Pregnancy and development

Multiple Choice

Which of the following is NOT a function of the oestrus cycle?

• To produce ova ready for fertilisation by the male

• To prepare the female reproductive tract to receive the fertilised ova

• To stimulate the female to stand still and allow the male to mate her

• To produce sperm for fertilisation

Multiple Choice

What is the first stage of the oestrus cycle?

• Pro-oestrus

• Oestrus

• Metoestrus

• Anoestrus

Multiple Choice

Which stage of the oestrus cycle will the bitch allow mating?

• Pro-oestrus

• Oestrus

• Metoestrus

• Anoestrus

Dropdown

Fertilisation

The egg (​

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) which is released at ovulation from the ​

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is surrounded by a thick protective coat

The inner layer comprises glycoprotein and is called the ​

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, whilst the outer layer is made up of small follicular cells and is called the ​

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Multiple Choice

Which of the following structures surrounds the ovum and is made up of small follicular cells?

• Zona pellucida

• Corona radiata

• Nucleus

• Cytoplasm

Multiple Choice

By doubling at each division, the conceptus has two, then four and then eight cells, before forming a solid ball of cells called a

• Follicle

• Zygote

• Morula

• Foetus

Reorder

Reorder the following

• Zygote

• 2 cell stage

• 4 cell stage

• 8 cell stage

• Morula

1

2

3

4

5

• 1
• 2
• 3
• 4
• 5

Dropdown

Three separate layers then develop, and these will finally form specific recognisable areas of the body:

The ​

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of the inner cell mass is called the ​

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– this will form the skin and the nervous system

The ​

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of the inner cell mass is called the ​

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– this will form several organ systems and the musculoskeletal system

The inner layer of the inner cell mass is called the ​

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– this will form the lining of the gastrointestinal tract and of other visceral organs

Open Ended

Explain the roles of the amniotic cavity, yolk sac, and allantois in early embryonic development as shown in the diagram.

Open Ended

Define the following: Yolk sac, Chorion, Amnion, Allantois, Chorioallantois, Zonary nature.

Multiple Choice

What is the main body cavity that forms within the embryo called?

• Coelom

• Amnion

• Chorion

• Allantois

Open Ended

Describe the changes that occur in the embryo between 3 and 5 weeks after ovulation.

Multiple Choice

At what week after ovulation do the amnion and allantois form in the developing embryo?

• 3 weeks

• 4 weeks

• 5 weeks

• 6 weeks

Multiple Choice

From approximately which day can the developing canine embryo be recognised as a dog and referred to as a foetus?

• Day 35

• Day 21

• Day 28

• Day 42

Open Ended

“All pregnant bitches should receive calcium supplements throughout pregnancy to prevent eclampsia.”

Excessive calcium during pregnancy suppresses the dam’s ability to mobilise calcium from her bones, predisposing her to eclampsia during lactation.

Ensure the bitch is fed a high-quality complete diet appropriate for gestation/lactation – no additional calcium unless prescribed by a vet.

Open Ended

“Vaccines can be given safely at any stage of pregnancy.”

Most vaccines should be avoided during pregnancy, especially live vaccines, due to risk to the foetus. Ideally, the bitch/queen should be fully vaccinated before mating.

Nursing Advice: Review vaccination status pre-breeding and plan appropriately.

Open Ended

“Pregnant queens should be isolated and not exercised.”

Moderate, gentle exercise helps maintain muscle tone and reduce obesity. Complete restriction may cause stress and reduce fitness for parturition.

Nursing Advice: Advise owners to maintain normal activity with reduced intensity.

Open Ended

“Pregnant animals should be fed twice as much from day one.”

Increased energy demands only occur in the final third of gestation. Overfeeding early increases the risk of obesity and dystocia.

Nursing Advice: Feed a maintenance diet early on, transitioning to a growth/lactation formula in the last 3–4 weeks.

Multiple Select

Which of the following are true regarding pregnancy diagnosis in bitches?

• Pregnancy can be determined by palpation from 28 days.

• Ultrasound can be used from as early as 16 days after ovulation.

• Radiographs can detect uterine enlargement from day 30.

• Pregnancy diagnosis is possible before day 16.

Dropdown

Pregnancy - the queen
Gestation = ​

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(range of 64-68 days)

Foetuses are palpable between ​

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after mating

Ultrasound can be used from about ​

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after mating and embryonic tissue can usually be seen from day 14

Radiograph can be used from ​

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to detect uterine enlargement, ​

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after mating to detect foetal skeletons

Multiple Choice

At what stage does the conceptus transition from a morula to a blastocyst?

• When the zona pellucida is shed

• When the inner cell mass differentiates into three germ layers

• When a central fluid-filled cavity develops within the morula

• When implantation occurs in the endometrium

Multiple Choice

In the bitch, implantation occurs at approximately:

• Day 7 post-ovulation

• Day 11 post-ovulation

• Day 14 post-ovulation

• Day 21 post-ovulation

Multiple Choice

Which embryonic germ layer gives rise to the musculoskeletal system and several organ systems?

• Ectoderm

• Mesoderm

• Endoderm

• Trophoblast

Multiple Choice

Which diagnostic method can first reliably confirm pregnancy in the bitch by detecting mineralisation of the foetal skeleton?

• Abdominal palpation at 28 days

• Ultrasound at 16 days

• Radiography at 30 days

• Radiography at 45 days

Multiple Choice

What is the key distinction between resorption and abortion in canine pregnancy?

• Resorption occurs during the foetal stage; abortion during the embryonic stage

• Resorption involves loss before term; abortion involves stillbirth

• Resorption occurs during the embryonic stage; abortion during the foetal stage before term

• Resorption and abortion are interchangeable terms

Multiple Choice

A lactating bitch presents with restlessness, panting, tremors, and pyrexia 20 days post-whelping. What is the most likely underlying cause?

• Hypoglycaemia due to foetal demand

• Hypocalcaemia due to calcium loss in milk

• Infectious cause of abortion

• Failure of implantation