Dog and Cat 2 Flashcards
Skin infections causes what are the most common and more occasional agents
- Staphylococcus pseudintermedius (common) - all over the dogs skin most concentrated around mouth and nose
- Malassezia pachydermatitis (common) - over the skin
○ OPPORTUNISTIC - MRSP (increasing big problem)
- Other Staphylococcal spp or yeast (occasional)
- Pseudomonas (occasional)
List 4 reasons dogs have a higher prevalence of skin infections
- Higher skin pH
- Less epidermal lipids -> atopic dogs have even less
- No follicular lipid plug -> prevents topical chemicals getting into hair follicle
- Atopic dermatitis is common in dogs -> 10% of population
List 6 reasons dogs get skin infections
- Anatomical reasons - skin folds (increased environment for infection) - brachycephalic dogs
- Microclimate changes - swimming especially with thick coat dogs - not drying thoroughly
- Decreased exfoliation/follicular obstruction - long term corticosteroid therapy (stop turnover of skin cells (exfoliation))
- Decreased Immunity
- Self-trauma (scratching) - break the skin and liberate proteins that the agents can use
- Atopic dermatitis
What are the 3 main types of skin infections and
- Surface
○ Malassezia are almost always SURFACE infection
○ Skin fold pyoderma, hot spots, otitis - classic - Superficial - MRSP common
- Deep - usually painful not itchy
Surface infections what is the main clinical presentation and common areas
Common presentation - No papules, pustules or cellulitis - Hyperpigmentation - Can be greasy or scaly/dry depending on the dog - Hot spots -> rapid development, aggressive, intensely pruritic Common areas - Skin folds - Most areas - humidity - Thickened skin
What breed is important in terms of surface skin infections and what occurs
Westies - Breed variation ○ Something in the skin that reacts with the bacteria ○ Non-specific inflammation ○ Hyperproliferative skin - Clinical importance ○ Difficult to control colonisation ○ Cytostatic therapy?
For surface infections what diagnostic techniques used, treatment and maintenance/prevention
Cytology 1. Tape preps 2. Roll preps 3. Direct impression Treatment Surface infections do better with surface treatment (topical treatment) - topical anti-bacterial/fungal Maintenance/prevention - Surgery (anatomical problems) - Control environmental wetting - Treat underlying disease (eg atopy) - Shampoos ○ Pyohex conditioner ○ Malaseb (miconazole, chlorhexidine) ○ Mediderm (piroctone olamine)
superficial infections what are the 2 main causes and how to diagnose the different presentations
Causes - Folliculitis ○ Demodicosis ○ Dermaophytosis - Pustules ○ Pemphigus foliaceous ○ Contact allergy - lesions look like pustules BUT NOT PUSS Diagnosis - Pustules ○ direct smear - Papules ○ direct smears ○ blunt scrape - Crusts ○ direct smear - Annular scale (dry lesions) ○ tape cytology
In terms of treating bacterial superficial infections what is an important drug and how long administer and why
- Cephalexin 22mg/kg bid (Rilexine) - PRIMARY CHOICE AS WORKS FOR MRSP
Treat for at least 7 days AFTER clinical resolution MINIMUM of 3 weeks - Watch out for MRSP
MRSP - Methicillin Resistant Staphylococcus pseudintermedius how transmitted, why an issue and risk factors
- Cultured from veterinary clinics -> carrier dogs will shed in this environment, susceptible animals then pick this up, not an issue until selected for via antimicrobials
○ Issue when gets into clinic and - Generally staph sensitive to beta-lactam antibiotics
○ Resistant -> low affinity penicillin binding protein - beta-lactams don’t work
○ Resistant genes can be transferred and have areas in DNA where other resistant genes can insert
§ Generally multi-drug resistant - Risk factors - going into veterinary clinics (waiting room), giving beta-lactam antibiotics with corticosteroids/apequal, going to dog groomers, antibiotic ear drops (absorb some into bloodstream)
Deep skin infections how generally present, how occur, causes and treatment
- Usually painful not itchy
- Is an extension from superficial infection after follicular rupture
- Often mechanical reasons
○ Over bony points
○ Weight bearing interdigital areas
Treatment
○ 6-8 weeks antibiotics
○ Anaerobic PLUS staph activity
○ Deep culture
○ Choosing antibiotic
§ Must be able to reach infection
§ Clindamycin good empirical choice
□ Get into cells (neutrophils/macrophage with bacteria within)
□ Good for Anaerobic bacteria
□ Can miss MRSP
§ NO STEROIDS!!
