The endocrine system of dogs and cats is almost identical to that of humans, in structure and function. The endocrine system is made up of a number of glands in the body that secrete hormones to control a range of important functions – from growth and metabolism, to reproduction, blood pressure, mineral balance and homeostasis in the body. Its overall purpose is the regulation and control of various functions to keep the body in balance. The canine or feline body is in a constant state of detecting stimuli (threats, thirst, reproductive opportunity, hunger, temperature, etc.). It is the endocrine system that responds to those external stimuli in ways that keep the body in balance. 

The immune system of dogs and cats

The canine and feline immune system affects each and every system and cell in their body. It is a barrier of detection and elimination that stands narrowly between the healthy cells of the body and invading organisms like viruses, bacteria, parasites, cancer cells, pollen or food molecules. The immune system is the body’s defence against illness, disease, infection and allergies, and it has a few mechanisms of protection against pathogens that may attack a healthy animal.

In our previous article on the female reproductive system of dogs and cats, we showed how a complex system of reproductive organs and hormones work together to facilitate fertilisation, gestation and birth. The male reproductive system in dogs and tomcats also consists of a variety of organs and hormones that work together to facilitate fertilisation and to ensure the perpetuation of the species. It influences many of the males’ behaviours, making a good case for neutering when owners of male dogs and cats do not intend to breed with their pets.

Dogs and cats are placental mammals that carry their foetuses in the uterus to full term, giving birth to a litter of live offspring that are almost fully developed. Offspring are initially fed on milk secreted by the bitch or queen’s mammary glands, with puppies and kittens suckling on the five or four pairs of teats, respectively.

The reproduction process requires a number of different organs, hormones and events that all work together in a system, to produce puppies and kittens. In this article, we’ll explore the components and functions of the female reproductive system, the disorders that can affect reproduction, and what to look out for when problems affect the reproductive organs.

The musculoskeletal system of dogs and cats is a complex, multi-part, multi-functioning system that gives animals their shape, size, health, flexibility and speed. It can be fed and protected to turn a dog or cat into a biological machine… or it can become painfully dysfunctional, affecting their health and quality of life.

The lymphatic system is one of the lesser talked-about, but equally important systems in your pet’s body. It works alongside the circulatory function of the cardiovascular system, the elimination function of the digestive system and the defence function of the immune system. There are several important organs in your pet’s body that make up the lymphatic system and its network of vessels, ducts, lymphatic fluid, lymphocytes and lymph nodes.

The cardiovascular system comprises the heart (cardio) and veins (vascular) that pump and transport oxygenated and deoxygenated blood throughout the body. While the respiratory system is responsible for bringing oxygen into- and carrying carbon dioxide out of the blood, it’s the heart and veins that circulate the oxygen throughout the body. Just like humans, dogs’ and cats’ cardiovascular system performs the same function, is also controlled by the autonomic nervous system and is also susceptible to disorder and disease.

Breathing is an essential function of life, but it is just one function of the respiratory system in our pets. The respiratory system brings air into your dog or cat’s body, humidifies that life-giving air, heats it up and filters it, and then uses the components of that air to energise cells and balance the body’s pH levels. It then removes the resultant waste products. All of this is done involuntarily – your pet doesn’t have to think about breathing; it just happens. 

As we explore the bodily systems of our furry and purry friends, there is one system without which all the others would not be able to function: the nervous system. The nervous system consists of the brain, spinal cord and all the nerves and connective tissue that runs between them and the rest of the body’s organs. Think of the nervous system not only as the electrical wiring that powers the house, but with its own power source and smart system – the brain – that maintains equilibrium in every room.

Your dog’s skin and coat make up a multi-functional super system. They are a barrier of protection, a convenient thermostat and water meter, as much as they are a barometer of your dog’s internal health. Your dog’s skin and coat also function as his largest sensory organ, as well as a very important communication tool.

In this article, we’ll explore the structure and function of the canine skin and coat. We’ll suggest ways to keep your dog’s skin and coat healthy, discuss the symptoms of an unhealthy skin and coat, issues that may arise and when to see the veterinarian as a result.