The guinea pig (Cavia porcellus) is a well known friend animal and a typical research model.

The guinea pig (Cavia porcellus) is a well known friend animal and a typical research model.

Key Points

  • Intact female guinea pigs are “sows” and intact males are “boars”.
  • Mature boars have distinct scrotal pouches and testes that are large.
  • Male guinea pigs have actually a few sex that is accessory, including big, paired seminal vesicles or vesicular glands, that can be seen erroneously as uterine horns.
  • Puberty does occur at around 2 months in females and between 2-3 months in men.
  • The pubic symphysis separates within the last times of maternity.
  • Separation associated with pubic symphysis may be insufficient in sows bred after 7-8 months of age and dystocia can lead to these people. Other possible factors behind dystocia consist of obesity and big fetal size.
  • Sows frequently give delivery to 2-4 big, precocial pups. Other rodent types generally have big litters.
  • Pregnancy toxemia is definitely a essential reason behind perinatal mortality in guinea pigs. This disorder is frequently noticed in primiparous, overweight sows in belated gestation. The prognosis is normally guarded. Reduce the danger of being pregnant toxemia by motivating workout, preventing obesity, and minimizing stress in the sow that is pregnant.
  • Unilateral or bilateral ovarian cysts are quite typical, especially in older sows.
  • Ovariohysterectomy or ovariectomy is preferred to stop the growth of ovarian cysts as well as other reproductive issues in non-breeding friend sows.

Introduction

Guinea pigs are helpful in reproductive studies since they share numerous traits that are reproductive humans (Fig 1). 26 Like people, guinea pigs have a very hemochorial placenta, for which maternal bloodstream is available in direct experience of the fetal chorion, in addition to comparable trophoblast intrusion habits and uterine vasculature that is comparable. 20 , 23 , 26 The guinea pig’s gestation duration can certainly be split into trimesters, analogous towards the condition that is human. 26 needless to say, some options that come with guinea pig reproductive anatomy and physiology are distributed to other people in purchase Rodentia, along with other features are unique for this species that is special. This short article product reviews structure and physiology of this guinea pig reproductive tract and summarizes some clinically significant medical issues.

Figure 1.Guinea pigs (Cavia porcellus) are helpful in a lot of studies that are reproductive.

Intact male guinea pigs, or “boars”, enter puberty between 70-90 times, nonetheless males start to show intimate behavior, such as for example mounting, at four weeks of age. 9 , 17 , 23 At 2 months, boars start to ejaculate while mounting. 23 Expression of intimate behavior and real development is notably suppressed in the event that boar is housed using its mom and/or siblings. 11

Boars are usually bigger than females, with both sexes having a single couple of inguinal mammae. 5 Mature boars have big, paired testes, that are situated on either region of the perineum in distinct, superficial scrotal sacs (Fig 2). 5 , 9 , 23 The testicles are frequently completely descended to the scrotum by 81 times. 2 In the event that testes have never descended by 4 months of age, the guinea pig is highly recommended cryptorchid. 9 The inguinal canals remain available for a lifetime. 9 , 19 to avoid herniation post-castration, numerous clinicians use a shut strategy or even a modified available method, where in fact the tunica is roofed within the suture which is used to connect from the spermatic cable and vessels. 32

Figure 2.Gross image associated with the testicle (arrow) in an adult boar (Cavia porcellus). The epididymis lies across the dorsolateral surface regarding the testis. The end of this epididymis provides increase into the ductus deferens. Credit: Drury Reavill, DVM, DABVP (Avian Training), DACVP. Click image to expand.

Clinical Suggestion: Although large, paired testes are clear in mature boars, sex identification could be challenging in young pups. In the event that testicles aren’t apparent, sexing can be facilitated by putting mild stress at the bottom associated with prepuce to partially extrude your penis. 23

The S-shaped penis comprises of a human body and glans. Guinea pigs have a penis that is os which will be discovered inside the dorsal area of this whole duration of the glans. 9 , 19 Like other hystricomorph rodents, your penis comes with minute, saw-toothed spurs that are white dorsolaterally in 2 synchronous lines through the urethral orifice to your glans. Addititionally there is an intromittent sac on the ventral surface associated with glans penis. 9 During erection, the sac everts and two horny styles protrude. 5 , 9 , 23 the big event of the 3-5 mm projections that are long unknown. 9

Male glands that are reproductive the seminal vesicles (vesicular glands), coagulating glands, bulbourethral glands, and also the prostate (Fig 3). 5 , 27 A rudimentary preputial gland may additionally be contained in the boar. 9

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