion-in-large-animals/abortion-in-horses
Link: Eastern tent caterpillar
https://en.wikipedia.org/wiki/Eastern_tent_caterpillar
A two-year-old male neutered cat is presented for annual vaccinations. History and physical exam are normal. A routine fecal exam reveals tiny oocysts that are 38-51 micrometers in length. What do you tell the owner?
Answer: Treatment is not necessary.
No treatment is needed for this asymptomatic coccidiosis in an adult cat. Follow this link to see coccidian oocysts (in a bearded dragon lizard, no less).
Coccidiosis is an incidental finding in healthy cats and dogs so Tx is typically unnecessary.
Young, stressed animals and the immunocompromised may show clinical signs.
Tx sick animals with sulfadimethoxine. Can use amprolium or ponazuril (both off-label) as alternatives.
Link: Coccidiosis of Dogs and Cats
https://www.merckvetmanual.com/digestive-system/coccidiosis/coccidiosis-of-cats-and-dogs
Coccidiosis of Cats and Dogs: Key Information for Veterinary Professionals
Definition and Causative Agents:
• Coccidiosis: Intestinal infection caused by protozoan parasites of the genus Cystoisospora.
• Species: Cystoisospora canis, C. ohioensis, C. felis, C. rivolta.
Clinical Findings:
• Symptoms: Diarrhea, abdominal pain, anorexia, vomiting, dehydration.
• Severe Cases: Hemorrhagic diarrhea, weight loss, and possible death in young or immunocompromised animals.
Diagnosis:
• Fecal Examination: Identification of oocysts via flotation techniques.
• PCR Assays: Molecular confirmation.
Treatment:
• Anticoccidial Drugs:
• Sulfadimethoxine: 55 mg/kg initially, then 27.5 mg/kg daily for 5-20 days.
• Toltrazuril: 10-20 mg/kg once daily for 2-3 days.
• Ponazuril: 50 mg/kg once daily for 3 days.
Prevention and Control:
• Sanitation: Regular cleaning of living areas.
• Reduce Stress: Minimize factors predisposing to infection.
Cytology from nasal exudate in a dog shows an organism with narrow, hyaline, septate, branching hyphae. What is the diagnosis?
Histoplasmosis
Cryptococcosis
Coccidioidomycosis
Aspergillosis
Blastomycosis
This is the fungal infection Aspergillosis, which typically localizes to the nasal cavity and sinuses in dogs. Dogs typically present with nasal discharge which progresses to epistaxis, sneezing, nasal pain, and depigmentation of the affected nares.
Look for narrow, hyaline, septate, branching hyphae. Remember that because the organism is ubiquitous in the environment culture of the organism alone does not confirm diagnosis. Look for organisms on cytology of the affected area with concurrent evidence of tissue invasion.
Image courtesy of CDC/Dr. Hardin.
Link: Aspergillosis in Animals
https://www.merckvetmanual.com/generalized-conditions/fungal-infections/aspergillosis-in-animals?autoredirectid=21102
Aspergillosis in Animals: Key Information for Veterinary Professionals
Definitions and Causative Agents:
• Aspergillosis: Fungal infection primarily caused by Aspergillus fumigatus and other Aspergillus spp.
• Penicillium spp: Rarely involved, similar presentation to Aspergillus.
Clinical Findings and Lesions:
• Birds: Bronchopulmonary infections, dyspnea, gasping, nodules in lungs/air sacs.
• Ruminants: Mycotic pneumonia, mastitis, abortion; signs include fever, nasal discharge, moist cough.
• Horses: Guttural pouch mycosis, mycotic keratitis; symptoms include epistaxis, dysphagia, ocular issues.
• Dogs: Nasal/paranasal infections, sneezing, nasal discharge, CNS signs; disseminated aspergillosis in German Shepherds.
• Cats: Sinonasal, sino-orbital disease; severe facial swelling, exophthalmos, neurologic signs.
Diagnosis:
• Tissue Invasion: Essential for diagnosis, supported by imaging (CT, MRI), histopathology, culture.
• Specific Tests: Endoscopy for horses, radiography for birds, histopathology for ruminants.
Treatment:
• Topical Antifungals: Clotrimazole, enilconazole for nasal infections in dogs.
• Systemic Antifungals: Itraconazole, voriconazole, posaconazole, amphotericin B.
• Surgical Intervention: Ligation or embolization for guttural pouch mycosis in horses.
