L04: Digestive System Pt. 2 (Brown) Flashcards
Common oral cavity infections
- Gingival and periodontal: Gram - anaerobes ie. Porphyromonas; can be 2ary to FeLV or FIV in cats
- Histoplasma capsulatum –> oral granulomas in dogs
Stages of periodontal dz
1) gingivitis, no attachment loss
2) early periodontitis, 50% loss
Routes of infection of the liver
- portal vein
- hepatic a.
- ascending via biliary system
- contiguous spread from adjacent sites of infection
*can have systemic spread of virus
Common pathogens of the intestines
C. Perfringens
Enterotoxigenic E. Coli
Rotavirus
Vaccination decreases viral enteric infection**
Therapy of diarrhea
- fluids
- electrolyte replacement
- maintenance of acid/base balance
- control of discomfort
- motility-modifying drugs
*bacterial etiology usually not identified, abx effectiveness usually unproved; EXCEPTION: neonates will deteriorate rapidly before C&S results
Diarrhea in neonates
- loss of intestinal mucosal integrity inc. risk of septicemia or endotoxemia –> severe bloody d, fever, scleral injection, dehydration, altered leukogram (early leukopenia followed by leukocytosis)
- systemic abx w/ NSAIDs WARRANTED
Best abx. For neonatal diarrhea
Broad-spec abx:
- fluoroquinolones**
- penicillin or cephalosporin + aminoglycosides
- ampicillin
- tetracyclines
- potentiated sulfonamides
- chloramphenicol
parenteral administration may be needed if GI absorption altered in septic animals
Cause of hemorrhagic gastroenteritis
Unknown but Clostridium suspected + presence of enterotoxin
CS of hemorrhagic gastroenteritis
- Acute onset profuse bloody diarrhea
- vomiting, anorexia, lethargy, abd. Pain
- marked peracute fluid loss can precede CS of dehydration**
*small dogs at bigger risk
Most commonly prescribed abx in dogs/cats for dz assoc. gastrointestinal system
Dogs:
1) metronidazole
2) Tylosin
Cats:
1) Metronidazole
2) Clavamox
Features of metronidazole
- tx for systemic and enteric obligate anaerobics (ie. Clostridium, fusobacterium, bacteroides), and some protozoa
- MOA: destroys bacterial DNA fx
- can’t use in food animals
Features of Tylosin
- macrolide
- active against most aerobic and anaerobic G+, and atypical mycobacteria, mycoplasma, chlamydia, rickettsia sp.
- MOA: interferes w/ protein synthesis
- more active at high pH
Natural defense mechs. Of urinary tract
- urine washout
- bacterial interference via colonization of distal urethra
- glycoprotein layer
- epithelial desquamation
- local/systemic immune system
Antimicrobial properties of urine
- high osmolality
- urine pH
- urea, methionine, hippuric & ascorbic acid, ammonium nitrogen in urine have bacteriostatic properties
Natural genital defenses against infection
1) anatomic (stratified squamous epithelium, cervix, length of male urethra)
2) hormones (ie. Estrogen)
3) immune system
Normal flora in distal urethra
Coag-neg staph
Strep
Corynebacterium
Enterococcus
Normal flora in vulva/prepuce
Diphtheroids Micrococci Coliforms Proteus spp. Enterococci Yeasts Anaerobes
Normal flora in vagina
Alpha/beta hemolytic strep Coliforms Proteus spp. Diphtheroids Lactobacilli Mycoplasmas Yeast Fungi
dynamic flora influenced by hormones, estrus cycle, age, preg. State
Most common infectious dz in dogs
UTI
Routes:
- ascending (most common)
- hematogenous (rare)
*rare in cats except geriatric cats w/ renal failure
Common fungal and algal infections of the digestive system of the dog
Fungi: Histoplasma capsulatum –> d, oral ulcers, wt. loss
Algae: Prototheca –> bloody d, multiorgan system failure
none in cats
CS of UTI
- Dysuria
- Increased frequency and volume
- excessive thirst
- pyuria and/or hematuria
- crystalluria/uroliths
- lower back pain
Rule-outs for UTI
- neoplasm of bladder
- renal masses
- urinary obstruction
- urolithiasis
Which breeds predisposed to urolithiasis?
- Miniature schnauzer
- Dachshund
- Dalmatian
- Pug
- Bulldog
- Welsh corgi
- Basset hound
- Beagle
- Terriers
Gram POSITIVE Bacteria most likely to cause UTI
Enterococcus
Coag-pos staph
Gram NEGATIVE Bacteria most likely to cause UTI
E. Coli (42-26%)
Proteus mirabilis
Klebsiella sp.
