Category Archives: Dog Health

Disorders of the Penis and Prepuce

1) My intact male dog always has a glob of green “goo” hanging by his prepuce. Is that abnormal? All intact male dogs make prostatic fluid all the time, whether they are being used for breeding or not. Most of the prostatic fluid runs into the bladder, but some runs through the penis and accumulates at the tip of the prepuce; this is normal. If the dog licks excessively, the surface of the penis is red or rough, or there is such a large amount of discharge that it drips, that is abnormal and the dog should be seen by a vet. Persistent penile frenulum Development The penis and prepuce are joined during embryonic development by a tissue called the balanopreputial fold. This fold should dissolve, under the influence of testosterone, before birth. In some dogs, persistence of a portion of this fold leads to a permanent connection between the ventral portion of the penis and the prepuce, such that the penis cannot be completely extruded. The penile frenulum also may be associated with the penis only, usually causing ventral deviation of the tip of the penis as the frenulum attaches the tip to the shaft (). Signalment There is no breed predisposition described for this uncommon condition. It is a congenital condition Read more […]

Fracture of the os penis

Development The os penis is a small bone that lies within the penis and allows the male to introduce the penis into the bitch before it is fully erect. Any trauma to the penis may fracture the os penis; examples of penile trauma include racing injuries, fight wounds, twisting of the penis during mating, and vehicular accidents. Signalment There is no breed or age predisposition to fracture of the os penis. History and clinical signs Dogs may fracture the penis and show no clinical signs. This is because the os penis lies tightly enclosed within the penile tissue, which may act as a natural splint after trauma. Clinical signs that may be present include urinary tract obstruction with inability to urinate or pain when urinating, bruising or swelling of the penis, obvious lacerations to the penis, or inability or reluctance to breed. Diagnosis Fracture of the os penis is best diagnosed with radiographs. Contrast radiography, in which a fluid that appears very white on radiographs is infused into the urethra, or ultrasound may permit better visualization of the urethra. If the animal has urinary tract obstruction, bloodwork must be performed to assess for presence of systemic disease. Fracture of the os penis: Treatment Obvious Read more […]

Phimosis, paraphimosis, and priapism

Development Phimosis is the inability of the penis to be extruded from the prepuce (). Paraphimosis is the inability of the nonerect, extruded penis to be withdrawn into the prepuce. Priapism is persistent erection and an inability of the erect, extruded penis to be withdrawn into the prepuce. Phimosis can occur whenever there is narrowing of the external portion of the prepuce. It is uncommon and usually occurs as a congenital defect in puppies. Paraphimosis may occur because of a congenital defect in which the muscles allowing the penis to be drawn into the prepuce are dysfunctional or the external orifice of the prepuce is too small, but more often it occurs in older dogs that have historically been able to replace their penis within the prepuce. It may occur secondary to inflammation or injury of the penis. Most often, paraphimosis in older dogs has no identifiable cause. Priapism occurs with obstruction of normal outflow of blood from the engorged penis. This may occur secondary to neoplasia, thromboembolism (blood clot), neurologic defect, or unfortunate placement of sutures during castration. Signalment Phimosis is usually a congenital defect. The Boston terrier breed may be predisposed. Paraphimosis most Read more […]

Male Contraception

1) My wife wants me to get my hunting dog neutered. I do not want him to get fat and lose interest in hunting. Does neutering affect a dog’s hunting ability? There is no evidence that neutering a male dog interferes with his hunting ability. There are a lot of good female hunting dogs that prove testicles are not needed to hunt. Castrated male dogs only get fat if they are fed too much and not exercised properly.   Contraception is treatment of an animal to prohibit its ability to reproduce. Castration is by far the most common contraceptive method in the United States at this time. Research continues to try to develop less invasive contraceptive techniques for use in male dogs and as a model for contraceptive techniques for use in wild and exotic canids. Surgical Castration The common term, neuter, actually can refer either to castration of male dogs or to spaying (ovariohysterectomy) of female dogs. Castration is the more exact term for male dogs and is defined as surgical removal of both testes and epididymes. Another term for this surgery is orchidectomy. The animal is placed under general anesthesia and laid on his back. The groin is shaved and surgically prepped. A single incision is made just Read more […]

Anatomy and Normal Reproductive Physiology

1) When should I expect my male dog to be fertile? That depends on his breed. Animals of most species go through puberty and become sexually mature when they reach about 80% of their adult body weight. For a Maltese, that may occur when he is 4 months old. For a Leonberger, that may not occur until he is almost 2 years old. The only ways to know for sure that a male is fertile are either to breed him or to collect semen for evaluation. 2) My dog has poor libido. Does he have a testosterone deficiency? No. I have never documented lack of testosterone as a cause of poor libido in dogs nor has anyone else, to my knowledge. Embryology and anatomy of the male reproductive tract Determination of gender is dependent on the type of sex chromosomes present in the embryo. All dogs have 78 chromosomes, two of which are sex chromosomes; in females both are X chromosomes, and in males there is one X and one Y chromosome. Two tubular tracts are present in the developing embryo: the mullerian (paramesonephric) duct system, which goes on to form the female reproductive tract, and the wolffian (mesonephric) duct system, which goes on to form the tubular portions of the male reproductive tract. In the presence of a Y chromosome, Read more […]