§ Re-assess each 2 weeks
§ Beware foreign bodies
What are some causes of repeat and recurrent infection
repeat - environmental riggers, anatomical reasons, foreign bodies, underlying disease recurrent infection - Atopy - Demodicosis - Other hypersensitivity diseases - Endocrinopathies - Keratinisation defects
Dermatophytosis - ringworm what are the 3 main types, animal within, does it fluroesces and zoonoses
Microsporum canis (cat) - Kittens, long haired cats (Persians) - Hair fluoresces - ZOONOTIC Trichophyton metagrophytes (rodents, GPs) - Dogs that hunt, rural exposure - Doesn't fluoresces - Not zoonotic Microsporum gypseum (soil) - Dogs that dig (face and forelegs)
3 ways to diagnose dermatophytosis and treatment
Diagnosis
- Wood’s lamp -> fluorescents so good for Microsporum
- Culture - good for Microsporum canis and trichophyton NOT MICROSPORUM GYPSEUM
- Biopsy - good for Microsporum gypseum
Treatment
- anti-fungal
- treat for 14 days past negative culture - ZOONOSIS
Give 5 indications for ovariohysterectomy
- Elective -Desexing/Population control
- Reduction of mammary neoplasia risk
- Treatment of behavioral conditions
- Treatment of other medical conditions
- Council registration
What is standard practice for desexing females, what occurs in shelters and claims for this
- Standard practice to desex females at age of about 6 months - before first or second oestrus
- More recently shelters 8-12 weeks -> debatable
○ Claimed decreased stress and operative time.
○ Assurance that the animal is desexed when it is re-homed.
○ Anaesthetic risk?
○ Decreased maturation of external genitalia
○ Increased incidence of oestrogen responsive urinary incontinence.
○ Increased risk of bony neoplasia in giant breeds?
What is an important difference with desexing female in season and what important if have a litter
○ Uterus more friable and increased blood supply - need to be confident with ligatures and haemostasis
○ Oestrogen can have a detrimental effect on haemostatic mechanisms.
○ If possible delay for 4 weeks after the onset of pro-oestrus.
§ Desexing an early pregnant bitch is easier than in season.○ After a litter, wait until 3 weeks after weaning to allow mammary tissue to involute.
How does the risk of mammary neoplasia change based on when spay
- Reduction in risk is a major benefit of canine OHE/OVE: (Lifetime risk of Mammary Neoplasia)
○ 0.5% if spayed cf intact before first oestrous -
○ 8% if spayed cf intact after the first oestrous
○ 26% if spayed cf intact after the second oestrous
○ No decrease in risk if spayed after 4 oestrous cycles
Entire cats have 7x the incidence of mammary tumours cf spayed queens
What are the 3 main ligaments of the female reproductive system and what connect
1) The broad ligaments consist of the mesovarium, mesosalpinx and the mesometrium.
2) The suspensory ligament is the cranial continuation of the broad ligament from the ovary –coalesces into a distinct band which inserts on the middle and ventral thirds of the last two ribs.
3) The proper ligament attaches the ovary to the uterine body - between ovary and uterine horn
Blood supply of the female reproductive tract what are the 2 main arteries and connections
1) Ovarian artery is a direct branch off the aorta.
§ The ovarian artery supplies the ovary and cranial aspect of the uterus
○ The right ovarian vein drains into the caudal vena cava.
○ The left ovarian vein drains into the left renal vein
2) Uterine artery
○ Branch of the internal pudendal artery
○ Positioned on the lateral aspect of the uterine body bilaterally
○ Enters the mesometrium at the level of the cervix
Anastomoses between the ovarian and uterine arteries are believed to exist
what are the lymphatics and innervation of the female reproductive tract
Lymphatics - Drain to the hypogastric and lumbar lymph nodes Innervation - Hypogastric plexus - sympathetic Pelvic nerves - parasympathetic
what is an important difference with canine and feline ovaries in terms of neutering
- Canine ovaries are difficult to expose (if on heat easier) and the cervix is easily mobilised
- Feline ovaries are easily exposed and the cervix is less mobile
ventral midline vs flank for neutering which better and why
- Ventral midline is MY preference over flank:
○ Better access to peritoneal cavity if problems occur
○ Can check haemostasis
○ Access to right ovary can be difficult through flank approach
○ Anecdotally increased incidence of seroma with flank procedures ( 3 x muscle layers)
○ BUT Flank approaches commonly performed in UK and at some welfare centresand private practices - Flank -> can be done depending on the clinic, generally done if have mastitis
what are the 7 main steps in ovariohesterectomy up to clamping ovary
1) express bladder
2) Canine - at or 1-2cm caudal to the umbilicus extending 5cm -> more cranial if younger due to suspensory ligament
- Feline - 3-4cm incision centred over the midpoint between the cranial rim of the pelvis and the umbilicus
3. Finding uterine horns
○ lies ventral to the rectum and dorsal to the bladder
4. Spay hook - introduce hook parallel to the body wall and rotate 90 degrees and move toward the midline
5. Exteriorise ovary –right is more difficult.
○ Stretch, break or cut suspensory ligament
6. Ligate the ovarian pedicle –create a window in the mesovariumcaudal to the ovarian vessels and triple clamp with Carmault-Rochester forceps.
7. 3 clamps proximal to ovary if possible otherwise one clamp between the ovary and uterus