Repro and Genetic disease VT121 PowerPoint

Reproductive and Genetic Diseases Notes

Reproductive Terminology

  • Root Words:
    • cervic/o - narrowing, cervix
    • colp/o – vagina
    • episi/o - vulva
    • galact/o or lact/o – milk
    • gravid/o – pregnancy
    • mamm/o or mast/o– mammary gland
    • metr/o - uterus
    • omphal/o - umbilicus
    • orchid/o – testicle
    • ovari/o - ovary
    • phall/o or priap/o – penis
    • prostat/o – prostate
    • salping/o - oviduct

Reproduction Terminology Definitions

  • Breech Presentation: An abnormal posterior-first position of a fetus at birth.
  • Ectopic Pregnancy: The implantation of the embryo at an abnormal site (outside of the uterus).
  • Paraphimosis: Narrowing of the prepuce, swelling in the glands prevents retraction.
  • Cesarean Section (C-section): Delivery of offspring through an incision made in the abdominal and uterine walls.
  • Pseudocyesis: Pseudopregnancy, a false pregnancy.
  • Colostrum: The first milk-like substance produced by the female after parturition; it is thick, yellow, high in protein and antibodies.

Reproductive Diseases Covered

  • Vaginitis
  • Pseudopregnancy
  • Eclampsia
  • Pyometra
  • Dystocia
  • Inappropriate Maternal Behavior
  • Lactation Disorder
  • Benign Prostatic Hyperplasia
  • Prostatitis
  • Prostatic Abscess
  • Prostatic Neoplasia
  • Priapism and Paraphimosis
  • Neoplasia of the Testicles
  • Penile, Preputial, and Scrotal Tumors
  • Transmissible Venereal Tumor (TVT)
  • Tumors of the Female Genital Tract
  • Tumors of the Mammary Gland

Diseases of the Female Reproductive Tract

Vaginitis

  • Puppy Vaginitis:

    • Common in females before their first heat.
    • Clinical Signs: Yellowish vulvar discharge.
    • Treatment: Keep them clean; usually resolves after the first estrous cycle without treatment; antibiotics may be used.

  • Adult Vaginitis:

    • Caused by anatomical abnormalities, bacterial infection, traumatic injuries, or chemical irritation; canine herpesvirus can also be a cause.

Pseudopregnancy (Pseudocyesis)

  • Due to normal hormones of estrus, some dogs exhibit signs of pregnancy when they are NOT pregnant.
  • Usually occurs 6 to 12 weeks after estrus and may last 1 to 3 weeks.
  • Clinical Signs: Weight gain, mammary gland enlargement and lactation, mucoid vaginal discharge, carrying around stuffed toys, increased mothering behavior.
  • Treatment: Signs are usually self-limiting; remove any stuffed toys treated like puppies; consider ovariohysterectomy if needed.

Eclampsia

  • Emergency condition from low blood calcium levels in nursing dogs.
  • Seen in small and medium breeds, particularly heavily lactating females.
  • Occurs within 2 to 3 weeks after whelping.
  • Clinical Signs: Nervousness, tremors, ataxia, seizures, salivation, stiff gait.
  • Diagnosis: History and clinical signs; check for hypocalcemia.
Eclampsia Treatment
  • Emergency Treatment: Slow intravenous administration of 10% or 20% calcium gluconate; monitor heart rate for bradycardia or arrhythmias.
  • Follow-Up: Oral calcium supplements may be introduced after clinical signs regress; recurrence in subsequent pregnancies is common; advise against using affected dogs for breeding.
  • Prevention: Maintain good prenatal nutrition and calcium supplementation.

Pyometra

  • Accumulation of pus in the uterus due to bacterial infection; caused by rising levels of progesterone in intact females.
  • Most commonly occurs in middle-aged or older intact female dogs and cats within 60 days of their last estrous cycle.
  • Types of Pyometra:
    • Open Pyometra: Cervix is open.
    • Closed Pyometra: Cervix is closed.
Pyometra Clinical Signs
  • Vulvar discharge (open pyometra), abdominal enlargement, vomiting, lethargy, polyuria (PU) or polydipsia (PD), dehydration, azotemia, fever.
Pyometra Diagnosis
  • Imaging: Abdominal radiographs or ultrasound.
  • Complete Blood Cell Count (CBC): May show leukocytosis, neutrophilia with a left shift, dehydration.
  • Serum Chemistry: May reveal increased alkaline phosphatase levels and elevated blood urea nitrogen.
  • Vaginal Cytology: Shows degenerative neutrophils, endometrial cells, and bacteria; a dilated, fluid-filled uterus.
Pyometra Treatment
  • Preferred Method: Ovariohysterectomy; ensure dehydration and azotemia are corrected before surgery.
  • Broad-spectrum antibiotics are necessary;
    • If the animal is for breeding, medical treatment options may include Prostaglandin F2α (Lutylase).
  • Prevention: Routine ovariohysterectomy.

