Strategic Objectives

PARVO VIRAL DIARRHOEA

These guidelines for Parvo virosis (or any very ill puppy with severe acute diarrhoea) were compiled by members of and are currently in use at Onderstepoort in the Section of Small Animal Medicine, Department of Companion Animal Clinical Studies, Faculty of Veterinary Science, University of Pretoria.

Compiled by: Dr. Dave Miller This email address is being protected from spambots. You need JavaScript enabled to view it. P/Bag X 04, Onderstepoort, 0110, SA

Introduction:

Acute diarrhoea is second only to pruritus in prevalence in dogs presented to veterinarians. There is, however, a large difference in the pathophysiology and the consequences between a " run of the mill acute diarrhoea" and a puppy suffering from parvo viral diarrhoea.

Until recently we have treated all acute diarrhoea cases alike! No food until the vomiting and diarrhoea have stopped and then small amounts of low fat foods if the dog would eat voluntarily. This implies that many of these young puppies would go 3-10 days without food!

Over the years advances have occurred in the fields of pain control, fluid administration, antibiotic therapy and basic care of these patients. There has also been a paradigm shift in our thinking towards feeding! We have recognised that puppies with parvo are not just acute diarrhoea cases and not only must we feed them as soon as possible, but if they do not eat on their own, we should tube feed them!

Table1: Normal physiology of the small intestines.

The Mucosal lining of the GIT.

The intestinal epithelial cells carry out a multitude of functions:

Villus crypts: function primarily to secrete fluid into the bowel.
After division, the cells migrate up the villus from the crypt reaching the tip in 3-5 days. During migration, the cells mature and change their primary function from secretion to surface digestion and absorption.
Villus tip: carries out final stages of protein and carbohydrate digestion together with absorption of nutrients, salts and water.
Normal mucosal integrity and function are usually restored in 2-3 days, provided the inciting cause is eliminated and the initial insult was not sufficiently severe to damage the crypts.
Rapid cell turnover is the major reason why most acute diseases of the small intestine are self-limiting.

Acute Small Intestinal Diarrhoea.

This is an otherwise healthy dog that has diarrhoea. The dog has an acute onset of diarrhoea with or without vomiting and the dog may or may not be depressed (e.g. overeating, garbage disease [preformed toxin], diet change etc.).

Abrupt onset diarrhoea that has a short clinical course that ranges from transient and self-limiting to fulminating and explosive.
Typical treatment of acute diarrhoea:

Needs only supportive and symptomatic therapy, since most animals that die from diarrhoea do so not as a result of the inciting cause but from the loss of electrolytes and water, with subsequent dehydration, acidosis and shock.

Non-specific, symptomatic treatment of acute diarrhoea:

In cases, where foreign bodies and systemic diseases causing the diarrhoea have been ruled out, treatment may not always be indicated as many animals improve spontaneously in a day or two without treatment.

General treatment measures (if needed) include:

- Dietary restriction 6- 12 hours (preferably not longer in young puppies or toy breeds).

(Dogs over 4-6 months can go 12-20 hours without food.)

- Maintenance of fluid and electrolyte levels and acid-base homeostasis.

- Rarely anti-bacterials

- Anti-emetics

Anti-emetics

PLEASE DON’T LET THEM VOMIT!!!!!!!!!!!!!!

Once FB ruled out – dispense metoclopramide (0.2-0.5 mg/kg po or sc Tid/Qid)

Dietary Restriction:

- Rest the GI tract. Withhold food 6-12 hours (or more).

Biological system -Toy breed puppy 4-6 hours, adult Staffie 6 - 18h.

- Feed small, bland meals frequently when resume feeding (as soon as possible)

[We use commercial intestinal diets]

- Gradually convert to regular commercial puppy/adult food over 2-3 days once the

diarrhoea resolves.

Antibacterials: (For acute diarrhoea in non-collapsed dog)

Antibiotics have long been part of standard treatment of acute and chronic diarrhoea; yet there is no evidence for bacterial infection as a major cause of diarrhoea in small animals. Therefore, there is little or no indication for the routine use of oral antimicrobials in the treatment of diarrhoea in small animals.

