Farm Animal Dermatology Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

What are the possible diagnostics available when it comes to dermatology?

A
  • Skin scrapes
  • Sticky tape
  • Skin biopsy: including the edge of the lesion for both normal and abnormal histopathological comparison
  • Whole lesion removal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

When considering treatment for dermatological cases in farm animals, what must be considered?

A

1) Most chronic skin disease have a secondary bacterial dermatitis and therefore antibiotics are likely needed
2) Meat and milk withdrawals must be considered
3) The use of steroids in pregnant animals is contraindicated
4) Topical treatments are not practical on a herd/flock basis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the common and uncommon skin diseases of cattle?

A

Common:

  • Besnoitia besnoiti
  • Ectoparasites: Sarcoptic, Psoroptic, Chorioptes, Lice
  • Photosensitization
  • Ringworm
  • Vitamin and trace element deficiencies/ toxicities
  • Anagen Defluxion: stress-induced
  • Genetic Skin Diseases: Follicular Dysplasia or Epitheliogenesis Imperfecta
  • Immunological: Type 1 Hypersensitivity
  • Cellulitis
  • Cutaneous Actinobacillus
  • Actinomycosis = Lumpy Jaw
  • Bovine Papillomatosis
  • Eosinophilic Granuloma
  • Melanoma
  • Toxic Gangrenous Mastitis
  • Urticaria: Hives

Uncommon:

  • Ergotism
  • Cutaneous lymphoma
  • Squamous Cell Carcinoma
  • Type 2, 3, and 4 Hypersensitivities
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the common skin diseases of sheep?

A

Common:

  • Cobalt Deficiency
  • Seasonal Allergic Dermatitis: hypersensitivity to Cullicoides bites
  • Photosensitization
  • Ringworm
  • Psoroptes ovis = sheep scab
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Besnoitia besnoiti is an ___________

A

Obligate intracellular protozoan parasite

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How is Besnoitia Besnoiti transmitted?

A
  • Still 100% unknown, but experimentally can be transmitted mechanically through blood-sucking insects
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

There are 2 distinct sequential clinical stages to the Besnoitia Besnoiti infection, what are they?

A

Acute Stage:

  • Pyrexia
  • Subcutaneous oedema
  • Swollen Joints: limping
  • Conjunctivitis + Scleral cysts
  • Photophobia
  • Respiratory problems: due to pinpoint-sized cysts lining the mucosa

Chronic Stage:

  • Skin nodules may be seen on the legs, ears and back
  • Skin thickening = “Elephant skin”
  • Alopecia
  • Hyperpigmentation
  • Poor BCS
  • Scleral Cysts
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Where does Besnoitia Besnoiti reside in chronic infections?

A
  • Dermis
  • Subcutis
  • Vestibulum of vagina
  • Testis
  • Muscle
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How can Besnoitia Besnoiti be diagnosed?

A
  • White nodules in scleral conjunctiva (even in sub-clinical cases)
  • Histology of skin biopsy
  • ELISA and IFA for antibodies in serum
  • PM: looking for multifocal white pinpoint granular structures (tissue cysts) in the Upper Resp Tract
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the treatment for Besnoitia Besnoiti?

A

NO treatment

- Sulfamides to decrease the severity of clinical signs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How can Besnoitia Besnoiti be prevented/ controlled?

A
  • Test all new entries into herd
  • Avoid sharing pastures
  • Avoid natural mating
  • Cull animals with clinical signs
  • Bug repellents when animals kept indoors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the possible DDx to the Acute stage of Besnoitia Besnoiti?

A
  • IBR
  • Photosensitization
  • Blue Tongue Virus
  • Malignant Catarrhal Fever
  • Mycoplasma bovis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the possible DDx to the Chronic stage of Besnoitia Besnoiti?

A
  • Photosensitization
  • Mange
  • Ringworm
  • Vitamin or Trace element deficiencies
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How can Besnoitia Besnoiti be diagnosed?

A
  • Clinical signs: tissue cysts on scleral conjunctiva and/ or vaginal mucosa + skin thickening
  • Skin Biopsies
  • Serology: ELISA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the types of photosensitization in cattle?