Dystocia

  • Definition: Difficulty giving birth; various factors can contribute:
    • Large fetuses (large puppy or kitten, fetal anasarca, or hydrocephalus).
    • Abnormal positioning (transverse presentation).
    • Narrow birth canal.
    • Uterine inertia (lack of coordinated contractions or exhaustion of uterine musculature from prolonged contractions).
Dystocia Clinical Signs
  • Labor exceeding 4 hours without producing a fetus.
  • Green vaginal discharge during parturition; more than 1 hour has elapsed between births.
Dystocia Diagnosis
  • Methods: Physical examination with digital palpation of the vagina; radiography to evaluate fetal position, size, and number.
  • Ultrasonography: To evaluate fetal viability and distress.
Dystocia Treatment
  • Options:
    • Manual manipulation: a fetus lodged in the vaginal canal may be manually dislodged through careful manipulation.
    • Provide fluids and dextrose, +/- oxytocin as needed.
    • If medical treatment fails to resolve the situation, a cesarean section is advised.

Inappropriate Maternal Behavior

  • Normal Behaviors: Nursing, retrieving, grooming, and protecting are all expected; however, some animals may not display appropriate behaviors.
  • Clinical Signs:
    • Mother is restless.
    • Neonates continuously crying.
    • Mother actively attacks and kills her young.
  • Diagnosis: Observational assessment.
  • Treatment: Tranquilization (acepromazine, diazepam), early weaning or bottle-feeding may be necessary.

Lactation Disorders

  • Mastitis: A septic inflammation of the mammary gland; the most common issue.
  • Agalactia: Lack of milk production; can occur due to stress, malnutrition, premature parturition, or infection.
  • Galactostasis: Milk stasis leading to painful engorgement of the mammary glands.
  • Clinical Signs: Mammary discomfort or reluctance to nurse, firm, hard, red swelling(s) in glands, discolored milk, fever.
Lactation Disorders Diagnosis
  • Methods: CBC, milk cytology, and culture/sensitivity tests.
Lactation Disorders Treatment
  • Broad-spectrum antibiotics may be necessary.
  • Administer warm compresses; then express the affected glands.
  • Cabbage Wrap: Can assist in reducing swelling.
  • For severe cases, hospitalization on IV fluids and surgical debridement may be required.

Diseases of the Male Reproductive Tract

Benign Prostatic Hyperplasia (BPH)

  • Definition: Non-cancerous enlargement of the prostate gland associated with testosterone; most commonly diagnosed prostate disease in male dogs.
  • Age of Onset: Occurs as early as 2.5 years of age.
  • Clinical Signs: Weak stream of urine, straining to urinate; cases may be asymptomatic.
BPH Diagnosis
  • Physical examination via digital rectal examination; ultrasound may be utilized.
BPH Treatment
  • Castration can result in a 70% decrease in gland size within 7 to 14 days.
  • Medication: Finasteride may be administered for breeding dogs.

Prostatitis

  • Definition: The prostate is predisposed to bacterial infection from both the urinary system and direct infection of the gland.
  • Clinical Signs:
    • Acute Prostatitis: Anorexia, fever, lethargy, stiff gait in rear limbs, caudal abdominal pain.
    • Chronic Prostatitis: May be asymptomatic; often has a history of chronic, periodic urinary tract infections.
Prostatitis Diagnosis
  • Methods: Urinalysis showing blood, increased WBC count, the presence of bacteria; digital rectal examination; urine culture and sensitivity.
Prostatitis Treatment
  • Antibiotic treatment according to urine culture/sensitivity results.
  • Castration may also be beneficial.

Prostatic Abscess

  • Description: A severe form of bacterial prostatitis where pockets of purulent exudate (pus) develop within the gland.
  • Clinical Signs: Tenesmus, urethral discharge, lethargy, pain, vomiting, hematuria, fever, depression.
Prostatic Abscess Diagnosis
  • CBC may show leukocytosis or normal WBC count, liver enzymes may be elevated; +/- hypoglycemia and hypokalemia.
  • Prostatic Aspiration: May reveal hemorrhagic, purulent, and septic fluid.
Prostatic Abscess Treatment
  • Surgical drainage is crucial.
  • Additional treatments include castration and antibiotic therapy (fluoroquinolones).

Prostatic Neoplasia

  • Incidence: Uncommon in dogs but observed in cats; can occur in both intact and neutered males; always malignant.
  • Clinical Signs: Similar to other prostatic diseases.
  • Prognosis: Poor.