Antibiotics are only indicated when extensive damage to the intestinal mucosal barrier occurs. Mucosal damage is thought to allow penetration of the intestinal wall by bacteria with subsequent entry into the systemic circulation. The following findings indicate the need for antibacterial therapy.

- Fever

- Collapse

- Left shift neurophilia with or without degenerative or toxic neutrophil changes.

- Haemorrhagic diarrhoea

Normal intestinal flora are protective of the host, inhibiting colonisation by pathogenic organisms. The disruption of bacterial flora exposes the host to more pathogenic processes and may prolong the return of normal intestinal function and homeostasis.

Fluid therapy:

Mild dehydration often causes anorexia.

Unless the patient needs i.v. fluids, we often give 5% rehydration fluids sub-cutaneously or intra-peritonealy and the patient is sent home.

[BW x 5% x 10 = fluid (ml) administered]

WHAT ABOUT PARVO?

Parvo virus colonises fast-dividing cell lines and through it’s replication process, destroys them. The typical parvo puppy thus loses:

- its bone marrow, lymphoid tissue and the enterocytes lining the GIT.

So one is left with an immunocompromised dog which is likely to develop septicaemia from enteric bacteria.

2002: Treatment Protocol for Canine Parvo Virus:

This is the "Ideal General Approach" to cases - Remember this is a "biological system" so be flexible!!!!!!!!

At admission

Place IV catheter / IV amoxycillin / Ht / TSP/glucose/K

Replacement fluid with 20 meq. KCL(1 vial) + 20 ml 50% dextrose in 1l ringer lactate.

[This gives a 1% dextrose solution - "Maintelyte with glucose 5%" glucose to high for rehydration and causes glycosuria]

Pain killers for abdominal pain – synthetic opioids (Temgesic).

1st 2 hours

Work out the sum of re-hydration + Maintenance (off table) for 1st 12 hours

Give ¼ to ½ of amount over first 2 hours to correct intra-vascular volume and blood pressure (warm fluids to body temp).

If in shock – apply first principles for shock therapy.

After 1st 2 hrs

Give rest of fluid over next 10 hours. Test Ht + TSP + K + Glucose

Warm patient on heating pad at this point [NB – not before as progresses shock!]

(Spike drip with more glucose if needed. [50ml 50% =2.5% or 100ml 50% = 5%]

Approx.

2-3 hrs

Metoclopramide either as an I.V. bolus or a constant rate infusion (CRI) - to treat ileus and/or vomiting (doses later in the document).

Approx. 4 - 5 hrs.

Start to feed (aim for at least 1/3 of requirements over next 24 hours)

Work out requirements with formula – [(bwx30) +70] x illness factor (1.25 – 1.5)

Approx. 12 hrs.

Re-assess hydration: continue rehydrating or change to

1 to 1 ½ x maintenance rate

Approx. 12 hrs

Gentamicin IV if patient is rehydrated to cover gram-negative bacteria.

(check for urine in bladder, CRT<2 sec’s)

Monitoring the Parvo puppy.

The following should ideally be monitored at admission, after 2 hours of fluids and then on a daily basis in patients that are still ill:

USE PAEDIATRIC SAMPLING TUBES OR TAKE VERY SMALL QUANTITIES OF BLOOD.

Fluid Therapy

Rehydration

- Body mass x 10 x % dehydration = volume in ml (give over 12 hours)

Maintenance

- Refer to fluid tables!!!! (appended at the end)

(The formula 40 – 60 ml/kg/24 hours is not valid in patients under 10 kg)

Ongoing losses

Estimated at 10 – 20 ml/kg/24 Hrs (if still vomiting and diarrhoea)

Fluid Selection

Calculate the re-hydration + maintenance + ongoing losses for first 12 hours and then rehydrate with:

 

è ¼ - ½ over first 2 hours then rest over 10 hours (check K infusion rates)

Only once rehydration is achieved can maintenance fluids be used:

Decision dependant on patient condition.
You should ideally place a central catheter.

Short notes on spiking drips.