What is the predominant white blood cell on this peripheral blood smear from a dog, and with what disease process is it often associated?
Monocyte; chronic viral disease
Eosinophil; allergy
Lymphocyte; stress
Band neutrophil; severe bacterial infection
Progranulocyte; neoplasia
Answer: Eosinophil; allergy
This is eosinophilia - most often seen with allergic disorders or parasitism. To identify eosinophils look for granulocytes with a pink cytoplasm.
Here is more information from Cornell’s Eclinpath website on eosinophils.
Also think of hypoadrenocorticism causing eosinophilia in contrast to a stress leukogram, which is characterized by eosinopenia, along with mature neutrophilia, lymphopenia, and monocytosis.
A stress leukogram is a common pattern seen in dogs (and cats) with any type of disease. Elevated blood cortisol causes the classic leukogram changes.
Monocytosis is associated with a stress leukogram, inflammation, or chronic infection. Monocytes become macrophages when they enter tissues or fluids.
Link: Leukocytes
https://eclinpath.com/hematology/morphologic-features/white-blood-cells/normal-leukocytes/
Normal Leukocytes in Animals: Key Information for Veterinary Professionals
Leukocyte Categories:
• Granulocytes:
• Neutrophils (Segmented and Bands): Predominant, innate immunity, first defense against bacteria.
• Eosinophils: Orange granules, defense against parasites, and allergic reactions.
• Basophils: Dark purple granules, involved in allergic responses and parasite defense.
• Mononuclear Cells:
• Lymphocytes: Adaptive immunity, produce antibodies, cytotoxic activity.
• Monocytes: Phagocytosis, differentiate into macrophages and dendritic cells in tissues.
Morphologic Features:
• Neutrophils: Segmented nuclei, pale pink cytoplasm.
• Eosinophils: Orange/red granules.
• Basophils: Purple granules.
• Lymphocytes: Round nuclei, small rim of cytoplasm.
• Monocytes: Large, kidney-shaped nucleus, gray-blue cytoplasm.
Assessment and Differentiation:
• Blood Smears: Identifying different leukocyte types and stages.
• Differential Cell Count: Classification based on morphology.
Diagnostic Relevance:
• Infection and Inflammation Indicators: Changes in leukocyte count and morphology signal infections, inflammation, or bone marrow disorders.
Corticosteroid-induced or Stress
Response in Animals
In this very common leukocyte response, endogenous steroid release from stress or treatment with exogenous corticosteroids results in a leukogram with multiple changes. Lymphopenia is the most consistent change, and mature neutrophilia is usually present. Monocytosis and eosinopenia are expected changes in dogs but are more variable in other species. Eosinopenia cannot be determined when the lower reference value is zero.
Neutrophilia is due to decreased adherence to the vascular endothelium, which inhibits margination and increases circulating time. As a result, neutrophils may also become hypersegmented. There may also be increased marrow release of neutrophils. Lymphocytes become redistributed to lymphoid tissues instead of remaining in circulation. This response may be misinterpreted as inflammation, but a left shift and toxic changes are not usually present.
What is the primary pathologic etiology of wobbler syndrome in young horses?
Sarcocystis neurona
Malformation of axis and atlas
Demyelination of dorsal funiculi, brain stem
Stenosis of cervical vertebral canal
Occipitoatlantoaxial malformation
Cervical vertebral stenotic myelopathy (a.k.a. cervical vertebral malformation-malarticulation, cervical vertebral compressive myelopathy, or equine wobbler syndrome) in young horses is caused by stenosis of cervical vertebral canal. Look for younger horses (1-3 years) with normal mentation, but pronounced hindlimb ataxia, a clumsy “tin soldier” gait, knuckling, and stumbling. You can make the hind end sway when pulling on the tail (positive tail test, suggesting paresis). Another version of this syndrome is also seen in older horses with arthritis of the cervical vertebrae.
Canine caudal cervical spondylomyelopathy (also called wobbler syndrome) may be due to a combination of stenosis of cervical vertebral canal, malformation of cervical bone or ligaments and/or a disc protrusion.
Click here to see a radiograph of canine cervical spondylomyelopathy.
Equine occipitoatlantoaxial malformation (OAAM) is due to a congenital C1-Occipital malformation, particularly in Arabian horses. In dogs, atlantoaxial subluxation is most commonly a congenital problem of young toy or miniature breeds. Occasionally occurs large breeds, like Rottweilers and Doberman Pinschers.
