RUMINANT MEDICINE Flashcards
study for semis
Congenital condition causing absence of skin and/or mucous membrane at birth. Can be accompanied by deformed or absent hooves/claws. Common in cattle (especially Holstein-Friesian)
Epitheliogenesis Imperfecta/ (Aplasia Cutis)
a genetic condition characterized by the partial or complete absence of the hair coat in animals, along with potential developmental defects. This condition is most significant in cattle, where it manifests in six distinct syndromes.
Inherited congenital hypotrichosis
Poll Dorset Sheep: _________ on the face, ears, and lower legs.
Baldness
- Found in Guernsey and Jersey cattle
- Complete absence of body hair except eyelashes and tactile hair
- Animals can survive with shelter but are sensitive to temperature extremes
- Normal horn/hoof growth
- Inherited as recessive trait
Viable Hypotrichosis
- Complete hair loss with abnormal thyroid
- Fatal shortly after birth
Nonviable Hypotrichosis
- X-linked condition affecting bull calves
- Missing teeth and hair follicles
- Caused by mutation in EDA gene
- Impairs growth and increases susceptibility to cold
Hypotrichosis with Anodontia
- Sex-linked semidominant trait in Holsteins
- Causes irregular narrow streaks of hair loss
Streaked Hairlessness
- Found in Hereford cattle
- Short, curly hair at birth with some coarse hair later
- Poor growth but survivable
- Recessive inheritance
Partial Hypotrichosis
- Affects Simmental crosses with black/blackpied cattle
- Characterized by diluted coat color and sparse, malformed hair
- Particularly affects tail switch
- Linked to PMel17 gene
- Lower winter growth rates
“Rat-Tail Syndrome”
- Disease characterized by alopecia and horny epidermal plates covering the skin
- Also known as “fish-scale disease”
- Affected Breeds in cattle:
Holstein
Norwegian Red Poll
Possibly Brown Swiss calves - Also occurs in humans
Cutaneous Ichthyosis/ Inherited Congenital Ichthyosis
Clinical Characteristics of Cutaneous Ichthyosis/ Inherited Congenital Ichthyosis
- Newborns appear partially or completely hairless
- Skin covered with thick, horny scales
- Scales separated by fissures along skin wrinkle lines
- Fissures may:
- Penetrate deeply
- Become ulcerated
- Normal hair follicles and hairs present initially but lost in scaled areas
characterized by a congenital deficiency of melanin pigmentation affecting multiple structures including the integumentary system and uveal tract. This condition manifests through distinct phenotypic presentations and follows specific inheritance patterns.
Albinism (Inherited Albinism)
Severity Categories of Albinism
- Complete: Total absence of melanin
- Partial: Residual melanin present
- Incomplete: Similar to partial, with significant melanin
Clinical Manifestations of Albinism
- Depigmented hair coat
- Non-pigmented skin
- Pink irises
- Photophobic behavior
represents a congenital connective tissue disorder characterized by defective collagen production.
Cutaneous Asthenia
Skin Abnormalities of Cutaneous Asthenia
- Marked fragility
- Hyperextensibility
- Present from birth
_______________ represents a group of congenital and hereditary mechanobullous diseases characterized by defective dermal-epidermal attachment structures.
Epidermolysis bullosa
- _________: Affecting epidermal basal cell layer
- _________: Located within basement membrane
- _________: Involving subepidermal anchoring fibrils
- Simplex
- Junctional
- Dystrophic
Pathological Features of Epidermolysis Bullosa Syndrome
- Dermal-epidermal separation
- Formation of flaccid bullae
- Development of glistening, flat erosions post-bullae rupture
Anatomical Predominant Lesion Distribution of Epidermolysis Bullosa Syndrome
- Gingivae
- Palate
- Lips
- Tongue
- Feet
Also known as inherited epidermal dysplasia, is an autosomal-recessive lethal condition primarily observed in Holstein–Friesian calves. This genetic disorder is characterized by a progressive loss of hair and overall condition in affected calves.
Baldy Calf Syndrome
Affected calves (Baldy Calf Syndrome) appear normal at birth; however, symptoms
typically ______________________________
manifest between 1 to 2 months of age.
Known as inherited dyserythropoiesis and dyskeratosis, is a genetic disorder observed in polled Hereford calves. It is believed to be inherited as a simple autosomal-recessive trait.
Congenital Anemia, Dyskeratosis, Progressive Alopecia
The clinical signs of congenital Anemia, Dyskeratosis, Progressive Alopecia typically commence ___________________
around 2 months of age
Encompass several conditions, including hereditary parakeratosis, lethal trait A46, edema disease, and hereditary thymic hypoplasia. These syndromes are observed in various breeds, notably Friesian, Shorthorn, Angus, and Black Pied cattle.