Always label drip bag!
Never give potassium (K) as a bolus!
Supplement K as shown in the table below only after rehydration is complete! Potassium given too fast is cardiotoxic

– do not exceed 0.5meq of K /kg/h

POTASSIUM SUPPLEMENTATION (1 vial KCL 15 % = 20mEq)

Serum Potassium mEq/l of patient

Supplementation potassium (per 1000ml ) replacement fluid

(mmol KCL = meq K+)

MAXIMAL FLUID INFUSION RATE

(ml/kg/h)

3.5 – 5.5 (Normal)

20 mEq K (1 vial of 15%)

25

3.0 – 3.4

30 mEq K

18

2.5 – 2.9

40 mEq K

12

2.0 – 2.4

60 mEq K

8

<2.0

80 mEq K

6

Antibiotic Therapy.

Need to cover gram negative and positive as well as aerobic and anaerobic bacteria. The following antibiotics can be used:Amoxycillin - Amoxil 15 – 20 mg/kg IV TIDthen- penicillin’s p.o. s.c. i.v. 20 mg/kg BID(Change over when perfusion is deemed to be GOOD)Gentamicin - 3 mg/kg TID or 5 mg/kg BID, once patient is rehydrated

Bladder filling with urine shows rehydration and renal perfusion.

- Use until patient is clinically improved- 3-5 days max. (Not all patients will need Genta)Enrofloxacin - 2.5mg/kg BID IM/SC

used when gentamicin is contraindicated)

OWNER CONSENT IS NECESSARY!

Avoid in large breeds - cartilage damage.

Nutrition.

The previous "NIL PER OS" is not followed anymore!!

Start to feed once rehydration is underway (+/- 4-12 hours after admission)

(We try to never starve a puppy for longer than 6 hours once in hospital)

If possible aim for a minimum of 1/3 of nutritional requirements over next 24 hours

([Body weight x 30] + 70) x illness factor. 1.25 -1.5 depending on clinical findings.

If still vomiting a lot, miss out 1-2 hours, cut back slightly on quantity but do not starve!
Naso-oesophageal tube: can be placed at admission or 4-6 hours later.

Information on Kcal/ml of some of the commonly fed foods formulated for this purpose in the isolation unit can be obtained from Council’s office.

We send them home with the 800gram Intestinal formula puppy food bags and instructions to feed only that for at least 3-7 days.

Additional Therapy if Required:

Anti-emetics

Metoclopramide - first iv or sc and see the effect, if still vomiting, we use a CRI- 0.2 -0.4 mg/kg q6-8 hrly (iv/sc/im)- 1-2 mg/kg/day as a Constant rate infusion(CRI)Prochlorpronazine - 0.5 mg/kg im/sc q 8 hrly

(No prokinetic effect)

Plasma transfusion - 20 ml/kg if albumin < 20 g/dl

or - TSP < 40.

Blood transfusion to be administered if the patient is not improving and/or the Ht <15–20.
Hetastarch – 5-20 ml/kg bolus when patient is not improving but pain is controlled and the Ht, potassium, glucose and albumin levels are normal.

In cases "not doing well" we use a constant rate infusion (CRI) of ½-2 ml/kg/h.

Deworm – 1ml/kg panacur OID P.O. 5 d. (If vomiting – Ivomec - need owner consent)
Temgesic 0.01mg/kg iv 6 hrly if ANY abdominal pain (need only a few treatments)
Sucrulfate 1ml/3kg q6-8 hrly if dogs vomiting a lot (for reflux oesophagitis)

Cimetidine 10 mg/kg I.V. TID or Ranitidine 2 mg/kg BID I.V.

NB: ALL NSAIDs ESPECIALLY THE OLDER PRODUCTS LIKE PHENYLBUTAZONE, AND FLUNIXIN MEG. ARE NEPHROTOXIC AND CAUSE GASTRIC ULCERS AND MUST BE AVOIDED IN ALL DOGS AND CATS WITH LOW BLOOD PRESSURE.

[e.g. general anaesthesia, diarrhoea, vomiting, heat stroke, hit by car, Babesiosis, shock etc.]