Priapism and Paraphimosis

  • Priapism: Persistent abnormal erection of the penis often seen in dogs; may cause pain and tenderness.
  • Paraphimosis: Inability to retract the penis into the preputial sheath.
Treatment for Priapism and Paraphimosis
  • For acute cases, sedation is required.
  • Removal of any causative agents and immersing tissue into a cold hypertonic glucose solution to reduce swelling.
  • Gentle cleaning of the penile tissue is beneficial.

Neoplasia of the Reproductive Tract

Neoplasia of the Testicles

  • Prevalence: Approximately 5% to 15% of all tumors seen in male dogs are testicular tumors.
  • Risk Factors: Cryptorchidism and inguinal hernias significantly increase risk; most common in older, intact male dogs (ages 9-12 years).
  • Incidental Finding: Commonly identified during physical examination.
Neoplasia of the Testicles Clinical Signs
  • Non-painful testicular enlargement may be noted.
  • Feminization Symptoms: Occurs in approximately 25% to 50% of dogs with Sertoli cell tumors, leading to bilateral non-pruritic alopecia, hyperpigmentation in the inguinal region, gynecomastia, nonregenerative anemia, and thrombocytopenia.
  • Enlarged lymph nodes may be palpable in some animals (10%-20%).
Neoplasia of the Testicles Treatment
  • Primary Treatment: Castration is the treatment of choice for testicular neoplasia.

Penile, Preputial and Scrotal Tumors

  • Common Tumor Type: Transmissible venereal tumor (TVT) is most prevalent in dogs.
  • Transmission: Occurs in temperate climates and areas with large free-roaming dog populations; spread during sexual contact and can also be transmitted through licking and sniffing.
Penile, Preputial and Scrotal Tumors Clinical Signs
  • Typically observed in sexually intact male dogs.
  • Tumors appear on the penis, prepuce, or scrotum as cauliflower-like masses; lesions may also be seen on the vulva and face.
Transmissible Venereal Tumor (TVT) Diagnosis
  • Cytology: Impression smears will show large, round-to-oval cells with abundant pale cytoplasm containing many vacuoles; nuclei will show frequent mitotic figures and visible nucleoli.
Transmissible Venereal Tumor (TVT) Treatment
  • TVTs are immunogenic; they may spontaneously regress with adequate tumor stimulation.
  • Surgical excision is another option; chemotherapy may also be utilized.

Tumors of the Female Genital Tract

  • Types: Include ovarian tumors, uterine and cervical tumors, vaginal and vulval neoplasia, and tumors of the mammary glands.
  • Vaginal and vulvar tumors are most common in the female genital tract of dogs.
  • Clinical Signs: A pedunculated mass protruding from the vulva may be visible; perineal swelling, vaginal discharge, dysuria, or constipation may also occur.
  • Treatment: Surgical removal with ovariohysterectomy prevents recurrence.

Tumors of the Mammary Gland

  • Most prevalent tumor found in female dogs.
  • Risk Factors: 0.5% risk for bitches spayed before their first estrus, 8% for those spayed after one estrous cycle, 26% for those spayed after two or more cycles.
  • Approximately 50% of canine mammary tumors are benign; in cats, only 10% to 20% are benign.
Tumors of the Mammary Gland Clinical Signs
  • A firm nodule may be palpable in the mammary chain or gland; local lymph nodes may be enlarged.
Tumors of the Mammary Gland Diagnosis
  • Methods: Physical examination, CBC, serum chemistries, and thoracic radiographs should be evaluated before surgery.
Tumors of the Mammary Gland Treatment
  • Surgical removal is the typical treatment approach.

Genetic Diseases

Understanding Genetic Diseases

  • Genetic Blueprint: Genes provide the fundamental instructions for life and characteristics of all lifeforms.
  • An abnormal or defective gene can lead to disease.
  • Purpose of Genetics Study: To predict disease susceptibility and manage the spread of defective genes through informed breeding practices.

Genetics Terminology

  • Punnett Square: A grid used to predict the genotypes and phenotypes of offspring.
  • Genotype: The actual genes that an animal carries for a specific trait.
  • Phenotype: The observable physical appearance resulting from the genotype.
  • Alleles: Variants of the same gene that determine a trait; one is inherited from each parent.
  • Homozygous: Both alleles are identical.
  • Heterozygous: Both alleles are different.
  • Dominant: A trait expressed when at least one copy of the allele is present.
  • Recessive: Both alleles must be present in order for the trait to be expressed.