Canine Geriatrics: The Nervous System

Key Points (1) Age-related changes in the central and peripheral nervous sys(CNS and PNS) are responsible for many of the physioloand behavioural changes commonly associated with advancing age and senility. (2) Many of the age-related degenerative CNS changes reported to occur in humans are believed by veterinary neurologists to occur in dogs and cats but they have been poorly documented. (3) In decision making about treatment and prognosis it is important to relate observed neurological changes to the site of the underlesion. For example, it is important to differentiate upper motor neuron deficits from lower motor neuron deficits in patients with locomotor disease. (4) The onset of seizures in old animals should promote a search for extracranial causes (e.g. hepatic disease) and for structural lesions in the CNS (e.g. brain tumours). (5) Old patients requiring anticonvulsant therapy for seizures should be screened for liver disease and should be monitored for early detection of hepatotoxicity. (6) Neuroendocrine disorders are probably much more common in old animals than is currently recognised clinically. (7) The process of ageing may be a manifestation of a failure to regulate neuroendocrine Read more […]

Neurological diseases of old age chronic ‘old dog’ encephalitis

Canine distemper is most prevalent in young dogs, but chronic ‘old dog’ encephalitis is the neurological manifestation of canine distemper virus (CDV) infection that is seen in adult dogs which have survived the acute infection. Dogs developing this condition are usually over 6 years of age and have serological evidence of systemic immunity. The neurological signs (see Table Neurological signs seen in the ‘old dog encephalitis’ form of canine distemper) may occur without previous evidence of systemic disease and are usually progressive and irreversible (). The involuntary muscle twitching (myoclonus) is typical of CDV infection. Table Neurological signs seen in the ‘old dog encephalitis’ form of canine distemper. Hyperaesthesia Cervical pain Seizures Cerebellar and vestibular signs Visual deficits Behavioural changes Head-pressing Circling Paraparesis or tetraparesis Ataxia Myoclonus CSF examination for increased protein and increased lymphocyte count may be helpful in diagnosing dogs exhibiting neurological signs. Histologically there is perivascular lymphoplasmacytic infiltration in areas of demyelination and neuronal degeneration which may progress to sclerosing panencephalitis Read more […]

Anaesthesia and Surgery in Geriatric Patients

Key Points (1) Advancing age is not in itself a contraindication to general anaesthesia or major surgery. (2) Preoperative screening of old patients for the presence of subdisease or impaired organ function is necessary before anaesthesia or surgery. (3) Anaesthetic doses should be based on lean body weight not actual body weight if the animal is obese. (4) Generally, anaesthetic and other drug doses need to be reduced in ageing patients. (5) Attempts must be made to avoid the development of hypothermia and hypotension during anaesthesia of old patients. (6) Reduce exposure to known risk factors for acute organ failure, especially acute renal failure. Objectives of surgery in old patients The objective of performing surgery in geriatric patients is to prolong active, enjoyable life and procedures that offer no benefits to the patient should be avoided. However, a policy of avoiding all ‘high risk’ surgery would deny some patients with responsive conditions the benefits of surgical treatment. The decision to perform elective surgery on old patients has to be a clinical judgement following full discussion with the owner. Owners should be made aware that older patients generally need preoperative Read more […]

General Anaesthesia in Geriatric Patients

Preparation Animals should be fasted for 12 hours, with water being withdrawn 1-2 hours beforehand. Water deprivation in old animals can precipitate a uraemic crisis so overnight deprivation is not recommended if there is evidence of renal incompetence and an i.v. fluid line should be established before the administration of a sedative or anaesthetic. All patients should be weighed before computation of drug dosages to avoid errors. If the animal is obese the lean body weight should be estimated. Premedication Acepromazine can be given in low doses (0.02-0.05 mg/kg i.m.) but should not be used in the presence of cardiovascular disease such as endocardiosis and congestive heart failure, as it can cause rapid hypotension. Acepromazine should also be avoided in dogs prone to seizures, and it is contraindicated in the presence of renal impairment. Intravenous administration can cause profound hypotension and it should only be used by this route with great care. The author has witnessed a geriatric dog collapsing and dying immediately following the intravenous administration of acepromazine. Xylazine and medetomidine should only be used with extreme care in geriatric canine and feline patients because they can cause Read more […]

Age-related tissue changes that may affect anaesthesia or surgery

Age-related changes that may affect anaesthesia or surgery include: Nervous System Cardiovascular system Respiratory system Renal Liver Endocrine Obesity Nervous system Central nervous system Reduced functional tissue in the CNS is probably one of the factors that reduces the anaesthetic dose needed in older patients. Old patients often have sluggish, impaired or absent reflex responses (e.g. pupillary light reflex) which may complicate monitoring during anaesthesia. Loss of function of the special senses such as sight and hearing may lead to apprehension in strange environments (especially in cats), and sometimes sedation is needed to reduce preoperative stress which otherwise can significantly increase sympathetic simulation. Geriatric animals have reduced ability to generate body temperature and are susceptible to develop hypothermia, particularly during prolonged surgery or the postoperative recovery period. In this context it is important to remember that core body temperature may differ from peripheral measurements, and the use of oesophageal thermometers or infra-red thermometers (applied in the aural canal) may be preferable to rectal temperature recording. Peripheral nervous Read more […]