A

All of these lead to the presence of a photodynamic agent in the skin

  • Primary: ingestion of St. Johns Wort, Bishops weed, or Tetracyclines
  • Secondary: impairment of liver function causes an accumulation of chlorophyll depositing in the skin
  • Tertiary: inherited altered pigment synthesis = Bovine Erythropoietic Protoporphyria, more commonly seen in Limousine cattle
  • Idiopathic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the treatment for Photosensitization?

A
  • Move indoors/ remove from direct sunlight
  • Corticosteroids (NSAIDs if pregnant)
  • Antibiotics if secondary infection: Amoxicillin LA
  • Treatment for liver fluke if that is the offending cause on the liver
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is Anagen Defluxion and why does it happen?

A

Widespread loss of hair over the neck, trunk, limbs and head = Baldy Calf Syndrome

Typically this will follow an acute episode of systemic stress/ pyrexia, e.g. calf diarrhea, pneumonia, septicemia leading to extensive hair loss

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the treatment for Anagen Defluxion?

A
  • Treat the underlying cause of the stress/ fever

- Multivitamin injection may help too

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

A calf is born with raw ulcerated areas of skin, the skin generally is quite thin and easily damaged
What is this suggestive of and what can be done?

A
  • Suggestive of Epitheliogenesis Imperfecta, which is an inherited condition

This condition is life threatening and most are euthanized

20
Q

What are the most common causes of hives (urticaria) in cattle?

A
  • Milk allergy: in the Channel island breeds
  • Insect bites
  • Certain drugs: pen-strep, oxytet, sulphas
  • Plants
  • Feeds (wheat, maize, soya and ricebean)
21
Q

How can hives (urticaria) be treated/ managed in cattle?

A
  • Avoidance of the offending cause, e.g. remove drugs, insects or move to a simple diet
  • Dexamethasone 0.1 mg/kg, or oral prednisolone 1mg/kg
  • Adrenaline in life-threatening angioedema
22
Q

What is the most common etiological agent in cellulitis in cattle?

A
  • Anaerobic bacteria (often it is Clostridium, in which case it is called malignant edema)
  • The bacteria will enter the SQ due to a penetrating wound, and track along the fascial planes causing severe edema and necrotic tissue
23
Q

What is the treatment of cellulitis in cattle?

A
  • Open up the tissue to the atmosphere and remove necrotic muscle
  • Provide parenteral penicillin or oxytetracycline

note: prognosis is guarded due to the poor response to antibiotics

24
Q

Why does Actinomyces. bovis cause lumpy jaw in cattle?

A
  • Localized lesions in the mouth due to scratches, shedding of teeth or coarse feed allow the bacterium to get into the jaw bone
  • Causing Infection and inflammation of the bone (osteomyelitis)
25
Q

Ergotism is caused by what fungus?

A

Claviceps purpurea

26
Q

What is the pathophysiology behind ergotism?

A
  • Ergot alkaloids in fungus contaminated feedstuffs are ingested
  • Ergot alkaloids cause vasoconstriction and capillary endothelial damage
  • Ischemic necrosis
  • Gangrene
27
Q

What is the treatment for Ergotism?

A

None

28
Q

What are the subtypes of Bovine Papillomavirus, and where are they found on the bovine?

A
  • Type 1: on the penis
  • Type 2: most commonly on the head and neck (pedunculated)
  • Type 3: anywhere on the body (non-pedunculated)
  • Type 4: causes benign papillomas of the alimentary tract in cattle. In certain regions of Scotland, when cattle graze on bracken, these papillomas progress at a high rate to malignant carcinoma
  • Type 5 + 6: small, found on the teats
29
Q

How long does it take for bovine Papillomavirus warts to resolve?

A

Anywhere from 1-12 months
The animal does need a cell-mediated response, therefore immunosuppression will prevent resolution e.g. stress or BVD infection

30
Q

How can Bovine Papillomavirus warts be treated or controlled?