Hereditary Zinc Deficiency Syndrome
What is Hereditary Zinc Deficiency Syndrome?
Encompasses several conditions, including hereditary parakeratosis, edema disease, and hereditary thymic hypoplasia.
What are common breeds affected by Hereditary Zinc Deficiency Syndrome?
Friesian, Shorthorn, Angus, and Black Pied cattle.
What are the dermatological manifestations of Hereditary Zinc Deficiency Syndrome?
Symmetric, predominantly acral hyperkeratosis and crusting of the skin.
What general health issues are associated with Hereditary Zinc Deficiency Syndrome?
Unthriftiness, poor growth, and increased susceptibility to infections.
What specific clinical signs are observed in affected animals?
- Conjunctivitis
- Ptyalism (excessive salivation)
- Rhinitis (inflammation of the nasal mucosa)
- Diarrhea
What does Porphyria refer to?
A group of disorders caused by an abnormal accumulation of porphyrins.
What is the inheritance pattern of Congenital Porphyria in cattle?
Typically inherited as a recessive trait.
What is the economic impact of Congenital Porphyria?
Generally considered of low economic importance.
What are the clinical findings associated with Porphyria in cattle?
- Discolored urine (amber to port-wine)
- Discoloration of teeth and bones
- Severe photosensitivity
What dietary intervention may alleviate symptoms of zinc deficiency?
Dietary Zinc Supplementation.
What challenges exist in treating Hereditary Zinc Deficiency Syndrome?
Complete absorption failure necessitates injectable zinc, which is impractical for production animals.
What diagnostic methods are used for Hereditary Zinc Deficiency Syndrome?
- Exclusion of other conditions
- Skin biopsy
- Serum zinc levels measurement
What necropsy findings may indicate immune compromise in affected cattle?
Hypoplasia of the thymus and lymph nodes.
What urine analysis result is significant in affected cattle?
Significantly elevated levels of porphyrins.
What blood findings may be observed in cattle with Porphyria?
Macrocytic, normochromic anemia and reduced erythrocyte survival.
How can Porphyria be confirmed in a diagnosis?
High levels of porphyrins in blood and urine.
What management strategies are recommended for affected animals?
Keeping affected animals indoors to avoid sunlight exposure.
Why is breeding control important in the management of Hereditary Zinc Deficiency Syndrome?
Elimination of carrier animals from breeding programs is essential to prevent the condition’s occurrence.
What is Leucocyte Adhesion Deficiency (BLAD)?
A genetic disorder primarily impacting Holstein-Friesian cattle characterized by severe immune deficiencies.
BLAD is an autosomal recessive trait.
What type of inheritance pattern is associated with BLAD?
Autosomal recessive trait
Homozygous individuals are non-viable, while heterozygotes are carriers without clinical signs.
What are the clinical manifestations of BLAD?
Signs typically appear between 2 weeks and 8 months of age and include:
* Persistent fever
* Diarrhea
* Cough
* Difficulty breathing
* Delayed healing
* Stunted growth
* Severe periodontal gingivitis
* Chronic pneumonia
Oral health problems include significant bone resorption and premature tooth loss.
What is neutrophilia and its significance in BLAD?
Persistent increase in neutrophils without a left shift, indicating an infection response.
It reflects the body’s attempt to fight infection despite immune deficiencies.
What is urticaria?
A skin condition characterized by the development of dermal edema, resulting in wheals.
It primarily affects horses but can occur in other species, including cattle.
What are the common causes of urticaria?
Common causes include:
* Allergic reactions (insect stings, drug reactions)
* Non-allergic triggers (physical stress, temperature extremes, infections)
* Chronic cases (idiopathic)
Acute urticaria resolves within 12 to 24 hours, while chronic urticaria can persist for days or months.
What is the pathogenesis of urticaria?
Primarily due to the degranulation of mast cells, leading to:
* Capillary dilation
* Wheal formation
This process releases inflammatory mediators.
What genetic mutation is linked to BLAD?
A single point mutation in the CD18 gene, crucial for leukocyte adhesion.
This mutation leads to impaired immune responses.
What are the management strategies for BLAD?
Management strategies include:
* PCR testing to detect heterozygotes
* Eradication programs
* Genotype publication
* Avoiding carrier mating
These strategies aim to reduce the prevalence of BLAD.
Fill in the blank: Affected individuals of BLAD are typically _____ due to severe immune deficiencies.
non-viable
True or False: Heterozygotes for the BLAD mutation show clinical signs.
False
Heterozygotes are carriers and show no clinical signs.
What are the clinical findings associated with urticaria?
Clinical findings include:
* Wheals (0.5 to 5 cm in diameter)
* Minimal itching
* Acute onset of lesions
* Possible respiratory distress in severe cases
Lesions often appear on the neck and body.