DAILY WATER REQUIREMENTS FOR DOGS AND CATS

Daily Water

Requirements for the Dog*

Daily Water

Requirements for the Cat**


Body weight

(kg)

TOTAL

WATER

ml/day

/kg

/h


Bodyweight

(kg)

TOTAL

WATER

ml/day


/kg

/h

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

35

40

45

50

55

60

70

80

90

100

 

132

214

285

348

407

463

515

566

615

662

707

752

795

837

879

919

959

998

1037

1075

1112

1149

1185

1221

1256

1291

1326

1360

1394

1427

1590

1746

1896

2041

2182

2319

2583

2836

3080

3316

132

107

95

87

81

77

74

71

68

66

64

63

61

60

59

57

56

55

55

54

53

52

52

51

50

50

49

49

48

48

45

44

42

41

40

39

37

35

34

33

6

9

12

15

17

19

21

24

26

28

29

31

33

35

37

38

40

42

43

45

46

48

49

51

52

54

55

57

58

59

66

73

79

85

91

97

108

118

128

138

 

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

 

80

108

135

159

182

205

226

247

268

 

80

72

67

64

61

58

57

55

53

 

3

5

6

7

8

9

9

10

11

 

Source from Haskins SC. A simple fluid therapy planning guide. Semin Vet Med Surg (Small Anim) 3:232. 1988

* *Nutritional requirements of the cat. National Research Council. Bethesda, MD. 1985

Source from Haskins SC. A simple fluid therapy planning guide. Semin Vet Med Surg (Small Anim) 3:232. 1988

* Nutritional requirements of the dog. National Research Council. Bethesda, MD. 1985

2002 Treatment Protocol for Canine Parvo Virus:

This is the "Ideal General Approach" to cases - Remember this is a "biological system" so be flexible!!!!!!!!

At admission

Place IV catheter / IV amoxycillin / Ht / TSP/glucose/KReplacement fluid with 20 meq. KCL(1 vial) + 20 ml 50% dextrose in 1l ringer lactate.

[This gives a 1% dextrose solution - "Maintelyte with glucose 5%" glucose to high for rehydration and causes glycosuria]

Pain killers for abdominal pain – synthetic opioids (duprenophine / butorphanol).

1st 2 hours

Work out the sum of rehydration + Maintenance (off table) for 1st 12 hoursGive ¼ to ½ of amount over first 2 hours to correct intra-vascular volume and blood pressure (warm fluids to body temp).

If in shock – apply first principles for shock therapy.

After 1st 2 hrs

Give rest of fluid over next 10 hours. Test Ht + TSP + K + GlucoseWarm patient on heating pad at this point [NB – not before as peripheral vascular dilation progresses shock!]

(Spike drip with more glucose if needed. [50ml 50% dextrose =2.5% or 100ml 50% dextrose in 1 litre = 5%]

Approx.

2-3 hrs

Metoclopramide either as an I.V. bolus or a constant rate infusion (CRI) - to treat ileus and/or vomiting

Approx.

4 - 5 hrs.

Start to feed (aim for at least 1/3 of requirements over next 24 hours)

Work out requirements with formula – [(bwx30) +70] x illness factor (1.25 – 1.5)

Approx.

12 hrs.

Re-assess hydration: continue rehydrating or change to

1 to 1 ½ x maintenance fluid rate .

Approx.

12 hrs

Gentamicin IV once patient is rehydrated to cover gram-negative bacteria.

(check for urine filling of the bladder, CRT<2 sec’s)

(Published- September 2002, courtesy of Dr D Miller)

Links to African Council websites

Veterinary Statutory Bodies in Africa
http://www.rr-africa.oie.int/en/RC/en_vsbs.html

Veterinary Council of Namibia
http://www.van.org.na/section.php?secid=10

Veterinary Council of Zimbabwe (department of livestock and veterinary services)
http://www.dlvs.gov.zw/

Kenya Veterinary Board
http://kenyavetboard.org/

Veterinary Council of Tanzania
http://www.mifugouvuvi.go.tz/vertinary-council-of-tanzania/

Botswana Veterinary Association
http://www.bva.org.bw/bva_content.php?id=2

You are here: Home About Council Strategic Objectives SAVC Guidelines Guidelines - Parvo Viral Diarrhoea