Horses 2 Flashcards
Ovarian haematoma size, what look like, treatment and cause
- Very large ovary (>15cm) ○ Differential for granulosa theca cell tumor - Wont luteinise - Might have to be removed surgically - Cause unknown
Silent oestrus how to detect, possible causes, how to treat
- Teasing technique
○ Not observing well
○ Foals at foot -> not showing oestrus
○ Dominant or submissive - may never or always look like in heat - Synchronize cycle (PGF2alpha) and tease every second day
- AI (if possible)
Persistence of the CL define, 3 causes and treatment
- Characterized by lifespan > 13-16days
- Can be caused in 3 ways:
1. Dioestral (mid-cycle) ovulation - day 10-11 from first follicular wave - not common
2. Chronic endometrial disease (loss of functional endometrium)
§ Pyometra, endometrium eroded so prostaglandin not being made
3. Early embryonic death: CL will persist until D70 - Treatment: PGF2alpha injection
Retention of endometrial cups when should remove and how long persist, how to identify, diagnosis and treat
- Should only be around to day 100-120 until immune system removes
- Persist throughout pregnancy and beyond
- Therefore foal and then shows no signs of heat - no foal heat
- Diagnose: generally not via ultrasound alone, use an endoscope
○ Generally at the base of the horn - Treatment: have to cut them out -> Referral case
Endometritis how common, when occur, and common bacterial causes
- Probably most common cause for infertility in the mare
- Most common: opportunistic bacteria take advantage of compromised immune defences but can be non-infectious
○ Post-partum breeding endometritis - Primary uterine pathogens possible
- Remember: bacteria are commonly introduced into mare’s uterus without causing disease
Commonly isolated pathogens - Streptococcus equi sp. zooepidemicus
- E. coli
3 below - primary causes - Pseudomonas aeruginosa
- Klebsiella pneumoniae
- Tayorella equigenitalis
Opportunistic -> treated for bacterial - Yeast
- Fungi
Endometritis what are important anatomical defences and how does doiestrus change this
Defence mechanisms
- Phagocytosis by macrophages and neutrophils
- Cilial activity of endometrial cups
- Antibody binding
- Muscle contractions
- Barriers - cervix, vestibulo-vaginal sphincter, vulva
Dioestrus dangers
- Defences are physiologically compromised in dioestrus
○ Decreased immune functions
○ Closed cervix prevents drainage
○ No flushing effect (that are present in oestrus)
○ Muscle contractions ↓
Endometritis diagnosis
- Possible signs:
○ Breeding history with infertility
○ Anatomical defects - negative pressure should be present so suck air in after put in endoscope
○ Vaginal discharge (also check tail) - Cytology: rarely false results
- Culture: may yield false positive or false negative
- Swab should be taken in dioestrus
Endometritis treatment
- Treat during oestrus when endogenous defences are high - can start end of dioestrus
- Aim at breeding during same oestrus
- Uterine flushes with or without antibiotics
○ Make sure intrauterine drugs do not cause irritation and/or fibrosis
§ Yeast -> give 0.5% iodine flush leads to irritation -> prostaglandin -> short cycle - Breed mares by minimal contamination technique (MCT)
Cervical defects what is general history and how to detect
- Often “classic history”: barren since last foaling for unexplained reason (esp. if hx. Of dystocia)
Manual Exam to be done during dioestrus -> may have cervical tear
What are the 3 main techniques for assessing stallions
- Physical examination of the reproductive organs
○ Tease stallion with a mare to get penis out - Observation of sexual behaviour and Mating ability
- Collection and examination of semen (field &Lab)
○ Tests for infectious disease
○ Tests for inherited disease
Where to collect samples for serology, what testing for
- Culture sites = pre-and post-ejaculatory urethral swabs, semen, penis, prepuce, accessory gland fluid.
- Pseudomonas aeruginosa, Klebsiella pneumoniae, Tayorella equigenitalis(CEM), EHV-3(coital exanthema) lesions?