What is the consequence of impaired leukocyte adhesion in BLAD?
Increased susceptibility to pathogens and chronic intestinal ulcers.
This leads to poor body condition and delayed wound healing.
What is dermatophilosis?
A bacterial skin condition commonly seen in cattle, sheep, goats, and horses
Lay terms include ‘lumpy wool’ and ‘strawberry foot rot.’
What bacterium causes dermatophilosis?
Dermatophilus congolensis
It is a gram-positive, facultative anaerobic actinomycete.
What are the two forms of Dermatophilus congolensis?
- Filamentous Hyphae: The vegetative form
- Motile Zoospores: The infectious form that can spread
How is dermatophilosis transmitted?
- Direct contact between infected and healthy animals
- Contaminated environments (wet or soiled areas)
- Biting insects and ectoparasites as vectors
- Asymptomatic animals carrying and transmitting the infection
What environmental factors increase susceptibility to dermatophilosis?
- Prolonged moisture
- Humidity
- High temperatures
- Ectoparasites (like ticks and lice)
In which regions are sporadic outbreaks of dermatophilosis linked to rainfall?
Temperate regions
Often linked to artificial wetting such as shower cooling.
Which cattle breeds are resistant to dermatophilosis?
- N’dama
- Muturu
Which cattle breeds are susceptible to dermatophilosis?
- Zebu
- White Fulani
- Renitleo
- European breeds
Which sheep breeds show resistance to dermatophilosis?
Native African breeds
Merino breeds are more susceptible.
What is the economic impact of dermatophilosis on sheep?
- Wool value reduction: Up to 30%
- Skin value reduction: Up to 40%
- Secondary losses: Shearing difficulties, increased risk of blow-fly strikes, potential lamb mortality
What are common clinical findings in affected populations?
- Most common in young, moisture-exposed, or immunosuppressed animals
- Lesion characteristics: Paintbrush lesions in cattle, pyramid-shaped scabs on wool in sheep
What must zoospores do to cause dermatophilosis?
Reach skin areas with compromised protective barriers (e.g., abrasions or wounds)
What is the role of phagocytosis in dermatophilosis infection?
The body attempts to resist infection through phagocytosis of zoospores; however, limited immunity develops once the infection is established.
What are the characteristics of chronic infections in sheep?
Intermittent invasions from affected hair follicles lead to scab formation and further spread of the infection.
What are the attack rates during outbreaks of dermatophilosis?
Can reach up to 50% during outbreaks.
What is the prevalence of dermatophilosis in tropical regions?
Can be as high as 15%, sometimes reaching 100% in certain herds.
Which factors worsen the severity of dermatophilosis in tropical regions?
- Tick infestations
- High/medium rainfall areas
What are the impacts of dermatophilosis on cattle?
- Direct deaths
- Reduced work capacity in draft animals
- Reproductive failures
- Decreased milk production (approximately 23% reduction)
- Hide damage
- Calf starvation
- Culling rates of 2-17% during severe outbreaks
What is the most practical method for diagnosing dermatophilosis?
Cytologic examination
Stained smears or histological sections can confirm the presence of D. congolensis.
What conditions may mimic dermatophilosis in differential diagnoses?
- Dermatomycoses
- Warts
- Other skin diseases
What is contagious ecthyma also known as?
Orf
What type of dermatitis does contagious ecthyma cause?
Viral, pustular dermatitis
Which animals are primarily affected by contagious ecthyma?
Young sheep and goats
Where do lesions typically develop in contagious ecthyma?
On the lips, but may also affect the coronet, face, and ears
What is the causative agent of contagious ecthyma?
Parapoxvirus, Family Poxviridae
How is the virus of contagious ecthyma transmitted?
By direct contact
How long can the virus remain viable in dried crusts?
Up to 12 years
What are the stages of lesion development in contagious ecthyma?
- Papules
- Vesicular Stage
- Pustular Stage
- Crusting
- Proliferation
- Healing
What occurs during the papule stage of lesion development?
Small, raised bumps form
What occurs during the vesicular stage of lesion development?
Papules turn into fluid-filled blisters
What impact does contagious ecthyma have on feeding?
Affected lambs may struggle to suckle or graze due to pain
What are potential consequences of feeding difficulties in lambs with ecthyma?
- Refusal to Eat
- Poor weight gain and development
- Secondary Infections
What microscopic feature is indicative of contagious ecthyma infection?
Eosinophilic Cytoplasmic Inclusion Bodies
What are some differential diagnoses for contagious ecthyma?
- Ulcerative Dermatosis
- Foot-and-Mouth Disease
- Bluetongue
- Staphylococcal Folliculitis