A
  • Large warts with a narrow stalk can be twisted and pulled: use local anesthetic, good restraint +/- sedation if needed
  • Autogenous vaccines: fresh warts are harvested and sent to the lab for the production of a vaccine, then injected intradermal
  • Cryotherapy, Cautery or Surgical removal: for warts near the eyes, penis or scrotum
31
Q

How can you diagnose and treat a sheep with Cobalt deficiency?

A
  • Measure MMA (methyl malonic acid) in the urine
  • Measure Cobalt in the feed
  • Inject with Vitamin B12 and see if there is a response to treatment

Treatment: Vit B12 injection

32
Q

Seasonal Allergic Dermatitis is the same as _________ in horses

A
  • Sweet Itch

It is a hypersensitivity to the Cullicoides midges +/- a secondary bacterial infection of the skin

33
Q

How can Seasonal Allergic Dermatitis be treated/ prevented in sheep?

A
  • Remove from pastures where midges are most prevalent
  • Antibiotics for secondary bacterial infections
  • Wash affected areas with diluent chlorhexidine
    +/- steroids (unless pregnant)
  • The use of fly repellants
34
Q

What are the Biting and Sucking Lice species that usually affect cattle?

A

Biting: Damalinia bovis

Sucking: Hematopinus spp + Ligognathus vituli

35
Q

What are the clinical signs associated with a lice infestation in cattle?

A
  • Itchiness!
  • Over-grooming
  • Alopecia
  • Hairballs
  • Anemia
36
Q

Where on the cows body do the Sucking lice (Hematopinus spp + Ligognathus vituli) typically infest?

A
  • Head, neck
37
Q

Where on the cows body do the Biting lice (Damalinia bovis) typically infest?

A
  • Back and rump
38
Q

What is the term used to describe a lice infestation?

A

Pediculosis

39
Q

What are the important mites that affect cattle?

Where on the cow do these mites preferentially infest?

A
  • Sarcoptes scabei + Demodex bovis (burrowing mites) = ventral neck and chest and tail base
  • Chorioptes bovis + Psoroptes ovis (non-burrowing mites) = shoulder, tail base and perineum
40
Q

What are the blood-borne infectious agents which are transmitted by the Ixodes ricinus tick?

A
  • Babesia divergens
  • Louping ill virus
  • Tick-borne fever = anaplasma phagocytophilum
41
Q

How can ectoparasites be controlled/ treated in cattle?

A

1) Pour-Ons = Cypermethrin, Deltamethrin, Alphacypermethrin (All are zero milk withdrawal)
2) Washes = Amitraz
3) Avermectin Pour-On/ Injectable = good against sucking lice, not as good against biting lice. Psoroptes bovis and other mange need 2 treatments that are 10 days apart

42
Q

What is the important lice in pigs?

Where on the body of the pig does this louse like to infest?

A

Hog louse = Hematopinus suis (sucking lice)

Found on the skin folds of the neck

43
Q

What is the important mite in pigs?

A

Sarcoptes scabiei = scab mite

burrowing mite

44
Q

What is the treatment for Sarcoptes scabiei in pigs?

A

1) Injectable avermectin

2) Wash/ Spray: Amitraz or deltamethrin

45
Q

What is the important mite in sheep?

A

Psoroptes ovis

46
Q

Where on the sheep does the Psoroptes ovis mite like to live quietly during the summer and early autumn months?

A
  • Axilla
  • Groin
  • Infra-orbital fossa
  • Inner surface of the auditory canal
47
Q

How can Psoroptes ovis mite be treated/ controlled?

A
  • Ivermectin injection: 2 injections 10 days apart (doesnt kill the eggs, so must kill the newly hatched mites)
  • Short-acting Moxidectin: 2 injections, repeat after 10 days. Used in outbreaks
  • Long-acting Moxidectin: prevents infection/ reinfection for 60 days
    Note: injections have a long meat withdrawal of 37 - 104 days
  • Plunge Dipping sheep: Cypermethrin, Diazinon
    Note: dipping have a meat withdrawal of 2 weeks
  • Premises should be left vacant for 1 month to allow all mites to die in the environment and prevent reinfection