TV4101 - Avian 13 - Guinea Pigs

Guinea Pig Anatomy - Features?

Monogastric hind gut fermeters

• Requires finely tuned flora for perfect function

Has large cecum, up to 65% of GIT volume

Obligate nasal breather

Very small thoracic area

Guinea Reproductive Aspects?

• Very advanced offspring

• Must be bred or desexed early to avoid future dystocia issues due to

pelvic size

Guinea Pigs can start breeding at?

When can they be desexed?

4-8 weeks of age and may be

desexed at 5-6mths of age for a female and 3-4 mths for a male

A female guinea pig should have her first litter before?

Why?

6 months of age.

After this age the pelvic bones become fused and can cause problems during labour.

Desexing reduces the incidence of?

Sterilised guinea pigs and behaviour?

Ovarian cysts and reproductive tumours in females and faecal impaction in males

In almost all cases sterilised guinea pigs will bond better with

their owners and other guinea pigs

Signs of illness in Guinea pigs

• Weight loss

• Eating less

• Only eating soft foods, no longer eating hay

• Drooling

• Diarrhoea

• Less active than normal, lethargic

• Unkempt coat, not grooming

• Lumps or bumps anywhere on body

• Hair loss

• Scratching all the time

• Coughing

• Sores on their feet

Large percentage of guinea pigs are presented as?

Collapsed, moribund and severely hypothermic (<35 C) - End stage

What this?
CS?
DX?

TX?

Guinea pig mites

CX

• Oft presented “seizuring” as pruritis is so intense

• Hair loss, flaking skin, self excoriation - back, thighs, shoulders and neck

DX - clinical signs and skin scrapings

Treatment – mectins – ivermectin, selamectin – 2-3 treatments , 10 days

apart, antibiotics if infection • Treat all in contact animals

Vit C deficiency

Why does it occur?

Predisposed in?

Other features?

Guinea pigs cannot produce vitamin C independently and must obtain it from their diet

Young growing, pregnant, elderly, and/or sick guinea pigs are at a higher risk of vitamin C deficiency

Complete vitamin C deficiency generally leads to a more rapidly progressing form of the disease

Clinical symptoms of chronic Vit C deficiency including

Behaviour?

External appearance?

Other features

Behaviour

• Lameness, decreased mobility , partic hind legs

• Teeth grinding, vocalising from pain

• Anorexia or difficulty eating

External appearance

• Flaky, rough coat

• Painful swollen joints

• Bruising

• Bloody urine or diarrhoea

Other

• Delayed wound healing

• Secondary bacterial infections

• Gastrointestinal stasis

• Death

Vit C def TX?

Supplements and stuff

• Vitamin C supplementation via injection or oral medication is

often administered in the first instance.

• Oxbow Vitamin C supplement tablets

• Vitamin C may be added to drinking water, but the vitamin is

unstable in light and is most likely inactivated quickly.

Vit C def TX

Dietary requirements?

A good quality guinea pig food pellet should provide at least?

Fresh fruits and vegetables that are high invitamin C, such as ? should be given daily

Storage aspects?

Most guinea pigs require a daily vitamin C requirement of around

10-50mg/kg.

10-30 mg of vitamin C per day

Red or green capsicum, kale, broccoli, parsley and spinach

Vitamin C is easily destroyed by heat, light, and oxygen, so it's essential to store guinea pig food in a cool, dark place

What this? Describe it

CS?

Pododermatitis

• Pressure sores on feet, usually on heels of hind but front can also be affected

CS

Early signs - inflammation/redness of the exposed skin

As condition worsens:

• lameness, swelling, ulcers, bleeding and

  infection

Pododermatitis

A combination of factors may cause this, including?

Husbandry problems:

• Small cages,

• Hard floor surface

• Dirty/damp bedding

• Poor diet

• Inactivity

Conformation:

• Overweight animals,

• Very thin body condition

• Pregnancy

• Deformed leg

Physical:

• Trauma causing inflammation or lameness,

• Chronic joint (arthritis) or back pain resulting in inactivity or poor grooming

• Scalding of the feet by urine or faeces

What is this?

Seen in who

Why?

CS?

TX?

Faecal impaction

• Entire males, >2-3 years

Increased size of the testicles and fat deposit in the scrotal sac prevents faeces from falling out of the rectum. This ‘dilates’ this area causing more faeces to accumulate

Still pass normal faeces but usually show symptoms of straining to defecate or an unusual odour

• Prevented by early castration

• Manual cleaning 1-10 times weekly, depending on the boar

What is this?

CS?

Caused by?

DX?

Vestibular disease

CSX – head tilt, rolling, “seizures”, nystagmus

Common causes of Vestibular disease are bacterial infections, ear infections, protozoal infections, and trauma

• Often secondary to dental or respiratory disease tracking into middle ear

DX – ear examination, radiographs

Dental Disease

Why does it occur?

Result?