Click here to see a radiograph of OAAM in a dog.
https://www.merckvetmanual.com/nervous-system/congenital-and-inherited-anomalies-of-the-nervous-system/congenital-and-inherited-spinal-cord-disorders-in-animals
A 13-year-old Quarterhorse mare presents with an acute onset of continuous chewing movements, frequent yawning, and lip curling. Frothy saliva is present on her muzzle, and she often appears to grimace, repeatedly tensing her lips and facial muscles. Her gait is normal, however, she often walks aimlessly with her head low. She is unable to eat or drink normally. The owner has observed her submerging her head deeply into her water bucket, then tipping her head back in an attempt to drink. Ingestion of which one of the following plants is most likely to cause this spectrum of clinical signs?
Centaurea spp. (yellow star thistle, Russian knapweed)
Tetradymia glabrata (horsebrush)
Xanthium spp. (cocklebur)
Acer rubrum (red maple)
Quercus spp. (oak)
Answer: Centaurea spp. (yellow star thistle, Russian knapweed)
Chronic ingestion of Centaurea spp. (yellow star thistle, Russian knapweed) causes this presentation of clinical signs. Several toxic substances have been isolated from the plants, however, a dopaminergic neurotoxin is thought to be the principle toxin. Both fresh and dried plants are poisonous.
Also called “chewing disease,” characteristic signs of toxicity are involuntary chewing movements, twitching of the lips, facial hypertonicity, an open mouth with a protruding tongue, lip curling, frothy saliva, and frequent yawning.
Horses are unable to prehend or chew, although they can still swallow. The disease is also called Nigropallidal Encephalomalacia because malacia of two of the basal ganglia, the substantia nigra and the globus pallidus, is seen on necropsy.
The tendency to put the head all the way down into the water to try and drink is a classic sign of this disease.
The damage is irreversible, therefore euthanasia is recommended.
What clinical abnormality is evident in this picture of a foal’s face (it is a little blurry but still diagnostic)?
Anemia
Anisocytosis
Purpura hemorrhagica
Icterus
Severe dehydration
Answer: Incterus
This is icterus, which means yellow/jaundiced. In this case, the foal has a kind of hemolytic anemia called neonatal isoerythrolysis, a disease where the foal’s antibodies (from the mother’s colostrum) attack the foal’s own red blood cells.
The yellow color comes from excess bilirubin (a breakdown product of hemoglobin from phagocytized RBCs) in the tissues. Can be due to increased breakdown of erythrocytes or, in other cases, decreased clearance of bilirubin by the liver (i.e., with liver disease).
Purpura hemorrhagica presented with petechiae of the mucous membranes (i.e., gums), not icterus.
An anemic animal might have ghostly pale, white sclera and mucous membranes. A severely dehydrated animal would have tacky, dry mucous membranes.
What is the physiologic basis of von Willebrand disease?
Megakaryocyte dysplasia
Factor X, VII defect
Autoimmunity to subendothelial glycosaminoglycans
Coagulation factor deficiency
Congenital platelet adhesion disorder
Answer: Congenital platelet adhesion disorder
Von Willebrand disease (VWD) is a congenital platelet adhesion disorder; it is the most common hereditary coagulation disorder in dogs. Multiple breeds are affected. Von Willebrand factor (VWF) is needed for the first step in clot formation and animals with VWD are deficient in this factor. VWF is required for adhesion of platelet to subendothelial surfaces. Buccal mucosal bleeding time is significantly prolonged in dogs with VWD.
Suspect VWD in dogs with bleeding disorders with a normal platelet count and normal coagulation testing. Signs include gingival bleeding, epistaxis, and hematuria. Also think of excessive bleeding after vaccination, venipuncture, or surgery.
Chediak-Higashi syndrome is a congenital platelet function defect associated with dilute hair color e.g., smoke-blue Persian cats and beige mice. Not seen in dogs.
Pelger-Huet anomaly is a platelet and white cell defect. Granulocytes, especially neutrophils, are stuck in band form. A CBC shows an apparent left shift with a normal WBC count. Usually an incidental finding because cell function is normal. Click here for an image of Pelger-Huet anomaly in a dog.
Link: Platelet disorders in animals
https://www.merckvetmanual.com/circulatory-system/hemostatic-disorders/platelet-disorders-in-animals
Link: Leukogram abnormalities in animals
https://www.merckvetmanual.com/circulatory-system/leukocyte-disorders/leukogram-abnormalities-in-animals?autoredirectid=17110
