Diseases of the neonatal calf and related mortality is major cause of economic losses in animal husbandry. Among these, diarrhoea is one the most common diseases reported in calves up to 3 months old.
Calf diarrhoea (scouring) is a multi-causative disease that can result in serious financial and animal welfare implications during early period of life. Calf diarrhoea is attributed to both infectious (viral, bacterial, protozoa) and non-infectious factors.
The environment and management practices, mineral imbalances also influence disease severity or the outcome of calf diarrhoea. The multifactorial complexities of calf diarrhoea makes the disease difficult to control effectively in modern husbandry practices.
Acute diarrhoea in calves is responsible for major cause of deaths in dairy husbandry during the pre-weaning period. Calf mortality during early 1-2 months may vary from 10-30% and 60% of these results from calf diarrhoea.
The economic losses occur not only from mortality but also from treatment costs and time spent on care as well as subsequent chronic ill thrift and impaired growth performance.
Calf diarrhoea is often recognized by passage of soft fluid to watery or sometimes bloody faeces, abnormal colour, rapid body weight loss and metabolic changes due to dehydration and electrolyte loss. The presented article aims to bring awareness about calf diarrhoea, its possible causative agents and factors and preventive measures.
Causal agents of Diarrhoea:
Calf diarrhoea during early life results mostly from infectious origin. Before parturition growing foetus is protected in near sterile, climate controlled environment of the dam’s womb. Immediately after birth the calf is exposed to heavy environmental pathogens and extremes of climatic situations and responds differently depending upon the vigor, passive and maternal immunity, management practices and genetic resistance.
The causative pathogens can be primary agents which may be bacterial, viral or protozoal pathogens or many may act as secondary agents to amplify the deteriorating changes in the system.
Most common causative agents in calf diarrhoea during early 3 months of life has been implicate to enteropathogenic Escherichia coli, rotavirus, coronavirus, salmonella species, cryptosporidium, coccidia, clostridium and few newly emerging enteric pathogens such as bovine torovirus and caliciviruses (bovine norovirus and nebovirus).
Inclement weather conditions such as low or high temperatures, heavy rain, wind and high moisture may act as stress factors to young calves and increase the susceptibility of calves to diarrhoea. There is also seasonal variation related to colostrum uptake by calf intestine. Early immunity in neonatal calves depends almost entirely on antibodies ingested through the colostrum intake.
Colostrum taken after 72 hrs provides local protection in the gastrointestinal tract against potential infectious agents. Failure of passive transfer of immunoglobulins through inadequate intake of colostrum predisposes the neonates to gastrointestinal and systemic infections.Passive transfer is influenced by the concentration of colostral immunoglobulins, the volume of colostrum intake and the time passed by after birth.
Larger herd size is associated with an increased incidence of calf diarrhoea attributed to favourable chance of transmission. The seasonal variation of rotavirus diarrhoea in India varies in different geographical regions with high incidence in winter months at low relative humidity in north India.
Table 1: Causative agents of calf diarrhoea and its epidemiology
|Causative agent||Susceptible age||Characteristic symptoms||Transmission|
|< 3-5 days old||
Non-inflammatory secretory diarrhoea with Profuse amounts of liquid feces passed, and the calves rapidly become depressed and recumbent.
|Salmonella sp||2–12 week of life, generally within 14 days of life||Feces that are foul smelling and contain blood, fibrin, and copious amounts of mucus. Septicemia, with high fever and depression progressing to prostration and coma, is the salient manifestation of salmonellosis||Fecal-oral route, but may also through contaminated saliva, milk/colostrum|
|Clostridium perfringens||Few days old and upto 8 weeks||fatal hemorrhagic enteritis, abdominal pain, and death within a few hours||Fecal-oral route|
|Rotavirus||5–15 days old but can affect calves up to several months of age||Mal absorption diarrhoea; Feces are voluminous, soft to liquid, and often contain large amounts of mucus. Affected calves are only moderately depressed and often continue to suck or drink milk.||Fecal-oral route, fecal aerosol|
|Coronavirus||1 to 2 weeks of age||Causes profuse watery diarrhoea with mucus. Affected calves will become dehydrated very quickly and will develop a fever and loss of appetite||Fecal-oral route, respiratory aerosol.|
|Cryptosporidium parvum||5–35 days old but most commonly in the second week of life.||persistent diarrhoea that does not respond to therapy, hypoglycemia||Fecal-oral route, dust in the air|
|Giardia duodenalis||Any age more common in 1 and 3 weeks of age||Associated with chronic mucoid diarrhoea||Fecal-oral route|
|Dietary diarrhoea||<3 weeks old||Voluminous feces of pasty to gelatinous consistency.||-|
Pathogenesis of Calf Diarrhoea:
Scour occurs when the intestine does not complete absorption of electrolytes and water from luminal contents in gastro-intestinal tract. Calf diarrhoea depending on the causal agents occurs due to following pathological events:
It occurs due to abnormal amount of fluid is secreted into the gut, exceeding the resorptive capacity of the intestinal mucosa impaired fluid and electrolyte absorption by gastro-intestinal tract.