Guinea pigs fed mainly on pellets or guinea pig mixes lack the high fibre need for normal teeth wear

Curved inward lower cheek teeth aren’t worn down and eventually entrapping the tongue

Dental Disease

CSX

stops eating certain types of food or any food at all. Weight loss common, start producing fewer or smaller droppings, excessive saliva (drooling) leading to fur matting under the jaw.

Dental Disease

DX

Diagnosis

• Oral exam, difficult without appropriate equipment – nasal speculum attachment on otoscope

• Radiographs to confirm degree of overgrowth

Dental Disease
TX?

• Surgery to grind down teeth

• Requires special dental jigs to open mouth as oral cavity very

small

• Grind teeth back with dremel/dental burrs

• May need to be carried out as often as 6 weekly if chronic changes

Dental Disease Prevention

Feeding a diet that includes at least :

70% grass and good quality hay (oat, timothy or orchard hay)

20-30% fruit and vegetables

No more than 5-10% pellets

What is this?

How can we tell?

Other signs?

Functional ovarian cyst (secreting hormones)

Bilateral symmetric hair loss in the flank region, crusty nipples

Being irritable or seeming uncomfortable in their abdomen

With large cysts may show signs of anorexia, depression and lethargy

Ovarian Cysts

Signalment?

Ovarian cysts may be associated with?

Female entire guinea pigs aged 2-4 years

Uterine disease and can become significant space-occupying masses if left untreated

Ovarian cysts often increase in size

with time, and the pressure of the cyst

on other organs may cause ?

What else can form?

DX?

Pain and gut stasis

Adhesions can also form, which can cause problems at a later date

Confirmed by palpation, an abdominal ultrasound or radiographs

Ovarian Cyst TX?

Exploratory abdominal surgery to remove the cyst and perform

an ovariohysterectomy or ovariectomy (completely removes ovaries so better option)

Ultrasound-guided aspiration of the cysts under sedation -

provides a temporary solution however carries some risk

Gut Stasis

Caused by what?

Give explicit examples that should be avoided

Typically antibiotic induced

Explicitly avoided: clindamycin, lincomycin, ampicillin, amoxicillin, amoxicillin-clavulanic acid, cephalosporins, erythromycin, and penicillin if given orally

Gut Stasis

SAFE OPTIONS to prevent this shit?

Penicillin (SC or IM only), trimethoprimsulfamethoxazole, chloramphenicol, metronidazole, and fluoroquinolones

Pododermatitis TX

1. Address underlying issue - flooring, wt, RG for OA/spinal issues

2. Treat lesions → debriding surgery to remove dead tissue and then appropriate dressings up to 6 months

3. Infections may lead to osteomyelitis - ABs and pain relief

Clinical symptoms of antibiotic associated enterotoxemia begin?

Signs include?

DX?

If overgrowth of Clostridia - can be confirmed with?

1 to 5 days after antibiotic administration

Anorexia, dehydration, and hypothermia

Diarrhoea sometimes

Based on clinical history and clinical signs

PCR or ELISA for C. difficile toxin

Routine GI stasis

TX?

comprehensive supportive care (aggressive fluid hydration, pain management, and assisted nutrition)

• Warmed fluids 25-35ml/kg every 8 hours orally or SC

• More severe hydration may require IV

• Minimise anxiety with injectable midazolam (0.25–0.5 mg/kg

  IV/IM)

• Pain controlled with analgesics, buprenorphine then to meloxicam after adequate hydration (0.2 mg/kg IM/SC/by mouth every 24 hours

  in guinea pigs).

Routine GI stasis

Once obstruction has been ruled out, what next?

Prokinetic agents can be used

Including metoclopramide (0.5 mg/kg SC/by mouth every 8–12

hours) and/or cisapride (0.5 mg/kg by mouth every 8–12 hours)

Routine GI stasis - TX?

Reducing Gas Distension?

Simethicone (20 mg/kg by mouth every 8–12 hours) can be

used

Routine GI stasis

If Gastric ulcers are likely, what use?

Ranitidine (2 mg/kg IV every 24 hours, 2–5 mg/kg by mouth every 12 hours) used in cases with prolonged anorexia

Routine GI stasis - Nutrition?

Syringe feeding (15 mL/kg every 8 hours) of an herbivore critical care formulation

Prolonged nutritional support can be provided by nasogastric tube

Routine GI Stasis - ABs?

Antibiotics should only be used in cases complicated by

enterotoxemia and bacterial enteritis

For cases of enteritis caused by bacterial overgrowth, fecal

bacterial culture and sensitivity can be helpful to guide

antiobiotic therapy such as?

broad-spectrum agents, including

trimethoprim-sulfamethoxazole (30 mg/kg by mouth every 12 hours)

or enrofloxacin (15 mg/kg by mouth every 24 hours)

Enteritis from bacterial overgrowth?

Dysbiosis?

What can help suppress Clostridial Overgrowth?

Attempts to correct the dysbiosis including transfaunation and commercial probiotics containing Lactobacillus spp (anecdotal success)

Chloramphenicol (50 mg/kg by mouth every 8 hours)