Genetic Diseases Covered

  • Von Willebrand's Disease (vWD)
  • Polycystic Kidney Disease (PKD)
  • Progressive Retinal Atrophy (PRA)
  • Patent Ductus Arteriosus (PDA)
  • Canine Hip Dysplasia

Von Willebrand’s Disease (vWD)

  • Description: Most common bleeding disorder in dogs; associated with Von Willebrand’s Factor (vWF) important for blood clotting.
  • A decrease in vWF concentration or function leads to an inability to clot and results in hemorrhage.
  • Breed Disposition: Common in Dobermans, German Shepherds, Poodles, Golden Retrievers, and Shelties.
  • Inheritance Pattern: Autosomal dominant trait with incomplete penetrance.
Clinical Signs of vWD
  • Easy bruising in predisposed breeds.
  • Prolonged bleeding during estrus and from venipuncture.
vWD Diagnosis
  • Tests: Buccal mucosal bleeding time (BMBT) and vWF level measurement.
vWD Treatment
  • For severe hemorrhage: may require fresh frozen plasma or whole blood transfusion and/or DDAVP (clotting promoter) to increase vWF levels.
  • Prevention: Dogs with this disease should not be used for breeding.

Polycystic Kidney Disease (PKD)

  • Description: Development of small, fluid-filled sacs in the kidney leading to kidney failure.
  • Breed Predilection: Mainly affects Persians, but also Himalayans and British Shorthairs.
  • Inheritance Pattern: Autosomal dominant trait.
PKD Diagnosis
  • Methods: Genetic testing and abdominal ultrasound.
PKD Treatment
  • Treatment focuses on managing kidney failure.

Progressive Retinal Atrophy (PRA)

  • Description: Degeneration of the retina leading to impaired vision and often blindness.
  • Breed Predilection: Common in Toy Poodles, Miniature Poodles, Golden Retrievers, Irish Setters, Cocker Spaniels, Miniature Schnauzers, Collies, Samoyeds, Gordon Setters, and Norwegian Elkhounds.
  • Inheritance Pattern: Autosomal recessive trait.
Clinical Signs of PRA
  • Defective night vision, slowly progressive loss of day vision, and cataract formation.

Patent Ductus Arteriosus (PDA)

  • Definition: A congenital heart disease in juvenile dogs where the ductus arteriosus fails to close properly, shunting blood from left to right.
  • Breed Predilection: Affects Chihuahuas, Collies, Maltese, Poodles, Pomeranians, English Springers, Keeshonds, Bichons Frises, and Shetland Sheepdogs.
  • Illustration: Normal heart versus heart with PDA.
PDA Diagnosis
  • Methods: Detection of a loud murmur, thoracic radiography, electrocardiography (ECG), and echocardiography.
PDA Treatment
  • Surgical Intervention: Endovascular stent or coil placement to close a PDA.

Canine Hip Dysplasia

  • Description: A common disease involving the canine hip where genetic, environmental, and dietary factors may contribute.
  • Results in improper positioning of the femoral head within the acetabular cup which can harm the joint.
Clinical Signs of Canine Hip Dysplasia
  • Vary with age; common symptoms include difficulty rising, stiffness that improves with exercise, pain during palpation of the dorsal pelvic area, and in older dogs lameness and waddling gait.
Canine Hip Dysplasia Diagnosis
  • Methods: Pelvic radiographs, Orthopedic Foundation for Animals (OFA) Certification, and the Penn Hip Method.
Canine Hip Dysplasia Treatment
  • Conservative Approach: Moderate exercise, weight control, anti-inflammatory medications, and nutraceuticals.
  • Surgical Options: Femoral head ostectomy (FHO), total hip replacement, triple pelvic osteotomy.

Punnett Squares

Overview of Punnett Squares
  • Utilize Punnett squares to predict genetic outcomes in offspring, helping understand gene inheritance patterns.
Simple (Autosomal) Dominance
  • Definition: An allele is fully expressed if present in the genotype.
  • Example: The dense pigment gene (A) in black cats, where A = dark hair coat pigmentation and a = dilute pigmentation (blue).
Punnett Square Example
  • Scenario: Crossing a heterozygous black mother (Aa) with a heterozygous black father (Aa).
  • Setup:
    • Place X maternal alleles over columns:
    • A
    • a
    • Place paternal alleles at the start of rows:
    • A
    • a
Solving the Punnett Square

  • Results:

    • 25% chance of having genotype AA (homozygous).
    • 50% chance of having genotype Aa (heterozygous).
    • 25% chance of having genotype aa (homozygous recessive).

  • Phenotype Outcomes: 75% black offspring; 25% dilute offspring (blue).

  • Punnett Square Representation:

    • Mother Aa:

      | A | a |
      :---:|:---:|:---:|
      A | AA | Aa |
      a | Aa | aa