Click here to return to the Wildlife Information Network home pageWildproSpeciesChemicalsPhysical"How to..." DiseasesEnvironmentsRefs & Gloss.HelpClick here for the Electronic Library

DISEASE SUMMARY PAGE

Pregnancy Toxaemia in Lagomorphs and Ferrets

Summary Information
Diseases / List of Miscellaneous / Metabolic / Multifactorial Diseases / Disease summary
Alternative Names Ketosis
Eclampsia
Disease Agents
In Rabbits:
  • Environmental stress, hyperthermia or inadequate nutrition may lead to pregnancy toxaemia. (J296.62.w2)

The definitive aetiology for pregnancy toxaemia in rabbits has not yet been determined. Theories include:

  • Insufficient arterial blood flow (due to poor development of the uterine vasculature, obesity, or a large fetal mass) to the uterus that results in a metabolic derangement. (B614.15.w15)
  • An abnormal hypophyseal function due to environmental changes leading to an endocrine imbalance. (B614.15.w15)
In Ferrets:
  • Pregnancy toxaemia develops in the late stages of gestation. (B232.11.w11, B602.5.w5, B631.27.w27, B631.28.w28)
    • Negative energy balance combined with stress, leading to fat breakdown, hepatic lipidosis and ketosis. (B232.11.w11)
    • Abnormal energy metabolism may lead to hyperlipidaemia, hypoglycaemia, ketosis or hepatic lipidosis (indicates underlying metabolic disease). (B631.27.w27)
    • This can be due to accidental starvation, if the owner changes the ferret's diet in late stages of pregnancy and the ferret refuses to eat the new diet. (B602.5.w5, B631.27.w27)
  • Pregnancy toxaemia is more likely to occur in ferrets that are pregnant for the first time (B631.28.w28), if they are stressed, have large fetuses, or a large number of kits. (B602.5.w5, B631.27.w27)
    • This can be associated with the need for increased energy. (B631.27.w27)
    • If the primiparous ferret, on an average or poor diet, has a period of anorexia late in gestation, for whatever reason. (B232.11.w11)
    • Even jills on a good diet may develop pregnancy toxaemia if they develop anorexia while carrying a large litter. (B232.11.w11)
    • Note: a period of anorexia as short as 24 hours can trigger this condition. (B232.11.w11)
Infectious Agent(s) --
Non-infectious Agent(s)
Physical Agent(s) --
General Description
Clinical signs
In Rabbits:
The clinical appearance of this condition varies greatly with some rabbits only demonstrating a mild, nearly asymptomatic condition through to the other end of the spectrum where rabbits may be afflicted with a severe, rapidly fatal disease. Recovery has been reported in mild to moderate cases. (B614.15.w15)
In Ferrets:
  • The onset is usually sudden. (B232.11.w11, B631.27.w27, J14.45.w2)

General signs:

  • Lethargy and weakness. (B232.11.w11, B627.10.w10, B631.27.w27, J14.45.w2)
    • Especially in late gestation/just before the jill's due date. (B232.11.w11, B602.5.w5)
    • This may be due to hypoglycaemia. (J14.45.w2)
  • Sternal recumbency. (J14.45.w2)
  • Dehydration. (B232.11.w11, B602.5.w5, B627.10.w10, B631.27.w27, J14.45.w2)
  • Hair loss. (B627.10.w10, B631.27.w27, J14.45.w2)
  • Neurological signs. (B631.28.w28)
  • Hypothermia. (B602.5.w5, J14.45.w2)
  • Glazed eyes. (B602.5.w5, J14.45.w2)
  • Sudden death. (B602.5.w5, B631.27.w27, J14.45.w2)

Gastrointestinal:

Respiratory:

  • Shallow breathing. (J14.45.w2)
Clinical Pathology
In Rabbits:
  • Marked increase in serum non-protein nitrogen and phosphate. (B614.15.w15)
  • Decreased serum calcium. (B614.15.w15)
  • Acidosis, ketonaemia, hyperkalaemia, hypocalcaemia and hyperphosphataemia may be noted. (B604.5.w5, B614.15.w15)
  • Tests for serum acetone are positive. (B614.15.w15)
  • Urinalysis: colourless, clearer than nomal (reduced calcium carbonate crystals), pH 5 - 6 (acidic, i.e. lower than normal), ketones and protein present. (B601.9.w9, B603.3.w3, B604.5.w5, B606.13.w13)
In Ferrets:
  • The blood glucose concentration may be less than 50 mg/dL. (B602.5.w5, B627.10.w10)
    • Terminally, hyperglycaemia (above 150 mg/dL) may occur. (B627.10.w10)
  • Ketonuric. (B602.5.w5, J14.45.w2)
  • Primary renal failure, followed by glucose intolerance. (B602.5.w5)
  • Anaemia. (J14.45.w2)
    • Low haematocrit (under 30%; reference values for pregnant jills are over 40%). (B627.10.w10)
  • High levels of nitrogen compounds in the blood. (J14.45.w2)
    • Blood urea nitrogen may be above 100 mg/dL. (B627.10.w10)
  • Bilirubinemia. (J14.45.w2)
  • Hypoproteinemia. (J14.45.w2)
  • High liver enzymes. (J14.45.w2)
Pathology
In Rabbits:
  • Gross
    • General: obese rabbits with actively secreting mammary glands (even in pseudopregnant does). (B614.15.w15)
    • Stomach: reduced gastric content. (B604.5.w5)
    • Mesenteric fat: areas of necrosis. (B614.15.w15)
    • Liver, kidneys and heart:
      • Pale. (B614.15.w15)
      • Liver: tan colour; greasy on cut surfaces. (B604.5.w5)
    • Thyroid and adrenal glands:
      • small and pale; (B614.15.w15)
      • adrenal enlargement and haemorrhage. (B604.5.w5)
    • Pituitary gland: enlargement of this gland is common. (B614.15.w15)
    • Ovaries: large corpora lutea. (B614.15.w15)
    • Uterus: uterine and placental haemorrhage; dead and decomposed fetuses. (B604.5.w5)
  • Microscopic
    • Vascular system: disseminated intravascular coagulation. (B604.5.w5)
    • Liver: focal necrosis; severe fatty infiltration. (B601.9.w9, B604.5.w5, B614.15.w15)
    • Heart: fatty infiltration. (B614.15.w15)
    • Kidneys:
      • fatty infiltration; (B614.15.w15)
      • glomerular and tubular cells may be necrotic; (B604.5.w5)
      • proteinaceous casts in the Bowman's capsule and tubular lumina. (B604.5.w5)
    • Adrenal glands: fatty infiltration in the cortex especially within the thickened zone fasciculata; there are often cortical adenomas. (B614.15.w15)
    • Thyroid glands: follicles lined by low cuboidal epithelium and filled with pale colloid. (B614.15.w15)
    • Pars distalis: has been reported to contain many acidophils and multiple adenomas. (B614.15.w15)
    • Pars intermedia: thickened. (B614.15.w15)
In Ferrets:
Further Information
Susceptibility/Transmission
In Rabbits:

Pregnancy toxaemia occurs due to a combination of decreased gastrointestinal space and a high energy requirements. (B603.3.w3)