Pseudomonas sp.
Most likely pathogens responsible for mastitis in dogs
E. Coli
Staphylococcus sp.
Abx to treat mastitis in dogs
Cephalexin or clavamox
**don’t use tetracycline, chloramphenicol, or aminoglycosides because abx can pass to offspring
Predisposing causes of metritis in SA
Prolonged delivery
Dystocia
Retained fetuses or placenta
Most common pathogens responsible for metritis in SA
E. Coli
Strep
Staph
Proteus spp.
Primary CS of metritis
Purulent vulvar discharge
Others: Depressed Febrile Lethargy Inappetence
Metritis diagnostics/clinical findings
- Large/flaccid uterus on palpation
- rads to determine if fetuses or placentas are retained
- chemistry: +/- leukocytosis with left shift
Tx of metritis in SA
- IV fluids
- supportive care
- abx based on C/S
- prostaglandin to evacuate uterine contents
- OVH after stable
Cause of pyometra
- Hormonally mediated diestrual disorder –> cystic endometrial hyperplasia w/ SECONDARY bacterial infection
- usually in older bitches (>5 yrs) 4-6 wks post estrus
Factors assoc. with occurrence of pyometra
- use of long lasting progestational compounds to delay or suppress estrus
- admin. Of estrogens to mismatched bitches
- postinsemination or postcopulation infections
Why is pyometra less common in queens than bitches?
Queens require copulatory stimulation to ovulate and produce progesterone from CL
Most common pathogens assoc. with pyometra
E. Coli #1
Others: staph, strep, pseudomonas, proteus spp., etc.
CS of pyometra
-Variable; lethargy, dehydration, anorexia, PU/PD, vomiting
-20% of cases have fever
+/- shock
-uterine enlargement, sanguinous to mucopurulent vaginal discharge
When most common time to see pyometra?
During diestrus (4-8 wks after estrus), or after admin. Of exogenous progestins
Chemistry findings of pyometra
- normal or leukogram
- leukocytosis with neutrophilia and left shift
- *leukopenia may occur if animal is septic
- mild normocytic normochromic nonregenerative anemia
- hyperproteinemia due to hyperglobulinemia
Chars. Of prostatitis
- hematogenous or ascending from urethra in origin
- can cause concurrent UTI
- usually suppurative and may cause abscesses
- painful!
Potential agents causing prostatitis
E. Coli
Staph
Strep
Mycoplasma/ureaplasma
CS of prostatitis
- pain, fever, dehydration
- septicemia/shock in severe cases
Clinical findings of prostatitis
- Chemistry: neutrophilia w/ L shift, monocytosis, +/- toxic WBC
- UA: hematuria, pyuria, bacteriuria
- US: hypoechoic areas = pockets of fluid
Tx of prostatitis
- fluid therapy if dehydration or shock
- abx selected from S testing
- surgically drain large abscesses
- consider castration after infection resolved
- chronic bacterial prostatitis difficult to resolve*
Which pathogens/viruses linked to abortion in SA?
Canine herpesvirus
Brucella canis
Mycoplasma ?
Which virus linked to immune complex glomerulonephritis in SA?
Canine adenovirus 1
Which virus linked to balanoposthitis and female infertility in SA?
Canine herpesvirus
+/- Mycoplasma
Which pathogens linked to epidydimitis in SA?
Brucella canis
E. Coli
Which pathogen assoc. with orchitis?
E. Coli
Which pathogens assoc. with prostatitis?
E. Coli
Mycoplasma
E. Coli can cause what urogenital issues?
Cystitis Epidydimitis Orchitis Prostatitis Pyometra Vaginitis
Leptospira sp. assoc. with what urogenital issues?
Interstitial nephritis
Renal failure
Feline infectious peritonitis virus causes what urogenital issue?
Immune-mediated pyogranulomas of kidney
Feline leukemia virus causes what urogenital issues?
Immune-mediated glomerulonephritis
Fetal absorption
Abortion
Renal lymphoma
Feline panleukemia virus causes what urogenital issues?
Abortion
Congenital abnormalities
Feline rhinotracheitis virus causes what urogenital issues?
Abortion
Most frequently prescribed abx for DOGS with UTI
1) Clavamox
2) Amoxicillin
3) Fluoroquinolones
4) Cephalexin
5) Convenia
Most frequently prescribed abx for CATS with UTI
1) clavamox
2) fluoroquinolones
3) cefovecin
4) amoxicillin
5) cephalexin