It may result either frombacterial toxins produced by pathogenic bacteria or reduced absorptive surface area due to bile acids, laxatives, circulating hormones (histamine), drugs (chloramphenicol, neomycin, or tetracycline) and poisons in intestine. Most cases of acute and chronic diarrhoea are due to this mechanism.
Malabsorption or Exudative diarrhoea:
Destruction of mature enterocytes and/or activation of the enteric nervous system by vasoactive components from the damaged cells and secretion of a viral enterotoxin account for maldigestive/malabsorptive diarrhoea.
This occurs due to impaired capacity of the mucosa to absorb fluid and nutrients.Malabsorptive diarrhoea may be aggravated by the colonic fermentation of nutrients such as lactic acid and which acts as osmotically active substances and further aggravates the condition.
Dietary diarrhoea generally results from osmotic diarrhoea due to malabsorption.
Irrespective of mode of pathogenesis, calf suffers from net loss of water, sodium, potassium, and bicarbonate. In severe diarrhoea, the calf may develop hypovolemia, hyponatremia, acidemia, hypoglycemia and pre-renal azotemia.It may result in body weakness and septicemia.
Treatment strategies in calf diarrhoea aims to maintain and restore fluid and electrolyte losses in the body based on extent of dehydration and electrolyte imbalance, correction of acid- base disturbances (in general acidosis)alternation in diet, and eliminate source of infection by antimicrobials and herbal antidiarrhoeal.
Fluid therapy: Fluid therapy should be initiated as soon as possible regardless of evidence of clinical symptoms of dehydration in calf suffering from diarrhoea. Fluid therapy can be given either as oral fluid rehydration or by intravenous route. The choice depends on severity of dehydration, physical vigor of affected calf, palpebral reflex, body weight loss and acidosis. Generally dehydration in calves can be assessed using skin tent test as indicated below in table 2.
Table 2: Assessment of dehydration in calf
|Skin "tents" for 4 seconds or less, standing calf:||less than 5 % of body weight|
|Skin "tents" persisting for 5seconds, calf lying down upright||Upto 7% of body weight|
|Skin "tents" persisting for more than 5seconds, calf lying down flat||Severe dehydration upto 9% of body weight|
Table 3: Fluid replacement method and amount is calculated based on following guidelines:
|% dehydration||Amount of fluid requirement||Route|
|Less than 5% of body weight||50ml x Body weight + 50 ml x Body weight per day||Oral solution having bicarbonate, sodium, amino acid electrolyte and energy, example intalyte® powder (Intas Pharma)|
|Upto 7% of body weight||70ml x Body weight + 50 ml x Body weight per day||Oral and IV|
|Severe dehydration up to 9% of body weight||90ml x Body weight + 50 ml x Body weight per day||IV fluid and electrolyte therapy|
|If calf starts to urinate normal volume may be used as indicator of sufficient rehydration|
Colostrum feeding is most important aspect of providing immunity to new borne calves. Colostrum not only contains essential nutritional components required for calf survival but also immunoglobulins and growth factors. There are few rules for effective attainment of protection from colostrum feeding, which needs strict compliance.
- Good quality of colostrum refers to colostrum from dam giving less than 10 kg milk will have better immunoglobulin concentration to very high yielders
- Appropriate quantity of colostrum should be ingested or forced feed to the calf. The requirement is at least one tenth of body weight of calve and should be given in 2-3 divided doses.
- Strategic time refers to colostrum feeding as soon as possible after birth and before 24-48 hrs of birth.
- 2-3 litres in consequent days under our condition where weaning is not practice.
