Page 51 - Canine-Diseases

to have a cyclic nature, with periods of worsening symptoms the Müllerian duct which is a vestigial embryological remnant of
followed by periods of improvement. The pain often shifts from the paramesonephric duct system in males and has been associated
leg to leg. Each episode of lameness may last for a few days to with clinical signs such as dysuria, incontinence, tenesmus and
a few weeks, and the period between episodes is often about a urethral obstruction in dogs. These cysts attach to the prostate but
month, but may vary. It can occur with any breed, but it is more do not communicate with the urethra. The fluid contained within
common in medium- to large-sized dog breeds including German the cysts is usually pale yellow to orange. The interior of the
Shepherds (most common), Great Danes, Golden Retrievers, cysts is smooth and cartilage or calcified areas may be present.
Labrador Retrievers, Rottweilers, Doberman Pinschers, and Some paraprostatic cysts may contain blood and these are called
Basset Hounds. hemacysts. The signs are similar to those seen with other types of
prostatic enlargement and usually become apparent only when the
Papilloma: A neoplasm of the epithelium often caused by the cyst reaches a size sufficient to cause pressure on adjacent organs.
canine papillomavirus. One of the most common canine skin Large cysts may result in abdominal distention.
neoplasms. The virus is transmitted by direct contact or via
fomites. Incubation period is 1-2 months. Latent infections may Pasteurella: A rod-shaped, gram negative species of bacteria
become active if animals are immunosuppressed. Also called which is a facultative anaerobe. The genus is named after the
“warts” and “verrucae”. Presentations in dogs include cutaneous French chemist and microbiologist, Louis Pasteur, who first
inverted papillomas (younger dogs, ventrum and inguinal region identified the bacteria now known as Pasteurella multocida as
mostly), oral papillomatosis (frequently younger dogs), cutaneous the agent of chicken cholera. Pasturella are a genus of zoonotic
papillomas (often older dogs) and multiple pigmented papules bacteria which can be transmitted through the bite of a dog. They
or plaques. Squamous type papillomas are more common than are a natural inhabitant of the skin, digestive tract and oral cavity
fibrous papillomas. Warts may be bleed or become infected with of a dog, but can cause disease under the right circumstances.
bacteria.
Patent ductus arteriosus (PDA): Is the most common congenital
Papule: A primary lesion. A small, solid raised area of skin up heart disease in dogs. It is the failure of a large blood vessel,
to 1cm in diameter, often forming part of a rash on the skin and the ductus arteriosus, to close just after birth. In fetal life, blood
typically inflamed but not producing pus. It can be brown, purple, entering the right heart largely bypasses the non-functional lungs
pink or red in color, and can cluster into a papular rash. Papules through either the foramen ovale or the ductus arteriosus. The
may open when scratched and become infected and crusty. Papules ductus arteriosus effectively shunts blood from the pulmonary
most often result from the local accumulation of inflammatory artery into the descending aorta (right-to-left shunt). At birth,
cells. Dogs with flea allergy dermatitis commonly present with the vessel should close within hours, directing blood to flow into
papules reflecting the inflammatory response at the site of flea the newly inflated lungs. PDA will usually result in significant
bites. Papules are also commonly seen in canine pyoderma. left sided heart enlargement and ultimately left sided congestive
heart failure. Dogs with left sided heart failure will usually cough
Paraphimosis: Refers to the inability to completely retract the and have labored or difficulty breathing. The most commonly
penis into the preputial cavity which usually occurs after erection. affected breeds are Maltese, Miniature Poodles, Pomeranians,
It is seen most often after semen collection or coitus. The skin at Keeshonds, Bichon Frise, Chihuahuas, German Shepherds,
the preputial orifice becomes inverted, trapping the extruded penis Shetland Sheepdogs, Cocker Spaniels, Shih Tzus, Collies, and
and impairing venous drainage. Other causes of paraphimosis Welsh Corgis. Dogs with PDA should not be used for breeding,
include a small preputial opening, priapism (persistent erection of regardless of breed.
the penis), foreign objects around the penis, a constricting band
of hair at the preputial orifice, or trauma. The condition becomes Pediculosis: Also known as canine pediculosis, is the infestation
more serious when irritation and dryness occur on the surface of the with lice which are external parasites that chew on the skin or suck
penis after the glans has protruded for minutes to hours and comes the blood, causing skin irritation, itchiness, and possible anemia
into contact with environmental surfaces (the ground, carpets, in severe infestations. Dogs can be infested with one species of
etc.). Additionally, edema will occur as a result of restriction of bloodsucking lice, Linognathus setosus, and two species of chewing
blood flow back from the head of the penis. This further prevents lice, Trichodectes canis and Heterodoxus spiniger. Untreated pets
the glans from retracting and restricts the proper flow of urine can develop pediculosis over the entire body. Infestations are
through the urethra, which leads to bladder enlargement and more common in young pups, debilitated/malnourished animals
discomfort. German shepherd dogs and Golden Retrievers have a or geriatric animals in unsanitary conditions. A dog with lice often
possibly inherited condition in which the opening of the prepuce has a rough, dry coat. If the lice are abundant, the hair might also
is narrow or the sheath is shorter than normal, and the penis can be matted. Sucking lice cause small wounds that can become
become trapped outside the prepuce. infected.

Paraprostatic cysts: Are fluid-filled sacs found adjacent to the Pemphigus: Pemphigus complex is a group of uncommon
prostate and are connected to the prostate by a thin stalk or tissue autoimmune diseases of the skin and mucous membranes resulting
adhesions. The cysts are an uncommon occurrence in male dogs from a type II hypersensitivity. Lesions include vesicles, bullae,
of medium or large breeds. Paraprostatic cysts are thought to and pustules and are characterised by loss of cohesion between
originate from the blind-ended uterus masculinus, formed from keratinocytes (acantholysis). There are four types of pemphigus

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