  • Does in late gestation:
    • This condition primarily occurs in does in late gestation (often in the their final week of pregnancy); however it is also seen in postpartum and pseudopregnant does. (B601.11.w11, B602.20.w20, B603.3.w3, B604.5.w5; B614.15.w15)
    • It is thought that a large fetal load may either overextend or compress the blood supply to the uterus. (B604.5.w5)
  • Multiparous does:
    • The incidence in multiparous does has been reported to be around four times that of primiparous does. (B614.15.w15)
    • However, another source states that this condition is often seen in the primiparous doe. (B603.3.w3)
  • Breed:
    • Dutch, Polish, and English breeds have been reported to have the highest incidence of pregnancy toxaemia. (B604.5.w5, B614.15.w15)
    • There is also a reportedly increased incidence of this condition in carriers of cretinism in the Dutch breed and dwarfism in the Polish breed. (B614.15.w15)
  • Age: Very young or very old does may be predisposed. (J296.62.w2)
  • Obese rabbits are predisposed to this condition. (B601.11.w11, B602.20.w20, B604.5.w5, B614.15.w15, J296.62.w2)
  • Fasting / anorexic animals are predisposed to this condition. (B601.11.w11, B602.20.w20, B604.5.w5)
  • Sudden stress may lead to pregnancy toxaemia. (B602.18.w18)
  • Other predisposing factors include:
    • Change in diet (B604.5.w5)
    • Change in feeding regime (B604.5.w5)
    • Lack of exercise (B604.5.w5)
    • Environmental stress or hyperthermia. (J296.62.w2)
Occurrence
In Rabbits:
  • Pregnancy toxaemia is a condition that is seldom recognised in domestic rabbits. (B603.3.w3, B606.13.w13, B614.15.w15)
Diagnosis
In Rabbits:
  • Based on clinical signs and results of necropsy. (B604.5.w5)
In Ferrets:
  • Typical clinical signs in a jill during late pregnancy. (B232.11.w11)
  • Ultrasonography may indicate the number and size of the fetuses present. (B631.27.w27)
  • Urinalysis, biochemistry and haematology can be used for diagnosis. (B631.27.w27)
    • Anaemia. (B631.27.w27)
    • Hypoproteinaemia. (B631.27.w27)
    • Azotaemia. (B631.27.w27)
    • Hypocalcaemia. (B631.27.w27)
    • Increased liver enzymes. (B631.27.w27)
Differential diagnosis
In Ferrets:
Treatment
In Rabbits:
In Ferrets:
  • A Caesarean section needs to be carried out as soon as possible. (B602.5.w5, B631.27.w27, J14.45.w2)
    • Gaseous anaesthetic should be used. (B232.11.w11, B602.5.w5, J14.45.w2)
      • The jill may have reduced ability to metabolise injectable anaesthetic drugs. (B232.11.w11, B627.10.w10)
    • Mid-line incision provides the best access to both the uterine horns. (B602.5.w5, J14.45.w2) 
    • Each uterine horn should be incised with an incision midway along the horn. (B602.5.w5)
    • Keep the ferret warm during surgery, but monitor closely. Note: Care should be taken not to over heat the ferret. (B602.5.w5)
  • Post-operative supportive care is important. (B602.5.w5, B631.27.w27)
  • Note: Ferrets often have no milk for several days after surgery. (B602.5.w5, B631.27.w2)
    • The kits will need to be fostered with other jills. (B631.27.w27)
    • Ensure some of the kits are rotated between the mother and foster mother to encourage development of lactation. (B602.5.w5)
    • Feeding the kits at least six times a day is required if leaving them with the jill to see if milk production starts. (B627.10.w10)
      • Hand- rearing kits can be very difficult and is usually unsuccessful. (B602.5.w5, B631.27.w27)
    • See: Rearing of Mammals (Mammal Husbandry and Management)
Prognosis
  • Prognosis is poor for ferrets showing clinical signs, such as lethargy. (B602.5.w5, J14.45.w2)
  • Immediate surgery is necessary for a good prognosis, but this can depend on the extent of liver damage. (B602.5.w5)
  • If the kits are born before forty days or there is no foster mother available, the kits should be euthanased. Hand-rearing kits is very difficult. (B602.5.w5)
Prevention
In Rabbits:
  • Avoid fasting or underfeeding does while they are pregnant. (B602.18.w18, B604.5.w5, B614.15.w15)
  • Avoid breeding obese does. (J296.62.w2)
  • Prevent obesity in pregnant does. (B602.20.w20, B603.3.w3, B604.5.w5)
  • Provide a high energy diet during late gestation. (B601.11.w11, B602.18.w18, B604.5.w5)
  • Increase exercise in breeding does. (B603.3.w3)
  • Avoid stress (as this may lead to anorexia) particularly in primiparous or second litter breeders. (B603.3.w3, B604.5.w5)
In Ferrets:
  • Owners should be educated regarding goof ferret nutrition. (B602.5.w5, B631.27.w27)
    • It is important for the ferret to eat correctly at a young age and at late stages of pregnancy. (B631.27.w27)
    • If the jill appears to be carrying a large litter, hIgh-calorie foods or nutritional supplements should be provided in late gestation, e.g. Nutri-Cal (Tomlyn), Ensure Plus (Abbott Laboratories). (B602.5.w5)
  • Ensure adequate water is given to the jill, in both a dish and a bottle to ensure enough fluids are drunk. When ferrets are not provided with enough water to complement a dry diet they may stop eating. (B602.5.w5)
  • Several small dishes of food should also be given to the ferret, to ensure enough food is being consumed. (B602.5.w5)
Associated Techniques Rabbits

Ferrets

General
Host taxa groups /species
Disease Author Nikki Fox BVSc MRCVS (V.w103); Bridget Fry BSc, RVN (V.w143)
Referees John Chitty BVetMed CertZooMed MRCVS (V.w65); Aidan Raftery MVB CertZooMed CBiol MIBiol MRCVS (V.w122)

Return to top of page