Many commercial available herbal anti-diarrhoeal products are available in market in different preparation and labels. Most are used for non-specific diarrhoea for reducing the severity of scouring, acts as absorbent, GI mucosa protectant and sometimes may have anti-bacterial effect.
Few common preparation are diarroak (Ayurvet), neblon powder (Natural remedies) etc. which are given in dose rate of 20-50 gm daily for 5-7 days. Most common herbal plants or its parts used as anti-diarrhoeal have either astringent activity or high content of tannin or mucilage or absorbent activity or anti-microbial activity.
These include pulp of semi-ripe bael (Aegle marmelos L), leaves of Sisho tree (Dalbergia sissoo), leaves and bark of Acacia catechu, whole plant of Alocasia sp, Cannabis sativa leaves (Bhang),sweet flag (Acorus calamus)etc.
Use of antimicrobials in calf diarrhoea has remained controversial. Antimicrobials are not indicated in neonatal diarrhoea of virus, protozoa or nutritional origin. Mixed infections with enteric pathogens are commonly diagnosed in calves with naturally acquired diarrhoeaand even diarrhoea associated primarily with viral origin, the clinical signs and pathologic damage are more severe when E coli is also present.
Calves with diarrhoea may also have failure or partial failure of transfer of colostral immunity and under such circumstances, there is more chance of development of bacteraemia or even septicaemia. However many antimicrobials are not safe to be given to neonatal calves and may itself cause diarrhoea by alteration of intestinal flora, example neomycin, chloramphenicol, penicillin, etc.
The four critical measures of success of antimicrobial therapy in calf diarrhoea are mortality rate, growth rate in affected calf, severity of diarrhoea in affected calf, and duration of diarrhoea in affected calf.
Success of antimicrobials in calf diarrhoea also depends on the route of administration and whether the dissolving capacity of antimicrobial in vehicle in which it is administered.
Antimicrobials which can have beneficial effect in calf diarrhoea are amoxicillin, fluoroquinolones (norfloxacin, enrofloxacin, ofloxacin and marbofloxacin) after oral administration.
Oral administration of potentiated sulfonamides is notrecommended for treating calf diarrhoea because of the lackof efficacy studies. It is advised to avoid use antimicrobials in calf diarrhoea without any systemic illness.
General Prevention Measures:
- Maximize the neonate calf natural resistance and colostral passive immunity prior to exposure.
- Avoid condition of dystocia, provide proper nutrition and body condition of pregnant cow in last trimester of pregnancy.
- Minimize exposure to infectious agents by
- minimizing density of susceptible calves
- Minimizing pathogens survivability in environment by maximizing drying and exposure to sunlight of calf shed and paddock.
- Calf born from pregnant heifer are more susceptible to these pathogen compared to pregnant cow.
- Remove infected animals especially with viral pathogens, few cows remain chronic carriers and they intermittently shed low numbers of the viral scour agents.
- Sanitize all equipments and feeding utensil to be used for calf rearing
- If possible separate calf shed will give protection from source of infection originating from cow shed.
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- Kumar, Manish; Bhilegaonkar, K.N; Agarwal, R.K. (2008). Prevalence and rapid detection of Salmonella and E.coli in diarrhoeal cases of children and calves and piglets.International symposium on “Food safety, Quality Assurance & Global Trade: Concerns and Strategies” on the occasion of Annual conference of Indian Association of Veterinary Public health Specialists, GBPUA&T, Pantnagar, Uttarakhand, India.
- Cahn, C.M., Line, S. (Eds.), 2005. The Merck Veterinary Manual. Pp 228-233.Merck & CO, INC
- Meganck, V., Hoflack, G. and Opsomer, G., (2014). Advances in prevention and therapy of neonatal dairy calf diarrhoea: a systematical review with emphasis on colostrum management and fluid therapy. Acta Veterinaria Scandinavica, 56(1): 75-83.
- Constable, P.D. (2004) Antimicrobial use in the treatment of calf diarrhea. Journal of veterinary internal medicine, 18(1):8-17.
Pankaj Kumar1, S J Pandian2, Bidya Shankar Sinha3, Rashmi Rekha Kumari4, and Manish Kumar5
1,2ICAR Research Complex for Eastern Region, P.O B V College, Patna-800014
3 SMS, KVK Shekpura; 4 Assistant Professor, BVC, Patna and 5Assistant Professor, IIT, Guwahati