- Serology: EHV-3 (equine herpes virus) - cause ulcerations on penis
Testicles how suspended and measured
- Testes are suspended in a horizontal plane
- Measured using scrotal calipers across their width (average 80-100mm) and length (80-140mm)
Total scrotal width what used for and how
- Assuming testicular consistency is satisfactory, TSW can be used to estimate sperm production and output
○ Length is related to the amount of sperm produced
○ Sperm output = concentration of sperm x by the volume on the 5-7 days following serial ejaculations
§ Daily sperm output = different to the amount of sperm within 1 ejaculate within a day
WIDTH not always normal -> may be pathological why so large
What is involved with examination of accessory sex glands
- Palpation/endoscopic ○ Pelvic urethra ○ Body of prostate -> prostate not as well involved in large animals ○ Seminal vesicles § Size, consistency ○ Lobulation and symmetry § Bulbo-urethral glands § Ampullae - diameter, consistency
Sperm production how much produced per day and how long does it take so what is important about this and 2 ways to collect semen
- 5-6 billion spermatozoa per day
- Takes about 2 months to produce -> IF HAVE ISSUE WHAT 2 MONTHS TO REEXAMINE
1) artifical vagina - most common
2) dummy mare or surrogate mare
How to prepare an artifical vagina for a stallion
- Temperature 42 to 48 degrees
- Pressure, lubrication
- Protection of sample from cold shock and sunlight
- Strict hygiene
What evaluating with sperm characteristics and stain used
- Vol of the ejaculate (40-200 ml) x concentration = total sperm count. ( 500mill per dose)
- Sperm cell morphology
- pH of semen - 7.2-7.9
- Bacterial cultures, e.g. for Taylorella equigenitalis(contagious equine metritis; CEM), Pseudomonas, Klebsiella spp.
- Motility analysis (motility = % moving acitvely forward), chromosomal analysis, sperm chromatin assays, acrosome reactions etc.
Stain nigrosineosin stained smear - black sperm DEAD
Semen extension for artifical insemination what are the 6 main functions
- Increases volume of the ejaculate
- Permits effective antibiotic treatment of semen containing pathogenic or potentially pathogenic organisms
- Prolongs survival of spermatozoa
- Protects spermatozoa from unfavourable environmental conditions
- Aids in proper evaluation of sperm motility
- Increases pregnancy rates due to more viable spermatozoa
Squamous cell carcinoma characteristic, where commonly occur, treatment and prevention
Characteristics - Locally aggressive but rarely metastasise
Where else do these commonly occur
- Eye lids, Nose, Third eyelid, Genitalia - penis, prepuce
Areas without hair protecting the unpigmented skin
Treatment
1. Surgical resection - wide margins and checked with histopathology
2. Local chemotherapy, cryotherapy
If small lesion on the eye
- Removal of eyelid
Prevention
- Keep out of the sun
- Keep inside during day and outside at night to graze - ideal
- Sunscreen
- Light rug in summer
- Face mask
Sarcoid what is it, characteristics and causes
Common tumour of horses
- Non-regressing and locally invasive
- Involve both the epidermis and dermis but will invade
Causes - association with bovine papilloma virus 1 and 2 (BPV-1,2)
- Always found in Sarcoids but also normal skin
Sarcoid treatment and what if located around the eye
Goals - destroy all tumours cells and minimise damage to healthy tissue
- Immunstimulant creams - imiquimod, flurouracil
OWNERS SHOULD WEAR GLOVES
- Resection of the sarcoid
○ If don’t remove all cells will then come back so need histopathology to ensure adequate margins
- Leave it until active (starts to change)
EYE
- Hard to resect with good margins
- Don’t use caustic creams near the eye
What are the 4 types of sarcoids and appearance
- Occult sarcoids, which are smooth, flat and usually hairless.
- Verrucous sarcoids, which have wart-like appearance.
- Fibroblastic or nodular sarcoids – these are sometimes referred to as two different types, with fibroblastic sarcoids usually being ulcerated and nodular sarcoids being lumps under otherwise normal-appearing skin. However, fibroblastic sarcoids are more likely a progression of the nodular form.
- Mixed sarcoids contain components of two or more of the above types. They most likely represent a transition between different types.
Melanoma common locations and therefore main presenting problems
Common locations
- Ventral tail, anus, perineum, external genitalia, parotid region
What are the main problems
- Generally benign
- Physically obstructing ability to defecate
NOT GOING TO KILL THE HORSE
Melanoma treatment 3 options
- Surgery resection? -> anal sphincter issues
- Palliative care - intralesional chemotherapy
- Cimetidine - unsure on how works but can help
Eosinophilic granulomas characteristics, cause and how to confrim diagnosis
Characteristics - Non-tumour nodular skin disease - Lumps - smooth nodules that are well-circumscribed, haired, firm and non-pruritic Cause - unknown Confirm with biopsy! - Presence of eosinophils
Eosinophilic granulomas treatment
- Anti-inflammatories -> prednisolone
- Insect control
- If small amount could excise them
- Corticosteroids can inject into the lesions -> avoid systemic (hard if multiple lesions
viral papillomas cause, transmission, treatment and prevention
Cause
- Viral papilloma’s that are species specific
Transmission
- Via direct contact
Treatment
- Nothing - spontaneously resolve
- If large - cryosurgery
No vaccines
Prevention
- Disinfection of track, brushes to minimise fomite transmission
Housing young horses individually rather than in large groups but may not be practical
Rain scald (dermatophilosis) clinical signs, cause and how transmitted
- Significant hair loss over face, dorsum, extending ventrally
- Crusting bald/ulcerative
- Housed outdoors, recent rainfall
- No scratching/itching but painful
Cause - Dermatophilus congolensis
Required for development- Moisture
- Skin abrasions
- A carrier animal
Transmission
- Flies, biting insects, fomites
Rain scald treatment and prevention
Treatment 1. Wash with benzamidine, chlorhexidine 2. Topical disinfectants 3. Get horse out of the rain Prevention - Collect ulcerations as act as carrier of the spores Keep dry with adequate shelter
Dermatophytosis (ringworm) cause, transmission
cause - trichophyton and Microsporon - Warmth and humidity
Transmission
- Contact with other infected animals or infected hair shafts
- Younger animals more susceptible - immunity after exposure
Dermatophytosis (ringworm) treatment
- Probably go away by itself but if want resolved quickly
1. Malaseb - medicated wash
2. Imaverol - systemic antifungal? - only if immunosuppressive - NOT IN PREGNANT ANIMALS
Still takes time for hair to grow back
Pastern dermatitis predispoing factor and treatment
Predisposing factors
- Draft or feathered breeds
- Excess hair aids in keeping the area wet and prepetuation of bacterial growth
Also predisposed to chorioptic mange that can lead to dermatitis
Treatment
1. GET OUT OF THE MUD
2. Dry and clip the hooves
3. Topical disinfectants - dilute chlorhexidine scrub and topical ointments such as silversulfadiazine
4. Systemic antibiotics in severe cases -> procaine penicillin G
○ Should do culture and sensitivity if infection remains
Cutaneous habronemiosis what known as, cause and locations
Also known as “summer sores” due to increased occurrence during warm months
Cause
- Deposition of larvae Habronema microstoma/muscae or Draschia by flies (intermediate host) into wounds or moist skin sites rather than mouth (normally)
- Results in hypersensitivity reactions to dead and dying larvae
Locations
- Media canthus of the eye
- Third eyelids
- Distal limb
- Penis or prepuce
Cutaneous habronemiosis diagnosis, treatment and prevention
Diagnosis
Biopsy with histopathology usually revealing granulomatous inflammation
Treatment
- Ivermectin (moxidectin)
- Corticosteroids may be needed to control hypersensitivity reaction
Prevention
- Good fly control - with prompt removal and disposal of manure containing larvae and insect repellent application to affected and at-risk horses
Culicoides hypersensitivity “queensland itch” what results from, where located and age of onset in what climates
- Hypersensitivity reaction to midge saliva proteins
○ May be a hereditary predisposition for developing hypersensitivity (most likely type 3 - antibody/antigen mediated)
○ Nature of the hypersensitivity response to unknown - Present mainly over the base of the mane, neck, dorsum and ventral midline
- Age of onset usually 2-4 years and more common in warm, tropical climates - where midges are
Culicoides hypersensitivity “queensland itch” problem list diagnosis
Problem list
- Pruritis - presenting complaint
- Crusty/ulcerated skin lesions
○ Dorsal distribution - head, neck, back, tail
- Tropical/subtropical geographical location
Diagnosis
- Clinical based on history, pruritis, typical distribution of lesions and geographical location
Culicoides hypersensitivity “queensland itch” what are the important treatment/prevention
Insect control
- Midges active at dawn and dusk
1. Spraying horses with insect repellents
2. Use of rugs and hoods to prevent contact with midges and the skin
3. Keeping horses indoors, especially during peak midge activity
4. Fans placed in barns -> prevent midges from entering?
Lice main problems and diagnosis
Main problems
- Pruritis - self-trauma is very common
- Patchy alopecia as damages the hair follicles
- Anaemia for chronic severe sucking lice infestations
Diagnosis
- Physical examination
- Presence of lice on the horse -> generally can find
- Type of lice via skin or hair scraping under microscope
Lice treatment what medications and how many applications
- Most only kill lice and NOT EGGS -> 2-3 treatment administered 2 weeks apart
○ In order to kill emerging nymphs and adults from pre-existing eggs
1. Ivermectin - administered systemically for SUCKING LICE ONLY
2. Topical insecticides may be used FOR NOTH TYPES - fipronil and pyrethroids spray - Single application include imidacloprid (advantage)
○ Kill the larvae and adults
ALL in-contact horses should also be treated
Atopic skin disease what type, how develop, desposition and common allergens
- Allergic, pruritic skin disease -> type 1 hypersensitivity - IgE mediated
- Develop sensitising antibodies to certain allergens
- Breed disposition -> thoroughbred and Arabian horses
Owners - can try doing elimination trials however some cannot be eliminated -> environment
1. Parasites
2. Insects
3. Drugs - common NSAIDS, phenothiazines, sulfa drugs, ANY DRUG
4. Vaccines
5. Plants - environmental
Feed - not as common as small animals
